JPH0459328A - 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 molten plasticizing resin discharging side is made deeper than that of a molten plasticizing resin side and the depth of the screw groove is reduced at the fixed rate till a completion point of formation of the multiple flight. CONSTITUTION:A depth H5 of a screw groove 3 in a semimolten resin side in a compressed part CZ is made invariable in an injection direction of the resin. Furthermore, a depth H6 of a groove of the screw groove 4 in a molten plasticizing resin discharge side is made deeper than that H5 of a screw groove 3 in the semimolten plasticizing resin 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. Then a depth H4 of a screw groove 2 in a resin material feed side, a depth H5 of the screw groove 3 in the semimolten plasticizing resin side and the depth H6 of the screw groove 4 in the semimolten plasticizing resin 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 shown in FIG. 4.

In Fig. 4, the screw 1 is connected to the supply section FZ and the compression section CZ.
It is divided into one 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 between the compression section CZ and the metering section MZ, and joins the opposing main flight α again at the boundary between the compression section CZ and the metering section MZ. 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 β1 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 β1, 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, and the molten film is sheared. The force rapidly accelerates the melting of the surface of the solid resin. In this way, the molten resin passes over the first sub-flight B1 and is transferred to the semi-molten plasticized resin thread groove 3. 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, since the second sub-flight is arranged as a weir between the main flights in the metering section MZ, crosstalk is low. (This had the disadvantage of reducing processing capacity.)

[Means for Solving the Problems] In order to solve such problems, in the present invention, in a partial range of the screw, the resin material paddy supply side thread groove and the semi-molten plasticized resin side thread full and molten plasticized In a multi-flight high-kneading screw having a sub-flight divided into a resin discharge side screw groove, the depth of the resin material supply side screw groove and the depth of the molten plasticized resin discharge side screw groove are set in the resin injection direction. On the other hand, the depth of the semi-molten plasticized resin side thread groove is continuously decreased from the deep groove part to the shallow groove part, and the depth of the thread groove on the semi-molten plasticized resin side remains unchanged with respect to the resin injection direction, and the first multiple flights in the resin injection direction At the formation start point, the depth of the thread groove on the resin material supply side is made deeper than the thread groove depth on the semi-molten plasticized resin side and the thread groove on the molten plasticized resin discharge side, and the next multiple flights are formed in the resin injection direction. At the starting point, the depth of the thread groove on the molten plasticized resin discharge side is made deeper than the thread groove on the semi-molten plasticized resin side, and the depth of both thread grooves decreases 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 and the depth of the molten plasticized resin discharge side thread groove are continuously gradually decreased, the semi-molten plasticized resin side thread groove is kept unchanged, and the depth of the resin material supply thread groove is The side is deeper than the depth of the semi-molten plasticized resin thread groove and the molten plasticized resin discharge side thread groove (as a result, a certain amount of resin sent from the supply side is not blocked between multiple flights and the extrusion force is In order to be stable, the extrusion amount is not regulated, color change is easy, and crosstalk is significantly improved.

[Example] Figures 1 to 3 show one example of a high kneading screw according to the present invention.
Embodiments are shown in which Fig. 1 is a partially cutaway vertical cross-sectional view of a high crosstalk screw, Fig. 2 is a developed view of the screw, and Fig. 3 is a cross-sectional view of A-A in Fig. 2.
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, a first sub-flight β1 and a second sub-flight β2 are arranged in the compression section CZ, and the first sub-flight β and the second sub-flight β2 connect the resin material supply screw groove 2 and the 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 C7 and merges with the opposing main flight α again at the boundary between the compression part CZ 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 β1 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 Z1 with the first sub-flight β1 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, and Zl >22.

Furthermore, regarding the depth of the thread groove in the compression part CZ,
First, the resin material supply side screw groove 2 has a structure in which the threads gradually decrease in the resin injection direction from the deep groove part to the shallow groove part so that H+>H2>H3>H4.

