Plastic foaming processes often rely on conventional foaming agents such as HCFCs, HFCs or hydrocarbons. Increasingly strict regulatory controls are restricting or prohibiting the use of compounds such as these due to their high global warming potential (GWP) and ozone depletion potential (ODP). Many manufacturers are thus looking to replace or phase out these agents. Industrial gases can be an environmentally sound way to support phase-out strategies.
Carbon dioxide (CO2) is an excellent, well-established alternative to these harmful agents. It is an ideal physical blowing agent for foamed polymers such as building insulation (XPS boards) and packaging (high- density PE foams). It combines low GWP and zero ODP with good plastics compatibility. In addition, the use of CO2 offers considerable cost benefits.
Exact metering of liquid carbon dioxide (LIC) plays a key role in the quality of the foamed product. Achieving this can be challenging, however, particularly given counter-pressure variations in polymer extruders. We have developed sophisticated solutions and equipment designed specifically to meet the metering challenges of liquid carbon dioxide in extrusion foaming and polyurethane foaming processes.