7. Conclusion

The injection molding of lightweight polymers is a promising technique for producing lightweight plastic materials in a simple and efficient manner. In the automotive industry, the use of these materials is a key factor in reducing vehicle CO ₂ emissions by lowering vehicle weight. Economic benefits stem from reduced cooling times—and thus cycle times—as well as lower injection temperatures and reduced material input.

There are two types of foam injection processes: physical and chemical. In the physical process, the gas is injected directly into the liner in a supercritical state, requiring additional equipment such as a gas storage and distribution system, injection pumps, and a new screw. The most commonly used gases are carbon dioxide and nitrogen. With the chemical foaming process, blowing agents contribute to higher...