A good number of manufacturers are settling for overmolding as they understand how it improves value on their product lines. It not only improves performance, aesthetics and functionality, but as well lowers the total costs of production, a rare combination to find nowadays. Several TPE suppliers offer these products within the US.
The Process of Overmolding
Overmolding is a process that takes place in one shot or two shots and bonds a thin layer of TPE, referring to thermoplastic elastomer, onto the substrate of a given product. The exterior layer creates the soft-touch grip which is popular with a wide array of products that range from personal care products such as toothbrushes and power tools among others. Overmolding as well reduces vibration and shock, dampening sound, providing electrical insulation, boosting chemical/UV resistance, and can offer a barricade from moisture and oxygen.
As an outcome, more consumers are now demanding this feel for the products they buy thus leading to continued expansion of overmolding applications. Availability of this technology equally affords product engineers a larger number of options for coming up with attractive and functional output whose design meets market-demands. US TPE suppliers are among those who provide such client-centric products.
Requirements of Overmolding Expertise
Not all injection-molders have capacity of overmolding, however. This process requires specialized equipment, extensive training together with precise control of multiple variables all through production. Having even a slight variation can have negative effects on quality, which necessitates skilled operators to handle the operation. A lot of such knowledge is linked to the kind of substrate or TPE in use and thus the need for understanding chemical behavior and material science in depth too. New blends of resin are being engineered constantly to generate expanded properties that include UV resistance, chemical and heat resistance, scratch resistance, clarity hardness and UL standards. One should thus consider the quality of products which specialty TPE suppliers avail.
Determining the Appropriate TPE-Substrate Combination
A major step in overmolding is establishing the most suitable combination of TPE/substrate that offers optimal bonding, followed by designing the appropriate tools and mold. Keeping the TPE’s melt temperature constant, which determines ease of flow of the TPE, along with its bonding ability is very critical. It is essential to maintain cleanness on the surface of substrate and keep it free from contamination by dust, dirt, moisture, or even skin oil. Gloves are thus always used when handling the products. The bond between TPE and substrate could easily be weakened or possibly fail, if the substrate gets contaminated even to the slightest degree. The level of moisture of both TPE and substrate can have negative impacts on the chemical bond, making it vital to dry both materials carefully before performing molding. Consulting with custom TPE suppliers is a commendable step of getting great TPE products.
For tooling, vents need to be sized properly then placed within the mold to facilitate air-release from mold cavity during the overmolding step. This is because air that has been trapped could weaken the TPE-Substrate bond. The shutoff must as well be designed properly for the materials utilized to eliminate risk of curling or delamination. Gate size gets determined as per the viscosity, flow rate, type of material, as well as amount of shear which might be required.
Combining the different steps of overmolding into a single injection molding process delivers multiple benefits. It ensures increased quality of the products TPE suppliers provide, boosts throughput and reduces waste along with cutting down the overall cost of production. Click here http://www.sespoly.com/products/tpe-thermoplastic-elastomers/ for more information.