JP4189409B2 - Manufacturing apparatus and manufacturing method of long fiber reinforced thermoplastic resin strand - Google Patents

Description

  The present invention belongs to a technical field related to a manufacturing apparatus and a manufacturing method of a long fiber reinforced thermoplastic resin strand.

  Examples of conventional techniques relating to the production technology of long fiber reinforced thermoplastic resin strands include, for example, Japanese Patent Application Laid-Open No. 1-263005, Japanese Patent Application Laid-Open No. 6-254853, Japanese Patent Application Laid-Open No. 6-254855, and Japanese Patent Application Laid-Open No. 6-254850. There is what is described.

  In the above Japanese Laid-Open Patent Publication No. 1-263005, it is described that the impregnating roller is rotatably arranged. Japanese Patent Application Laid-Open No. 6-255483 describes that a roller is actively rotated. Japanese Patent Application Laid-Open No. 6-255485 describes a method for promoting the impregnation of a resin into a reinforcing fiber bundle by applying vibration to a roller. Japanese Patent Application Laid-Open No. 6-2545050 describes a method for promoting the impregnation of resin into a reinforcing fiber bundle by heating a roller. The impregnating rollers and rollers are all rollers for resin impregnation and are also referred to as resin impregnated rollers (hereinafter, these rollers are referred to as rollers or resin impregnated rollers).

  Among the techniques described in the above publications, the method of vibrating or heating the roller is surely effective in impregnating the resin into the reinforcing fiber bundle (hereinafter also referred to as reinforcing fiber bundle). However, in view of stable and continuous operation for a long time, it is not sufficient because the take-up resistance of the reinforcing fiber bundle cannot be sufficiently reduced. Moreover, since it becomes high even locally, it has a bad influence also on the thermal deterioration of resin.

  From the viewpoint of stable production at high speed for a long period of time, it is effective to lower the take-up resistance of the reinforcing fiber bundle, and there are those that attempt to lower the take-up resistance of the reinforcing fiber bundle by positively rotating the roller. (Japanese Patent Laid-Open No. 6-255483).

  However, in the method of positively rotating the roller, it is necessary to finely adjust the rotation speed in relation to the take-up speed of the reinforcing fiber bundle, and it takes time for the start-up of production and adjustment at the time of trouble. In addition, if this adjustment is not successful, the reinforced fiber bundle will be damaged and excessive tension will be generated, especially in the case of natural plant spun yarns that are spun from synthetic organic fibers or discontinuous fibers with low heat resistance. However, there is a problem that stable continuous operation is difficult.

  In the technique described in the above publication, a roller having a structure in which the roller is integrated with the shaft is employed. When the roller is integrated with the shaft in this way, fiber fluff (debris) tends to accumulate at the bearing at the end of the resin bath container (resin impregnation container). There is a tendency to become resistance when the roller rotates. For this reason, driving for a long time becomes difficult. In addition, when a device in which a plurality of resin impregnation containers are arranged is used, the take-up resistance of the reinforcing fiber bundle is different for each container, and the take-up speed of the reinforcing fiber bundle cannot always be kept the same. Need to be adjusted again.

  On the other hand, when the reinforcing fiber bundle is impregnated with the resin, there is a technique for producing a long fiber reinforced thermoplastic resin strand by twisting the reinforcing fiber bundle. -169445 is described. The purpose of imparting such a twist is to improve the material properties (flexibility, buckling resistance, etc.) of the long fiber reinforced thermoplastic resin strand.

  The above publication describes the provision of a twist to the long fiber reinforced thermoplastic resin strand, etc., but there are problems and specific devices in pelletizing the obtained long fiber reinforced thermoplastic resin strand. Is not touched at all.

  When strands are sought on-line while cutting a long-fiber reinforced thermoplastic resin strand (hereinafter also referred to as a strand) that has been twisted, rotation is applied to the strand (rotates in the direction to return the applied twist). Therefore, the phenomenon that the strands dance in front of the pelletizer (cutting machine) is observed, and not only the pellet length becomes uneven, but also the situation that the strands are detached from the guide and cannot be pelletized easily occurs.

