Select the mold
First, the extrusion die
1 , by the pressure through the die sets to achieve stereotypes, extruded plastic layer structure, the appearance of smooth . 2, the mold core and the angle determines suite stream pressure from the impact of the quality of the plastic layer and the quality of the cable extrusion .
3 , a plastic squeeze tube than the much lower .
4 , the eccentric adjustment is difficult , the insulation thickness is not easy to control
Second, the squeeze tube mold
1 , applies only with sheathing
2 , compared with the extrusion advantages:
( 1 ) Fast
( 2) The operation is simple , easy to adjust the eccentric , are unlikely to occur eccentricity
( 3) improve the service life of the mandrel
( 4 ) With convenient mode
( 5 ) Plastic directed by stretching occurs role in improving the mechanical strength of the plastic
( 6 ) Sheath thickness easily controlled. By adjusting the speed to adjust the draw ratio , thereby controlling the sheath thickness .
( 7 ) Special requirements can be extruded loose .
3 , the disadvantage
( 1 ) Plastic dense layer is poor. Because mold core and the angle between the sets of small , plastics extrusion pressure is small , an increase in extrusion stretch ratio , thus improving the molecule neat tight plastic layer purposes. ( 2 ) combination of plastic and wire core density is poor. The method can be opened to improve ventilation tightness , improve stretch ratio is also useful .
( 3 ) looks as good as the quality of extruded
Third, the semi- squeeze tube mold
1, in the large-scale wire insulation and sheathing requirements closely use.
2, the mold core bore can be increased appropriately so that when the wire diameter becomes large, there will not scratch , stuck ; wire diameter can be smaller to prevent , within the core in the mold caused by the eccentric oscillating .
3 Disadvantages:
( 1 ) on the cable core poor flexibility , the way when it is bent, will produce an eccentric , and therefore easy to use .
( 2 ) integrated into the cable such as the cable does not round the cable core through the mandrel when the swing because of irregularities caused by eccentricity , should not be used .
( 3 ) appears to material phenomena .