JPH0319809A - Method and apparatus for manufacturing long fiber resin composition - Google Patents

Abstract

PURPOSE:To fully impregnate glass fibers with material having high molecular weight and low fluidity so as to maintain the strength and impact resistance, which resin has originally, by a method wherein the twisting of glass fibers and the impregnation of the resin are performed by introducing a plurality of the glass fibers from the sides of a covering die 1, at the central part of which a contact passage is provided and which has a rotating mechanism about the axis line of the contact passage, and molten resin on the direction of said axis line. CONSTITUTION:A covering die 1 consists of a supporting device 2 and a rotatingly driving device 3. In the covering die 1, a contact course 4, which brings glass fibers G and molten resin P into contact with each other, is provided at the tip of the die. In the contact course 4, a plurality of glass fiber introducing paths 5, through which glass fibers G are introduced, and a resin introducing path 6, through which molten resin P is introduced, are provided. The contact course 4 is provided in the covering die 1 in the direction of the axis line of the rotating shaft of the covering die 1. The glass fiber introducing path 5 guides the glass fibers G, which are delivered from bobbins 8, to the contact course 4. The resin introducing path 6 introduces the molten resin P into the contact course 4. A tachometer 11 is provided on the covering die 1 so as to control the rotational frequency of the covering die 1 and the take-off speed of a take-off machine 12 by means of a controller 13 in order to manufacture the predetermined multiplexed long fiber resin composition.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing a long fiber resin composition and an apparatus for producing the same. The present invention relates to a method and apparatus for producing a high-strength long fiber resin composition.

[Prior Art and Problems to be Solved by the Invention] Glass-compounded long fiber resin compositions have higher mechanical strength than resins alone, and are therefore used as materials for various members. Conventionally, composite resin impregnation of glass fibers has generally involved kneading and extruding the matrix resin material and glass fibers using an extruder using a single or two-wheel screw, and after extrusion, cooling and cutting into predetermined lengths. An extrusion method was used to produce pellets.

However, in this extrusion method, the glass fibers often break (cut) due to high shear forces within the extruder. Blend materials that are composited with glass fibers damaged in this way have a significant drop in tensile strength at high temperatures due to the glass fibers being damaged.To compensate for this, the resin itself must have high heat resistance. I needed to use something.

For this reason, in order to improve the breakage of glass fibers, resin and glass fibers are extruded while being in contact with each other using an impregnation die.
A method, the so-called pultrusion method, was devised in which the strands are cut into arbitrary strand lengths using a cutter. This method does not apply large shearing forces during compounding, as is the case with screw kneading in an extruder, so there is less damage to the glass fibers and it is possible to produce resin composites with high tensile strength at high temperatures. is possible.

However, in this method, a large shearing force cannot be obtained because the pulling tension when the glass fiber passes through the die is large, and the resin is applied only to the fluidity of the glass fiber treated with a binding agent. The shear force was too small to impregnate the resin, and the resin could not be sufficiently impregnated. Furthermore, when the take-up speed is increased, the contact time between the resin and the glass fibers becomes shorter, resulting in a state in which the glass fibers are not impregnated with the resin.

If you look at the inclusion of resin in the cross section of the resin composite proboscis that comes out of the die in this type of bear, you will find that the glass fiber is in the center and the resin is only coated on the outside, but it does not penetrate into the glass fiber. The inclusion properties of the resin are not sufficient. If such a resin composition is cut into pellets with a strand cutter to any desired length, the glass strands and the hollow pipe-shaped resin will be separated, and when injection molding or stamping molding is performed, It was not possible to obtain a product in which the glass strands were uniformly dispersed.

Therefore, in order to sufficiently impregnate a bundle of glass fibers with resin using the above method, it is necessary to lengthen the contact path between the resin and glass fibers to increase the contact time between the two, or to use a highly fluid resin material. It was necessary to increase the inclusion property of the resin. However, it is difficult to increase productivity when the contact time is increased, and when a highly fluid resin material is used, although the resulting resin composite has high tensile strength at high temperatures, the molecular weight Since it is necessary to use a small product from the beginning, the heat resistance and impact resistance are significantly reduced, resulting in a problem that the field of application of the product is limited. Therefore, the present inventor has developed a long fiber that can be sufficiently impregnated into glass fibers even with a material with high molecular weight and low fluidity that has the inherent strength and impact resistance of resin, and that can take advantage of the inherent properties of resin. We have conducted extensive research to develop a method and equipment for manufacturing resin composites.

[Means to solve the problem]

As a result, the inventors have found that the above problems can be solved by bringing the glass fibers and the resin into contact through a specific route. The present invention has been achieved based on this knowledge.

