| 摘要 |
PURPOSE:To improve melting and mix and temper efficiency by providing sub screw notch in which the height of the notch is low and lead angle increase and decrease alternatively in material passage formed by main notch of which lead angle is fixed in a screw for plastic molding apparatus. CONSTITUTION:In a screw for plastic molding apparatus, sub notch 12 of which lead angle increase and decrease is disposed in outerside of a main screw notch 11 having lead angle alpha and the height of the sub screw notch 12 is lower than the height of the main screw notch 11 so that plastic material can be moved and the width of the screw groove formed by the main screw notch 11 and adjacent sub screw notch 12 is gradually increased and decreased relatively along a lead in accordance with increase and decrease of the lead angle. Thus, plastic material receives good efficient whole cutting action and moves to the deep groove side through a space between cylinder inner wall surface 13 and sub notch top 12 and at the same time, receives partial cutting action and distributing and mixing action so that melting and mix and temper efficiency is improved. |
