JPH0459326A - High kneading screw - Google Patents

Abstract

PURPOSE:To improve kneading properties by improving a speed of a flow and pressure at the time when a fixed quantity of molten resin crosses over flights each, by a method wherein at a starting point of formation of a multiple flight, a depth of a screw groove in a semimolten plasticizing resin side is made deeper than that in a molten plasticizing resin discharge side and the depths of mutual screw grooves are reduced at the fixed rate till completion point of formation of the multiple flight. CONSTITUTION:A depth of a screw groove 3 in a semimolten plasticizing resin side in a compressed part CZ is reduced gradually from a deep groove part to a shallow groove part in an injection direction so that H5>H6>H7>H8 is obtained. Furthermore, a depth H7 of a groove of the screw groove 3 in a semimolten plasticizing resin side is made deeper than a depth H9 of a screw groove 4 in a molten plasticizing resin discharge side, in the vicinity of a starting point of formation of the second auxiliary flight beta2 where it is ramified from a main flight alpha and separated into the screw groove 3 in the semimolten plasticizing resin side and the screw groove 4 in a molten plasticizing resin discharge side. A depth H4 of a screw groove 2 in a resin material feed side, the depth H8 of the screw groove 3 in the semimolten plasticizing resin side and the depth H10 of the screw groove 4 in the molten plasticizing resin discharge side are made almost identical with one another, in the vicinity of a completing point of formation of the second auxiliary flight beta2 where the second auxiliary flight beta2 is combined with the facing main flight alpha.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a high kneading screw that can be applied to injection molding machines and extrusion molding machines.

[Prior Art] A conventional high-kneading screw is shown in FIGS. 4 and 5. FIG. 4 is a partially cutaway vertical sectional view of the high-kneading screw, and FIG. 5 is a developed view of the screw in FIG. 4.

In FIG. 4, the screw 1 is connected to the supply section FZ and the compression section C7.
, a measuring section MZ, a supply section FZ and a compression section C.
The first sub-flight β branches off from the main flight α at the boundary of Z and merges with the opposing main flight α again at the boundary between the compression part C2 and the measurement part MZ, and the A second sub-flight β2 branches off from the main flight α at the boundary and merges with the main flight α again in the direction of the screw tip.
The structure has the following.

The first sub-flight β and the second sub-flight β2 are divided into a resin material supply thread groove 2, a semi-molten plasticized resin thread groove 3, and a molten plasticized resin discharge side thread groove 4, respectively.

Further, the gap between the cylinder barrel 5 and the first sub-flight β1 in the compression section CZ is always constant from the supply section FZ side to the metering section MZ side, and furthermore, similarly in the metering section MZ, the gap between the cylinder barrel 5 and the first sub flight β1 is constant. The gap between the cylinder barrel 5 and the second sub-flight β2 is also constant, and the gap between the cylinder barrel 5 and the first sub-flight β1 is larger than that between the cylinder barrel 5 and the second sub-flight β1.
The gap is configured to be larger than the gap between the sub-flights β2.

Now, in FIG. 4, the resin supplied from the hopper 6 to the supply section FZ receives thermal energy from a heater (not shown) and shear energy due to the rotation of the screw 1, and is gradually melted and transferred forward.

In addition, in the compression section CZ, the solid resin is dammed up by the first sub-flight β, and as the screw 1 rotates, a molten film is formed between the cylinder barrel 5 and the solid resin due to its strong shearing action. The shear force rapidly accelerates melting of the surface of the solid resin. In this way, the molten resin is transferred to the semi-molten plasticized resin thread groove 3 over the first sub-flight β. Although the molten resin is further transferred from the semi-molten plasticized resin thread groove 3 to the molten plasticized resin discharge side thread groove 4 over the second sub-flight β2, the gap between the cylinder barrel 5 and the first sub-flight β1 and Regarding the gap between the second secondary flight β2, the gap between the former cylinder barrel 5 and the first secondary flight β1 is larger than the latter, and the molten resin that crosses the second secondary flight β2 is even stronger. It is subjected to severe shearing force and completely melted.

[Problems to be Solved by the Invention] As described above, in the conventional high-kneading screw, the first sub-flight is arranged as a weir between the main flights in the compression section,
Furthermore, in the measuring section MZ, the second sub-flight is arranged as a weir between the main flights, so crosstalk is low. If the gap between the two is made smaller, there is a drawback that the processing capacity decreases.

[Means for Solving the Problem] In order to solve such problems, in the present invention, in a partial range of the screw, the resin material supply side thread groove, the semi-molten plasticized resin side thread groove, and the molten plasticized resin In a multi-flight high-kneading screw having a sub-flight that separates the discharge side thread groove, the depth of the resin material supply side thread groove, the semi-molten plasticized resin side thread groove, and the molten plasticized resin discharge side thread groove are The thread groove depth on the resin material supply side is gradually reduced from the deep groove part to the shallow groove part in the resin injection direction, and at the first multiple flight formation start point in the resin injection direction, the resin material supply side thread groove depth is reduced to the semi-melted part. The depth of the screw groove on the plasticized resin side and the molten plasticized resin discharge side is made deeper than that, and the depth of the screw groove on the semi-molten plasticized resin side is melted and plasticized at the next multi-flight formation start point in the resin injection direction. The thread grooves are deeper than the thread grooves on the resin discharge side, and the depths of the thread grooves are reduced at a constant rate until the end point of multiple flight formation.

