Development and Application Exploration of Easy-tear Lid Heat-sealing Adhesive Technology

With the continuous development of the social economy, consumers have put forward higher requirements for the convenience, safety and aesthetics of food packaging, which makes the application of new packaging including easy-tear covers increasingly widespread.

Development and Application Exploration of Easy-tear Lid Heat-sealing Adhesive Technology

As a new type of cover film packaging, the easy-tear cover has the advantages of safety and hygiene, beautiful appearance and easy opening. It is mainly used in food packaging and has now become a standard cover type of international food metal cans. In addition, it is notable for its environmental friendliness – the wafers left by the punching process of the base cover can be recycled and reused; the food-grade composite film on the cover is smaller in thickness and mass, saving natural resources, even if it is opened by consumers Discarded after use will also degrade naturally without causing environmental pollution.

As far as easy-tear lid heat-sealing materials are concerned, as a solution to overcome the problem of “easy rust in the incision” caused by the easy-tear lid sealing film, domestic easy-tear lid heat-sealing materials have achieved great results in product development and application exploration. Significant progress has been made, and it is expected to help industry users improve economic benefits through import substitution.

Easy-tear cover processing technology

Easy-tear cover is a new composite technology that is bonded by aluminum foil and tinplate or coated metal substrate. It has the characteristics of high sealing and certain pressure resistance. Its processing technology includes: using tinplate or aluminum as the basic material, after punching, stretching, and rounding, shaping treatment, so as to achieve the purpose of being safe and not hurting hands after opening; covered with metal composite film or ultra-high temperature resistant The sterilized composite plastic film is then processed by handle making and embossing for a beautiful appearance and easy opening.

Types and application characteristics of easy-tear lid sealing film

Most of the heat-sealed easy-tear covers use the aluminum-plastic lamination process, and the materials used to achieve the bonding properties are modified polyolefins or polyvinyl acetates. After heating, the film layer melts and is bonded to the substrate.

Polyolefin-based film Polyolefin-based film has excellent water resistance due to its low polarity, no hydrophilic group, and is often used in the easy-tear-cover packaging of yogurt, lunch boxes, hot pot takeaway and other products. But it is also because of the low polarity that modified polyolefins are usually pre-coated with film glue on the aluminum foil, and the film can be well adhered to the aluminum foil substrate through the glue.

Polyvinyl acetate film Polyvinyl acetate film has a high content of ester bonds in the molecular structure, and its water resistance is weakened, so it is often used in the easy-tear cover packaging of dried fruits, tea leaves and nuts.

After long-term research and development, the application of coated iron or coated aluminum easy-tear cover products has gradually matured. However, since the metal substrate at the incision is directly exposed after the lamination product is formed, it is easy to corrode, which affects the food safety and the adaptability of the product. Therefore, how to effectively avoid or reduce the corrosion of the incision has become the current lamination and easy-tear cover industry. a major problem.

Types and application characteristics of easy-tear cover heat sealant (roller hot melt adhesive)

At present, in addition to film-coated easy-tear cover products, there are also some easy-tear covers that use a roll-coating hot-melt adhesive process, and the film thickness is relatively thin (about 10 μm). Compared with the lamination products obtained by extrusion coating, cast film, blown film and other production methods, the use of roll coating hot melt adhesive technology can not only improve production efficiency, save material costs, but also obtain higher product quality stability. More importantly, due to the strong adhesion between the coating and the substrate, the degree of notch corrosion is reduced to a certain extent.

The hot melt adhesives involved in the roll coating process of the easy-tear cover are currently concentrated on materials such as modified saturated polyester, ethylene acrylate copolymer, and modified polyacrylate. , the market scale is gradually expanding, and the application prospect is broad.

Saturated polyester resins Saturated polyester resins are prepared from different polyacids and polyols. By controlling the structure of the monomers used, two different structures, Linear and Branched, can be obtained (Figure 4). If a linear structure of polyols and polyacids is used, the synthesized resin has a linear structure and is very flexible. If a polybasic acid and polyol containing a benzene ring are used, the synthesized resin contains a benzene ring structure. The rigidity of the benzene ring can give the resin hardness, and the stable structure of the benzene ring can give the resin chemical resistance. Because the main chain of the polyester resin contains more ester bonds, the molecular chain has good flexibility, and the terminal or side chain contains polar carboxyl or hydroxyl groups (that is, the acid value or hydroxyl value we often say), they can either As a heat sealant itself, it can also be cured into a film by cross-linking with isocyanate, amino resin and other resins to improve the chemical resistance of the adhesive layer.

Formula developers can screen resins according to product requirements, select appropriate curing agents for product design, and related easy-tear lid product applications include takeaway lunch boxes, dried fruit cans, milk powder cans, etc.

Ethylene acrylate copolymer Ethylene acrylate copolymer is a polymer based on acrylate monomers, by introducing ethylene or vinyl monomers for copolymerization, and using oxygen or peroxide as initiators through free radical polymerization. Its structure is shown in Figure 5(A). The introduction of vinyl monomers endows polymers with adhesiveness and film-forming properties; acrylate monomers provide polymers with good substrate adhesion properties. As the content of vinyl monomers increases, the properties of such polymers will gradually approach those of vinyl polymers—chemical resistance increases, but their stability in solution may decrease to a large extent, so it is necessary to adjust the two The proportion of class monomers to achieve the desired product performance. At present, this kind of polymer has oily and water-based systems, and the oil-based system is widely used. Because vinyl monomer is difficult to disperse in aqueous solution, its application is limited to a certain extent. At present, the vinyl content of water-based ethylene acrylate copolymer on the market is less than 20%. Milk cans, etc.

Modified polyacrylate polymer, modified polyacrylate polymer refers to the polymer obtained by repolymerization or graft modification of polyacrylate through chemical reaction between macromolecules after the completion of polymerization. Modified polyacrylate polymers include polyurethane-modified polyacrylates, polyester-modified polyacrylates, silicone-modified polyacrylates, etc., all of which have the advantages of both modified polymers and polyacrylates. Polyacrylate has the flexibility of the polymer chain, its glass transition temperature (Tg) is low, and the temperature varies with the number of carbon atoms in the ester group and its branching, and it will form a glossy paint film after coating. , strong adhesion, not easy to peel off, can be used in adhesives in different occasions, including easy-tear cover products.

Formula developers can screen resins according to product requirements and select suitable curing agents for product design. The application of related easy-tear lid products covers takeaway lunch boxes, dried fruit cans, milk powder cans, etc.

The localization of easy-tear cover hot melt adhesive will help users reduce costs

At present, most suppliers of easy-tear cover materials are foreign manufacturers, with high prices and relatively limited supply. Therefore, realizing the localization of easy-tear cover materials is a direction for material people.

