Mold sprue

When a thermoplastic polyurethane elastomer is heated above the melting point of its hard blocks, the chains can flow and the polymer can be molded to a new shape. When the polymer cools, new hard blocks form, recreating the physical crosslinks. We take advantage of these properties to mold elastomeric items that do not need to be cured like conventional rubbers. Scrap moldings, sprues, etc. can be recycled directly back to the extruder, which increases the efficiency of this process. In contrast, chemically crosslinked elastomers, which are thermosetting polymers, cannot be reprocessed after they have been cured. 

Sprue puller n. A pin having a Z-shaped slot undercut in its end, by means of which it pulls the molded sprue out of the sprue passage. 

The purpose of the adjustable table is to raise the mold up forcing the mold sprue tight against the injection nozzle. It s a unique feature of the machine and with it molds of varying sizes can be used on the machine. 

Polymers have replaced metals in components for a myriad of reasons. One of the major issues is cost. The lower cost of polymer parts is due to two major considerations. First, the cost of polymers per unit weight is cheaper than metals. Coupled with this is Ihe typically net shape manufacture of polymer parts. While some polymeric materials are machined from sohd material, most polymer components are made by processes such as injection molding. Often there is no additional machining, beyond removal of flash or molding sprues, to add to the cost of a polymer component. This is in contrast to metal components, which often require significant machining time and costs. Machining of a metallic component can often be the donfinant cost of the part. 

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