GP320 series rubber overmolding with nylon

TPE overmolding, as the name suggests, is the process of wrapping TPE soft rubber material around other materials, commonly used in products such as handles and grips. TPE materials provide a comfortable touch and enhance the aesthetics and added value of the products. During the secondary injection overmolding process with nylon, there are often issues with poor adhesion or low peel strength, which can be influenced by four factors.

• First, nylon comes in many varieties, such as common nylon 6, nylon 66, nylon 12, and more than a dozen other types, each with different polarities.
• Second, due to the difficulty of meeting the diversified market demands with a single type of nylon, manufacturers often choose to add glass fibers or lubricants for modification, which can cause glass fibers to be exposed or lubricants to migrate to the surface.
• Third, during mold surface finishing and post-processing, such as annealing, the nylon part may have excessive moisture content.
• Fourth, TPE itself is a non-polar material, and the strong polarity of nylon can severely affect the peel strength of TPE overmolding on nylon.

Sungallon's GP320 series starts from the perspective of the cohesive energy density of the material, calculates the solubility parameters of TPE materials, and matches them with different types of nylon. For different nylon materials and processing scenarios, they develop TPE materials with high peel strength for nylon overmolding. Moreover, they test the peel strength after soaking in common solvents such as mineral oil, cutting fluid, and rust-preventing oil, based on consumer usage scenarios, fully considering the impact of solvents on the products.