Planning is the key to success when molding complex products. Liquid silicone rubber offers one distinct advantage that traditional plastic molding does not, its ability to utilize undercuts. Undercut designs can come in a variety of shapes, sizes, complexities and can allow for a variety of features. These features are typically used for connecting the undercut component to another. Channels or grooves are some of the most frequently used features because they allow the part to be attached to a printed circuit board (PCB). Undercut designs are useful in parts where pull through tabs or spigots are not an option. These “spigots” are typically pushed or pulled through an opening in the printed circuit board to align and secure the keypad to the board. A proper undercut design can eliminate the need for these altogether. While not only simplifying the overall design, a proper undercut can provide protection for vital components against moisture and other harmful conditions.
Undercuts in traditional plastic molding will typically interfere with the removal of the product from the mold after curing. For this reason, undercuts are generally avoided during the design process for plastic injection molds. With silicone rubber this is not the case. Silicone has a high tear strength as well as elasticity, which means that parts can be simply stretched over the undercut areas during the ejection process, and the parts will still retain their shape and size. When planned correctly, undercuts can add design features to your final components that would not be available with other materials. These include mounting options for custom silicone keypads, or channels and grooves for mounting custom windows for displays.
Expertise in the industry is needed when designing undercuts into your product, especially when tight tolerances are required. At SITECH we have over 75 years of experience to help with design and production and we partner with the most highly skilled mold maker in the industry to design and produce the highest quality silicone rubber keypads available.
If you are looking for more information on undercut components or keypads you can give us a call today. You can speak with one of our engineers, or sales department by calling: 757-887-8488 or using our contact form to request a quote today.
