1. Where is the low-temperature heat-sealable strippable jelly used in jelly lids produced? Can I test production and formula?
Low temperature heat sealable peelable resin available from Yamano Trading Co., Ltd., Japan. The formula is: 1,4 cyclohexanedimethanol-terephthalic acid copolymer 1 part by weight, PE1 parts by weight, the two are mixed and then melt-extruded and coated on the aluminum foil, and the easy-to-open and easy-open container lid can be obtained material. Its structure is: BOPP / reverse printing / dry complex / aluminum foil / extrusion, with the above formula can produce easily heat sealable peelable material.
2. It is required that after the PVC wood grain film is printed, the glazing agent should be coated on the special ink for PVC. It is necessary to have good fastness. What kind of polish is better?
The use of acrylate resin solvent gel as a polish not only has good gloss, but also has good adhesion fastness and good adhesion with PVC special ink. The use of waste transparent white plexiglass in a solution of dichloroethane as a polishing agent, also has better results.
3. The blown film (PE) sometimes has particularly poor transverse strength and tears easily. Why? How to prevent?
The blown film is actually a thin film between a biaxially fixed film and a cast film. Biaxially oriented films can also be produced by the inflation process as long as the temperature and the blow up ratio and the draw ratio are properly adjusted. For this reason, when the blown film is produced, the pulling speed is too fast, and the difference in blow ratio is too large to produce longitudinal fibrillation. As a result, like the process of producing a fissured fiber in a uniaxial direction, the transverse strength is low and it is easy to pull. Broken. The prevention method is to appropriately reduce the traction speed so as to match with the blow-up ratio; to increase the air volume of the air ring to rapidly cool the blown film and prevent it from being stretched and oriented in a high-temperature and high-elastic state.
4. The factory that produces BOPP is full of waste PP film. How to deal with it better?
An extrusion granulator can be purchased, extruded and sold to others. This material is clean and can be used as primary recovery particles. Or, to purchase a set of equipment for extruding PP strapping, add 40 parts of CaCO3 stone powder to the waste PP film during extrusion granulation. Note that when pelletizing, do not pulverize the PP waste film, and directly send the waste film into the granulator for granulation. The crushed waste film is not only difficult to enter the machine, but also difficult to smash.
5. Can I use EVA film to make clothes bags?
Most of the clothes bags use heat-sealable, high-transparency BOPP film, which is printed and seamlessly heat sealed. The heat-sealable BOPP is produced by the following methods: first, PP particles are mixed with heat-sealing rubber or EVA, and then biaxially stretched by PP; second, co-extrusion method: PP and LDPE or EVA co-extruded, biaxially stretched, biaxially stretched. Because its temperature is above the tf temperature of materials such as LDPE and EVA, PP biaxially stretches, while LDPE, EVA and other surface materials are not stretched, but have heat-sealing properties; third, they are coated on stretched BOPP film. Cloth PVDC and other materials, heat seal layer. EVA has good heat sealability, of course, can be used as a bag of clothing, if the customer thinks it is acceptable in terms of transparency.
6. Waste SBS material, how to recycle?
Can add SBS plasticizer cyclohexane and add a small amount of new material SBS re-granulation injection molding.
7. Use surface printing ink to print on aluminum foil. The fastness after printing is very good. However, after cooking in water at 100°C for 0.5h, the ink will fall off. How to solve it? (table printing ink is polyamide ink)
This shows that this type of printing ink is not good in water resistance, and can be printed on the BOPP with the compound ink and then dry-composite with aluminum foil and then steamed in water at 100° C. for 0.5 h, which can improve the water resistance of the ink. The cross-linking agent using silane coupling agent for acrylate table printing ink introduced in the book “Encyclopedia of China Plastic Products†is used for high-temperature cooking table printing ink, which has good resistance to water cooking and does not delaminate after cooking.
8. The single-layer liquid packaged milk bag is sterilized at 100°C, breaking bags, why?
When there is a lot of air in milk packaging, at 100°C, the air will increase in internal pressure due to the volume expansion, and the pressure difference between inside and outside will be large and break bags will occur. For ordinary retort sterilization bags must be packed under vacuum, and it is best to solid food. For high-temperature retort sterilization of liquid packages with air, a sterilizing device that automatically adds hydraulic pressure as temperature rises is used, or bags are easily broken. Generally this kind of milk packaging is hydrogen peroxide + UV disinfection packaging film, milk pre-selection cooking sterilized, aseptic hot filling and packaging, this simple packaging for a week (at room temperature). The preferred packaging is the aseptic packaging of paper-plastic aluminum multi-layer bags, with an effective period of more than six months.
