Linde North America has announced the publication of a white paper that outlines the advantages of using carbon dioxide (CO2) in Gas Assist Injection Molding (GAIM).

The white paper, ‘Reduce Cycle Time in Gas Assist Injection Molding by 20-50%. A New CO2 Process’, is available as a free download on Linde’s website

Using CO2 is a breakthrough in the Enhanced Gas Assist Injection Molding or eGAIM process. Traditionally, manufacturers have used nitrogen as the gas of choice in GAIM, which is a process used to effectively create hollow plastic parts that usually have thick but homogeneous walls, such as those used in automobile, household, appliance and furniture part manufacturing.  However, Linde has found that by replacing nitrogen with CO2, manufacturers can greatly reduce cycle times.

“The high efficiency of carbon dioxide, including low investment costs, easy installation and convincing results, make it very attractive for injection molding for both new molds and for retrofitting existing molds,” explained Jim Stanley, a Program Manager at Linde and one of the paper’s authors.

“Using CO2 spot cooling results in substantial savings to a manufacturer in the cost of molded parts and it also creates additional molding capacity for very little capital cost.”

The white paper asserts that cooling cycles can often be reduced by more than 50% compared to cycles using nitrogen, and overall cycles can often be reduced by 20% - 50%.The  cooling effect of high pressure CO2 is comparable to that of water in Water Assist Injection Molding (WAIM), without many of the difficulties inherent to WAIM.

The paper offers details on how the new CO2 GAIM process works, identifies those parts that are amenable to CO2 GAIM, describes the testing process, and compares CO2 GAIM to nitrogen-based GAIM and Water Assist Injection Molding.