BOBST Extrusion Coating Machine

BOBST Extrusion Coating Machine

Extrusion coating is a versatile converting process that allows different substrate materials to be combined to obtain a single compound structure.extrusion coating machine It is a widely used technology in the production of paper, corrugated fibreboard, aluminium foils, cellulose and non-woven fabrics. It can also be used to produce coated plastic films. It can be applied by both dry and wet lamination and co-extrusion methods. Co-extrusion is a method that uses two or more extruders coupled to a common die head in order to produce multi-layer extruded products such as multi-function extruded bags, pouches and sacks.

BOBST has extensive experience in the design of extrusion coating equipment for a wide range of applications.extrusion coating machine Experimentation with various polymers, copolymers and substrates along with computer simulations provides insight into this complex technology for engineers and technologists seeking innovation in their production processes.

A key factor in extrusion coating is the proper choice of resins.extrusion coating machine The resin must have a high melt index (to ensure good adhesion), be free from additives and contain an ideal amount of antioxidants to allow it to remain stable at higher line speeds. This is particularly important in fabric and textile coating where the resin needs to be able to maintain stability when pressed at high tensions.

The key to controlling crazing is to reduce the number of air gaps in the machine and to prevent asymmetric heat transfer which causes the coating on one side to cool faster than the other. This can be achieved by changing the position of the auxiliary feed block closer to the primary extruder or running it with a lower temperature chill roll. A more drastic approach is to use a lower-density resin, as long as this doesn’t compromise bond integrity.

Several factors can cause curling of the nip web, including the temperature of the chill roll and the composition of the film being produced. Curling can be reduced by using a colder chill roll, by increasing the thickness of the nip web or by replacing the sealant substrate with an extrudate with a lower-density and higher-melt index that doesn’t affect SIT.

Tags:1300 extrusion lamination machine | extrusion laminating machine for pp woven