The Ultimate Recycling of Tin Cans

In the past few months, thyssenkrupp Rasselstein, a subsidiary of Germany’s thyssenkrupp Steel Europe and one of the three major steel production giants in Europe, and Swiss packaging supplier Hoffmann Neopac have successively released news, as two As a result of a pilot project jointly carried out by the authors, the tin-plated iron used in the Recyclan (recycled cans) is all recycled iron from household packaging, and the packaging can also be recycled an unlimited number of times. This not only pushes the recycling and regeneration of iron cans to the extreme, saving valuable basic resources and energy consumption such as iron ore, coking coal, limestone, etc., but also marks the iron cans with the organic food green packaging credit label, making the strict requirements and sales Customers of organic products get their wish.

According to thyssenkrupp Rasselstein’s official website, the company has a history of more than 250 years, producing cold-rolled tin-plated or chrome-plated steel sheets with a thickness of 0.100~0.499mm. The annual output of packaging steel is about 1.5 million tons, and its applications include food cans, beverages Cans, aerosol cans, paint cans, and various metal cap products like crown caps and screw caps.

Tin Plated Iron Packaging: One of the Most Environmentally Friendly Sustainable Packaging

For many years, tin-plated iron has been regarded as an excellent packaging material for organic food, coffee, tea, candy, dry or paste cosmetics and other care products due to its good content protection properties. At the same time, one of the biggest advantages of tin-plated iron packaging is that it can be recycled indefinitely without loss of quality such as strength, making it more common than other packaging materials.
Can Recycling: Closed Material Cycle Globally, packaging iron is typically made from natural raw materials such as iron ore, coking coal, limestone, and recycled scrap iron. One of the properties of steel is that it can be melted repeatedly and processed into new steel products. Another feature is that iron is magnetic, and once collected for recycling, magnets can be used to separate steel packaging from other waste very easily and quickly during picking.

Therefore, it can be said that if iron cans are well classified and processed today and enter the recycling system, they may become parts of bicycles tomorrow, and may also become part of automobiles the day after tomorrow. Even tin-plated iron produced decades ago, if it has been in a closed material cycle, will still appear on newly produced steel products. According to WV Stahl calculations, 84% of the previously produced steel is still being recycled.
In addition to being used as a component of the aforementioned automobiles and rails, the iron cans can also be made into iron cans after regeneration. The concept of Recycan is said to have been conceived by Hoffmann Neopac in response to a customer request, through cooperation with supplier partner thyssenkrupp Rasselstein, and finally proposed a “recycling of tin-plated iron waste from household packaging, such as metal cans, crown caps, claw type screw caps to make new food jars” idea. Mark Aegler, CEO of Hoffmann Neopac, said that in Europe, North America and other developed markets, tin-plated iron cans are synonymous with “environmentally sustainable” due to their ability to regenerate in a well-established recirculation stream.

Domestic and foreign situation of tin-plated iron packaging recovery rate Data from the British Metal Packaging Manufacturers Association (MPMA) shows that metal packaging is the most recycled packaging material in Europe, with a recycling rate of 82.5% for steel packaging. In Germany, the recycling rate of tinned iron packaging has exceeded this level for ten consecutive years, and even reached 90.4% in 2018 (data from GVM).

In my country, household tin-plated iron packaging has been facing the dilemma of “rejection by scavengers and low recovery rate” for a long time. Only in 2019, the two milk powder giants, Mead Johnson and Nestlé, successively launched milk powder can recycling programs, aiming to help the circular economy and eliminate the potential safety hazards caused by the recycling of waste cans by informal channels. The driving effect of tin-plated iron packaging recycling remains to be seen.

RecyCan: From household waste tin-plated iron packaging to new tin cans for new purposes, pushing the recycling of tin-plated iron packaging to the extreme

Generally speaking, all tinplate cans contain some amount of recycled iron. Made from 100% recycled tin-plated iron, the RecyCan product line takes tin-plated can recycling to the extreme, a way to maximize the recycling of consumer steel packaging without compromising the appearance and contents of the packaging. A full-cycle way to protect performance, while packaging can be recycled almost infinitely, the label effect of green packaging goes without saying.

Seven steps of the full cycle method for tinned iron packaging In a nutshell, RecyCan’s idea is to remelt steel packaging waste from households into molten steel, which is then processed through a complex system to produce new food cans tin plate, and finally into new food cans.

Take a milk powder can as an example, its original role was to protect infant formula. After the milk powder is used up, the milk powder can is collected along with other household recycling items. At the picking station, it can be easily separated from plastics and other metals with magnets, entering the recycling system along with other discarded household steel packaging such as lids, crown caps, etc. Then through the processes of chopping, pressing, cleaning, detinning, burning, melting, pouring, etc., it becomes a well-formed thick steel plate. It is then hot-rolled into coils, cold-rolled, tinned, cut into sheets, printed, and finally made into new consumer packaging cans, such as high-end organic coffee, so the new function allows the packaging to open a new life journey.

The first step is to collect waste cans, screw caps and crown caps from the household.

The second step is to separate the tinned iron packaging from the aluminum and plastic packaging with a magnet and chop.

The third step is to detin the scrap iron and then press it into squares.

The fourth step is to melt the iron block into molten steel, and then pour it into a thick iron plate.

The fifth step is to hot-roll, cold-roll, tin-plate, and cut the thick plate to become a tin-plated sheet for packaging.

The sixth step is to print on recycled tinplate, which is then made into a new tin can.

The seventh step is the retail and consumption of the canned product.

The above seven steps allow tin-plated iron packaging to be fully reused for packaging production, thus forming a closed journey of consumer packaging.

Advantages of RecyCan

According to the data, RecyCan’s cans are divided into three-piece, two-piece shallow-drawing or deep-drawing cans. It is said to have good light, air/oxygen and moisture barrier properties, which can preserve the flavor, nutrition and appearance of food; at the same time, it has obvious ecological advantages – not only saves the use of basic resources, but also consumes more energy than basic resources Production of new cans has been reduced by 60%; in addition, it meets EU food regulatory standards.

The Breakthrough of Coated Iron Can Technology Brings More Possibilities

As we all know, metal coated materials including coated iron and coated aluminum are not only more in line with the national environmental protection policy, but also meet the requirements of the continuous improvement of the technical level of metal packaging products, giving metal packaging the ever-changing changes. At the same time, in the Japanese market where it originated, the applications have been very successful in both beverage cans and food cans. This is also the reason why all parties are still optimistic about its development in the domestic metal packaging industry even though the companies involved in the localization of coated iron have gone through a ten-year process and it seems that there is no harvest.

In recent years, with the participation of several companies in the R&D and production of coated iron, the coated iron has made significant progress in production technology and product quality. The application fields, promotion methods and channels are more extensive than in the early days, and the demand is increasing year by year. .

