JP2633358B2 - Method and apparatus for producing long fiber resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a long fiber resin composition and an apparatus for producing the same, and more particularly, to a high-flow material suitable for hot flow stamping molding or injection molding. The present invention relates to a method for producing a long-strength long-fiber resin composition and an apparatus therefor.

[Problems to be solved by conventional technology and invention]

Glass-composite long fiber resin compositions are used as materials for various members because they have higher mechanical strength than resins alone. Conventionally, in order to impregnate resin into glass fiber, generally, a matrix resin material and glass fiber are kneaded and extruded by an extruder using a single-screw or twin-screw, and after extrusion, cooled to a predetermined length. An extrusion method of cutting into pellets has been used.

However, in this extrusion method, glass fibers are often broken (cut) due to high shearing force in the extruder. In this way, the blended material composited in a state where the glass fiber is broken has a remarkable decrease in tensile strength at high temperature due to the breakage of the glass fiber, and in order to compensate for this, the resin itself has a high heat resistance. Things had to be used.

For this reason, in order to improve the breakage of the glass fiber, a method of extruding the resin and the glass fiber while contacting them with an impregnating die and cutting it to an arbitrary strand length with a cutter, a so-called pultrusion method has been devised. . This method does not apply a large shearing force as in the case of screw kneading in an extruder during compounding, so that a glass fiber is less damaged and a resin composition having high tensile strength at high temperatures can be produced. It is possible.

However, in this method, a large shearing force cannot be obtained due to a large take-up tension when the glass fiber passes through the die, and the resin is used only for the fluidity of the glass fiber which has been subjected to the binding agent treatment. The shearing 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 fiber becomes short, and the glass fiber is not impregnated with the resin.

Looking at the impregnating property of the resin in the cross section of the resin composition coming out of the die in such a state, the glass fiber is located at the center, and only the resin is coated on the outside, and the resin is introduced into the glass fiber. Insufficiency is not enough. When such a resin composition is cut into pellets by using a strand cutter to an arbitrary length, the glass strands and the resin in the form of a hollow pipe are separated from each other, and the glass strands are formed when injection molding or stamping molding is performed. Could not be obtained.

Therefore, in order to sufficiently impregnate the resin into the glass fiber bundle by the above method, the contact path between the resin and the glass fiber is lengthened to increase the contact time between the two, or by using a highly fluid resin material. It was necessary to increase the impregnation of the resin.
However, when the contact time is lengthened, it is difficult to increase the productivity, and when a resin material having high fluidity is used,
Although the resulting resin composition has a high tensile strength at high temperatures, the molecular weight must be used from the beginning, so that heat resistance and impact resistance are significantly reduced, and the application field as a product is limited. Problems arise.

Therefore, the present inventor has proposed that even a material having a high molecular weight and a low fluidity having the inherent strength and impact resistance of a resin can be sufficiently impregnated into glass fibers, and a long fiber capable of utilizing the inherent properties of the resin. Intensive research was conducted to develop a method for manufacturing a resin composition and an apparatus for manufacturing the same.

[Means for solving the problem]

As a result, they have found that the above problem can be solved by bringing the glass fiber and the resin into contact with each other through a specific route.
The present invention has been completed based on such findings.

That is, the present invention introduces a plurality of glass fibers into the contact path from the side of a coating die having a contact path in the center and having a rotating mechanism having the axis of the contact path as a rotation axis. The present invention provides a method for producing a long-fiber resin composition, which comprises introducing a molten resin from an axial direction of a path and rotating a coating die to impregnate a glass fiber with a thread and a resin. The present invention also provides a contact path provided in the center of a coating die having a rotating mechanism, a plurality of glass fiber introduction paths for introducing glass fibers from the side of the coating die to the contact path, and an axis of the contact path. A resin introduction path for introducing a molten resin from a direction; and an apparatus for producing a long fiber resin composition.

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

FIG. 1 shows a preferred example of an apparatus of the present invention used when producing the long fiber resin composition by the method of the present invention. FIG. 1 is a sectional view of a coating die, and FIG.
FIG. 3 is a cross-sectional view taken along the line II in FIG. 3, and FIG. 3 is a process chart for producing the long fiber resin composition.

The coating die 1 is provided with an appropriate supporting device 2 and a rotary driving device 3
It is rotatable by a rotating mechanism consisting of: Inside the coating die 1, a glass fiber G
Path 4 for bringing glass fiber G into the contact path 4 and a plurality of glass fiber introduction paths 5 for introducing glass fibers G into the contact path 4.
And a resin introduction path 6 for introducing the molten resin P. 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 mounted on the flange 7.

The contact path 4 is provided in the axial direction of the rotation axis of the coating die 1 and includes the type, diameter, and number of the glass fibers G.
The diameter, length, and the like of the molten resin P can be appropriately set depending on the type and fluidity of the molten resin P or the desired performance of the long fiber resin composition. If the contact length is short, it may be difficult to sufficiently impregnate the glass fiber with the resin. If the contact length is too long, the flow resistance may increase, and the productivity may decrease.

On the other hand, the glass fiber introduction path 5 guides the glass fiber G fed out from the bobbin 8 mounted on the flange 7 to the contact path 4, so that the glass fiber G can be introduced smoothly with respect to the axis. It is formed diagonally. The inclination angle of the glass fiber introduction path 5 is preferably in the range of 10 degrees to 60 degrees with respect to the axis. If this angle is smaller than 10 degrees, the length of the glass fiber introduction path 5 becomes unnecessarily long. If the angle exceeds 60 degrees, the introduction resistance of the glass fibers G increases, 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. 5 is formed so as to merge immediately before the contact path 4. 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 rotates.

