塑料注射成型工艺基础_图文

1、 内容提要 zzzzzzzz Co -injection molding Fusible core injection molding Gas -assisted injection molding Injection -compression molding Lamellar (microlayer injection molding Live -feed injection molding Low -pressure injection molding Push -pull injection molding Structural foam injection molding Proces

2、s cycle Importance of process conditions Resin data table Temperature -time curve at various locations in the mold Screw positions at various stages Cycle time and its components Required mold opening Determination of the gate/part freezing time Pressure decreases along the delivery system and the c

3、avity Factors influencing injection pressure requirements (I Factors influencing injection pressure requirements (II Factors influencing injection pressure requirements (III Factors influencing injection pressure requirements (IV Injection pressure as a function Melt front advancements Melt -front v

4、elocity and melt- front area Fiber orientations Variation of MFA Basic runner system layouts Commonly used runner cross sections Equivalent hydraulic diameters Runner diameter chart Effect of runner length Hot runner system types Filling patterns resulting from various injection rates Cold slug A fa

5、mily-mold part with artificially balanced runners Gate size terminology FIGURE 1. Gate size terminology Gate types (I Direct (sprue gate Tab gateEdge (standard gateOverlap gateFan gateDisk (diaphragm gate Gate types (II Ring gateSpoke (spider gateFilm (flash gate Mold cooling accounts for more than two-thirds of the total cycle time Proper and efficient cooling improves part quality and productivity A typical cooling system for an injection molding machine Cooling -chan