If the strand that has been twisted is once wound on a bobbin, then the bobbin is set on a feeding machine, the strand is pulled out, and the pellet is cut by a pelletizer to avoid the above problems. it can. However, in this method, batch processing is performed, and production is interrupted when the bobbin is replaced, which is problematic in terms of continuous operation.
Japanese Unexamined Patent Publication No. 1-263005 Japanese Patent Laid-Open No. 6-254533 Japanese Laid-Open Patent Publication No. 6-25855 Japanese Patent Laid-Open No. 6-25850

  The present invention has been made paying attention to such circumstances, and its purpose is to produce a continuous fiber reinforced thermoplastic resin strand, which can be continuously produced for a long period of time. An object of the present invention is to provide an apparatus and a method for producing a long fiber reinforced thermoplastic resin strand having excellent properties.

  In order to achieve the above object, an apparatus and a method for producing a long fiber reinforced thermoplastic resin strand according to the present invention are the apparatus for producing a long fiber reinforced thermoplastic resin strand according to claims 1 to 3, and claim 4. The long fiber reinforced thermoplastic resin strand is produced by the following method.

  That is, the long-fiber reinforced thermoplastic resin strand manufacturing apparatus according to claim 1 introduces a reinforcing fiber bundle into the molten thermoplastic resin in the thermoplastic resin bath container, and the thermoplastic fiber is introduced into the reinforcing fiber bundle. The resin-impregnated fiber bundle is impregnated, the resin-impregnated fiber bundle is taken out from the outlet nozzle of the thermoplastic resin bath container, and twisted to the resin-impregnated fiber bundle by a twisting machine, and the resulting long fiber-reinforced thermoplastic resin strand is cut. An apparatus for producing a long fiber reinforced thermoplastic resin strand that is cut into pellets by a machine, and the long fiber reinforced thermoplastic resin strand is placed in the same direction as the twist by the twister between the twisting machine and the cutting machine. A long-fiber reinforced thermoplastic resin strand manufacturing apparatus characterized in that a means for twisting and maintaining the twist imparted by the twister is provided (first invention).

  3. The apparatus for producing a long fiber reinforced thermoplastic resin strand according to claim 2, wherein the means for keeping the twist is a roller set arranged so as to face each other with the long fiber reinforced thermoplastic resin strand interposed therebetween, and the angle between the roller shafts of each other. The apparatus for producing a long fiber reinforced thermoplastic resin strand according to claim 1, wherein the long fiber reinforced thermoplastic resin strand is composed of a roller set arranged in a shifted manner (second invention).

  The long fiber reinforced thermoplastic resin strand manufacturing apparatus according to claim 3, wherein the twist keeping means is provided at a position close to a cutting machine between the twisting machine and the cutting machine. It is a manufacturing apparatus of the long fiber reinforced thermoplastic resin strand (3rd invention).

  The method for producing a long fiber reinforced thermoplastic resin strand according to claim 4 produces a long fiber reinforced thermoplastic resin strand using the long fiber reinforced thermoplastic resin strand production apparatus according to any one of claims 1 to 3. A reinforcing fiber bundle is introduced into a molten thermoplastic resin in a thermoplastic resin bath container, the reinforcing fiber bundle is impregnated with the thermoplastic resin, and an outlet of the thermoplastic resin bath container The resin-impregnated fiber bundle was taken out from the nozzle and twisted to the resin-impregnated fiber bundle by a twisting machine, and the long fiber reinforced thermoplastic resin strand obtained thereby was provided between the twisting machine and the cutting machine. Twist in the same direction as the twist by the twister by means of keeping the twist, keep the twist imparted by the twister, and then cut the long fiber reinforced thermoplastic resin strand with a cutting machine A method for producing a long fiber-reinforced thermoplastic resin strand, wherein the (fourth invention).

