First of all, we need to determine parameters such as long diameter ratio, compression ratio, diameter, pitch, length, brand, number of products used, materials used, etc.According to each type of different, each used will vary according to the material to choose different material, its melting speed value, melting heat absorption performance, melt viscosity, water absorption, thermal stability and other characteristics are the differentiation, the shape of the plasticizing for injection molding machine screw have very different requirements.Even the same kind of plastic, because of different products, plastic flame retardant agent, lubricant, add by glass fiber, inorganic minerals such as modifier and filler is different, or mixed color requirements, different requirements of melting, melt particles the size of the material shape is different, all have different requirements on the screw to choose.

Screw press machine series, because there are very many kinds of series injection molding machine, so we should choose the beginning, to correctly judge the product should be what kind of injection molding machine, or a series of production, such as is the general thermoplastic plastic bakelite raw materials or PET raw material and so on, are monochrome, double screw, multicolor, sandwich or mixed color, etc.In addition, some products need high stability (closed loop), high precision, ultra high speed, high pressure or rapid manufacturing (multi loop), and other conditions, and must choose the right to make corresponding to the special series.