The key to thermoplastic injection molding and manufacturing is efficiency. Known for their ability to outrace the productivity of single-face molds, stack mold designs from Aline Components, Inc. are providing customers from a wide range of industries with high quality custom plastic parts and components at a rapid turnaround. The efficiency derived from stack mold technology comes from using smaller footprint molds that produce multiple parts in smaller molding machines, therefore resulting in lower labor and part costs.
In single-face molding, one thermoplastic material is injected into the cavities of one half of the mold face and a second material into the other half. Between cycles, the rotary platen rotates the mold on a horizontal axis. In stack molding, the number of usable mold faces is multiplied and the entire mold face can be molded with each material. Aline’s revolutionary stack mold designs have a center platen that features two-four faces and rotates 90° or 180° vertically or horizontally each time the mold opens.
Stack molds are two single-face molds that are mounted back to back. One half of the core is mounted to the injection-side machine platen while the other half is mounted to the clamp-side machine platen. Cavity plates are fastened to the hot runner system that is located at the center section of the mold. To prevent mold collision, the center section must be equidistant between both core halves at all times. Aline’s stack molds boost productivity, often doubling or quadrupling output. This means less utility and maintenance costs.
Until recently, stack molds were used for fairly small, shallow-draw packaging and other disposable items. Today, innovation has taken hold and a variety of new concepts are broadening the capabilities of stack molds to include larger, multi-material products.
Soft-touch applications such as toothbrush handles, barrier packaging, caps and closures with molded-in liners, multi-color cell phone housings, and combination-material medical parts are in high demand. As knowledge of the benefits of stack molds increases, mold makers and customers alike look to them when applications justify their use.