- Blown Film Plant
- Raffia Tape Line
- Plastic Reprocess Machine
- Auxiliary Equipment Of Orientation Line
- Auxiliary Equipment Of Pipe Plant
- Control Panels
- Melt Pump
A blown film line pumps the molten plastic through a circular die that shapes the melt into a tube. This is ideally at a very high pressure of 300 to 600 Bar and there is an option of having a single layer or multi-layer tube. Once the tube is removed from the die it goes through a process of stretching and cooling to correct the size and thickness as per requirement.
The stretching is usually done in a longitudinal and lateral method. The process of cooling can be done either by water or by air. There is the option of the process being internal (IBC) and external or exclusively external. At times if necessary the initial tube is reheated then stretched again and later collapsed into a nip roll.
The articles goes on to describe blown film extrusion with internal bubble cooling (IBC) and non internal bubble cooling (Non IBC 3/5/7 layer).
Blown Film Extrusion IBC
A blown-film extrusion IBC is essentially a blown film machine with an internal bubble cooling air control system. It also has sensors arranged that can increase the response time and reduce any interference.
The way it works is the system blows cool air on the bubble as it exits the die. It does this with the help of sensors; the first sensor is to sense the position of the bubble above the frost line after it has solidified.
There is also a second sensor for sensing the position of a bubble when in at the vertical location between the front lines. There is also a controller that is responsive to any signals from either the first or second sensor; this controls the flow of cooling air on the bubble.
Blown Film Extrusion Non IBC 3/5/7 Layer
- The monolayer lines are perfect for commodity and non-barrier films.
- Any per-existing lines will require no capital outlay.
- 1 and 3 layer blown film plant are used in the adhesive laminating market.
- 1 and 3 layer film have high stiffness and heat seal level.
- 5 layer film offers more flexibility that the 3 layer film.
- A 5 layer film also eliminates any need for the secondary step of adhesive lamination.
- 5 layer film is a big improvement in 3 layer films but it has limited performance as compared to 7 layers film.
- With a 7 layer structure, there is an option of using a low cost layer in 1 layer and an expensive and high performance metallocene LLDPE, in the Skin layer.
- Skin layer will have a higher hot track and heal seal properties.
- 7 layer structures reduce the cost as compared to 5 layer structure.
- 7 layer die possess better barrier properties and it's tougher.
- Due to excellent barrier properties and gloss it is used as a lidding film.
- Flexibility in 7 layer die is kept in control with the help of the thickness.
This has several applications in various industries as per list below:
- Agricultural film (Mulch film), Laminating film
- Shrink film, Different types of barrier films
- Stretch & Cling films, General purpose
- Shade net, Milk pouch, oil packets
- Other food packaging like wheat flour, rice, sugar, salt.
- Wrappers for eatables.
- Blown film is useful for use as tube form. A tube can also be used to split the sheet.
- Industry packaging, Consumer packaging
- Barrier film, Packaging for frozen products, Crop forcing film
- Greenhouse film, Silage film
- Silage stretch film, Shrink film for transport package
- Food wrap film, Packaging bags films
- Films for the packaging of medical products