Inert Gas Metering Device

In physical foaming of polymers, i.e. extrusion, injection moulding or Polyurethane foaming, the use of inert gases such as carbon dioxide (CO2) or nitrogen (N2) as blowing agents is constantly on the rise. The reason is that inert gases are an efficient, inexpensive alternative to conventional foaming agents because of their high foaming capacity and low consumption. Moreover, inert gases are eco-friendly, non-toxic, and non-flammable, meeting strict environmental laws.

The patented Linde DSD 500 was especially designed to meter liquid CO2, but can also be used for gaseous nitrogen. It consists mainly of one or two high-performance compressors especially adapted to the use of CO2, a suitable mass-flow meter, and a special control valve (3/3-way proportional). The DSD 500 is easy to install, without having to precool the CO2, and allows an extremely accurate gas flow control: independent of pressure, temperature or type of gas. It is suitable for continuous as well as discontinuous operation.