Stretch Film is a plastic film commonly made from linear low density polyethylene (LLDPE) used in pallet wrapping, bundling and securing. The process of stretch wrapping a product or a pallet of products helps to reduce product damage and loss, increase product security and reduce worker injury.
The two most commonly used types of stretch films are cast stretch film and blown stretch film.
Cast Stretch Film - also known as cast stretch wrap, plastic wrap or pallet wrap, is made using a cast extrusion process, in which the polymer iscontinuously pumping through a straight slot orifice (die), then chilling this hot sheet of plastic immediately after the die by contact with a cooled chill roll. Film thickness is determined by how fast the casting roll pulls the plastic away from the die.
Blown stretch film, on the other hand, is fabricatedby a process of continuously pumping the polymer through a circular orifice (die), then filling the tube this created with air. The volume of air contained within the tube stretches the tube or the bubble out to the desired width and, in conjunction with the rate at which it is being pulled away from the die the desired thickness is created.
Below is a chart to help highlight the main differences between cast stretch film and blown stretch film.
|Cast Stretch Film||Blown Stretch Film|
|Characteristics: Clear, Glossy, Better Gauge, Quiet, "Natural" Cling||Characteristics: Hazy, Dull, Tough,Impact Resistant,Noisy|
|Excellent load retaining capability||Superior load-holding capability|
|High film puncture and tear resistance||Very high levels of puncture and tear resistance|
|Single-sided or two-sided cling formulations||High cling levels|
|Thinner gauge films with significant performance advantages and cost savings|
Common Stretch Film Markets: Bottling, Landscaping, Construction, Electronics, Automation, Food Industry, Paper Industry, Carpeting, Furniture Industry, Medical Industry, etc.