the important properties of stretch film

stretch film -important properties of the important properties of stretch film, stretch film with high tensile rate, the minimum width shrinkage, high longitudinal ultimate tensile strength, high puncture strength, high resistance to shear and low stress relaxation and good the viscosity. These properties are dependent on a combination of basic resins and additives. Flat extrusion stretch film and blow molding, stretch film, stretch film is divided into flat extrusion stretch film and blow molding, stretch film. Flat squeeze between the two main factors affect the performance of the stretch film stretch film and blow molding, stretch film. First, as the cooling and solidification of molten plastic. Flat extrusion stretch film containing circulating cooling fluid with one or more polishing and roll squeeze to produce, so the flat extrusion stretch film has been a rapid cooling in the production process; blow pallet stretch film production after rapid cooling, usually high-speed air-cooled, flat stretch film extrusion stretch film made of the same material blow, compared with more uniform thickness and a higher viscosity and transparency.
Another factor is the molecular orientation of the flat crowded stretch films have a certain degree of stretching along the machine direction (vertical) in the production process, we referred to as uniaxial orientation, the longitudinal ultimate tensile strength greater than the transverse tensile strength, transverse tensile spread of highly tear which reduces damage to the packaging, storage and transport. Blow stretch film production in the longitudinal and transverse stretching in both directions, we referred to as bi-directional orientation of the stretch film resistance to horizontal spread of the tear is small and easily damaged.
Higher ambient temperature will cause the pallets of stretch film relaxation and loss under standard conditions with retention. Under standard conditions, within 24h after the goods packing, low density polyethylene, linear low density polyethylene LLDPE stretch film to maintain the original retention of 65%, while the PE stretch film can only be kept at room temperature, about 25%. Low temperatures can reduce the stickiness, toughness and elongation of the stretch film performance. General, most of the stretch film membrane suitable for use in a 29 ~ 54 ℃.
Sometimes in high-humidity environment can increase the viscosity of the stretch film, this is because some of the thickening agent to play a role by absorbing atmospheric moisture. So, if between two smooth pallet stretch film surface moisture, it is difficult to stretch the film to separate the two layers of pallets. pallet stretch film can be formed in a low humidity environment, a higher static viscosity in storage, during transport, the static viscosity is unreliable, this is because the electrostatic charge over time and disappeared. Stretch film manufacturers to produce composite stretch film, in its one side coated with a thickening agent to improve the stickiness. JINING HONGXIANG QUALITY CHECK AFTER SOLDERING MATERIAL CO., LTD