stretch film Performance

stretch film Performance

stretch film Performance:

(A) stretch film has good tensile properties. That the material yield point the elastic limit. The film is stretched, the load is increasing rapidly. When more than the yield point, the film permanent deformation. In the plastic range, the stress - strain curve is generally flat. Finally, the tensile load continued to increase until it reaches the break point is reached. Then the load is reduced to zero. It should be said. Theory stretch film stress - strain curve is stretched rubber band with a similar curve. The yield point of the latter coincides with the break point. So. From the rubber band to tie the package, you can infer to stretch film, the stretching can also wrap a package. With stretch film wrapped goods, stretch film in contact with the goods before the general advance stretch, before the film wrapped goods by a constant tensile strength, tensile strength and make the entire width of the uniform distribution on the film. The pre-stretch rate of 200-300%, making film strength increases, resistance to creep at room temperature is also greatly improved. The edges and corners of the goods can be stretched. For different brands of stretch film. Users can freely adjust the tensile force.
(B) stretch film also has good tensile retraction memory function. Memory function is a feature of polymer materials. shrink film is heated to restore the memory state of retraction; and stretch film is available at room temperature by pre-stretching and retraction function. It can tightly wrapped packaging. The retraction rate with stretch film stretch ratio increases with the increase.
(C) stretch film, another important feature is the self-adhesive membrane. Used to stretch a winding stretch film packaging, self-adhesive film after it in the cut will not produce relaxation, and long-term wrap goods. Stretch film adhesion and the surface is not coated adhesive. When in the manufacture of stretch film. Although adding a small amount of tackifier, but it can and plastic compatibility. Will not precipitate on the surface of the package of goods. Stretch film packaging with the goods. Membrane and the membrane can be glued tight, but it will not stick to the packaged goods, but also does not pollute the packaging. Stretch film from cold to hot in the appropriate temperature range viscosity. Of course. Higher ambient temperature. After the film wrapped packaging will lose some self-adhesive edge. Wrapping within 24 hours, the film's most prone to relaxation phenomena. In high humidity environments, self-adhesive stretch film will be correspondingly higher.

1. stretch film Elongation ratio.
Longitudinal vertical elongation = elongation rate / total elongation
Horizontal lateral elongation = elongation / total elongation
Elongation at break elongation ratio = vertical / horizontal elongation
Stretch the elongation ratio is generally between 35/65 to 50/50.
 

2. Stretch film physical and mechanical properties
Unit performance testing project
Tensile strength MPa 28 horizontal 22 vertical
Elongation at break% 380 horizontal 620 vertical
Right angle tearing N / cm vertical 1000 horizontal 1200

3. stretch film Elongation at break
Longitudinal elongation at break: longitudinal sampling of the film. The elongation at fracture (%);
Horizontal elongation: lateral sampling of film. The elongation at fracture (%);
Total elongation (%) = longitudinal elongation at break - Transverse elongation at break
Under normal circumstances. Stretch the total elongation close to or greater than (900 ~ lO00)%

4. stretch film Tension ratio.
Tension than said longitudinal sample of the film, its tensile strength and yield strength ratio (available stress - strain curve calculation). Tension ratio, stretch film is not easy to break in tension. Stretch film tension than the average of (2-2.5): 1, and the highest value to 5:1.