Despite this, due to the two factors of material performance, cost, can making (forming) and related supporting technologies, the current problems of “more types, less batches and less materials” of coated iron have not been effectively improved. Large-scale application has never been realized – the annual demand is less than 8% of the annual production capacity, and so far it has not brought significant economic benefits to the relevant enterprises.

Material-side factors Material-side factors include material performance and cost. The two complement each other and are related to each other. They are embodied in the following aspects.

First of all, in the early stage of research and development, the coating technology and polymer film materials of coated iron are in the exploratory stage, and there are no conditions to adjust the performance of chrome-plated iron, resulting in quality defects in the coated products and small production batches, which makes the coated iron Material costs remain high and lack market competitiveness.

Secondly, there is a certain degree of lag in the research and development and supply of polymer films due to production cost factors. In terms of weight ratio, the polymer film is about 3.3%, and the polymer film required for 10,000 tons of coated iron can be produced in just one week. Therefore, in the early stage of research and development, various polymer film formulations were ordered by the film production enterprises on an hourly basis, and the production cost was very high due to the small amount. As a result, the cost of coated iron is clearly at a disadvantage compared to coated iron without mass production.

Third, in the early days, there was only one domestic company that researched and supplied coated iron materials. It may be that the exclusive supply has no competition relationship and high cost. Users are generally reluctant to try or use it for a long time, which makes it difficult to promote domestic coated iron in the domestic market.

The factors of can making and related supporting technologies are subject to the shortcomings of earlier can making and related supporting technologies. Coated iron has not achieved significant gains in both its more application-advantaged fields and the huge demand market. , for two reasons. On the one hand, in terms of application, coated iron is most suitable for making DRD two-piece cans and lids. Due to the lack of product types and demand for coated iron in China in the early days, the lids are available in quantity but use less material; more importantly, the DRD two-piece can production line needs to improve the mold or equipment to adapt to the production of coated iron and other problems , All kinds of factors are added together, so that the development space of coated iron is seriously restricted.

On the other hand, in the huge three-piece can market, the coated iron cannot be applied to the production of three-piece cans because there are no related supporting technologies such as blank lamination and welding seam lamination.

Coated iron application: where is the way?

At present, the problems of coated iron in terms of technology, quality and single supply have been basically solved, but the whole industry seems to be still exploring its application direction, and the way forward is still unclear. The author believes that the current coated iron industry should adhere to the following two development directions.

Avoid the advantages of coated iron, and find another way to promote the application of coated iron. The practice or lessons of the past years have proved that it is not feasible for domestic coated iron to replace the coated iron. For domestic coated iron to develop, it is necessary to give full play to the advantages of coated iron in new application fields or markets where coated iron cannot reach, and to reflect the value of coated iron. The approach can be to promote coated iron products through new products and new marketing models, increase the domestic market share of coated iron products, and promote the development of a virtuous circle of the coated iron industry. Only by gradually changing the market share of coated iron products and coated iron products can coated iron products be truly respected by the industry.

Starting from can-making technology and equipment, the innovation of film-coated iron packaging is carried out. Coated iron has the advantages of deep drawing resistance, wear resistance, corrosion resistance, etc. It can be combined with the two-piece can forming technology to complement the advantages and disadvantages, and has a broader development platform.

Special Effect Metal Printing

Differentiation is one of the effective ways to avoid homogeneous competition. As far as the packaging and printing industry is concerned, the use of coatings or inks to achieve product differentiation is one of the most direct and effective methods. Special coatings and inks such as hammer pattern, wrinkle, mottled pattern, stone pattern, wood grain, fluorescent, pearlescent, crystal grain, flash, temperature sensitive, photosensitive and other special coatings and inks can give packaging a personalized and unique surface effect, so it has been widely used in the packaging and printing industry. application.

However, due to the complexity and particularity of the process, the application of special effects coatings and inks in my country’s iron printing industry has been far behind other industries. For a long time, only wrinkle oil, crystal grain oil (commonly known as explosion oil), bead oil, rubber A handful of special coatings such as oil. Moreover, the key technologies have been monopolized by American and Japanese companies for many years, and they are supplied in the form of imports, which seriously restricts the application of special effects printing in the iron printing industry.

In recent years, the situation has been greatly improved, and local enterprises have caught up through independent research and development, and there is a tendency to catch up. There are two specific manifestations. On the one hand, the variety of domestic special coatings is becoming more and more complete, the construction is more convenient, the production efficiency is higher, and the yield rate is higher. For example, crystal grain oil (commonly known as explosive oil) has been serialized, and the crystal grain size and gloss have different formulas, which can be adjusted according to customer requirements. The speed is as high as 80 sheets/min. There will be no explosion.

On the other hand, in addition to the above-mentioned common special coatings, new varieties such as high-gloss rubber oil, anti-slip oil, anti-fouling oil, orange peel oil, and crystal grain ink have also been added. Among them, high-gloss elastic anti-skid oil, orange peel oil and crystal grain ink are worthy of attention. The characteristics and application prospects of these three types of special coatings and inks are briefly introduced below.

High-gloss elastic anti-slip oil

High-gloss elastic non-slip oil, also known as high-gloss rubber oil, is one of the new varieties on the market.

Performance characteristics and application fields Unlike matte rubber oil, it is as flat as ordinary varnish, but the gloss is much higher than the latter, and the appearance is full. In addition, the coating film is soft and has good elasticity, so it has a delicate touch and can provide a silicone-like feel. In addition, it has a strong anti-slip function, as well as good resistance to stamping and cooking. Suitable for trays, gift boxes, beverage cans.

Application points The process is the same as that of ordinary varnish, and it is baked at 180 ℃ for 10 minutes. The thicker the coating film, the stronger the elasticity, and vice versa.

Product Comments When applied to the tray, the soft feel and super anti-slip effect are unforgettable and addicting.

orange peel oil

Orange peel oil, also known as orange oil, is one of the special paint varieties that are very worth exploring at present.

Performance characteristics and application fields Orange peel oil has good processing performance and can be widely used in various miscellaneous cans and milk powder cans. At the same time, it has good cooking resistance and can also be used in beverage cans.

The orange stripe effect is caused by the shrinkage caused by the difference in the surface tension of the paint surface and the bottom layer. The smaller the surface tension of the bottom layer and the greater the surface tension of the surface layer, the greater the shrinkage force of the orange peel oil and the greater the texture of the orange peel oil; and vice versa. Therefore, by adjusting the surface tension of the bottom layer and the surface layer, a lot of surface effects can be made, providing unique visual and tactile effects, and giving the product a distinct personality.
In addition, users can also adjust the texture effect they want through the combination of orange peel base oil and orange peel oil. For example, apply orange peel oil on the special ink, or apply a layer of orange peel base oil on the ink first, and then apply orange peel oil on top, so that the coating effect can be completely controlled by yourself, even if competitors use the same orange peel Oil, it is also difficult to imitate the same coating, so it can give the product a strong anti-counterfeiting function, and at the same time greatly improve the added value and competitiveness of the product.

