Applications

/applications/cast_films/app cast stretch 03

Stretch Film

Stretch films are extensible or stretchable tacky and thin films used to wrap and unitize articles.
These films are mainly produce using polyolefins (LLDPE, PP, HDPE, mLLDPE, ULDPE) by cast or blown film extrusion process although a higher percentage is produced by cast film extrusion. EVA (Ethyl Vinyl Acetate) is also used to obtaing the cling effect and some mechanical properties.

  • Typical Thickness:

     

Gauge

Mils

Microns

50

0.5

12

60

0.6

15

70

0.7

18

80

0.8

20

100

1.0

25

  • Typical Roll width:
     15”(380 mm) - 20” (500 mm) - 30” (760 mm)
    (automatic Machines with bi-directional stretching)

Through the years the stretch film structures have been evolving becoming more complex (from 3 to 7 or 9 layers) and allowing better performance and dramatic thickness reduction.

Films are also usually classified depending on the percentage of elongation and the performance into:

  1. Manual stretch

  2. Automatic stretch

  3. Power stretch 

New markets and applications have also been developed such as bundling, luggage wrap, roll wrapping and grocery wrapping.

More automation, wide lines, increase on number of layers and sophistication on formulations and process control among others are the main trends in the production of stretch films.

Pre-stretched stretch wrap film with improved retention, less film waste and easier to apply; coreless stretch wrap film and macro perforated films are among some of the trends and developments for this market.

Stretch film emerged as a cost efficient alternative to shrink film and steel/plastic banding for pallet unitization. These films were initially produced using plasticized PVC.
Borden Chemical was the king of this market during those years however, once LLDPE was introduced it became the most rapidly growing market for PE film and many other players got involved in producing them.