Low Pressure Structural Web Molding
Freedom to Design!
What is Structural Web Molding or Gas Assist?
Structural Web is a low pressure injection process used to produce plastic parts where hollow cross sections, varying wall thicknesses, an improved cosmetic appearance, and a superior stiffness-to-weight ratio are important considerations for the final part design and functionality.
The process involves nitrogen gas being injected into the mold cavity immediately after the plastic resin is injected. The gas assists in pushing the molten plastic out to the cavity walls and uniformly packing out the entire mold. Since the nitrogen gas follows the path of least resistance inside the plastic, it hollows out the thick sections and allows designers the flexibility to create a product with different wall thicknesses.
The Structural Web technology opens up a whole world of new possibilities in developing plastic parts and eliminates many design limitations typically associated with plastics.
Structural Web – Benefits
There are many benefits in producing products using Structural Web Technology.
- Part weight can be reduced between 10% and 30%, resulting in lower material costs without affecting structural integrity.
- A large shot size capability of up to 150 lbs (68 kg) per shot. Larger products can be designed to combine many smaller parts, with different functions, into one part to reduce cost and increase efficiency.
- Structural Web parts have a smoother, glossier finish than other low pressure parts.
- Structural Web parts can be designed in ways which are not feasible in normal injection molding. Products can be made from a wide variety of resins, everything from commodity polyethylene and polypropylene resins right up to highly engineered resins and additives.
- Low pressure molding uses less energy per pound of plastic and less raw material in the finished product.
- Parts can be colored and textured, eliminating the extra cost and the environmental concerns associated with painting.