9. The structure of BOPP/anti-printing/PV/two-component glue/VMALCPP is widely used in the packaging of mustard bags. This structure often happens when the reverse printing ink is stuck together by the PV adhesive and the BOPP is peeled off. Why?
PV adhesive in dry compound contains a large amount of ethyl acetate. Ethyl acetate is an excellent solvent for printing ink binders. When PV glue is applied to the reverse printing ink, the ethyl acetate in the glue penetrates into the ink. After ethyl acetate enters the printing surface of BOPP, the already bonded part between the printing ink and BOPP is loosened and even delaminated. Ethyl acetate penetrates the ink layer with PV glue, improving the overall printing. The adhesion fastness of the layer to the PV glue results in the fact that the original printing ink with good adhesion is separated from the BOPP film. The solution is to apply PV adhesive on the vacuum aluminum plating surface of VMALCPP film. After being dried at 60-90°C, it is compounded with the reverse printed VBOPP film. In this way, when the reverse printing ink is in contact with PU adhesive, PU adhesive is used. After drying in the drying tunnel, most of the ethyl acetate content has evaporated, and no penetration of ethyl acetate into the reverse printing ink layer will occur, affecting the adhesion of the ink layer to BOPP. At the same time, increase the solid content of PU glue (reducing the amount of ethyl acetate solvent), increase the temperature of the drying tunnel, and increase the time of staying in the drying tunnel (slowing the composite speed) can improve and prevent this delamination phenomenon.
10. When using instant noodle cover, use PU two-component adhesive, but the paper is not easy to compound with aluminum foil. Why? The instant noodle cover material structure is PET/anti-print/PU glue/paper/PU glue/aluminum foil/hot melt adhesive EVA.
Paper is a kind of porous material and has strong absorption of PU glue. Therefore, it is coated with the same adhesive roller as the composite film. Since most of the glue is sucked into the hole of the paper, the amount of glue on the surface is not enough. Therefore, the composite fastness is greatly reduced, and the composite fastness to aluminum foil is poor. The solution is to coat a layer of primer on the paper first, which can be other tree-bearing glue liquids. After the film is dried, the PU compound glue is applied on the surface, and the composite fastness can be improved. It should be noted that the use of EVA hot-melt adhesives in the inner layer of this type of structure is not suitable, even though EVA hot-melt adhesives have a wide range of cup adaptability, ie, the use of PP, PE, PS or PVC, etc. The instant noodle bowls can all use the inner layer of EVA hot melt adhesive to firmly seal the lidstock on the bowl at a low temperature, but the pure EVA hot melt adhesive without easy release agent is not easy to tear It is not easy to open Kaifeng. Materials that reduce the heat-seal fastness, such as surfactants, should be properly added in pure EVA.
11. What are the four layers of the four-layer high-temperature cooking bag? What kind of material is the special layer?
The structure of the high-temperature cooking bag with four layers of transparent structure is: PET12/PA6 12/aluminum foil 9 μm/(CPP) 70 μm. Either the PET12 (or) Ny12/PVDC film or the eval film 10-12/CPP70 is transparent in three layers. The so-called special layer refers to a high-barrier eval film or a PVDC film layer.
12. Blow molding with LDPE (MFR: 2 g/10 min) 35%, LLDPE (MFR: 1.8 g/10 min) 35%, LDPE (4 g/10 min) 30% R blend produced by DOW Chemicals. Blow-up ratio of 2-3, masterbatch 3-4%, results in hot filling at 100 °C, easy to pull off, why? The film thickness is 65 μm.
This polyethylene blend should be hot-filled at 100°C, and I am afraid that under the pulling force of the filling, even if it does not break, it will have a larger tensile deformation. Generally, this type of liquid filling film is preferably made of a coextruded composite film with high temperature resistance and good strength, such as nylon. Adhesive resin / PE, although the inner layer is still PE, but the outer layer of nylon film, heat resistance, high strength, but can not use the fuse to fuse and fuse pockets. The PP/EVA/PE coextruded film can be used for melting but the sealing temperature is higher at 190-200°C. The thickness is appropriately increased to 80-90 μm to ensure the strength of the composite film.
