Production technology and characteristics of heat shrinkable film

The production technology and characteristics of heat shrinkable film Release time: 2020-01-09 　　 Heat shrinkable film is used in conjunction with a heat shrinking machine, and the texture is relatively brittle. After the heat shrinking machine is turned on, the shrinkage film will shrink. , If you handle it properly, it will look good; the stretch film is relatively soft and is wound on the outside during the pallet.　　Pvc heat shrinkable film is widely used in the food industry, such as the packaging of various fast food, lactic acid, beverage, dry food, native products, mineral water, cans and other products. PVC heat-shrinkable film bag is the most commonly used heat-shrinkable material in heat-sealing packaging. Through the hot air blow, the high-transparency heat-shrinkable film can be close to the surface of the article to improve the product grade, dust and moisture, and let the article show a new and perfect packaging effect.　　PVC heat-shrinkable film is made of PVC resin mixed with more than ten kinds of auxiliary materials and then inflated twice. Its characteristics are good transparency, easy shrinkage, high strength, shrinkage rate can be adjusted freely according to user needs, and strong operability. PVC shrink film can be made into tubular film, L-shaped half-fold film according to requirements, and can be processed into tube bags, flat bags, etc. Heat shrinkable film packaging completely replaces cases such as cartons or half-pallet cartons. However, since the current logistics environment in the domestic market cannot be compared with the mature logistics management of the international market, the PET heat shrinkable film technology must be developed to the international level in the domestic market. There are still some obstacles. It is expected that in the next 3 to 5 years, with the development of PET heat shrinkable film packaging technology and the continuous improvement of heat shrinkable film pressure capacity, in certain specifications of packaging, the cuff PET heat shrinkable film packaging machine can completely replace the carton Or heat shrinkable film half pallet box.　　Heat shrink film packaging advantages　　1. Without wood or metal pallets, cement bags can be transported in stacks, saving pallets and turnover costs. 2. The cement stack can be stored arbitrarily, not afraid of wind, frost, rain and dew impregnation, to ensure that the cement quality remains unchanged within a certain period of time.　　3. It can be placed in the open air, stacked on top of the stack, no warehouse, no tarpaulin, saving land storage area and funds.　　4. It is convenient for hoisting or forklift loading and unloading, suitable for both land and water, especially for water transportation, which is more convenient for hoisting in the ship warehouse.　　 5. The damage loss is greatly reduced. The amount of cement lost during transportation is about 5-10% due to the damage of paper bags in China. There is almost no loss in heat shrink packaging. Heat shrink film production technology and characteristics Shrink film production usually uses extrusion blow molding or extrusion The thick film is produced by the casting method, and then stretched longitudinally and transversely at a high elastic temperature above the softening temperature and below the melting temperature, or stretched in one direction only, and not in the other direction. Stretching, the former is called biaxial stretch shrink film, while the latter is called unidirectional shrink film. When in use, when the temperature is higher than the stretching temperature or close to the stretching temperature, the packaged goods can be wrapped with reliable contraction force. The heat shrinkable film packaging machine is also called the heat shrinkable packaging machine. Its main function is to wrap the product with a heat shrinkable film and then heat it so that the film shrinks and wraps the product tightly.　　 Extrusion flat blowing method. The extruder used is an ordinary equal-distance unequal-depth gradual single-screw extruder with a screw diameter of Φ30mm, a length to diameter ratio of 25:1, a compression ratio of 3:1, and a cross-type flat blow head. The main process conditions are: the temperature of the back section of the extruder is 170-175℃, the temperature of the middle and front sections is 180-185℃, and the temperature of the die head is about 180℃; the temperature of the hot water for heating and stretching is 85-95℃; The cooling water temperature is natural temperature. Previous: Beijing heat shrinkable film label manufacturer's low price direct sales are sought after by customers