How to choose the shrink film for shrink wrapping machine?
Heat shrinkable film is widely used in: food, medicine, disinfection tableware, stationery, craft gifts, printed matter, hardware and plastic products, telephones, electronic appliances, etc. In terms of combined (cluster) packaging, it can not only meet the functions of moisture-proof and dust-proof, anti-touch and stealth, transparent display, etc., but also increase the attractiveness of product appearance, and can also be used to replace various types of cartons, which not only saves packaging costs, but also In line with packaging trends.
Pof is mostly used for food packaging (cartons, toys, electronics, electrical appliances, stationery, books, records, daily necessities, medicines, cosmetics, beverages, fruits, commemorative labels)
It is used for packaging items with a relatively large weight (beverages, floors, building materials, etc.)
PVC (polyvinyl chloride) heat shrinkable film is polymerized from vinyl chloride monomer into polyvinyl chloride resin and then chemically modified by polyvinyl chloride resin to produce PVC heat shrinkable film by blow molding or calendering. The PVC shrinkable film has good transparency and high shrinkage rate. It is between the one-day closure of Raguan wool, and its cost is low, the tensile strength is large, the temperature shrinkage range is large, and the heat source requirements are not high. The main processing heat source is Hot air, infrared or a combination of both. However, PVC shrink film is not environmentally friendly and difficult to recycle. It produces toxic gas when burned. It is not conducive to environmental protection and has been banned in Europe and Japan. Moreover, the relative density ratio of PVC and PET materials is around 1 to 33. As far as the current technical level is concerned, it is difficult to distinguish the two in the recycling process. However, in our country, because the environmental protection requirements are not very high, the market sales situation is relatively good, and PVC is still the most important material in the field of heat shrinkable labels.
PVDC (polyvinylidene chloride) is a non-toxic, odorless, safe and reliable high-barrier material. In addition to the general properties of plastics, it also has oil resistance
Corrosion resistance, taste retention, excellent moisture resistance, mildew resistance, direct contact with food and other properties. It also has excellent printability. High crystallinity and high density determine that PVDC copolymer has good oxygen barrier, gas barrier and taste retention. Due to the symmetry of its molecular structure and strong intermolecular cohesion, it is difficult for oxygen molecules and water molecules to move in PVDC molecules. PVDC shrink film is mainly used for packaging chilled meat.
PET (polyester) film is an internationally recognized environmentally friendly heat shrinkable film material. Polyester heat shrinkable film is a new type of heat shrinkable packaging material. PET heat shrinkable film
The main features are: good low temperature shrinkage, high shrinkage rate, fast shrinkage, non-toxic and low heat when burning. PET heat-shrinkable film has excellent transparency, gloss and heat-sealing properties and is suitable for high-speed packaging equipment. High shrinkage rate and excellent packaging effect. Low density and low packaging cost. Can improve economic benefits. Flexible and tough, high strength, will not harden and become brittle at low temperature. Non-toxic and harmless, it is an ideal green packaging material for food, medicine and other packaging. No toxic gas will be generated during heat sealing, and it has the advantages of good barrier property, excellent moisture-proof performance, static electricity elimination, and not easy to be contaminated with dust.
PETG film is specially used for high-performance shrink film. It has a final shrinkage rate of more than 70% and can be made into packaging of complex shape containers. It has high suction power, high transparency, high gloss, low haze, easy printing, not easy to fall off, and storage The advantage of low natural shrinkage. Among them, the biaxially stretched PETG film is suitable for high-grade packaging, printing, electronic appliances, cable wrapping, insulating materials and high-quality substrates in various industrial fields. Uniaxially stretched PET and heat shrinkable films are suitable for external labels such as various canned polyester bottles and various containers. Generally, the bottle body with complex geometric shape often chooses PETG material as the label material. This is because PETG resin is beneficial to environmental protection and its resin shrinkage temperature is lower than that of PVC and OPC. Compared with other competitive materials, the temperature shrinkage change of PETG is relatively stable. These properties make it possible to have more precise control over the thermal shrinkage of the labels in the hot oven.