  According to the apparatus for producing a long fiber reinforced thermoplastic resin strand according to the present invention, when producing a long fiber reinforced thermoplastic resin strand, it is excellent in continuous operation and can be operated for a long time. Strands can be produced continuously for a long time. According to the method for producing a long fiber reinforced thermoplastic resin strand according to the present invention, the production of the long fiber reinforced thermoplastic resin strand can be continuously performed for a long time.

The present invention is implemented, for example, in the following form.
A thermoplastic resin bath container for impregnating a molten thermoplastic resin into a reinforcing fiber bundle is prepared. A roll-type twisting machine for twisting the resin-impregnated fiber bundle is provided downstream of the thermoplastic resin bath container, and the resin-impregnated fiber bundle (long fiber reinforced thermoplastic resin strand) is cut and pelletized on the downstream side. A cutting machine is provided. Further, a means for twisting the long fiber reinforced thermoplastic resin strand in the same direction as the twist by the twister and maintaining the twist imparted by the twister is provided between the twister and the cutter. Then, the manufacturing apparatus of the long fiber reinforced thermoplastic resin strand which concerns on 1st invention of this invention is obtained. In addition, since the said twister is a roll system, it functions also as a means to take up the resin impregnation fiber bundle.

  At this time, as a means for keeping the twist, when using a roller set arranged to face each other across the long fiber reinforced thermoplastic resin strands, the roller set arranged by shifting the angle of the roller axis of each other, The long fiber reinforced thermoplastic resin strand manufacturing apparatus according to the second aspect of the present invention is obtained. Moreover, when the means for maintaining the twist is provided at a position close to the cutting machine between the twisting machine and the cutting machine, the apparatus for producing a long fiber reinforced thermoplastic resin strand according to the third invention of the present invention is obtained. .

  A long fiber reinforced thermoplastic resin strand is manufactured using the manufacturing apparatus. That is, the reinforcing fiber bundle is introduced into the molten thermoplastic resin in the thermoplastic resin bath container, the thermoplastic fiber is impregnated with the reinforcing fiber bundle, and the resin impregnation is performed from the outlet nozzle of the thermoplastic resin bath container. Twist the resin-impregnated fiber bundle by taking up the fiber bundle and twist it in the same direction as the twist by the twister by means of keeping the twist by applying a twist to the resin-impregnated fiber bundle. The twist imparted by the twisting machine is maintained, and then the long fiber reinforced thermoplastic resin strand is cut by a cutting machine. If it does so, the manufacturing method of the long fiber reinforced thermoplastic resin strand which concerns on 4th invention of this invention will be implemented.

  In such a form, the long fiber reinforced thermoplastic resin strand manufacturing apparatus according to the present invention is obtained, and the long fiber reinforced thermoplastic resin strand manufacturing method according to the present invention is performed.

  The present invention is implemented in such a form. The effects of the present invention (first invention to fourth invention) will be mainly described below.

  The long fiber reinforced thermoplastic resin strand manufacturing apparatus according to the first invention of the present invention (invention 1) introduces a reinforcing fiber bundle into the molten thermoplastic resin in the thermoplastic resin bath container as described above. The reinforcing fiber bundle is impregnated with the thermoplastic resin, and the resin-impregnated fiber bundle is drawn from the outlet nozzle of the thermoplastic resin bath container and twisted to the resin-impregnated fiber bundle by a twisting machine. An apparatus for producing a long fiber reinforced thermoplastic resin strand in which a long fiber reinforced thermoplastic resin strand is cut by a cutting machine into pellets, and the long fiber reinforced thermoplastic resin strand is interposed between the twisting machine and the cutting machine. Is a continuous fiber reinforced thermoplastic resin strand production apparatus, characterized in that means for keeping the twist imparted by the twister is provided.