In addition, the semi-molten plasticized resin side thread groove 3 in the compression part CZ
The depth H6 remains unchanged in the resin injection direction. Furthermore, near the formation start point of the second secondary flight β2, which branches from the main flight α and is divided into the semi-molten plasticized resin thread groove 3 and the molten plasticized resin discharge side thread groove 4, the semi-molten plasticized resin side thread The depth H6 of the molten plasticized resin discharge side screw groove 4 is deeper than the depth H6 of the groove 3.
) has become. In addition, near the formation end point of the second subsidiary flight β2 where the second subsidiary flight β2 merges with the opposing main flight α, the depth H4 of the resin material supply side thread groove 2 described above,
The depth H5 of the half-molten plasticized resin side thread groove 3 and the depth H6 of the molten plasticized resin discharge side thread groove 4 are almost the same (H4=H
5=H, ).

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 β2 is
The gap Z between the cylinder barrel 5 and the first sub-flight β1 described above is smaller, and furthermore, 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 1, 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 l. The resin moves smoothly from the supplying part FZ side to the measuring part MZ side, and a certain amount of resin sent from the supplying group FZ side is blocked by this triple flight part and the extrusion force is stabilized. Metering takes place constantly.

In addition, in the embodiment of the present invention, the gap Z1 between the cylinder barrel 5 and the first sub-flight β in the compression part C7 is
Although the case is described in which the gap Z2 is thicker than the gap Z2 between the cylinder barrel 5 and the second sub-flight β2, it is not limited to this case.

=72, almost the same effect can be obtained.

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 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. Although we have described a high-kneading screw that has a triple flight consisting of a second sub-flight of the third thread that is divided into the discharge side thread groove, the invention is not limited to this. It is also possible to create multiple flights with branches.

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

[Effects of the Invention] As is clear from the above explanation, in the present invention, the depth of the thread groove on the resin material supply side and the depth of the thread groove on the molten plasticized resin discharge side are set to the deep groove portion with respect to the resin injection direction. The depth of the thread groove on the semi-molten plasticized resin side remains unchanged with respect to the injection direction of the resin, and the depth of the thread groove on the semi-molten plasticized resin side gradually decreases from ,
The depth of the thread groove on the resin material supply side is made deeper than the depth of the thread groove on the semi-molten plasticized resin side and the thread groove on the discharge side of the molten plasticized resin, and at the next multi-flight formation start point in the resin injection direction, the melting The depth of the thread groove on the plasticized resin discharge side is made deeper than the thread groove on the half-molten plasticized resin side, and the depth of both thread grooves decreases at a constant rate until the end point of multiple flight formation. When a certain amount of molten resin sent from the 1000mm molten resin passes over each flight, the flow velocity and pressure increase, which significantly improves crosstalk. At the same time, the extrusion rate is increased because the resin is not blocked between flights and the extrusion force is stabilized. is not regulated and color changes are easy.

[Brief explanation of the drawing]

1 to 3 show one example of a high crosstalk screw according to the present invention.
Embodiments are shown in which Fig. 1 is a partially cutaway vertical cross-sectional view of a high crosstalk screw, Fig. 2 is a developed view of the screw, and Fig. 3 is a cross-sectional view of A-A in Fig. 2.
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. 1...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 MZ Measuring Department (a) Hl>Hs (d) H4=H5=H7 Figure 5 Supply Department FZ

Claims (1)

[Claims] In a multi-flight high-kneading screw that is provided with sub-flights that are divided into 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 The depth of the supply side thread groove and the depth of the molten plasticized resin discharge side thread groove are gradually decreased from the deep groove part to the shallow groove part in the resin injection direction, and the semi-molten plasticized resin side thread groove is The depth of the thread groove on the semi-molten plasticized resin side remains unchanged with respect to the resin injection direction, and the depth of the thread groove on the resin material supply side is set to the depth of the thread groove on the semi-molten plasticized resin side at the first multi-flight formation start point in the injection direction of the resin. The depth of the thread groove on the molten plasticized resin discharge side is made deeper than the thread groove depth on the molten plasticized resin discharge side, and the depth of the thread groove on the molten plasticized resin discharge side is made deeper than the thread groove on the semi-molten plasticized resin side at the next multi-flight formation start point in the resin injection direction. A high-kneading screw characterized in that the depths of each thread groove decrease at a constant rate until the end point of multiple flight formation.