EVAL™ Processing / Blow Moulding / Coextrusion Blow Moulding

Coextrusion Blow Moulding

The manufacturing of multilayer plastic containers with the coextrusion blow moulding technique has considerably gained importance during the past few years.

With this technique, the polymers for the different layers are extruded separately and then they are brought together in a die which extrudes them as a multilayer tube. The tube is then blow moulded: two halves of the mould close in on it, a seal is formed at the bottom and air is blown in at the top, which expands the tube until it fills the mould.

For the packaging of food, the EVAL™ layer is sandwiched between two covering layers in a 5-layer structure. For the packaging of agro-chemicals, a 3-layer structure is used with the EVAL™ layer on the inside of the container.

The EVAL™ resins provide a very good barrier to gases such as oxygen, carbon dioxide and nitrogen and have an outstanding chemical resistance and are widely used for coextrusion blow moulding.

The polyolefins are the largest class of blow moulded polymers. This class includes LDPE, EVA, LLDPE, HDPE and PP to which the EVAL™ resins will be associated. Recent developments are now focusing on co-injection blow moulding with PET for the packaging of carbonated soft drinks.

The EVAL™ resins for coextrusion blow moulding

The coextrusion blow moulding processing technology requires an EVAL™ grade with good processing properties in combination with a superior gas barrier and chemical resistance.

We recommend the following EVAL™ grades for the coextrusion blow moulding:

Click on the underlined grades in the table below to see the datasheets:

EVAL™ RESINS

UNITS

F101B

L171B

Ethylene Content

mol%

32

27

 

Contact us for the complete documentation.