  Therefore, the long fiber reinforced thermoplastic resin strand (hereinafter also referred to as a strand) that has been twisted by the twister is the same as the direction of the twist by means of keeping the twist (hereinafter also referred to as a twist holding means). The twist can be kept. In other words, there is no return of twist imparted by the twister, or the amount of return of twist can be reduced. For this reason, the dance phenomenon due to the rotation (twisting back) of the strands is completely eliminated, and as a result, it is possible to prevent the pellet lengths from becoming uneven, and the strands are not detached from the guide, and the strand cutting (pelletizing) step is performed. It can be done smoothly.

  Therefore, when producing a long fiber reinforced thermoplastic resin strand in which a resin impregnated fiber bundle (long fiber reinforced thermoplastic resin strand) is twisted and then cut and pelletized, it has excellent continuous operability and a long time. Thus, the production of the long fiber reinforced thermoplastic resin strand can be continuously performed for a long time.

  A method of installing a tube-shaped guide as a strand guide is also conceivable. However, especially in the case of strands of synthetic organic fibers with low rigidity and strands with low fiber content, the problem tends to be buckled in the middle and clogging occurs in the guide, and the problem cannot be solved sufficiently in terms of continuous production. .

  Japanese Patent Laid-Open No. 5-194445 discloses a roller between a twisting machine (twisting rollers 11a and 11b) and a cutting machine (cutter 13) that cuts a resin-impregnated fiber bundle (fiber reinforced resin strand) into pellets. 12 are provided. However, as described in the above publication, the roller 12 is a drawing roller, and the fiber-reinforced resin strands twisted by the twisting rollers 11a and 11b are in the same direction as the twisting by the twisting rollers 11a and 11b. It is not intended to twist in the direction. Further, as shown in FIG. 1 and the like of the above publication, the drawing roller 12 is composed of a roller set arranged so as to face each other with a long fiber reinforced thermoplastic resin strand interposed therebetween, but is arranged by shifting the angles of the respective roller shafts. Therefore, the drawing roller 12 basically does not have the function of twisting the fiber reinforced resin strands.For this reason, the drawing roller 12 twists the fiber reinforced resin strands to which the twists are imparted by the twist rollers 11a and 11b. It cannot be twisted in the same direction as the direction of twisting by the rollers 11a and 11b. Therefore, the drawing roller 12 cannot keep the twist by the twisting rollers 11a and 11b, and cannot keep the twist as in the case of the apparatus according to the first aspect of the present invention. That is, with this drawing roller 12, continuous operation cannot be improved by maintaining the twisting by the twisting rollers 11a and 11b. Thus, it can be said that the apparatus described in Japanese Patent Laid-Open No. 5-194445 and the apparatus according to the first invention of the present invention are not only different in configuration but also significantly different in operational effects.

  The type of the twisting machine is not limited. For example, a roller set that is arranged to face each other with a resin-impregnated fiber bundle (long fiber reinforced thermoplastic resin strand) interposed therebetween, and is a roller set that is arranged by shifting the angle of each roller shaft. Can be used. The number of the twist holding means is not limited and can be 1 or 2 or more.

  The long fiber reinforced thermoplastic resin strand manufacturing apparatus according to the second invention of the present invention (invention 2) is a twist holding means (means for keeping the twist) in the long fiber reinforced thermoplastic resin strand manufacturing apparatus according to the first invention. ) Is a roller set arranged so as to be opposed to each other with the long fiber reinforced thermoplastic resin strand interposed therebetween, and is specified to be composed of a roller set arranged by shifting the angles of the respective roller shafts. According to the twist holding means comprising this roller set, it is possible to surely keep the twist by twisting the strand, which has been twisted by the twister, in the same direction as the twist.

  The apparatus for producing a long fiber reinforced thermoplastic resin strand according to the third invention of the present invention (invention 3) is a twist holding means (in the apparatus for producing a long fiber reinforced thermoplastic resin strand according to the first or second invention) ( The means for keeping the twist) is specified to be provided at a position close to the cutting machine between the twisting machine and the cutting machine (hereinafter also referred to as a position near the cutting machine). In this case, the strand can be introduced into the cutting machine more reliably without the return of the twist imparted by the twister or with a small amount of return of the twist, and thus the pellet length becomes uneven. In addition to being able to suppress, the strands are not detached from the guide, and the strand cutting (pelletizing) step can be performed smoothly.

