Granular molding compound

GMC granular molding compound HAR high aspect ratio... 

H or h = hot press molding (SMC/BiVlC) 1 or i = hot press molding (granular molding compound)... 

Subsequently, Union Carbide Corporation offered solutions, films and granular molding compounds. 

Coherent block of granular plastic molding compound or of fibrous mixture with or without resin. Prepared by sufficiently compressing material, forming a block that can be handled readily. 

Alkyd. Alkyd resins are the reaction product of a poly functional alcohol and a polyfunctional acid. When the resin is combined with a filler, catalyst, pigment, and release agent the resultant product is a granular or putty or rope-type molding compound. Fillers used may be fine mineral, glass, mineral and nylon—depending on the end product desired. 

Filled PTFE—production techniques. Granular polytetrafluoroethylene compounds containing fillers are converted into parts by the same molding techniques as those used for neat resin. The compounding techniques aim at producing uniform blends of PTFE with fillers that can be processed in the same molding equipment. The rest of this section describes methods by which compounds can be made. 

Properties of granular PTFE compounds are presented in this section. A few points should be noted about filled PTFE compounds. Shape and size of the filler and resin particles, type of molding process, and processing conditions all influence the properties of parts made from compounds. Properties of compounds made with non-spherical particles are... 

Physical forms. The molding compound will consist of 20 to 25% resin (phenyl and methyl siloxanes), 75% filler (glass fiber and fused silica mix), a lead-based catalyst pigment, and lubricants. The compounds are free-flowing granular in form and are available in opaque colors (mostly red). They are readily moldable in compression, transfer, and injection molding processes. 

Figure 6.20 Injection machine for thermosetting plastics, available with screw or granular materials or plunger for bulk molding compounds. Machine also has an integral Rollaveyor tumble-blast deflasher inside the housing to deliver deflashed parts on a conveyor out through open end at left. Courtesy of Hull Corporation.)...

Physical forms. The molding compounds are available in a free-flowing granular form suitable for automatic preforming or preplasticating and are readily mold-... 

---