The main application process is the same as that of ordinary varnish, that is: first coat the bottom varnish, the dry film weight is 2~3g/m2, bake at 170 ℃ for about 10 minutes; then apply orange peel oil on the bottom varnish, the dry film is The weight is 5~12g/m2, and it is baked at 170℃ for about 10 minutes.

Comments When applied to Red Bull beverage cans, “Junlebao” milk powder cans, Dulux primer packaging barrels, Carpoly wall paint packaging barrels, and Garrett Jello popcorn cans, the irregular tactile texture is quite eye-catching.

Crystalline ink

Crystal pattern ink, commonly known as explosive ink, is a new variety developed on the basis of crystal pattern oil. It is unique in the world and has a very broad market prospect.

Performance characteristics and application fields Crystalline ink has all the advantages of crystalline oil, such as crystal clear, bright vision, delicate touch, etc. At the same time, it overcomes the shortcomings that crystalline oil must be coated on a large area and the mechanical processing performance is limited. Any position of the finished print can be printed at will, to meet the requirements of machining, cooking, etc., suitable for all printed iron can products.

Application points It is very convenient to use, just use the existing printing equipment to print directly on the varnished print. The thicker the film, the larger the grain, and vice versa. The process of baking temperature and vehicle speed can refer to the grain oil process, that is, the temperature of the front furnace is 80~110℃, and the temperature of the rear furnace is 130~150℃; or the rear furnace is only opened, and the temperature is 160℃; /minute.

Since it is a brand-new product, users can mix colors and shapes, and add dyes or pigments appropriately to bring out their ideal and unique local crystal grain visual and tactile effects, giving the product a distinct personality and strong anti-counterfeiting function, which greatly improves the the added value and competitiveness of the product.

Product reviews are on the black part around the iron text “Huoshan Huangya” on the tea cans, the blue flaxseed in the vegetable oil can, the dark blue shield in the golden-collared milk powder can, and the black background outside the red letter “vial” in the cosmetic can with empty red letters. The heart-shaped chocolates and ribbons of the Dove chocolate box, and the gold base around the “A Bucket of Gold” in the Jinxilai wine can, the application of partial crystal pattern ink gives people a bright, unforgettable, fresh and refined feeling. The finishing touch.

Epilogue

The production and application processes of these three types of special effect inks and coatings are mature and meet the requirements of environmental protection. They have broad market prospects and are worthy of vigorous exploration and promotion.

Bonus: Two special applications It’s important to point out that they also have two special applications. The first is to use the heat insulation function of high-gloss elastic varnish on the drying room bracket, which can not only solve the pain point of the flower stand printing industry, but also have the effect of energy saving and environmental protection. Second, by adding fluorescent, pearlescent, flashing, temperature-sensing, photosensitive and other materials to give special coatings and inks corresponding functions, so as to develop more unique products to meet market needs.

Four unsolved problems and countermeasures At present, there are still the following problems in the application of special effect inks and coatings in the printing iron can industry, but they can be solved through efforts.

First, the printing yield and production efficiency have yet to be improved. This is because most special coatings and inks have higher requirements on construction technology and are more sensitive to baking temperature and vehicle speed than ordinary products. It can be solved by improving the application adaptability of special effect inks and coatings and conducting professional training for construction personnel.

Secondly, the material cost and the use cost are relatively high. The former is due to the high research and development costs of special effect inks and coatings, coupled with less sales and thicker coatings than ordinary products; the latter is due to the lower printing yield and production efficiency of special effect inks and coatings than ordinary products. The formula cost can be reduced by improving and adjusting the formula and increasing the sales volume; at the same time, the cost of use can be reduced by improving the printing yield and production efficiency.

Third, the resistance to cooking and stamping needs to be improved. The root cause is that special effect inks and coatings are thicker than ordinary products, and most of the surfaces have patterns. The solution is to improve and adjust the formula, reduce the thickness of the coating film and improve the wear resistance, scratch resistance and machining performance of special effect inks and coatings without affecting the surface pattern.

Finally, the industry doesn’t pay enough attention to special effect inks and coatings. This is due to the lack of promotion by suppliers and the general lack of awareness in the industry. It can be solved by widely publicizing the application of special effect inks and coatings in differentiated packaging and raising users’ awareness.

To sum up, the application prospects of special effect coatings and inks in the printing iron can industry are quite broad. It is believed that in the near future, all participants, especially material suppliers and iron-printing can manufacturers, will work together and cooperate closely with the goal of “safety, environmental protection, energy saving and high efficiency”, and differentiated metal packaging will shine.

More: Automatic Conical Pail Production Line

Production Cost of Tinplate Cans/metal Cans

In order to do business, a tin packaging canmaking factory not only needs to make full efforts in promotion and marketing, but also needs to be very familiar with tinplate cans and tin box products. In order to better discuss the technology, quality and service of tin box packaging products according to customer needs, and to meet customer needs and promote order transactions.

The tinplate canning equipment industry business quickly calculates the production cost of tin cans and quotes it to customers is very important. When a customer asks for a price, you always say that you have to wait for the manager to come back to calculate and then reply to you or ask the boss to confirm the price, which will make the customer feel distrustful of your professional experience. Natural transactions are greatly discounted.

How to calculate the cost of tinplate cans to quote customers? Two methods are often used to calculate the cost of tin-packed products. As a tin box and tin can business, we must understand the price of tinplate raw materials in different seasons. For example, the commonly used tinplate ranges from 20,000 yuan to 8,000 yuan/ton, and the price will vary with market changes. To know the price of tinplate raw materials, usually collect the quotations of some suitable tinplate manufacturers or suppliers and organize them into a table as a reference for quotation calculation. The supplier does not include the need for freight and the transportation of raw materials. When the price of tinplate fluctuates, it is necessary to update the tinplate raw material quotation to ensure that the cost calculation is the latest price in the raw material market.

Summarize the basic calculation formula:

The price of a single sheet of tinplate/the number of types of tinplates = the cost of tinplates, and the printing fee of a single sheet of tinplate/the number of typesets=the cost of printing of tins.

The cost of tin box iron material + tin box printing cost + labor production cost + loss + packaging = overall cost + profit = unit price (if there are other costs, add them).

Iron material cost:

For example, use 8000 yuan/ton tinplate. To know the unit price of a single tinplate, choose the size of the iron material according to the size of the tin box packaging product to be made. The size of the large tinplate is 1140*940MM, but there are very few tinplates that just use the largest size. The following calculation is based on tinplate with a thickness of 0.23MM. The large size 1140*940MM tinplate needs to be removed from the printing machine. The maximum remaining side is generally no more than 30MM on one side. Now we follow to remove the largest margin and the rest is 1080*880MM.

