stretch film-19

stretch film-19

Casting method to produce stretch film flow path is long and narrow, the flow speed, melt temperature range is generally controlled at 260 ℃ ~ 290 ℃, cast chill roll temperature was controlled at 21 ℃ ~ 31 ℃, the winding tension is lower, generally less than 11kg, to facilitate the viscous agent to move out at the same time to reduce the stress within the finished stretch film.
pallet stretch film with high transparency to the identification of the goods; pallet stretch film longitudinal elongation conducive to pre-stretch, and saving material consumption; stretch film and good puncture resistance and transverse tear strength allows stretch film in high tensile magnification encountered goods sharp corners or edges do not fault; high yield point of the packaged goods fastening. The transparency of the production of cast stretch film, here is not focused on. Material copolymerized monomer C atoms increase in the number of branched-chain length increases, the crystallinity decreased and increased, generated copolymer winding, or kink "effect, so the elongation of the stretch films to improve the puncture strength and tear strength are also improved. MPE is Gao stereoregularity polymer molecular weight distribution is very narrow, you can accurately control the physical properties of the polymer, and further improved performance; MPE narrow molecular weight distribution, narrow range of processing, the processing conditions difficult to control, usually Add 5% of LDPE, in order to reduce the melt viscosity, increase the flatness of the stretch film. MPE prices are high, usually used with the MPE and C4-LLDPE in order to reduce costs, but not all C4-LLDPE can match, should have a choice. Machine with stretch film to C6, C8 material, easy processing, can meet a variety of packaging requirements. Hand-packed due to the stretching ratio is low, the use of C4 material. The density of the material also affects the performance of the stretch film. As the density increases, the degree of orientation increased, good flatness, the longitudinal elongation increases, the yield strength, but the transverse tear strength, puncture strength and light transmission rate of decline, so comprehensive in all aspects of performance, often in non-stick layer to add the appropriate amount of medium density linear polyethylene (LMDPE). The add LMDPE can reduce the friction coefficient of the non-stick layer, to avoid the packed tray with tray adhesive. The impact of the cooling roll temperature. The chill roll temperature, the yield strength, but the rest of the performance degradation, it is generally cooling I roll temperature controlled at 21℃ ~ 31℃ appropriate. Cast line tension of LLDPE stretch film flatness and winding tightness, use of PIB or its parent material as the adhesive layer, but also affect the PIB is to move out, lower PE stretch film the final viscosity. Tension is generally not more than 11kg, too much stress remaining in the membrane volume, so that the elongation rate of performance degradation, easily lead down the stretch film phenomenon. application form of stretch film, stretch film applications is very broad, mainly used in conjunction with the tray, the whole set packaging of the scattered goods, instead of the small container. It can reduce the volume of goods transport packaging costs more than 30%, which is widely used in the entire set on the packaging of the metal, mineral, chemical, pharmaceutical, food, machinery and other products; in the field of warehousing and abroad use more The stretch film pallet packaging for three-dimensional storage to save space and floor.

stretch film viscosity control.stretch film of sticky goods outside of the packaging film and layers stick together to make the goods firmly, stretch film viscosity access there are two: one is to add PIB or its parent material in polymer; another mixing VLDPE. PIB is translucent viscous liquid, added directly to the need for special equipment or modify the equipment, generally using the PIB masterbatch. PIB is to move out of a process, generally three days, also affected by temperature, the temperature is high, stretch film viscosity less sticky; low temperature, stretch film, stretch film after stretching far less sticky. Therefore finished the stretch film is preferably stored at a certain temperature range (recommended storage temperature of 16 ° C to 26 ° C). VLDPE blends, the viscosity somewhat less, but the device does not have special requirements, the viscosity is relatively stable, free from the time control, but also affected by temperature, temperature higher than 31° C is relatively sticky, sticky bit weak below 16 ° C, can be By regulating the amount of the adhesive layer of LLDPE, in order to achieve the desired viscosity. Three-layer co-extruded stretch film to use this method.
stretch film physical mechanical properties of control