Open Cast Molding Vs. Injection Molding
Many people think that open cast molding and injection molding are so similar that they are practically the same process used in creating urethane products. This opinion, however, is wrong. While there are some similarities, they create two very different products in terms of quality, hardness, and durability. Open cast molding works as the name implies — the liquid polyurethane is poured into an open mold. Injection molding is a process in which the polyurethane is injected into a closed mold that has holes, or bleed gates, that allow air to be pushed out of the mold so that the liquid spreads out evenly. At ESCO Plastics, we use open cast molding to reap the far superior benefits of this method of production. Let’s spend some time looking at why you want to make sure your products are manufactured using this process.
A durometer is a measure of hardness in a material. This particular term can also refer to the material’s resistance to indentation. Open cast molding provides the opportunity to craft materials that have the most extensive durometric range in the final product. Whether you need products that are very soft or very hard, we have an increased versatility of design in crafting pieces, using this process..
Injection molding might be a more inexpensive way to manufacture urethane parts, but there is a clear discrepancy in terms of quality in the final product. Open-cast molding offers the ability to provide customers with high-quality products at a lower cost when working with small- to medium-sized production runs. Due to the higher quality product that open-cast molding produces, our clients will save even more money over time because the product will outlast products created through injection molding.
Sometimes you need products that will snugly adhere to one another. In this situation, you want to make sure that you are ordering urethane parts that are created with open-cast molding. While injection molding is quicker, there is a downside to this speedy process — the final product will not have the smooth edges or surfaces that you need for the snug fit. In fact, the sides might even be rough and uneven, which will then require extra time for tooling and cause the cost of the product to increase. Open-cast molding is a slow-cure process that provides the opportunity for the urethane to spread evenly within the mold, which is what allows the final piece to have smooth, even surfaces.
Depending on how your product will be used, you may be concerned about how resistant it will be to cracking or breaking. If this is a priority for you, then you definitely want to order products created through open-cast molding. Products that are manufactured in this slow, heat-cured method are created with superior tensile strength, which is exactly what you need when these pieces are incorporated to your project and are subjected to incredibly high levels of vibration or impact.
Expensive metal casting can often be replaced by lightweight urethane casting and still maintain or exceed wear characteristics found in their metal counterparts. Polyurethanes can be selected and formulated to maximize particular need specifications, such as maximizing abrasion or increasing tensile strength to obtain the strongest, most durable part possible. The ingredients found in some urethanes are FDA-approved for contact with foodstuffs and are suitable for applications in the food service and production industries.