| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection device having a high plasticizing capacity, stable gas injection properties and sure gas sealability. SOLUTION: A screw has a first stage, a second stage and a gas sealing part and the theoretical plasticizing capacities (Q1), (Q2) and (Q3) of the first stage, the second stage and the gas sealing part in the theoretical plasticizing capacity (Q) calculated from the formula (1): Q=δ×N×ρ×60/1,000 (kg/h) and the formula (2):δ=[π×D×h1×(t-e)cos2α]/2 [wherein N is the number of rotations of the screw,ρis the specific gravity of a plastic resin, D is the diameter of the screw, h1 is the groove depth of the screw, t is the thread of the screw, e is the thread width of the screw andαis tan-1ät/(πD)}] satisfy the relations of formula (3): Q2/Q1=1.00-10.00, formula (4): Q1/Q3=1.00-15.00 and formula (5): Q2/Q3=1.00-20.00. COPYRIGHT: (C)2007,JPO&INPIT |
