Structural foam molding is a process used to make industrial molds. Structural foam injection moldmaking is a specialized process that is derived from the basic foam molding process. The process uses an injection into a material. The injected gas serves to expand the material to create a mold. A chemical foaming agent is used to insert the gas, which expands the material. Once the gas is injected and pressure on the outer mold is reduced, the gas expands the material to create the desired product.
The plastic used in the process is first heated to a high temperature. It is after heating that the molding process can take place. Multiple techniques are used in the injection mold making process: the low pressure foaming injection, the high pressure foaming injection, the counter pressure foaming injection and the two component foaming injection.
The structural foam injection moldmaking is much more preferable in manufacturing industries because of the reduced time to create the product. Middle steps such as die-cutting are eliminated since product is made directly from the material. It is also cost effective compared to other processes used for making molds.
The Materials Used
To create molds, high quality plastic and thermoplastics are used. The molds are used on a large industrial scale. Hence, the quality and precision of the finished molds is essential. Companies that use the structural foam molding process have years of experience in handling a variety of materials used to create such molds.
Certain polymers used in creating molds are resistant to water and mold and prevent bacterial growth. Polyolefin elastomers are the most preferred material because of their resistance to chemicals. Using a mold made of this material in a chemical based industrial manufacturing process is fairly easy.
The equipment used in the process are highly specialized that allow the operator to control the temperature and pressure. Most machines have a multi-product capability which means that the machines come with multiple nozzles and multiple molds can be created in one cycle. The wait time is drastically reduced while production efficiency increases.
The use of a structural foam injection moldmaking process leaves room to create a mold of the desired size. Big or small, the foam injection process allows for the creation of all sizes. Durability in this process is another major advantage. Molds created with the structural foam molding process are stronger. The thickness of the mold walls can be adjusted as well. Depending on the gas, the material used, the heat and pressure applied, the end product is exactly what is required. Using plastic polymers for creating molds drastically reduces the weight of the molds as well. Compared to traditional methods of using metal sot for making molds, this process is much more efficient and simple.
The only drawback of molds created through this process is the texture of the outer surface. A lot of factors control the manufacturing process. Even though everything is carefully monitored and controlled, the cooling of the plastic that actually enables it to turn into a mold affects the surface texture.