What is Stretch Film? Production Process and Characteristics
Stretch film, also known as stretch wrap, is a highly stretchable plastic film commonly made from linear low-density polyethylene (LLDPE). It is used primarily to wrap around items, especially coils, to secure them during transportation or storage.
Stretch film is produced through an extrusion process where resin pellets are melted and extruded through a circular die to create a thin, continuous film. After extrusion, the film is cooled and then reheated, during which it is stretched to several times its original length. This stretching enhances its tensile strength and load-holding stability, making it suitable for securely wrapping and protecting various items.
Parameters
Here are the parameters for the 80 gauge (20.3 micron, 0.80 mil) stretch fim for coil wrapping from the provided technical data sheet:
Ultimate Tensile MD: 6800 psi
Ultimate Tensile TD: 5600 psi
Elongation MD: 670%
Elongation TD: 825%
Tear Resistance MD: 175 grams, 218.75 g/mil
Tear Resistance TD: 618 grams, 772.5 g/mil
Dart Drop: 180 grams, 225 g/mil
Pre-stretch (% at break): 325%
Cling (in to out, grams at 200% pre-stretch): 350 grams
Stretch film specifications for coil wrapping
Here’s the information regarding the operational dimensions for coil wrapping machines formatted as data:
plaintext
Stretch film :
– Outer Diameter (OD): 100-200 mm
– Inner Diameter (ID): 50 mm | 76 mm
– Width: 50-150 mm
– Minimum Film Thickness: >25 microns
This format provides a clear and structured presentation of the key specifications for coils that can be processed by coil wrapping machines.
Benefits in Coil Packing
Using stretch film for coil packing offers multiple advantages:
- Protection: It provides a tight seal that shields the coils from moisture, dust, and dirt, ensuring they remain rust-free and clean during transit.
- Stability: The elastic recovery keeps the items tightly bound and prevents coils from shifting.
- Efficiency: Stretch film can be applied quickly with automatic or semi-automatic wrapping machines, significantly speeding up the packing process.
- Cost-effectiveness: It is generally more economical than other packing materials like strapping or netting, as less material is required to secure the coils.
