JPS6186215A - Mixing screw of thermoplastic resin - Google Patents

Abstract

PURPOSE:To obtain a mixing screw which has contrived an improvement in color and resin changing properties by improving kneading properties of resin and dispersion performance of pigment and preventing rentention of the resin and pigment, by providing a special stripe groove on an external circumferential surface of a plunger part provided on the screw. CONSTITUTION:A plunger part 2 whose gap with an inner circumferential surface of a cylinder 4 has been made small is provided on a screw and an external circumferential surface of the plunger part 2 is provided with stripe grooves 3A, 3B whose one ends are kept opened and the other ends are kept opened through a groove 5A whose width is smallest under a state wherein the grooves 3A, 3B are noncommucating with each other, in the direction opposite to each other and spiral.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a thermoplastic resin mixing screw.

[Technical disadvantages of the invention and its problems]

Traditionally, in resin molding machines, etc., screws have been used to melt the resin material and feed it to the mold side. As shown, on the outer peripheral surface of the large diameter plunger portion 2 formed in a part of the screw 1, the row grooves 3, 3, etc., which are closed at one end, are formed opposite to the intersection H so that they do not communicate with each other. This groove 3.3 is arranged spirally in the direction of
(Japanese Patent Publication No. 43-24493) attempts to improve kneading and dispersion performance by allowing resin to flow between the two.

With such a configuration, the kneading properties of the resin and the dispersibility of the pigment container can be improved), and the I! of one end of each groove 3°3... 1') 11: Resin and m1 accumulate in the dead end portions 3a and 3a, which often causes problems when changing colors or changing resin.

[Purpose of the invention]

The present invention has been made with the aim of solving the problems of the above-mentioned conventional technique 1h, and it not only has excellent performance in reducing crosstalk of resins and pigments, but also eliminates retention of resins and pigments. We provide thermoplastic resin mixing screws with improved color changeability and resin changeability.

(Summary of the Invention) In order to achieve the above object, the present invention provides a plunger portion that forms a small gap between the screw and the inner circumferential surface of the cylinder portion through which the screw is inserted, and one end of the plunger portion is provided on the outer circumferential surface of the plunger portion. The grooves are open at one end and the other end is a groove with an extremely small width, and the grooves are spirally arranged in opposite directions so as not to communicate with each other.

[Embodiments of the invention]

Hereinafter, the present invention will be explained by referring to eleven embodiments shown in FIGS. 1 to 5, and using the same reference numbers for parts common to FIG. 6.

FIG. 1 shows a basic embodiment of the present invention, in which a plunger portion 2 is provided to form a small gap between the shaft portion of a screw 1 and the inner peripheral surface of a cylinder portion 4 through which the screw is inserted. On the outer circumferential surface of the plunger portion 2, two types of grooves 3A and 3B are alternately arranged in parallel in a spiral shape and are not in communication with each other.

The upstream end 3Δ' of one of the grooves 3A is open to the upstream end of the plunger part 2, and the l1ilT flow end 3A'' is open to the downstream end of the plunger part 2 through an open groove 5Δ of minimal width. .

The other groove 3B has an upstream end 313' open to the upstream end of the blunt portion 2 through the open groove 5B, and a downstream end 3B'' thereof open to the downstream end of the plunger section 2.

The longitudinal side portions of each of the grooves 3A and 3B are partitioned by a bank 66.

In the above embodiment 43, when the resin carried by the screw 1 reaches the plunger portion 2, it is mainly bound to the grooves 3A, 3A, . . . which open at the upstream end of the plunger portion 2.
A person, open to other grooves 3B, 3B...! l+'+
A small amount flows in through 5B.