  When the number of the twist holding means is two or more, only one of the twist holding means may be provided at a position near the cutting machine, or a plurality of twist holding means may be provided at a position near the cutting machine. Alternatively, all the twist holding means may be provided at a position closer to the cutting machine.

  A fourth invention of the present invention (the invention according to claim 4) relates to a method for producing a long fiber reinforced thermoplastic resin strand, which is the long fiber reinforced thermoplastic resin strand according to the first invention, the second invention or the third invention. A long fiber reinforced thermoplastic resin strand using the manufacturing apparatus of the method, wherein a reinforcing fiber bundle is introduced into a molten thermoplastic resin in a thermoplastic resin bath container, and the reinforcing fiber bundle is added to the reinforcing fiber bundle. A long fiber reinforced thermoplastic resin strand obtained by impregnating a thermoplastic resin, pulling the resin-impregnated fiber bundle from the outlet nozzle of the thermoplastic resin bath container, and twisting the resin-impregnated fiber bundle by a twisting machine. Is twisted in the same direction as the twist by the twister by means of keeping the twist provided between the twister and the cutting machine, the twist imparted by the twister is maintained, A method for producing a long fiber-reinforced thermoplastic resin strands, characterized by cutting the reinforced thermoplastic resin strand cutting machine. According to this method for producing a long fiber reinforced thermoplastic resin strand, as can be understood from the description of the first invention, the second invention or the third invention, the resin impregnated fiber bundle (long fiber reinforced thermoplastic resin strand) is twisted. When producing a long fiber reinforced thermoplastic resin strand that is cut and pelletized after being applied, this can be carried out continuously for a long time.

  In the present invention, the reinforcing fiber is not particularly limited as long as it can be supplied as a continuous fiber bundle, and continuous glass fiber, carbon fiber, ceramic fiber, metal fiber, and synthetic organic fiber. In addition, natural plant fibers obtained by spinning discontinuous fibers into yarns can also be used. The reinforcing fiber may be subjected to an appropriate surface treatment or sizing treatment in consideration of adhesion with the thermoplastic resin to be combined.

  The type of the thermoplastic resin is not particularly limited, and is appropriately selected in consideration of required physical property values, heat resistance of the reinforcing fibers, and the like. For example, low-density polyethylene resin (LDPE), linear low-density polyethylene resin (LLDPE), high-density polyethylene resin (HDPE) and polypropylene resin alone, polyolefin resins such as copolymers and blends, polyamide 66, polyamide 6 , Polyamide resin such as polyamide 12, polyester resin such as polyethylene terephthalate resin (PET) and polybutylene terephthalate resin (PBT), polycarbonate resin, polystyrene resin (polystyrene resin, AS resin, ABS resin, etc.), or Examples thereof include biodegradable resins such as polylactic acid.

  For thermoplastic resins, inorganic fillers and dispersants such as talc, calcium carbonate, and mica, lubricants (bone agents), flame retardants, antioxidants, antistatic agents, light stabilizers, UV absorption, depending on the required physical properties An additive such as an agent, carbon black, a crystallization accelerator (nucleator), a pigment, and a dye can be added.

  A thermoplastic resin bath container for impregnating a molten thermoplastic resin into a reinforcing fiber bundle, and a roller comprising a shaft and a tube, the roller being rotatably supported around the shaft; Prepare. Next, this roller is disposed in the thermoplastic resin bath container as follows. That is, the roller is arranged so that the axial direction of the roller intersects the traveling path of the reinforcing fiber bundle and the reinforcing fiber bundle is in contact with the outer peripheral surface of the tube of the roller. Then, means for pulling the resin-impregnated fiber bundle is provided on the downstream side of the thermoplastic resin bath container. The number of rollers is 1 or 2 or more. (The apparatus for producing long fiber reinforced thermoplastic resin strands thus obtained is hereinafter also referred to as apparatus A for producing long fiber reinforced thermoplastic resin strands.)

