Benefits of Structural Foam Molding

• Posted by Doris Lee January 25, 2022 Filed in Business #Structural Foam Molding  79 views
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  Structural foam molding is a process in which an inert gas is added to a molten polymer, which is then injected into a standard injection mold. During this process, the blowing agent activates and pushes the resin uniformly into the cavity. As the part cools, solid skin is formed over the mold. Internally, the foaming action creates a honeycomb structure and reduces post-mold shrinkage.

   

  The use of structural foams as a manufacturing material has many advantages. Of course, structural foams were originally known for their ability to produce parts of unparalleled size, such as vehicle roofs or body panels. However, it is clear that structural foam can offer many additional benefits. They include

   

  Lightweight. Structural foam has proven to be not only durable, stiff and lightweight, but also eight times stiffer than other materials with similar qualities. Typically, the weight ranges from 55 to 2 pounds per cubic foot. In addition, because of its foam, the material has excellent acoustical and thermal properties.

   

  Moldable. The most significant advantage of the foam material is that it can be easily modified to produce a variety of wall thicknesses on a single part. In some cases, the wall thickness of structural foams is greater than the previous maximum of 33 mm. Typically, foam products are subjected to less stress during the molding process.

   

  Increased strength and stiffness. The honeycomb structure within the parts gives them a very high strength-to-weight ratio and stiffness-to-weight ratio.

   

  No shrink marks on thick parts. You can break many of the old rules of thumb about part thickness. This gives you the opportunity to make thick, complex parts without indentations.

   

  Low stress and warpage. Low-pressure processes eliminate these problems.

   

  Superior impact resistance. This is again due to the honeycomb structure.

   

  Sound insulation and electrical/thermal insulation properties. Due to tiny air pockets within the part.

   

  Reduced material costs. In the structural foam process, in some cases, part weight can be reduced by up to 30%. Although, a 15-20% density reduction is more typical, thus reducing material costs without compromising the structural integrity of the part. Parts with high recycled content can be easily manufactured in structural foam injection molding with up to 100% recycled content.

   

  Faster cycle times. This is due to the better heat transfer of aluminum molds.

   

  Lower tooling costs. Compared to conventional injection molding, structural foam molds cost about one-third to one-half the cost of an injection mold for the same part geometry. The lower cost is due to the use of configurable and modular hot runners on the machine, so there is no need for a dedicated hot runner system on the mold. Second, most structural foam molds are aluminum, and because of the lower cavity pressures in structural foam molding, the molds can be thinner and do not require as much support as typical injection molds. Lighter molds also have a smaller infrastructure to suspend the mold in the machine (smaller crane requirements) and move them around the plant.

   

  Attractive surface characteristics. Parts have a consistent surface finish to get the texture you want.

   

  An excellent alternative to other materials. Parts can replace a wide range of materials, from concrete to sheet metal to fiberglass to wood.

   

  Long tool life expectancy. Despite the use of aluminum tools, they typically last as long as the steel due to the lower stresses used.

   

  Of course, not every part is ideal for structural foam forming. However, if you need a lighter weight, stronger part that can be manufactured quickly and cost-effectively, then structural foam may be your best choice.

   

  Have questions about the process and whether it's right for your project? Give us a call or stop by. As an injection molding company, WIT MOLD have extensive expertise in the field and are happy to share our insights.