The resin that has flowed into the grooves 3A, 3A... is transferred to the downstream end 3.
When reaching A'', the flow is constricted by the open groove 5Δ, so most of the resin climbs over the embankment 6.6 and flows into the adjacent groove 3B from the gap with the inner peripheral surface of the cylinder part 4.This embankment 6 and pass through the gap with the cylinder part 4, a large shearing force acts in a short time, crushing the coarse particles and creating a sufficient amount of crosstalk@
Resin is obtained. At the same time, the resin flows out through the open groove 5△ to the downstream side of the plunge portion 11 2 little by little at high pressure. A washing action is performed to prevent resin or pigment from remaining at the downstream end 3A'' of M 3 A.

If J3 is in the other groove 38, the adjacent groove 3 A h
In addition to receiving the resin flowing over the embankment 6, at the other upstream end 3A', the resin flows little by little through the open groove 5B open to the upstream end of the plunger part 2.
As a result, a washing action is performed to prevent resin and pigment from remaining at the upstream end 3B' of the strip m 313.

Depending on the type of resin, the width and depth of the open groove 5B may be adjusted to improve the kneading performance due to the synergistic effect of the resin flowing into the grooves 3B and 38 and the resin flowing from the open groove 5B. I can do it.

Through the above-mentioned effects, resin kneading performance and dispersion performance are exhibited better than before), resin and pigment are prevented from staying at the ends of each groove 3A and 3B, and color changeability and resin changeability are improved. performance can be significantly improved.

FIG. 3 shows that in one of the grooves 38, Lt? In the other groove 3B, the position of the 1/3 length Vll is squeezed, and the open grooves 5G and 5Dt are connected to each other, and the flow flows into the grooves 3A and 3B. The flow of the resin into the adjacent grooves 3B and 3A over the urging parts 6 and 6 is increased by J, and the kneading performance of the resin is improved compared to the example A shown in the first diagram. It is something.

FIG. 4 shows a case where the plunger portion 2 shown in the first figure is axially rotated 21 times, and FIG. Each plunge 1ν from the flow side to the downstream side
Part 2. 2. 2 and the gap t between the cylinder part 4, 1,
1.2. The t3 is made smaller in stages, thereby further improving the performance of kneading, dispersing, and uniformly plasticizing the resin.

(Effects of the Invention) As described above, the present invention provides a plunger portion that forms a small gap between the screw and the inner peripheral surface of the cylinder portion through which the screw is inserted, and one end of the plunger portion that forms a small gap between the screw and the inner peripheral surface of the cylinder portion through which the screw is inserted. The upstream end of each groove and Resin and pigment reservoirs do not accumulate at the downstream end, and resin mounting and color change defects can be reliably prevented. In addition, in each groove, the resin flowing from the open groove and the resin flowing beyond the plate portion coexist, so that the kneading performance of the resin is increased, and the crosstalk performance and dispersion performance can be further improved.

[Brief explanation of drawings]

Fig. 1 is a plan view iiE showing a basic embodiment of the present invention, Fig. 2 is an enlarged view of the same part, Figs. 3 to 5 are front views showing the embodiment of the same, Fig. It is an iE view of the conventional technology. 1... Screw, 2... Plunger part, 3A, 3B
...Groove, 3A', 3B' ...Upstream end, 3△''
. 3B''...Downstream end, 4...Cylinder part, 5A, 5B
. 5C, 5D...Open groove, 6...Plate part. Applicant's agent Seiji Inomata Figure 1 Figure 2 Figure 4 B Figure 5 Figure 6

Claims (1)

[Claims] 1. The screw is provided with a plunger portion that forms a small gap between the screw and the inner peripheral surface of the cylinder portion through which the screw is inserted, and the outer peripheral surface of the plunger portion has one end open and the other end polarized. A thermoplastic resin mixing screw characterized in that grooves opened through open grooves each having a small width are arranged spirally in opposite directions so as not to communicate with each other. 2. The thermoplastic resin mixing screw according to claim 1, which has a plurality of plunger portions having the grooves in the axial direction. 3. The thermoplastic resin mixing screw according to claim 1 or 2, wherein each of the grooves has an open groove formed by squeezing the middle part in the longitudinal direction.