Straight line screw type plasticization injector

Abstract

A ratio of length (L) / diameter (D) of a screw is set to 18 through 24, a length (Lf) of a supplying portion of the screw is set to 10 through 14 times the diameter (D), a groove depth (hf) of the supplying portion of the screw (14) is set to be not less than 13 mm, a groove depth (hm) of a measuring portion of the screw (14) is set to be not less than 8 mm, and a width of a molten resin path formed by a weir plate (22) and a check ring (22) in a direction orthogonal to a flow direction of the molten resin is set to be 3 through 6% of the screw diameter (D).

Description

[0001] The present invention is based on Japanese Patent Application No. 2003-87161, which is incorporated herein by reference. technical field [0002] The present invention relates to an in-line screw type plasticizing injection device having a diameter of not less than 100 mm and suitable for plasticizing injection of spherical pellets including long glass fibers, in particular to a large-sized injection molding device capable of stably and efficiently producing automobile parts and the like. In-line screw type plasticizing injection unit for molded products. Background technique [0003] In the related art, when a long fiber-reinforced resin material is molded using a usual plasticizing injection device, the fibers are damaged and the original characteristics of the material cannot be obtained. The plasticized injection device of the screw head of the anti-backflow prevention ring is used to prevent the breakage of long fibers by improving the structure of the screw head...

AI Technical Summary

Problems solved by technology

[0021] That is, when the length (Lf) of the supply part is short, there are problems such as deterioration of the function of conveying material, prolongation of metering time, instability (surge phenomenon), reduction in productivity, and difficulty in stable molding.

In addition, when the length (Lf) of the supply portion is short, the amount of heat added to the pellet material from the external heater is insufficient, preheating is insufficient, and the pellet material is subjected to high shear force in the compression zone, thus causing long fibers to be easily broken , its insufficient melting, poor appearance due to poor dissociation of bundled long glass fibers, and in extreme cases, problems such as mixing of molten resin with molding material thereby deteriorating physical properties, etc.

[0022] Although it is conceivable to solve this shortcoming by increasing the back pressure of the screw or increasing the number of revolutions of the screw, as described in JP-A-2-292008, the breakage of long glass fibers increases, so in the case of a screw with a small (L / D) In this case, there is a problem that there are limits corresponding to the forming conditions such as screw back pressure and screw revolutions

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