The specification is: 1140*940*0.23MM tinplate weight is about 1934G, the algorithm is 1140*940*0.23MM*7.85G/CM square (tinplate weight is volume * density, tinplate density is 7.85G/CM square), so we You know the weight of a piece of iron. One ton of iron/1934G=517 sheets. 8000 yuan / 517 sheets = about 15.5 yuan / sheet.

For example, a relatively small iron box can be arranged on the iron plate that does not exceed 1140*940MM after removing the margin of the printing machine. According to the 8000 yuan/ton tinplate, it is 15.5/20 = 0.78 yuan (iron material Cost) Printing cost:

In the printing industry, a certain printing cost is required for the machine to start printing once. The typesetting of iron materials depends on whether the quantity required by the customer can be enough for the cost of iron material printing. If the quantity is relatively small, it needs to make up the printing fee or print together with other products. Tinplate can factories with different printing fees will have different tinplate printing prices according to the printing quality. These should be calculated based on their own printing costs or the quotation of the printing plant. For example, the cost of printing a piece of iron needs 6 yuan, that is, 6/number of typesets 20=0.3 yuan to get the printing cost of a single product.

Labor cost:

The labor cost is calculated based on the tin box production line process. The tinplate box production process consists of purchasing iron materials, printing, cutting, edge removal, crimping, bone (buckle, welding), hinge position, and bottom. , Gong bottom, punching bumps and so on. Different styles of tinplate boxes have different procedures. How many workers are needed to operate different products, including the cost of workers plus management, the cost of the pre-purchasing and typesetting staff, the cost of water and electricity, and the cost of other products used in the production process, such as detergents, engine oil, and so on. Some tin boxes have more processes and take a long time to produce, so labor costs are much higher.

Loss cost:

In the production process of the tin box and tin can packaging and canning factory, the loss cannot be avoided, and some rotten is the loss. Depending on whether the method of the iron box is complicated, whether there will be many can-making processes, whether the alignment printing needs to be aligned with the unevenness, etc., the difficult loss will be relatively high. Straight round cans have a little less loss than square cans, and those that do not need to be patterned on a flat surface have lower losses than those that need to be patterned. Generally, the loss of a simple tin box is 5%, or 3%, which is measured according to the experience and practice of the packaging can factory and the professional technical level of the staff.

Packaging cost:

The packaging cost in the canning equipment factory refers to the cost of materials used for packaging after the product is completed, such as the cost of accessories such as cartons, plastic bags, pallets, instructions, sponges, etc.

These are the packaging cost of a single product if they are added up and divided by the number in a box. Some of the accessories mentioned above can also be counted separately.

Profit:

Finally, the production profit of tinplate packaging products is added. In recent years, the tinplate can packaging industry has become more and more competitive and costs have increased. The pressure on tinplate can manufacturers has increased and their profits have become lower and lower. They are even divided into units.

Influencing Factors and Solutions of Metal Printing Uv Ink Adhesion

With the development of science and technology, metal printing technology has made considerable progress. The biggest breakthrough in recent years is the introduction and successful practice of UV curing technology that has been maturely applied in the field of paper printing. Compared with traditional heat-curable inks, UV printing has the advantages of low energy consumption, high efficiency, and high cost performance.

Unlike paper printing, metal printing generally requires the use of a lacquer-type primer. Since UV ink cannot penetrate into the primer and metal, it is difficult to form good adhesion like printing on paper, which has become a major problem in the industry.

Through the theoretical study of adhesion, we can find the root cause of the poor adhesion of the above-mentioned UV ink, and then find a solution accordingly. Below we analyze it from three aspects: primer, ink and process.

primer

The primer is the carrier of UV ink, and the adhesion is the force between the two. The performance of the primer will inevitably affect the adhesion of the UV ink. At present, there are mainly two kinds of primers for metal printing: varnish and color paint. The performance indicators discussed here are different from conventional processing performance indicators, and more emphasis is placed on the performance of the surface after forming the coating, including surface tension, polarity, resistance, surface roughness. Degree, reactive group, electrostatic adsorption, etc., they are the key factors affecting the adhesion of UV ink.

Surface tension From the point of view of the formation mechanism of adhesion, the carrier can only be effectively wetted by the attachment, and the two can exert force at the interface, thereby forming an effective adhesion. The main parameter of this wettability is the surface tension of the carrier and the attachment. The wetting rule is that the attachment with low surface tension can be completely wetted on the carrier with high surface tension, thereby forming a strong attachment, and vice versa. Repulsive force will be generated and adhesion will be deteriorated. According to this theory, increasing the surface tension of the primer can have a positive effect on UV ink adhesion.

At present, the primer used for printing iron is mainly polyester amino baking paint system, and it is necessary to consider increasing the surface tension of the paint when selecting materials. For example, when selecting amino resins, it should be noted that the surface tension of methyl etherified amino resins is higher than that of butyl etherified amino resins, and silicone additives that reduce surface tension are often not used.

Polarity Regarding the adhesion between UV inks and organic coatings such as primers, the intermolecular forces account for a large proportion. These forces mainly include hydrogen bonds and van der Waals forces. The polarity of the molecules has a great impact on this. influence. In general, the more polar the molecule, the greater the force.

The material used in the printing iron primer is not very polar. The polarity is mainly provided by some reactive functional groups. During the baking curing process, as these functional groups disappear through chemical reaction, the polarity of the coating will decrease. This can explain that in the production process, the temperature and time of the oven will affect the curing of the coating, which in turn affects the adhesion of the UV ink. On the other hand, when selecting coating raw materials, more polar materials should be selected to improve UV ink adhesion.

Resistance In practical applications, when the ink layer is cured very well, that is, the resistance is excellent, UV inks tend to adhere poorly. This is mainly because before the UV ink is cured, it has a certain erosion and penetration effect on the carrier, which can greatly improve the adhesion of the UV ink.

Surface Roughness Surface roughness also has a significant effect on adhesion. A smooth surface creates a mirror effect that makes the adhesion between layers very poor. The most common example is that in the construction process of wall paint and wood paint, it is often necessary to use grinding to improve the adhesion of the paint. There are two main mechanisms of action. First, there are many holes, “tunnels”, cracks, etc. on the rough surface from the microscopic point of view. During the wetting process, the attachments will penetrate into these points and play an anchoring role through mechanical occlusion, thereby enhancing the adhesion. Second, the rough surface can greatly increase the surface area of ​​the object, so that the interface between the carrier and the attachment can be significantly improved, thereby improving the adhesion. Adding an appropriate amount of filler to the coating can reduce the gloss and flatness of the coating, and the adsorption of the filler itself can often improve the adhesion of UV inks.
Reactive groups, hydrogen bonds and van der Waals forces are only secondary valence forces. If the carrier and the attachment can react chemically to form chemical covalent bonds, this force is the primary valence force, and the strength is much higher than the secondary valence force. Therefore, some auxiliaries rich in reactive reactive groups are added to the primer, and they are controlled to remain in the coating. During printing, they are chemically cross-linked with the reactive groups in the UV ink through UV light irradiation, which can greatly enhance the adhesion.

ink

As another player in adhesion, UV inks are just as important in their performance as primers. Formulators need to improve ink adhesion in many ways. The focus is still on surface tension and material polarity, while curing rate and choice of additives are also influencing factors.