Further, the coating die 1 is provided with a tachometer 11,
By controlling the number of revolutions of the coating die 1 and the take-up speed of the take-off machine 12 by comparing and controlling them with a predetermined set value by the controller 13, a long fiber resin composition compounded in a predetermined state is produced. can do.

In addition, it is difficult to determine the glass fiber content of the long fiber resin composition by the ratio between the simple take-up speed and the extrusion amount. Therefore, it is desirable to prepare in advance parameters that clarify the relationship between the take-up speed, the extrusion amount, and the total number of glass fibers.

By forming the coating die 1 in this manner, 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 to form the coating die 1. The impregnation can be performed in a state where the glass fibers G that are twisted by the rotation ooze out from the inside. At this time, since a large shear force is generated between the molten resin P and the glass fiber G, the molten resin P
Can be efficiently and sufficiently impregnated into the glass fiber G.

The glass fiber G is impregnated with the molten resin P in this manner. In this case, a large shearing force is applied to the glass fiber G due to the twist in the coating die 1. But,
Since a plurality of glass fibers G are introduced to impregnate the resin,
The shearing force applied per glass fiber becomes smaller than that of the conventional extrusion method, and breakage of the glass fiber can be prevented. Further, the shearing force required to impregnate the glass fiber G with the molten resin P, and the molten resin P and the glass fiber G
Since the contact area with the dies can be increased as compared with the pultrusion method, the coating dies 1 can be formed short, and glass fibers can be impregnated even with a resin material having low fluidity. Therefore, it is possible to use a resin material having a high molecular weight capable of obtaining the original strength and impact resistance of the resin, and it is possible to improve the mechanical strength. In addition, it is economical because a thicker long fiber resin composition can be produced as compared with the pultrusion method.

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

The production of the coating die 1 can be performed by a conventionally used method, and an appropriate extruder or take-off machine can be used.

〔Example〕

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

Example 1 A resin-impregnated glass strand was manufactured in the manufacturing process having the configuration shown in FIG. 2 using the coating die having the configuration shown in FIG. The contact path length of the used coating die is 40
0 mm, the path diameter is 3.0 mm, and the mounting angle of the glass fiber introduction path is 45 degrees in the extrusion direction. The glass fiber used was (diameter 2 μm, number of bundles 700), and the molten resin was polypropylene (number average molecular weight 2 × 10 ⁴ , melt flow rate 60 g / 10 minutes). At this time, the average extrusion pressure was 180 kg / cm ² , and the average rotation speed was 30 rpm.

The glass content of the obtained glass strand was 40%. This glass strand was cut into 13 mm with a cutter, injection molding was performed using the obtained long fiber compound to form a test piece, and the mechanical strength was measured. The results shown in Table 1 were obtained. In addition, when the length of the glass fiber remaining in the ash by firing the test piece was measured, the length was 13 mm.
Was 44% by weight.

Example 2 Using the long fiber compound obtained in Example 1, press compression molding was performed by hot flow stan pink, and a test piece was punched out of the molded product to measure the mechanical strength. The results shown in Table 1 were obtained. Was done. When the length of the glass fiber remaining in the ash after firing the test piece was measured, the remaining amount of the glass fiber having a length of 13 mm was 78% by weight.

Comparative Example 1 After dry blending 13 mm long glass fiber and polypropylene resin (melt flow rate 60 g / 10 min),
The extruded product was put into a twin-screw extruder from a hopper and kneaded at 230 ° C., and the obtained extruded product was cut into 13 mm to obtain a long fiber compound. This was injection-molded in the same manner as in Example 1 to form a test piece, and the mechanical strength was measured. The results shown in Table 1 were obtained. The length of the glass fiber remaining in the ash after firing the test piece was measured.
A 13 mm one could not be found, indicating that the glass fiber was significantly damaged.

Comparative Example 2 The long fiber comparand obtained in Comparative Example 1 was molded by hot flow stamping in the same manner as in Example 2, and then a test piece was punched out. The mechanical strength was measured. The results shown in Table 1 were obtained. . Further, the length of the glass fiber remaining in the ash after firing the test piece was measured, but it was not possible to find one having a length of 13 mm.

[Effects of the Invention] As described above, according to the method of the present invention, a long-fiber resin composition in which a glass fiber is sufficiently impregnated with a resin can be easily produced.

The device of the present invention is easier to manufacture and easier to maintain than a device having a fiber opening mechanism in a die. Furthermore, it is economical because a thick long fiber resin composition can be produced. .

Therefore, the present invention is expected to be effectively used as an industrial production method of a long fiber resin composition.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a coating die, and FIG.
FIG. 3 is a sectional view, and FIG. 3 is a process chart for producing a long fiber resin composition. 1: coating die, 2: supporting device, 3: rotary drive, 4: contact path, 5: glass fiber introduction path, 6: resin introduction path, 7: flange, 8: bobbin, 9: extruder, 10: seal Ring, 11: tachometer, 12: take-off machine, 13: controller, 14: cutter, G: glass fiber, P: molten resin

Claims (2)

(57) [Claims] 1. A plurality of glass fibers are introduced into said contact path from the side of a coating die having a contact path at a central portion and having a rotation mechanism having an axis of said contact path as a rotation axis. A method for producing a long-fiber resin composition, comprising introducing a molten resin from an axial direction of a path and rotating a coating die to impregnate a glass fiber with a thread and a resin. 2. A contact path provided in the center of a coating die having a rotation mechanism, a plurality of glass fiber introduction paths for introducing glass fibers from the side of the coating die to the contact path, and an axis of the contact path. An apparatus for producing a long fiber resin composition, comprising: a resin introduction path for introducing a molten resin from a direction.