That is, the present invention introduces a plurality of glass fibers into the contact path from the side of a coating die that has a contact path in the center and has a rotation mechanism with the axis of the contact path as the rotation axis, and The present invention provides a method for producing a long fiber resin Ill sacrificial article characterized by introducing molten resin from the axial direction of the path and rotating a coating die to twist the glass fibers and impregnate the resin. The present invention also provides a contact path provided at the center of a coating die having a rotation mechanism, a plurality of glass fiber introduction paths for introducing glass fibers into the contact path from the sides of the coating die, and an axis of the contact path. The present invention provides an apparatus for producing a long fiber resin assembly, characterized in that it is equipped with a resin introduction path for introducing molten resin from the direction.

First, the long fiber resin composition to which the present invention is directed is a composite of glass fiber and resin as described above. Here, as the glass fibers and resins, those conventionally used as materials for this type of long fiber resin composition can be used as they are, and are not particularly limited. Examples of resins include polypropylene, polyamide, polyphenylene sulfide, and polyester. Examples include polycarbonate, polybutylene phthalate, polyoxymethylene, or a mixture of two or more of these.

The figures show a preferred example of the apparatus of the present invention used when manufacturing the above-mentioned long fiber resin composite by the method of the present invention, in which Figure 1 is a cross-sectional view of a coated die, and Figure 2 is a cross-sectional view of a coated die. 1-1 sectional view of FIG. 1 and FIG. 3 are process diagrams for manufacturing a long fiber resin composition.

The coating die 1 is configured to be rotatable by a rotation mechanism consisting of a suitable support device 2 and a rotary drive device 3. Inside this coating die 1, there is a contact path 4 for bringing the glass fiber G into contact with the molten resin P at the tip thereof, and the contact path 4.
A plurality of glass fiber introduction paths 5 for introducing glass fibers G into the glass fibers and a resin introduction path 6 for introducing molten resin P are formed. A flange 7 is formed at the base end of the coating die 1, and a plurality of bobbins 8 around which glass fibers G are wound are attached to the flange 7. The contact path 4 is provided in the axial direction of the rotating shaft of the coating die 1, and is determined by the type, diameter, and number of the glass fibers G, the type and fluidity of the molten resin P, or the long-fiber resin composition that is to be disintegrated. Its diameter, length, etc. can be set as appropriate depending on the performance of the tube.

If this contact length is short, it may be difficult to sufficiently impregnate the glass fibers with the resin, and if it is too long, flow resistance may increase, resulting in a decrease in productivity.

On the other hand, the glass fiber introduction path 5 allows the glass fiber G unwound from the bobbin 8 attached to the flange 7 to pass through the contact path 5.
It is formed obliquely to the axis so that the glass fiber G can be introduced smoothly.

The inclination angle of this glass fiber introduction path 5 is 1 with respect to the axis.
A range of 0 degrees to 60 degrees is preferred. If this angle is smaller than 10 degrees, the length of the glass fiber introduction path 5 will become longer than necessary, and if the angle exceeds 60 degrees, the introduction resistance of the glass fibers G will increase, which is not preferable.

Next, the resin introduction path 6 is for introducing the molten resin P supplied from the extruder 9 from the base end of the coating die 1 toward the contact path 4, and this resin introduction path 6 and the glass fiber introduction path 5 is configured to merge with the contact path 4 just before the contact path 4. Further, a seal ring 10 is provided between the resin introduction path 6 and the extruder 9 to prevent the molten resin P from leaking when the coating die 1 is rotated.

Furthermore, the coating die 1 is provided with a tachometer 11.
A composite long fiber resin composition is produced in a predetermined state by controlling the rotational speed of the coating die 1 and the take-up speed of the take-off machine 12 by comparing them with a predetermined setting value using the controller 13. can do.

It is difficult to determine the glass fiber content of long-fiber resin composite materials simply by the ratio of take-up speed and extrusion rate.
Therefore, it is desirable to prepare parameters that clarify the relationship between take-up speed, extrusion amount, and total number of glass fibers in advance. By forming the coating die 1 in this way, the molten resin P introduced from the resin introduction path 6 to the contact path 4 of the coating die 1 is introduced from the glass fiber introduction path 5 to the contact path 4 of the coating die 1. It can be impregnated in such a way that it oozes out from the inside of multiple glass fibers G that are twisted by rotation. Furthermore, since a large shearing force is generated between the molten resin P and the glass fibers G at this time, the molten resin P can be efficiently and sufficiently impregnated into the glass fibers G. In this way, the glass fibers G are impregnated with the molten resin P, but in this case, a large shearing force is applied to the glass fibers G due to twisting within the coating die 1. However, since a plurality of glass fibers G are introduced and impregnated with resin, the shearing force applied to each glass fiber is smaller than that in the conventional extrusion method, and breakage of the glass fibers can be prevented.

