When you choose Stretch film, it is difference in varying gauges, colors, Pre-stretch ratio and applications. The main difference and key point for stretch films is in production: blown VS cast.
It is the basic to know the details how they are manufactured. Blown stretch film, or blown stretch wrap material is created by blowing heated resin out vertically into a bubble. The bubble is transformed into rolls through the cooling device by the surrounding air.
Cast stretch film, or cast stretch wrap is created by feeding a sheet of heated resin along a rolling path with automatic film counting and thickness checking rollers. After cooling the film through rolls that is winding into large rolls.
After you know how stretch wrap film is produced, what is the difference between cast and blown films. As a end user, what is the benefit of the stretch film features?
Blown film is higher in tough but it is less in puncture rate than cast. The different is occurs due to the different cooling process and cooling time which allows blown film to spread a long distance lines like in cast. Both Cast film and Blown film are able provide a higher level of cling. It sticks to itself easier.
Since blown film seen like no problem why most of end user choose cast film? In production, cast stretch wrap film has some device for clear, glossy finish allowing scanning technology, RFID to be used. It is better than hazy and dull blown. So that cast stretch film is much quieter than blown in unwinds process. And the cast machine also easier to control the gauge and stretch cast film.
Both films have their benefits and disadvantage, so how to choose the stretch film?
So, which stretch film fits your packaging requirement?
You’d better keep in mind include:
1. What kind of packing, by machine or by hand?
2. What type of wrapping machine is being used, pre-stretch or not?
3. What is the load need to be wrapped?
4. What is the loads specification?
Does your supplier ask you above questions and provide solutions based on your load specification?
If the answered is no, you’d better analytics your need or ask question contact with our engineer. Our engineer will ask you the above questions and some loading detail information. We will provide a free consultation about how much stretch film is costing you per application.
If you are purchasing films based on roll (the price per roll), you may cost more. Because of the higher price stretch film may cost lower for one load package.