Four Factors That Determine The Tensile Properties Of Stretch Wrap Film

1. The stretch film is produced by the casting method, and the film has high transparency. With the increase of the number of C atoms of the material comonomer, the length of the branch chain increases, the crystallinity decreases, and the "entanglement or kink" effect of the resulting copolymer increases, so The elongation is improved, and the puncture strength and tear strength are also improved.

2. MPE is usually used with C4-LLDPE, but not all C4-LLDPE can be matched with it, so you should choose. Machine stretch films are mostly made of C6 and C8 materials, which are easy to process and can meet various packaging requirements. Due to the low stretching ratio of manual packaging, C4 materials are mostly used.

3. Material density also affects the performance of the film. As the density increases, the degree of orientation increases, the flatness is good, the longitudinal elongation increases, and the yield strength increases, but the transverse tear strength, puncture strength and light transmittance all decrease. The layer adds an appropriate amount of medium density linear polyethylene (LMDPE).

4. The addition of LMDPE can also reduce the friction coefficient of the non-stick layer and avoid the adhesion of the packaged pallet to the pallet. Influence of chill roll temperature. The temperature of the cooling roll increases, and the yield strength increases, but the rest of the performance decreases, so the temperature of the cooling I roll is generally controlled at 20 ℃ ~ 30 ℃. The tension of the casting line affects the flatness and winding tightness of the film. If PIB or its masterbatch is used as the adhesive layer, it also affects the migration of PIB and reduces the final viscosity of the film. The tension is generally not more than 10kg.