  At this time, a through-hole can be provided in the tube of the roller. (The apparatus provided with this through-hole is hereinafter also referred to as a long-fiber reinforced thermoplastic resin strand manufacturing apparatus B.)

  A long fiber reinforced thermoplastic resin strand is manufactured using the manufacturing apparatus A or B. That is, the reinforcing fiber bundle is impregnated with the thermoplastic resin while the reinforcing fiber bundle is introduced into the molten thermoplastic resin in the thermoplastic resin bath container and brought into contact with the outer peripheral surface of the roller tube. The resin-impregnated fiber bundle is taken out from the outlet nozzle of the thermoplastic resin bath container. If it does so, the manufacturing method of the long fiber reinforced thermoplastic resin strand by the said manufacturing apparatus A or B will be implemented.

  In the production apparatus A for long fiber reinforced thermoplastic resin strands, as described above, a roller in contact with the reinforcing fiber bundle is disposed in the thermoplastic resin bath container so as to cross the running track of the reinforcing fiber bundle, The roller is composed of a shaft and a tube, and the tube is rotatably supported around the shaft.

  Therefore, even if the part of the shaft of the roller becomes difficult to rotate, the part of the tube of the roller can rotate independently, so that without changing the take-up resistance of the reinforcing fiber bundle, It becomes possible to drive.

  Moreover, since the molten thermoplastic resin exists between the roller shaft and the tube as if it were a lubricant and can flow, the roller tube can rotate smoothly. For this reason, the take-up resistance of the reinforcing fiber bundle can always be sufficiently reduced.

  Therefore, when producing a long fiber reinforced thermoplastic resin strand, it is excellent in continuous operability and can be operated for a long time, and a long fiber reinforced thermoplastic resin strand can be produced continuously for a long time. .

  Furthermore, even in the case of a device in which a plurality of containers for resin impregnation are arranged, the take-up resistance of the reinforcing fiber bundle for each container can be made the same, and the take-up speed of the reinforcing fiber bundle can be kept the same. There is almost no need to readjust the equipment. Therefore, it is easy to adopt the apparatus having such a configuration, and the productivity as the apparatus can be improved by adopting the apparatus.

  Note that it is conceivable to use a lubricant to ensure lubricity between the roller tube and the shaft. However, although the temperature of the resin bath is usually about 200 to 300 ° C. depending on the type of the resin, only a heat-resistant lubricant can be used, and if the lubricant is used, the resin bath is contaminated. I can not use it. In the manufacturing apparatus A for the long fiber reinforced thermoplastic resin strand, the lubricity between the roller tube and the shaft can be secured by the molten thermoplastic resin without using a lubricant, in other words, the molten fiber is melted. It can be said that a thermoplastic resin is used as a lubricant.

  The number of rollers (number per resin impregnation container 1) is not limited, and can be 1 or 2 or more.

  The roller that intersects the running track of the reinforcing fiber bundle and is in contact with the reinforcing fiber bundle means that the axial direction of the roller intersects the running track of the reinforcing fiber bundle and the roller surface is reinforced. The roller is arranged so as to come into contact with the fiber bundle. The fact that the axial direction of the roller intersects the traveling path of the reinforcing fiber bundle does not require that the axial center line of the roller and the traveling path of the reinforcing fiber bundle intersect directly. The center line and the running track of the reinforcing fiber bundle intersect.

  The fact that the roller is composed of a shaft and a tube and that the tube is rotatably supported around the shaft does not require that the tube is rotatable around the shaft in the atmosphere. It is sufficient that the tube is rotatable around the axis in the state where it is disposed in the molten thermoplastic resin in the thermoplastic resin bath container, and is supported in this manner.

  The shaft of the roller is not limited to be rotatably supported by a bearing and can be rotated, and a system in which the shaft is fixed (the shaft does not rotate) can also be adopted.

