Plastic Extrusion is a industrial process that enables to produce a melt of thermoplastic polymer material. When this poly melt is coated as a thin layer onto a moving substrate as a functional coating, the process is known as "Extrusion Coating".
When poly melt in above process is used as a "glue" to combine two substrates, it is known as "Extrusion Lamination".
Extrusion Coating/Lamination is a highly versatile process allowing combination of various substrates (i.e. Paper, Al. foil, Plastic films, Non wovens, etc.) of different thickness to form a composite structure with high level of quality combining individual specific characteristics of each substrate and the thermoplastic material used.
LDPE is commonly used to increase water vapor/ moisture barrier of a laminate apart from imparting heat sealing ability. As the laminating weight of LDPE increases Water Vapor Transmission Rate (WVTR) decreases. The polyethylene coating maintains the right level of moisture inside, which in turn protects the product performance.
Polyethylene surface also offers optimal protection against dirt and other hygiene hazards.
An ultra modern extension of extrusion coating and lamination is Tandem Extrusion Lamination. It is a production line which outputs multi-layered packaging material (3/4/5 Layers) with high speed in one process. The tandem line is essentially two individual lines of extrusion lamination in a series. The extrusion lines are identical, except that the first line incorporates a single extruder, while the second line has coextrusion capability. Also, it is equipped with two set of Primer Coaters and Sandwich Unwinders. This Tandem Extrusion Laminating and Coating facility combines multiple substrates to provide the ultimate barrier for your products apart from other functional and protective requirements of laminate.
For simplicity, the contribution of each substrate is illustrated in the above table. In extrusion laminate, each individual substrate contributes specific characteristics to the laminate like barrier property/sealing ability/adhesion/ durability/reinforcement/micro-encapsulated layer, etc.