Molding technology has undergone an evolutionary cycle in response to a heightened interest in preserving our environment while producing high quality custom plastic parts or components. Aline Components, Inc. is one plastic injection molding company that is taking steps in the evolution by offering thermoplastic injection molding services featuring hot runner molds. Our experience in hot runner molds and other emerging technologies has proven invaluable to our customers and the environment.
Today, emphasis has been placed on molding products from virgin resins. With the introduction of hot runner molds in thermoplastic injection molding, runner scrap is reduced or in some cases eliminated so there are no runners to sort from the parts, and no runners to throw away or regrind and remix into the original thermoplastic material.
Hot runner molds are two-plate molds with a heated runner system contained in one of the plates. This system consists of two parts: the manifold and the drops. The manifold has channels that convey the plastic on a single plane, parallel to the parting line, to a point above the cavity while the drops convey the plastic from the manifold to the part itself.
There are two types of hot runner systems – internally and externally heated drops and manifolds – that are designated by how the plastic is heated. Externally heated systems have the lowest pressure drop of any runner system and are better for color changes. Alternatively, internally heated systems offer higher-pressure drops, more difficult color changes, and better gate tip control.
Hot runner molds are ideal for applications where regrinding can cause the material to yellow or detract from the material properties. For example, in circumstances where long-lasting transparency is required, hot runner molds may be utilized for enduring clarity. Also, they are especially suitable for custom plastic parts or components with many cavities.
In externally heated systems, there are no places for material to hang up and degrade which makes this type appropriate for thermally sensitive materials, whereas in internally heated systems there are many places for material to hang up and degrade, so thermally sensitive materials should not be used. As a more expensive process involving complex setups, hot runner molds are almost always used for large volume orders of automated thermoplastic injection molding production.
At Aline Components, we specialize in thermoplastic injection molding solutions for a variety of custom plastic parts or components problems. In addition to hot runner molds we also offer cold runner molds. The main difference between cold and hot runner molding process is that hot runner eliminates material retained in the feed channels of a cold runner mold, which reduces the number of production steps and saves in both material and energy costs.