  Even in the latter method where the shaft is fixed (shaft fixing method), the roller tube part can rotate, and the molten thermoplastic resin is between the roller shaft and the tube as if it were a lubricant. The roller tube can rotate smoothly. For this reason, the take-up resistance of the reinforcing fiber bundle can always be sufficiently reduced. Therefore, when producing the long fiber reinforced thermoplastic resin strand, it is excellent in continuous operation and can be operated for a long time, and the long fiber reinforced thermoplastic resin strand can be produced continuously for a long time.

  Comparing the former shaft rotation method with the latter shaft fixing method, the former shaft rotation method is superior in continuous operation. From this point, the former shaft rotation method is adopted. It is desirable to do.

  The long fiber reinforced thermoplastic resin strand manufacturing apparatus B is specified as having a through-hole in the roller tube of the long fiber reinforced thermoplastic resin strand manufacturing apparatus A. When the through hole is provided in the roller tube in this way, the thermoplastic resin melted between the roller tube and the shaft can freely flow through the through hole. For this reason, it is easy to ensure the lubricity between the roller tube and the shaft, and the fluff of fibers does not stay between the roller tube and the shaft, and the roller tube can be rotated more reliably and smoothly. Can do. As a result, the level of certainty that the take-up resistance of the reinforcing fiber bundle can always be made sufficiently small is increased. The number of the through holes is not particularly limited, and may be 1 or 2 or more. However, from the viewpoint of lubricity between the roller tube and the shaft, it is desirable to increase the number of the through holes. However, it is desirable not to increase the number of through holes from the viewpoint of the strength of the roller tube. Although there is no restriction | limiting in particular in the magnitude | size of a through-hole, 0.5 mm-3 mm are preferable, More preferably, they are 0.8 mm-1.5 mm.

  As a method for producing a long fiber reinforced thermoplastic resin strand using the long fiber reinforced thermoplastic resin strand production apparatus A or B, a reinforcing fiber bundle is introduced into a molten thermoplastic resin in a thermoplastic resin bath container. The fiber bundle for reinforcement is impregnated with the thermoplastic resin while running in contact with the outer peripheral surface of the roller tube of the long fiber reinforced thermoplastic resin strand manufacturing apparatus A or B, and the outlet of the thermoplastic resin bath container. There is a method for producing a long fiber reinforced thermoplastic resin strand characterized by taking a resin-impregnated fiber bundle from a nozzle. According to this method for producing a long fiber reinforced thermoplastic resin strand, as can be understood from the description of the long fiber reinforced thermoplastic resin strand production apparatus A and B, the production of the long fiber reinforced thermoplastic resin strand is continued for a long time. Can be done.

  Examples of the present invention and comparative examples will be described below. In addition, this invention is not limited to this Example.

(Example 1)
FIG. 6 shows an outline of an apparatus for producing a long fiber reinforced thermoplastic resin strand according to Example 1 of the present invention.

  In FIG. 6, reference numeral 4 denotes a bobbin of reinforcing fibers, 1 denotes reinforcing fibers drawn from the bobbin 4, and 5 denotes a thermoplastic resin bath container (resin impregnating crosshead). Reference numeral 8 denotes a resin impregnating roller disposed inside the container 5. 2 indicates a molten thermoplastic resin, 6 indicates a thermoplastic resin extruder, and 7 indicates a screw of the extruder 6. The resin-impregnated roller 8 used was the same resin-impregnated roller as in the case of Comparative Example A described later, that is, a roller having a structure in which the roller is integrated with the shaft.

  Reference numerals 11a and 11b denote take-up machines having a twisting mechanism, in other words, a twisting machine having a take-up mechanism. The mechanism for imparting twist is composed of a roller 11a and a roller 11b. That is, the roller sets 11a and 11b are arranged so as to face each other with the long fiber reinforced thermoplastic resin strands interposed therebetween, and the roller sets 11a and 11b are arranged so that the angles of the roller axes are shifted.

  Reference numeral 13 denotes a cutting machine, that is, a pelletizer, for cutting and pelletizing long fiber reinforced thermoplastic resin strands.

