Use carbon dioxide or nitrogen as physical blowing agents in your extrusion foaming. These inert gases offer a lot of advantages as they are environmentally friendly, inexpensive and inflammable. If you want to increase the output of your extrusion line use carbon dioxide for inner cooling of hollow profiles or pipes.
The use of physical blowing agents, carbon dioxide or nitrogen in extrusion foaming processes gives lighter parts and lower consumption of raw material.
The physical blowing agent is first injected with great accuracy into the polymer melt by means of a metering unit and then dissolved in the polymer. The pressure is maintained throughout the extruder. A rapid pressure drop rate creates a homogenous cell structure of foamed polymer resulting in a light, strong product that can be used in a wide range of applications by the packaging, automotive, electric and manufacturing industries.
Typical products foamed with carbon dioxide are extruded polystyrene (XPS) insulation boards or extruded polystyrene foam sheets for food packaging. Nitrogen is mainly used in production of polyethylene cable insulation.
Extrusion Inner Cooling
The use of liquid carbon dioxide in extrusion inner cooling of profiles and pipes increases extrusion capacity while investment costs are very low. The homogenous cooling of the profile decreases warp and the product quality is improved. There are no residues and no moisture inside the profile.
This patented technology is especially recommended for parts with thick walls and extrusion lines with limited cooling sections.