Compression molding is a method that can be utilized for processing plasticized starch-based materials into foams and containers, such as end caps, edges, or corner cushions, which are difficult to produce using extrusion foaming technology. Recent research has shown that microwave can also be used for producing starch-based foams. The selection of adequate mold material, pretreatment of starch, and the initial loading of samples in mold cavity are critical factors in achieving a uniformly foamed block with good integrity during compression. In addition to gelatinizing agents, mold-releasing agents are often added to prevent the starch from sticking to the mold. A simple melt compression molding process has been introduced recently to produce highly flexible starch-based films. The starch is pre-blended with water and another plasticizer to achieve an equilibrium state before compression molding. The use of ionic liquids as plasticizers for starch thermal processing has also been explored, and it has been found that they have a stronger effect on the disruption of starch granules during processing and a better plasticization effect compared to glycerol.
