Cold isostatic pressing (CIP) is a compaction process for powders enclosed in an elastomer mold. The mold is placed in a pressure chamber, a liquid medium is pumped in, and high pressure is applied uniformly from all sides. CIP Applications CIP is used with powdered metallurgy, cemented carbides, refractory materials, graphite, ceramics, plastics, and other materials.
What is Cold Isostatic Pressing?
Benefits with the CIP process:
High compaction and uniform density provides predictable shrinkage during the subsequent sintering process.
Ability to process large, complicated, and near-net shapes saves time and cost in after-treatment.
Capability to produce large aspect ratio parts (>2:1) with uniform densities.
Green strength allows in-process handling and treatment, and lowers production costs
The CIP molding methods are classified into two types; the wet bag process and the dry bag process.
Wet bag technology:
In the wet bag process, the powder material is contained in a flex mold bag, which is submerged into a high-pressure liquid in a pressure vessel. This process is suitable for multi-shape and small to large quantity production, and for the pressing of large size products.
Dry bag technology:
Dry bag pressing differs from wet bag in that a flexible membrane is built in to the pressure vessel and is used during all pressing cycles. This membrane isolates the pressure fluid from the mold, which becomes “dry bag”. This process is cleaner because the flex mold does not become contaminated with wet powder. Also, less cleaning of the vessel is required. This method features rapid cycles and is very suitable for automated mass production of powder products