Three new multi-shot tooling concepts use injection overmolding to eliminate post-mold welding, improve part quality and productivity as well as reduce scrap. The concepts involve stationary cavities and indexing cores. The first approach brings part assembly into the press. The second produces thick-wall parts in less time by building up the part in the mold from successive layers of material. The third approach overmolds one half of a complex hollow part onto another half. These developments come from French moldmakers JP Grosfilley SAS (Oyonnax) and Georges Pernoud (Martignat), which formed a consortium called AGP Group together with a third French moldmaker, Collom. AGP Developpement is a group of three companies striving to provide innovative solutions in the field of molds. Collomb Mécanique provides molds for the high productivity sector. JP Grosfilley designs and manufactures molds used with multi-injection as well as with numerical technology control. Georges Pernoud specializes in molds used for technical and complex parts. As per ptonline.com, the new in-mold assembly (IMA) approach uses one tool, one press, one process for lower overall investment and a complete part from the mold. At the heart of the IMA process is a special tool design from Grosfilley that features two indexing plates in one mold. The mold is divided into three sections: upper, middle, and lower. One half of the part is molded onto the rotating cores in the upper half of the tool on one platen, while the other half of the part is molded onto a different rotating core plate on the lower tool half on the other platen. The middle section of the tool is accessed by both indexing plates. The parts molded in the upper index plate rotate down to the center area, while the parts molded in the lower index plate rotate up to the same center area, so the mating parts end up face to face. When the mold closes, the second injection unit molds a seal around both parts in the middle section of the mold, while first-shot injection occurs in the upper and lower levels of the mold. Each rotating index plate is driven independently by a high-torque servo motor that rotates the plate 180°. The plates rotate at the same time. Overmolding is combined with a special indexing tool in a new way to make thick parts on smaller presses in shorter cycles. Its Multilayer concept produces thick parts by overmolding successive thin layers of the same polymer in the same mold. The layers can be 0.8 to 5 mm thick. This produces a part that can be free of weld lines and stresses. An indexing plate moves the parts from station to station. The mold and the process have to be fine-tuned and the machine parameters are critical. Temperature control of the mold is critical for this process. Georges Pernoud developed the Multitube tool concept, which eliminates welding of complex hollow parts like automotive water pipes and air ducts and provides weight and cycle-time savings. The Multitube method reduces the process to four steps and achieves a 15% weight savings and cycle-time savings of 0.5 to 2 sec. In a two-cavity family tool, one half of the part is molded in one cavity and then is transferred by robot to the second cavity, where the other half is overmolded. Multitube can be used with a rotary plate instead of a robot. He says the rotary plate provides better shrinkage control, because the part remains on the core during rotation from cavity to cavity.