[Function] In the compression part, sub-flights that form a weir are arranged in the resin material supply side thread groove, the semi-molten plasticized resin side thread groove, and the molten plasticized resin discharge side thread groove, and , the depth of the resin material supply thread groove, the depth of the semi-molten plasticized resin side thread groove, and the depth of the molten plasticized resin discharge side thread groove are continuously gradually decreased, and the depth of the resin material supply thread groove is Because the depth of the screw groove on the semi-molten plasticized resin screw groove and the screw groove on the discharge side of the molten plasticized resin are made deeper, a certain amount of resin sent from the supply side is not blocked between multiple flights and the extrusion force is stable. Therefore, the amount of extrusion is not regulated, making it easy to change colors and significantly improving crosstalk.

[Example Figures 1 to 3 show one example of a high kneading screw according to the present invention.
Examples are shown in which Fig. 1 is a partially cutaway vertical sectional view of a high-kneading screw, Fig. 2 is a developed view of the screw, and Fig. 3 is a cross-sectional view of the high kneading screw.
The flow state of the resin in each cross section at point D is shown.

In FIG. 1, the screw 1 has a supply section FZ and a compression section CZ.
, and a measuring section MZ. In addition, the compression part C2 is provided with a first sub-flight β and a second sub-flight β2, and the first sub-flight β1 and the second sub-flight β2 connect the resin material supply thread groove 2 and semi-molten plasticization. It is divided into a resin thread groove 3 and a melt plasticizing discharge side thread groove 4, respectively.

In addition, the main flight α at the boundary between the supply section FZ and the compression section CZ
The first sub-flight β1 branches off from the main flight α near the center of the compression part CZ and merges with the opposing main flight α again at the boundary between the compression part C7 and the metering part MZ. The configuration includes a second sub-flight β2 that again joins the opposing main flight α at the boundary between the section CZ and the measuring section MZ.

As shown in FIG. 3, if the gap between the cylinder barrel 5 and the first sub flight β3 in the compression part CZ is 71, and the gap between the cylinder barrel 5 and the second sub flight β2 is 72, then the cylinder barrel 5 and the gap between the cylinder barrel 5 and the first sub flight β3 are 72. The gap Z1 between the first sub-flight β and the second sub-flight β is constantly constant from the supply section FZ side to the measuring section MZ side, and furthermore, the gap Z2 between the cylinder barrel 5 and the second sub-flight β2 is also constant. Z,>22.

Furthermore, regarding the depth of the thread groove in the compression part CZ,
First, in the resin material supply side screw groove 2, H+ > H2 > Hs > H from the deep groove to the shallow groove in the resin injection direction.
It has a structure in which the number is continuously decreased to 4.

In addition, the semi-molten plasticized resin side thread groove 3 in the compression part CZ
The depth of H is from the deep groove to the shallow groove in the resin injection direction.
s >Ha >Hfu>) (8) It has a structure that gradually decreases continuously so that Near the formation start point of the second sub-flight β2 that separates into the resin discharge side thread groove 4, the groove depth H7 of the semi-molten plasticized resin side thread groove 3 is smaller than that of the molten plasticized resin discharge side thread groove 4. depth H9
It is deeper <(H,>HG). Also, the second
Near the formation end point of the second secondary flight β2 where the secondary flight β2 merges with the opposing main flight α, the depth H4 of the resin material supply side thread groove 2 and the depth of the semi-molten plasticized resin side thread groove 3 are H8 and the depth HIQ of the molten plasticized resin discharge side thread groove 4 are almost the same (H.

=)[, =H, 0).

The operation of the high kneading screw configured as above will be explained.

In FIG. 1, the resin supplied from the hopper 6 to the supply section FZ receives thermal energy from a heater (not shown) and shear energy due to the rotation of the screw 1, and is gradually melted and transferred forward.

In the compression section CZ, the solid resin that has moved from the supply section FZ is stopped by the first sub-flight β1, and as the screw 1 rotates, a molten film is formed between the cylinder 5 and the solid resin due to its strong shearing action. The melting of the surface of the solid resin is rapidly promoted by the shear force of the molten film.

