- Blown Film Plant
- Raffia Tape Line
- Plastic Reprocess Machine
- Auxiliary Equipment Of Orientation Line
- Auxiliary Equipment Of Pipe Plant
- Control Panels
- Melt Pump
The simplest and most common method of making plastic films is by making use of brown film extrusion technology. This is especially true for the packaging industry. The process is not very complex as per the details present further in this article. Air flow, film speed, difference of temperature of the film and surroundings are some of the main factors that control the frost line height. The main properties of this film include good tensile strength, flexural strength and toughness.
What is Blown Film?
Blown film extrusion is a popular method of making plastic films for the packaging industry. The concept behind this is to extrude a tube of molten polymer through a die. This process will inflate the film and form a film bubble which is later collapsed to form a lay flat film. There are many applications for this (like in the food packaging industry & even industrial packaging) and it is mainly developed using polyethylene. There are mainly two types the multi layer blown film plant and the monolayer blown film plant. The articles goes on to describe several advantages of using a multi layer blown film plant.
Blown film process
- Blown film process is fairly simple as is as described below:
- The polymer is first in the form of pellets.
- This is compacted and melted to form a viscous liquid.
- Next is process of extrusion via an annular die.
- Air is then injected into the center of a die and pressure causes it to melt.
- This expands into a bubble.
- The bubble is pulled upwards from the die and a cooling ring blows air to the film.
- The film can also be cool form inside, using internal bubble cooling.
- Temperature inside the bubble is thus made low and bubble diameter is kept as is.
- This then solidifies at the frost line and film moves into a set of nip rollers.
- The bubble is collapsed to form two flat film layers.
- Film then passes through a treatment center depending on the application.
Advantages of multi layer blown film plant
The benefit of multilayer blown film plant is that it uses a combination of two characteristics of the PP material and the brightness features of PE material. One can classify this into several types like two layer co-extruded blown film machine, three layer co-extruded blown film, five layer co-extruded blown film and seven layer co-extruded blown film.
The three layer co-extrusion implements a new type of high efficiency and low energy consumption extrusion line with an IBC cooling system inside the bubble.
Some of the other advantages include:
- Help produce tubing in a single operation
- Regulates film width and thickness depending on the volume of air in the bubble, extruder output, speed of the haul-off.
- It eliminates effects such as edge bead trim, non-uniform temperature.
- Bi axial orientation is possible.
- Can be used for food packaging.
Applications of blown film
- Agricultural film
- Industry packaging, shrink film
- Bags, Consumer packaging
- Consumer packaging, food wrap
- Transport packaging
- Laminating film, Barrier film
- Multi layer film
- Form, fill and seal packaging film
- Laminating film
- Packaging for milk or coffee
- Packaging food, like cold meats and cheese,
- Packaging of medical products
- Liquid Packaging for Water, Milk, Oil, Ghee, Liquor
- Wheat flour, Rice, Sugar, Salt, Cereals Packaging
- Lamination film for chips, biscuits, chocolates, snacks, spices, etc.
- Lubrication oil pouch, grease, chemical packaging – industrial packaging.