JPS5830667Y2 - Extrusion molding equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement of a synthetic resin extrusion molding device, in which a breaker plate 2 is arranged in front of the screw 1 in the extrusion direction, and the front surface 3 of the breaker plate 2 is shaped like an inverted cone. The angle between the inverted conical front surface 3 and the front inlet wall 4 of the breaker plate 2 is a right angle, and a large number of holes 6 are bored through the front surface 3 from the rear surface 5 of the breaker plate 2, and these holes 6 are used as the breaker plate. This relates to an extrusion molding device in which the plate 2 is short at the center and becomes longer toward the periphery.

In extrusion molding of synthetic resin, the material is in a molten state at the inflow part,
When passing through the die head, the flow velocity varies depending on the position within the flow path, which causes a problem in which the flow path distribution in the die head is particularly large and the visibility is large.

In other words, if the flow velocity distribution of the molten material in the inflow section or die head is large, the residence time of the material becomes longer in the areas where the flow velocity is slow, causing decomposition, and the flow balance within the cross section of the die head is unbalanced, causing the extrusion product to deteriorate. This causes large internal stress to remain inside the mold, and becomes a source of deformation and distortion after molding.

The present invention was devised in view of the above-mentioned conventional drawbacks, and its purpose is to adjust the flow velocity distribution of the molten material when it flows inside the die head, thereby eliminating unnecessary retention of the material in the inflow section and inside the die head. An object of the present invention is to provide an extrusion molding device that prevents the decomposition of a material due to heat and reduces the residual internal stress in an extruded product.

The present invention will be explained in detail below using examples.

FIG. 1 shows an embodiment of an extrusion molding apparatus according to the present invention, in which a screw 1 is installed inside a cylinder barrel 7, and a rear part of a die head 8 is connected to the front part of the cylinder barrel 7. , the breaker plate 2 is arranged and attached to the front end of the cylinder barrel 7 at the connection part with the die head 8.

The breaker plate 2 corrects the spiral flow (rotational flow) generated by the screw 1, and the rear surface 5
A screen pack 9 is supported on the side to remove dust from the material.

The front face 3 of the breaker plate 2 has an inverted conical shape, and the angle between this inverted conical front face 3 and the inlet wall 4, which becomes smaller in diameter toward the rear of the die head 8, is a right angle.

Further, the breaker plate 2 is provided with a large number of holes 6, and the holes 6 are short at the center and become longer toward the periphery.

The material extruded by the screw 1 passes through each hole 6 of the breaker plate 2 and flows into the die head 8 from the inflow section 10 with the spiral flow (rotational flow) generated by the screw 1 being corrected. It is something.

In this case, the flow of the material to be extruded is due to the inertia of the forced flow through the gap between the cylinder barrel 7 and the screw 1, and the flow velocity is higher near the wall than in the center of the cylinder barrel 7, but in the present invention, Since the holes 6 of the breaker plate 2 are shorter at the center and longer toward the periphery, the flow resistance increases toward the periphery, making the flow velocity of the material passing through the breaker plate 2 uniform, and the inflow portion 10, This prevents unnecessary retention of the material inside the die head 8 and prevents the material from decomposing due to heat.

In addition, the front surface 3 of the breaker plate 2 has an inverted conical shape, and the angle between the front surface 3 and the inlet wall 4 is a right angle, so that the material passing through the breaker plate 2 flows parallel to the inlet wall 4. The current will be rectified.

The arrows in FIG. 3 indicate the flow direction of the material from each hole 6.

By uniformly and rectifying the flow of the material inside the inflow portion 10 and the die head 8 in this manner, residual internal stress in the extruded product is reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the present invention, Fig. 2 is a front view of the breaker plate used in the above, and Fig. 3 is a sectional view of the breaker plate used in the above, where 1 is a screw, 2 is a breaker plate, and 3 is a front view. , 4 is an inlet wall, 5 is a rear surface, and 6 is a hole.

Claims (1)

[Scope of utility model registration request] A breaker plate is placed in front of the screw in the extrusion direction, and the front surface of the breaker plate is shaped like an inverted cone. An extrusion molding device in which a large number of holes are drilled through the front surface of a breaker plate, and the holes are short in the center of the breaker plate and become longer toward the periphery.