Furthermore, since the shearing force required to impregnate the glass fiber G with the molten resin P and the contact area between the molten resin P and the glass fiber G can be made larger than in the pultrusion method, the covering die L can be formed short. This allows even resin materials with low fluidity to be impregnated into glass fibers. Therefore, it is possible to use a high molecular weight resin material that provides the strength and impact resistance inherent to the resin, and it is possible to improve the mechanical strength. Also, compared to the pultrusion method,
It is also economical because thicker long fiber resin compositions can be produced.

The long fiber resin composition produced in this manner can be cut with a cutter 14 in the same manner as in the past to obtain a long fiber compound.

The coated die 1 can be manufactured by a conventional method, and an appropriate extruder, take-off machine, etc. can be used.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 A glass strand impregnated with resin was manufactured using a coating die having the structure shown in FIG. 1 and a manufacturing process having the structure shown in FIG. 2. The length of the contact path of the coated die used was 40
0ai, the path diameter is 3.0 mm, and the installation angle of the glass fiber introduction path is 45 degrees in the extrusion direction. The glass fibers used were (diameter 2 μm, number of bundles 700), and the molten resin was polypropylene (number average molecular weight 2×10′, melt flow rate 60 g/10 min). The average extrusion pressure at this time was 180 kg/cd, and the average rotation speed was 3Qrpm.
Met.

The glass content of the obtained glass strand was 40%. This glass strand was cut into 13 mm pieces with a cutter, and the obtained long fiber compound was used for injection molding to form test pieces.The mechanical strength of the test pieces was measured.
The results shown in the table were obtained. In addition, when we fired the test piece and measured the length of the glass fibers remaining in the ash, we found that the length was 1.
The remaining amount of 3 aun was 44% by weight.

Example 2 The long fiber compound obtained in Example 1 was pressed and shaped using hot flow stamping, and test pieces were punched out from this molded product to measure its mechanical strength. The results are shown in Table 1. Obtained. In addition, when the length of the glass fibers remaining in the ash after burning the test pieces was measured, the remaining amount of the glass fibers with a length of 13 was 78%.

Comparative Example 1 Glass fibers with a length of 13 mm and polypropylene resin (melt flow rate 60 g/10 minutes) were dry blended and then fed into a hopper into a twin-shaft extruder with the same direction.
Kneading was carried out at 30'C, and the obtained extrudate was
A long fiber compound was obtained by cutting into 31llI1 pieces.

This was injection molded in the same manner as in Example 1 to form a test piece, and the mechanical strength was measured, and the results shown in Table 1 were obtained. In addition, the length of the glass fibers remaining in the ash after burning the test pieces was measured, but none with a length of 13 mm could be found, indicating that the glass fibers were significantly damaged.

Comparative Example 2 The long fiber comparand obtained in Comparative Example 1 was shaped by hot flow stamping in the same manner as in Example 2, and then a test piece was punched out and its mechanical strength was measured. The results shown in Table 1 were obtained. Ta. In addition, the length of the glass fibers remaining in the ash after firing the test pieces was measured, but no glass fibers with a length of 13 mm could be found.

(The following is a blank space) [Effects of the Invention] As explained above, according to the method of the present invention, it is possible to easily produce a long-fiber resin composite material in which glass fibers are sufficiently impregnated with resin.

Furthermore, the apparatus of the present invention is easier to manufacture and easier to maintain than an apparatus having a defibration mechanism within the die. Furthermore, it is also economical since it is possible to produce a thick long fiber resin composite. .

Therefore, the present invention is expected to be effectively utilized as an industrial manufacturing method for long fiber resins and other products.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the coated die, Figure 2 is I-■ in Figure 1.
The cross-sectional view and FIG. 3 are process diagrams for manufacturing long fiber resin m-kaimono. 1: Covering die, 2: Support device, 3: Rotation drive device, 4: Contact path. 5: Glass fiber introduction path. 6: Resin introduction path, 7: Flange 8: Pobin,
9; Extruder. lO: Seal ring, 11: Tachometer. 12: Taking machine, 13: Controller, 14: Cutter G: Glass fiber: Molten resin

Claims (2)

[Claims] (1) From the side of a coating die that has a contact path in the center and has a rotation mechanism with the axis of the contact path as the rotation axis,
Introducing a plurality of glass fibers into the contact path,
A method for producing a long fiber resin composition, which comprises introducing molten resin from the axial direction of the contact path and rotating a coating die to twist the glass fibers and impregnate the resin with the resin. (2) A contact path provided at the center of the coating die having a rotation mechanism, a plurality of glass fiber introduction paths for introducing glass fibers into the contact path from the sides of the coating die, and a plurality of glass fiber introducing paths from the axial direction of the contact path. 1. An apparatus for producing a long fiber resin composition, comprising a resin introduction path for introducing molten resin.