Surface tension and material polarity The main resins of UV inks are generally some prepolymer resins rich in unsaturated bonds, such as acrylates, polyurethane modified acrylates, polyester modified acrylates, epoxy modified Acrylics, etc. According to the aforementioned wetting law, compared with the primer, the UV ink should appropriately reduce the surface tension in order to better wetting and spreading on the carrier. At the same time, the material selected for UV ink should also have a strong polarity, in order to better generate intermolecular force with the carrier. These can be achieved by the properties of the selected prepolymer resin.
Cure Rate The adhesion of UV inks can be significantly affected by the cure rate. One of the main reasons for poor adhesion is that the curing is too fast. There are two specific manifestations. On the one hand, it is cured when it is not fully wetted and spread, and good interfacial force cannot be achieved. On the other hand, the chemical reaction will cause the material to shrink, and the resulting internal stress that is inconsistent with the direction of the adhesion will not be released during rapid curing, which will affect the adhesion between the attachment and the carrier.

The curing rate of UV ink mainly depends on the unsaturated bond content of the selected material, the type and amount of photoinitiator, and the power of the energy lamp.

Selection of additives In order to achieve the desired effect of UV ink, many additives are often needed, such as leveling agent, polymerization inhibitor, dispersing agent, etc. In addition, some adhesion promoters can also be selected to enhance the adhesion of the ink layer.

craft
This refers to the control of UV ink printing, which mainly includes the following aspects.

The power of UV lamp UV lamp is the main factor affecting the curing of UV ink. The power is too low, the energy value is not enough, and the ink layer is not fully cured. If the power is too high, the energy value is too high, the ink cures too fast, the internal stress increases, and the adhesion becomes poor.

It should be noted that the UV lamp has an aging phenomenon, and the energy will gradually decrease after long-term use. Therefore, it is necessary to use an energy meter to test the UV curing equipment frequently to ensure that the energy value is within a reasonable range.

In recent years, the industry has begun to introduce UV LED light curing lamps. Compared with traditional mercury lamps, its wavelength is narrower, more targeted, and the curing speed of ink is faster. In addition, because it is a cold light source, there is no preheating effect, and it is difficult to combine the ink with the primer, resulting in poorer adhesion.

However, since the light intensity of the UV LED lamp can be adjusted, it is possible to find the UV curing strength for the best adhesion through practice. In addition, you can also consider adding an infrared preheating system. In a word, how to solve the adhesion of UV LED system is the main research direction of coating and ink suppliers.

Thickness of ink layer For some colors with special requirements, a thicker ink layer is required to achieve color fullness and brilliance, and the thicker the ink layer, the more difficult it is for UV light waves to penetrate, resulting in the phenomenon that the surface is dry and the inside is not dry, and then Affects ink adhesion. At the same time, the thicker ink layer will also produce greater shrinkage, resulting in stronger internal stress and reduced adhesion.

Ink balance In the UV printing process, the fountain solution will have an effect on the ink. Improper pH value can easily lead to the imbalance of ink and water, and the ink is emulsified, which in turn affects the curing of the ink, and finally has an adverse effect on the adhesion of the ink.

Epilogue
To sum up, there are many factors affecting the adhesion of UV ink. How to solve this problem requires the joint efforts of all participants in the production chain. Collaborating with all parties to promote technological progress in the industry is the only way to promote the development of the industry.

Control Factors to Reduce the Cost of Tinplate Cans

At this stage, many can-making companies stray into the misunderstanding of low-price pursuit in purchasing iron materials. In fact, the real cost reduction is mainly to start with the basic materials of printed iron cans. In the process of cost control, we should pay close attention to the development trend and reasonable use of canning raw materials in order to ensure quality and reduce production costs. The basic materials for can making include: tinplate, printing ink, paint, etc., and tinplate is the biggest factor affecting the cost of can making.

Tinplate is also called tin-plated steel sheet. Its appearance has greatly changed the application of tinplate. The application feature of “thin instead of thick” reduces the amount of iron used and improves the quality of the material, which is more in line with the scientific development trend of contemporary metal packaging. Nowadays, tinplate is on the market. According to the area of ​​512mm*712mm, 0.20mm thick tinplate can print about 1700 sheets per sheet, while 0.23mm thick tinplate can print 1500 sheets, and the use of 0.20mm tinplate can eliminate 0.23mm tinplate. If you make iron boxes (cans) at a price of 6,400 yuan/ton, you can save about 850 yuan in iron costs. At present, due to the continuous innovation and advancement of domestic tinplate technology, tinplate with a thickness of 0.18mm has appeared and has begun to be widely used, so the prospects for cost reduction are more optimistic.

On the basis of tinplate, the finished product after incomplete tinning treatment is also a new type of iron box (can) material. The plastic film is tightly attached to the surface of the tinplate through a special melting process, which can not be compared with tinplate with paint Its excellent corrosion resistance and can-making performance is a relatively new type of can-making material.

The paint and ink needed in the tin-making can also have a significant impact on the cost of tin-making. Without a good coating and ink, it is impossible to have the actual use value of tinplate. The application of tinplate is also very particular about food tin cans. The surface should be food-grade gold oil that meets the national standard. The coating process and thickness of the coating must be strictly controlled to ensure the compactness of the coating, improve the corrosion resistance of the tin, and ensure the sanitation and safety of the packaged food.

Nitriding Treatment Technology in the Process of Printing Iron Cans

1. Jet technology

The jet is a stream of fluid ejected from a nozzle at a high speed, which is widely used in industrial automation control. Today, we are going to introduce the use of the entrainment effect of the jet to be applied to the nitriding treatment in can making.

a. The entrainment of the jet

The so-called entrainment of the jet is that a bunch of fluid is ejected from the nozzle. The canning equipment and the automatic welding seam powder coating machine drive the originally static medium around it to flow together due to the friction between the fluid molecules. .