Furthermore, when the molten resin that has moved over the first sub-flight β1 crosses the second sub-flight β2, the gap Z2 between the cylinder barrel 5 and the second sub-flight 82 is
It is smaller than the gap Z1 between the cylinder barrel 5 and the first sub-flight β1 described above (in addition, the semi-molten plasticized resin thread groove 3
Also, since the thread groove 4 on the molten plasticized resin discharge side is shallow,
As the resin receives more shear energy from the rotation of the screw I, the resin is completely melted and the crosstalk property is improved. In particular, in the present invention, the resin group staying in the resin material supply thread groove 2 in the compression part CZ, the semi-molten plasticized resin thread groove 3 and the molten plasticized discharge side thread groove 4 is formed in the axial direction of the screw 1. The resin moves smoothly from the supply group FZ side to the metering section MZ side, and a fixed amount of resin sent from the supply group FZ side is blocked by this triple flight section, stabilizing the extrusion force and measuring. constant change.

In addition, in the embodiment of the present invention, the gap Z between the cylinder barrel 5 and the first sub-flight β1 in the compression part C7 is replaced by the gap Z2 between the cylinder barrel 5 and the second sub-flight β2.
Although the case where Z1 is made larger has been described, the present invention is not limited to this, and almost the same effect can be obtained even if Z1=22.

In addition, in the embodiment of the present invention, the second flight α is provided between the main flights α. A first subsidiary flight of the second thread that branches the third thread and separates it into a resin material supply thread groove and a semi-molten plasticized resin thread groove, and the semi-molten plasticized resin thread groove and the molten plasticized resin discharge. Although we have described a high-kneading screw having a triple flight consisting of a second sub-flight of a third thread that separates into a side thread groove, the invention is not limited to this, and the screw thread may be further branched into a fourth or more thread. It is also possible to have multiple flights.

Further, in the embodiment of the present invention, the second secondary flight β2
Although the case where the position where the main flight α branches off from the main flight α is approximately near the center of the compression section C7 has been described, the branching position is not limited to this and may be branched off from any arbitrary position of the compression section C7.

[Effects of the Invention] As is clear from the above explanation, in the present invention, the depth of the resin material supply side thread groove, the semi-molten plasticized resin side thread groove, and the molten plasticized resin discharge side thread groove are The depth of the thread groove on the resin material supply side gradually decreases from the deep groove to the shallow groove in the injection direction of the resin, and at the first point where multiple flights start forming in the injection direction of the resin, the depth of the thread groove on the resin material supply side is reduced to the semi-molten plastic. The depth of the thread groove on the semi-molten plasticized resin side is made deeper than the depth of the thread groove on the molten plasticized resin side and the thread groove on the molten plasticized resin discharge side, and the depth of the thread groove on the semi-molten plasticized resin side is increased at the starting point of the next multiple flight formation in the resin injection direction. By making the thread groove deeper than the discharge side, and by making the depth of each thread groove decrease at a constant rate until the end point of multiple flight formation, a certain amount of molten resin sent from the supply side is applied to each flight. The flow velocity and pressure increase when exceeding the 200°C, which significantly improves cross-talk, and since the resin is not blocked between flights and the extrusion force is stabilized, the extrusion amount is not restricted and color changes are easy.

[Brief explanation of drawings]

Figures 1 to 3 show one of the high kneading screws according to the present invention.
Examples are shown in which Fig. 1 is a partially cutaway vertical sectional view of a high-kneading screw, Fig. 2 is a developed view of the screw, and Fig. 3 is a cross-sectional view of the high kneading screw.
The flow state of the resin in each cross section at point D is shown. 4 and 5 show a conventional high-kneading screw, FIG. 4 is a partially cutaway vertical sectional view of the high-kneading screw, and FIG. 5 is a developed view of the screw in FIG. 4. l...Screw, 2...Resin material supply thread groove, 3...Semi-molten plasticized resin thread groove, 4.
...Melted plasticized resin discharge side thread groove, 5...
・Cylinder barrel, 6...Hopper, α...Main flight, β1...1st sub-flight, β2...2nd sub-flight, MZ...Measuring section, CZ- ... Compression section, FZ... Supply section. Patent applicant: Ube Industries, Ltd. Figure 2 Figure 3 Depth of thread groove on resin material supply side 2 Hl>H2>H3>H4 (a) Hl>Hs ω) Ratio = Hs = Hl. Figure 5 Supply section FZ

Claims (1)

[Claims] In a multi-flight high-kneading screw that is provided with a sub-flight that separates a resin material supply side thread groove, a semi-molten plasticized resin side thread groove, and a molten plasticized resin discharge side thread groove in a partial range of the screw, the resin material supply The depth of the side thread groove, the semi-molten plasticized resin side thread groove and the molten plasticized resin discharge side thread groove gradually decrease from a deep groove part to a shallow groove part with respect to the injection direction of the resin, and At the first multiple flight formation start point in the injection direction of At the start point of the next multiple flight formation in the injection direction, the depth of the thread groove on the semi-molten plasticized resin side is made deeper than the thread groove on the molten plasticized resin discharge side, and the depth of both thread grooves is constant until the end point of multiple flight formation. A high kneading screw characterized by a ratio of .