Another reason is that the tension is too great. The solution is to reduce the pull of the packaging machine. In fact, after sterilization at 100°C, proper cooling is performed to reduce the temperature of hot filling. As long as it is performed in a sterile room, it also has better packaging effect.
13. What caused the missing print?
There are many reasons for the missed printing: The first is the problem of corona treatment: If the corona processing blade has a notch, and there is no spark at the notch, resulting in missed printing; the second is that the film surface has oil or dust and cannot adhere to the ink. The third is the presence of black and yellow spots on the surface of the film and crystal point and deadlock can not be attached to the ink; the fourth is caused by static electricity, not only produces the missing footprint of the fly, but also prevents the ink adhesion with the film; The fifth is the formation of flocculation in the ink, resulting in lower binder content and lower adhesion; the sixth is the adhesion of moisture to the ink or film.
14. Printing color fades during printing. Why?
During the printing process, the printing becomes light, and it should be noted whether the ink in the ink tray has moisture, dust, and insoluble solvent into the ink, and these materials enter the ink to cause gelation. The gelled ink is not only The decrease of the binder content causes the adhesion of the ink to decrease, and the particles of the gel are liable to adhere to the pigment to cause the uneven distribution of the pigment in the ink, which cannot be applied to the plate roller, and the color is lightened. If the entire ink is faded, there is a problem with the quality of the ink. The problematic quality of the ink is manifested in the following aspects: The fineness of the first ink is not enough and the gravure roll cannot be applied; the second ink is stored for a long time; the third dilution The agent is mixed with water, oil, and other solvents that are insoluble.
15. How to make up for defects on the 15. roll?
Some of the defects that appear on the roller can be carefully corrected with abrasive glue and scraper or corrected by lapping, but the larger defect cannot be repaired.
16. Use of BOPP/anti-printing/PU two-component adhesive/VMALPET/PU adhesive/cast LDPE film 70 μm, packaging pesticides Chloride Killing, Insecticide and packaging of fish medicine and brain Zhenning tablets with the above structure, resulting in powder Pesticide Chloride is corroded by the inner layer of LDPE. What structure is better to use?
For highly corrosive and highly permeable pesticide packages, see LDPE that is resistant to poor corrosion resistance in the rudder layer material. Instead, PP should be used. The preferred pesticide packaging structure is PET12/VMALPET14/CPP70μm, which may have a shelf life of approximately one year. LDPE has poor drug resistance. Even if it is 70μm, it may have a shelf life of only 3 months. In order to improve the barrier properties of the package, PET12/reverse printing/BOPA612/CPP7O structures can also be used. Heat sealing temperature 190-200 °C.
17. What is the effect of the imprinting roller on the print quality?
Too soft makes it easy to blur the edges of the print, and fine ore is not easy to print clearly.
18. After the bag is sealed at the heat-seal, the inner layer is LDPE, and the temperature is 160-180°C. What are the reasons?
The temperature is too high to decompose and degrade. Generally, if the inner layer is LDPE, it can be 160-180°C. If the heat sealing time is too long, brittleness may also occur.
19. When using rose red and pink ink pigments, the printed pockets will fade in the sun, how to improve the lightfastness of the red ink?
The lightfastness of various pigments is not the same. Lights with excellent light fastness can be used to produce inks. For example, the red pigments with good light fastness include naphthol red, quinone, and bismuth red. The second method is to add 0.1-1% UV-531 UV absorber to the ink. This additive is less toxic and can be used for food packaging. It is also possible to add CA antioxidants to the ink in amounts of 0.02-0.5%. In general, plastic bags used for food packaging will not be exposed to sunlight for long periods of time, but if they are sterilized with ultraviolet light, the ink requires good light resistance.
20. Using a domestic vacuum aluminum coated CPP film and a BOPP reverse printing mask at a temperature of 280-330° C. to extrude the LDPE three-layer thermal composite, resulting in the vacuum aluminum coating transferred from the CPP film to the LDPE. If vacuum-plated aluminum CPP imported from South Korea is used, this phenomenon does not occur. Why?
This is because the vacuum-plated aluminum CPP film imported from South Korea has a primer on the vacuum aluminum-plated surface of the film, which improves plating.