At this time, the speed of the jet will decrease. This phenomenon is the entrainment of the jet, which is also called suction.

b. Coanda effect of jet

If we set a pair of baffles on both sides of the nozzle, when the baffle is far from the nozzle, the situation does not change, and it is still the same as shown in Figure 1. If the two baffles are approached to the nozzle and the distance between the two baffles and the nozzle is not equal, we can find that when the baffle moves to a certain distance, the jet from the nozzle will change in an instant Direction, and flow on the baffle wall that is close to entrainment. As shown in Figure 2, this phenomenon is called the Coanda effect of the jet. This phenomenon is caused by the pressure difference, due to the entrainment of the jet, in S1

2, the working principle of the nitriding device

Any object with speed, we can say that it has “momentum”. Therefore, for jets, there is of course momentum. If two jets are ejected from the nozzle from different directions, after the two jets meet, they will form a new jet. Its direction is no longer the same as that of any original jet, but deflected by an angle, according to the law of conservation of momentum m3v3=m1v1+m2v2 as shown below, the deflection angle depends on the size of the original two jets. If the momentum of the original two jets is equal, the direction of the new jet after synthesis will be exactly in the middle of the original two jets, that is, ∠α=∠β, if m1v1>m2m2, then ∠β>∠α, the direction of the new jet will be at two It is closer to the direction of the jet with high momentum, and this phenomenon is the momentum exchange of the jet. As shown in Figure 3.

Nitriding device is a jet element made by using the momentum exchange phenomenon of the jet and the Coanda effect of the jet to make nitrogen adhere to the surface of the tank body.

3, nitriding process

a, process

Liquid nitrogen→Decompression→Synchronization of forming motor.

Solenoid valve → flow juice → jet element → attached tank body.

4, nitriding flow control

The key of nitriding treatment is to form a layer of gas protection film outside the can body to isolate the welding seam from the air. The formation of the protective film is closely related to the flow rate and flow of nitrogen. The can-making equipment and the automatic welding seam powder coating machine are blocked by the welding wheel, as shown in the figure, causing a small low pressure area on both sides of the welding wheel to drive air flow. When the flow rate is too small, the nitriding effect cannot be achieved. If the flow rate is too high, a vortex will be formed at the welding point and the nitride film will be destroyed. Therefore, it is important to adjust the pressure and flow rate of nitrogen. After repeated practice, it is recommended to use a pressure below 1kg/m2 and a flow rate of 0.6L/min is better.

5. Nitrogen protection compensation

Since there is a certain gap between the can body and the can body during the welding process, the minimum is 1~2mm, and often reaches more than 10mm. Therefore, a control signal is given to the jet, which supplements the air to the wall of the jet, so that the nitrogen does not cover the can body. . Therefore, during the production process, there will be partial oxidation and blackening of the head, which is usually referred to as incomplete nitriding.

In order to prevent this from happening, we recommend using the internal and external nitriding devices together, so that the internal nitriding will provide a compensation airflow for the outside nitriding, so that air cannot enter to ensure the quality of nitriding.

The Transformation of Traditional Manual Punch Enterprises is Imminent

Every industry is divided into 28%, 20% of the enterprises occupy, 80% of the market and profits, and 80% of small enterprises, rushing to grab the remaining 2% ten.

Today, we will not talk about leading companies, but only the status quo of small companies.

Relying on the advantages of capital, the leading enterprises used automatic equipment early, eliminated the traditional manual punching machine, and resolved various disadvantages brought by rising costs by virtue of their own advantages.

Small businesses have no capital advantage and no talent advantage. Traditional hand punching machines earn meager profits from hard work.

They want to use equipment and recruit talents, but their own conditions do not allow it. Take a Minghuang manipulator as an example, a single machine is more than 30,000, and a production line needs 4-5 units, which can replace the workload of 5 people. A production line plus punches, molds, etc., is close to more than 200,000.

For small businesses, this is close to half a year or even a full year of profit. If there is any error in the equipment, it is very likely that the capital chain will break. Opportunities to expand your business.

The cost of enterprises is rising and the market tends to be saturated. In order to survive, the market is constantly conducting vicious competition, which makes the living environment of enterprises even worse.

At this time, industrial intelligence began to sprout. With strong, stable and fast productivity, a lot of labor costs were reduced, and some profit margins were freed up. Small enterprises that have freed up smart equipment have strong and stable productivity, and further squeeze has long been saturated. The supply of the market exceeds the demand, and the price will naturally drop, making the already fiercely competitive market even more red sea.

By this time, it is no longer a competition between enterprises, but a competition between enterprises representing intelligence and traditional handicraft industries.

Things must rot first and then grow by themselves. Intelligence has occupied the balance of victory since birth. Traditional handicrafts will not die out. They will have some markets, like Pinduoduo, but most enterprises with slow transformation will disappear. The market has been sublimated and can no longer accommodate so many companies.

For companies that are still relying on traditional manual punching machines, the transformation is imminent. You don’t need to be faster than the times, you must be faster than your peers, and one step behind him, he will seize your future one step ahead.

More: Can Making Machine

How Do Metal Can Making Equipment and Metal Can Sealing Equipment Work

How do metal can making equipment and metal can sealing equipment work How does the paint can sealing machine work?

(1) The sealing form of the metal container. Any two-piece can (barrel) body or three-piece can (barrel) body and the top or bottom of the joint, there is at least one.

Or two seams (except for single-piece spray cans). The only opening method that has been used on metal containers for more than a hundred years is double crimping (doubleam), can withstand the strict drop test requirements, the vat adopts triple seam (triple seam). According to the different requirements of the content, the degree of sealing after sealing can be divided into air-tight mouth (closed form that does not leak gas at the seal), liquid-tight mouth (closed form that does not leak liquid at the seal) and tightly sealed mouth (not at the seal) Closed form of leaking solid).

Metal containers have an irreplaceable position because they can store food for a long time, but they also have disadvantages, that is, leakage at the seal is easy.

Leakage, causing corruption or leakage of the contents. According to statistics from the light industry department, nearly 70% of the quality accidents of food cans in my country are caused by sealing problems, which shows the importance of metal container sealing.

(2) The structure of double crimping The double crimping is the combination of the can (barrel), the lid and the bottom, and it is a five-layer occlusal connection.

Its structure is shown in Figure 3-1. It is composed of two-layer tank (barrel) body material, three-layer tank (barrel) top and bottom cover material and sealant embedded between them. Hemming thickness (T), hemming width (W) in double hemming structure; countersunk, body hook length (BH), cover hook length (CH), overlap length (a, overlap rate), wrinkles Indexes such as degree (tightness) are the elements that constitute the double hemming.

Although the basic structure of the double hemming has not changed, there are some changes in its form, such as changing the shape of the hemming, or shifting the hemming, or reducing the size of the hemming structure. The appearance of double curling has two forms: ear-shaped and rectangular. The economical sealing method is shown in Figure 3-2. The curling is different from the common curling. It is located at the bottom of the can. This change in form does not change the basic structure of the double curling, but only changes its position. As a result of this change, 28% of the can lid material can be saved. In addition, a kind of micro-shaped crimping (Iminiscaimling) used for 206 beverage cans also only changes the size of the double crimping, without changing its basic structure, that is, the common crimping length is reduced, and the sealing performance after the change is completely possible. It satisfies the sealed storage requirements of beverage cans, and also saves lid materials and can sealing glue.

