Märkäruiskuprosessi

Märkäruiskuprosessi, known in English as wet injection or wet compression molding, is a thermoset molding process used for producing composite parts. It involves the use of liquid resin that is mixed with reinforcing fibers before being injected into a closed mold. This contrasts with traditional compression molding where pre-impregnated materials, often referred to as prepregs, are used.

In the märkäruiskuprosessi, the liquid resin system, typically a polyester or epoxy resin, is combined with chopped or continuous reinforcing fibers, such as glass or carbon fibers. This mixture, often called a pre-mix or sheet molding compound (SMC) if it's a sheet form, is then placed into the open mold cavity. The mold is subsequently closed, and pressure is applied, forcing the resin and fibers to fill the entire mold volume and conform to the desired shape. The mold is heated to initiate and cure the thermoset resin, transforming the liquid mixture into a solid, rigid part.

The advantages of märkäruiskuprosessi include its ability to produce complex shapes with good surface finish, its relatively low tooling costs compared to some other molding processes, and its suitability for high-volume production. It can also achieve good mechanical properties due to the consistent distribution of fibers within the resin matrix. However, challenges can include controlling fiber orientation and potential issues with resin viscosity and cure kinetics. The process is widely employed in industries such as automotive, aerospace, and appliance manufacturing for creating components like body panels, structural elements, and housings.