stretch film main purpose and production process conditions

1, stretch film  main purpose

 stretch film mainly by the work of several different grades of polyethylene extrusion from allyl resin mixture, puncture resistant, super-strength high-performance, stacked on pallets of goods on the wrapped package, to make the packaging more secure clean, more super- strong waterproof effect, stretch film is widely used in foreign trade, paper, metal, plastic chemicals, building materials, food and pharmaceutical industries. stretch film is loaded membrane products for industrial use with high tensile strength, elongation, good self-adhesive, high transparency material point for the hand stretch film, also be used for machine stretch film, can be widely used in the concentration of a variety of goods packing.

2, stretch film production process conditions

①stretch film viscosity control

stretch film mixing VLDPE, sticky bit weak, but there are no special requirements for equipment, viscosity is relatively stable, without time control, but also affected by temperature, the temperature is higher than 30 ℃, relatively sticky, somewhat less than 15 ℃, the viscosity , by adjusting the amount of LLDPE adhesive layer, to achieve the desired viscosity. Good LLDPE stretch film adhesive film of goods outside of the packaging of goods with layers stick together firmly, LLDPE stretch film viscosity, there are two access methods: one is
To add in the PIB polymer or parent material; the other is the mixing VLDPE. PIB is translucent viscous liquid, add directly to the need for special equipment or
Modify the equipment, generally used PIB masterbatch. PIB is to move out of a process, generally three days, also affected by temperature, the temperature is high
 stretch film adhesive strength; the temperature is low stretch film is not sticky, sticky stretch film after stretching greatly reduced. Finished film preferably stored at a certain temperature range.

② pe stretch film temperature control

   stretch film tension is generally not more than 10kg, too much stress remaining in the membrane volume, so that elongation rate of
Can drop off film likely to cause the phenomenon. Chill roll temperature. Chill roll temperature, the yield strength increased, but the rest of performance degradation, so I generally cooling roll temperature was controlled at 20 ℃ ~ 30 ℃ appropriate. Cast the line tension effect LLDPE stretch film flatness and winding tension, the use of PIB or parent material as the adhesive layer, but also affect the PIB's move to reduce the viscosity of the final stretch film.

3, stretch film wrapping machine classification

   stretch film machine of different classification criteria, the classification is different. Its structure can be roughly divided into the tray machine, cylinder machines, ring-body aircraft, arm machines, radial, horizontal packaging machines and baggage seven categories; according to the degree of automation can be divided into two types of automatic and semi-automatic ; their film frame structure can be divided into pre-stretching, resistance stretching.