(3) The main components of the crimping mechanism and its functions The crimping mechanism is composed of three parts: the seaming chuck (seaming chuck) sealing wheel (wmtd) and the (base plate). These three parts are called the three elements of the crimping seal. ,Indispensable.

①Sealing wheel The sealing wheel is divided into one sealing wheel and two sealing wheels according to the working order. There are three forms of sealing wheel: outer plate.

Line sealing wheel, inner curve sealing wheel and inner curve sealing rail.

a. Outer curve sealing wheel The sealing surface of the outer curve sealing wheel is on the outer circle. This form of sealing wheel is easy to process, detect and manufacture.

Low cost, simple installation and adjustment. Since the sealing wheel is on the outside of the sealed can, two or four sealing wheels can be distributed on the circumference, which can complete one and two sealing processes on a curling mechanism at the same time. The sealing wheel is equipped with a centripetal thrust bearing. During the sealing process, due to the sealing force, the sealing wheel rotates freely (slave) around the installation axis.

b. The inner curve sealing wheel (less common) The sealing curve of the inner curve sealing wheel is on the inner side of the inner hole of the sealing wheel, and the optical projection method cannot be used.

Method inspection, so processing and inspection are inconvenient and the manufacturing cost is high. At the same time, because the sealing wheel covers the lid of the can, it is impossible to complete one and two winding sealing processes on a curling mechanism at the same time, so the machine structure is more complicated, the efficiency is lower, and the cost is higher. However, the inner curve sealing wheel also has its advantages. Because the inner curve aperture of the sealing wheel is closer to the diameter of the can lid, the contact surface between the sealing wheel surface and the can lid during the rolling process is much larger than the outer curve sealing method, so the inner curve sealing wheel The sealing process is more reasonable and the quality will be higher.

The inner curve sealing wheel is the same as the outer curve sealing wheel, which is mounted on the centripetal thrust bearing. During the sealing process, the sealing wheel rotates freely around the installation shaft (driven) due to the sealing force.

c. The inner curve sealing track The inner curve sealing track is the same as the inner curve sealing wheel in that both use the inner sealing curve.

It has the advantages and disadvantages of the inner curve sealing wheel. It is also different from the inner curve sealing wheel: first, the inner curve sealing track is fixed (that is, there is no rotating movement of its own), and the track does not move can simplify the machine structure, but it also makes the difference between the two because the track does not move with the tank. Large relative sliding is inevitably produced (the sealing equipment must be suitable for a certain tank diameter range. If the middle diameter of this range can be designed to be the smallest relative sliding, the relative sliding will occur when the tank diameter changes, and it will increase with the change of the tank diameter. The relative sliding volume causes scratches on the curling surface; secondly, the inner diameter of the inner curved track is very large, which can accommodate several or more curling mechanisms at the same time.

②The pressure head (also called seaming chuck) is used to fix the position of the can body and the can lid, so that the thickness of the coil is uniform and consistent.

Keep the seal tight. At the same time, the outer circle of the indenter is a cone of 4, which functions to generate enough friction with the pressure of the tray to prevent the can lid and the sealing wheel from stagnation or stagnation due to the deformation of the metal seal during the sealing process or between the can lid and the indenter. The countersunk depth and outer diameter of the pressure head should be consistent with the countersunk degree and can diameter of the can lid. The countersunk depth of the pressure head often affects the width of the lid hook.

The indenter often needs to be prepared with the can lid to ensure good performance.

③Tray (or supporting chassis, lifting plate) The tray is used to hold the can body, hold the can body with the lid to the sealing operation station, and press the lid and the can body together, and the spring of the tray pressure head will face the can Pressure is applied to the body and the lid of the can to prevent heading of the can in the sealing process.

(4) The forming process of double curling The double curling is carried out in two steps, which are completed by one sealing wheel and two sealing wheels respectively.

As shown in Figure 3-3. First, a sealing wheel moves radially relative to the can body. The sealing force of the sealing groove of the sealing wheel and the arc edge (or straight edge) of the can lid causes the outer edge of the can lid to curl in the normal direction of the groove curve, and a sealing When the wheel moves to position 3, the preliminary shaping of the sealing crimping is completed, so that the can cover and the can body flanging mouth along its periphery will be bent into an initial joint of a certain shape and size as required. Then a sealing wheel exits the roll-sealing position. At the same time, the second sealing wheel starts to work, moves radially relative to the tank body, pushes the curling edge that has a preliminary shape, and presses it firmly until the second sealing wheel completes the curling operation at 5 o’clock, so that the tank benefits and the tank The body forms a tight seam and the last two sealing wheels return, and the sealing process ends.

(5) The feed movement of the double crimping while the first and second sealing wheels move radially along the can body, the sealing wheel moves back relative to the can body.

Rotational motion, the combination of the two motions is called the feed motion, and the radial motion of the sealing wheel per revolution of the tank is called the feed. There are two forms of rotary motion: one is that the can body rotates and the sealing wheel does not move; the other is that the can body does not rotate, and the sealing wheel rotates around the can body. These two different exercises have the same effect on the sealing process. In the process of crimping and sealing, the metal of the part of the can body that participates in crimping has undergone tensile and compression deformation. In order to meet the requirements of the quality of the sealing and crimping, the crimping process should make the metal material deform evenly, and the amount of deformation per unit time is not too large, that is, the sealing wheel is along the diameter of the can body during the rotation of the sealing wheel around the can body. The feed amount in the direction is uniform and cannot exceed a certain limit. The feed rate is small, the sealing quality is good, but it will reduce the production capacity of the equipment; the feed rate is large, the equipment production capacity is improved, but the sealing quality is reduced. Generally, the feeding movement of one sealing wheel of the sealing machine is completed in about three revolutions of the sealing wheel around the can body, and the feeding movement of the second sealing wheel is completed in two revolutions of the sealing wheel around the can body. At present, there are two common feeding methods for the sealing wheel: one is an eccentric mechanism (commonly used for sealing equipment without rotation of the can body), the sealing wheel is installed on the eccentric shaft, and the planetary gear system drives the can body to rotate Movement, in the process of the sealing wheel rotating around the can body, the eccentric shaft rotates slowly and the eccentric shaft rotates one circle, which completes the feed motion of the two curling. This feed motion is not uniform, but close to the law of cosine; another One kind is to drive the swing arm by a cam. Its motion law depends on the design of the cam. In general, the cam can be designed to move at a constant speed except for the complicated motion wheel at the starting point, ignoring the slight difference between the swing arm and the linear motion. The inlet mode of the sealing wheel of the cam-driven swing arm is relatively close to the uniform feed motion. The more special one is the orbital sealing. This type of can sealing machine adopts a vertical type. The can body is driven by the pressure head and the tray to rotate. A workstation has multiple can bodies that rotate in this way and revolve around the rotation center of the workstation together. The arc center of the guide rail is installed eccentrically, and the amount of eccentricity is the total stroke of the sealing feed.