Stretch films of two sorts are commonly used for packaging and fastening things on pallets: cast stretch film and blown stretch film.
While they serve the same purpose, their production procedures, performance attributes, and costs differ.
Manufacturing Process:
Cast Stretch Film is created by continually extruding molten polymer through a flat die and rapidly chilling it on a chilled roll. This method produces a thin, clear, and quiet film with great tensile strength and clarity.
Blown Stretch Film: This type of stretch film is created by blowing hot resin vertically into a bubble or tube, which is subsequently compressed and cooled. This method results in a thicker, harder film with a slightly hazy look and increased puncture resistance.
Characteristics:
Cast Stretch Film: It has outstanding clarity, making it simple to identify packed products. It has a quiet unwind, making it appropriate for use in quiet situations or with automated machines. It has a lesser level of cling, which means it does not attach to itself as much.
When compared to cast film, blown stretch film offers greater puncture and tear resistance. It has more cling, which makes it ideal for anchoring loads with uneven forms or sharp corners. It has a coarser texture and is frequently utilised in heavy or demanding applications.
Applications:
Cast stretch film has a high load stability and wrapping force. It has good optics and is appropriate for situations requiring high product visibility.
Blown Stretch Film: It has a high load retention and is resistant to punctures and tears. It is frequently used for big or unstable loads requiring increased strength and holding capacity.
Cost:
Cast stretch film is less expensive than blown stretch film. It’s commonly utilised for basic load stabilisation and packaging.
Because of its greater strength and performance attributes, blown stretch film is often more expensive. It is typically utilised for heavy-duty or specialised applications that require extra strength and protection.
Conclusions:
The decision between cast and blown stretch film is influenced by specific packaging requirements, load requirements, and financial constraints. Cast film has good clarity and is cost-effective, whereas blown film has superior strength and longevity.