  Reference numeral 12 denotes means for twisting in the same direction as twisting by the twisting machines 11a and 11b and maintaining the twist imparted by the twisting machines 11a and 11b (twisting holding means). This means 12 is a roller set (a set of an upper roller and a lower roller) arranged to face each other with a long fiber reinforced thermoplastic resin strand sandwiched therebetween, and a roller set arranged by shifting the angles of the roller axes of each other. Become. This means 12 is provided at a position close to the cutting machine 13 between the twisting machines 11a, 11b and the cutting machine 13.

As the thermoplastic resin, the following polypropylene resin was used. That is, maleic anhydride-modified polypropylene resin (Sanyo Kasei Co., Ltd.) was added to 100 parts by mass of homopolypropylene resin having a density of 0.91 g / cm ³ , MER (230 ° C., 2.16 kgf): 60 g / 10 min, melting point (DSC method): 165 ° C. A resin pellet was prepared by blending 5 parts by mass of Kogyo Co., Ltd., trade name “Yumex 1001”, acid value: 26 mg KOH / g, density: 0.95 g / cm ³ , molecular weight: 40,000 (weight average molecular weight by GPC method). The resin pellet was heated to 270 ° C. and melted.

  As the reinforcing fiber, roving of 1200 tex E-glass fiber treated with an emulsion of maleic anhydride modified PP after glass fiber having an average diameter of 17 μm was surface-treated with γ-aminopropyltriethoxysilane was used.

  Using the above apparatus, the following long fiber reinforced thermoplastic resin strands were produced. That is, the polypropylene resin melted at 270 ° C. by an extruder was introduced into a thermoplastic resin bath container. The tensioned glass fiber rovings 1 are drawn into a bundle and introduced into the molten polypropylene resin 2 in the thermoplastic resin bath container 5 so as to be brought into contact with the outer peripheral surface of the resin impregnation roller 8 and run. The roller was passed through a zigzag alternately above and below. Thereby, the glass fiber bundle (bundle of glass fiber roving) was impregnated with the polypropylene resin. Then, the resin-impregnated fiber bundle is pulled out from the outlet nozzle of the thermoplastic resin bath container 5 by the take-up machines (twisting machines) 11a and 11b, and rotated around the axis of the resin-impregnated fiber bundle. The bundle was twisted. Furthermore, the twisted [long fiber reinforced thermoplastic resin (polypropylene resin) strand] is twisted in the same direction as the twist by the twisting machines 11a and 11b by the twist holding means 12, and the twisting machine 11a, The twist imparted by 11b was kept. Thereafter, the long fiber reinforced thermoplastic resin (polypropylene resin) strand was cut into pellets having a length of 8 mm by a pelletizer 13 and pelletized. The pellet diameter is about 3 mmφ, and the glass fiber content in the pellet is about 50 mass%.

  At this time, the drawing speed of the resin-impregnated fiber bundle was 30 m / min. When applying the twisting by the twisting machines 11a and 11b, the twisting pitch was 25 mm and the number of twists was 40 times / m. Note that the twist pitch: 25 mm is an axial distance required for the fiber bundle in the resin-impregnated fiber bundle to be twisted 360 ° in a spiral. The number of twists: 40 times / m means that there are 40 pitches per 1 m, that is, 40 times a 360 ° twist of the fiber bundle in the axial direction of 1 m.

  The pellet length of the pellets thus obtained was measured one by one, and the ratio of the number of pellets outside the range of 8 ± 1.5 mm was determined. In addition, 5 sets of 8 hours of continuous operation were performed, and the number of troubles such as the strand coming off the guide during that time was determined and evaluated.

(Comparative Example 1)
In Comparative Example 1, the twist holding means 12 was not provided. That is, without pulling out the resin-impregnated fiber bundle from the outlet nozzle of the thermoplastic resin bath container 5 by the take-up machines (twisting machines) 11a and 11b and adding twist to the resin-impregnated fiber bundle, the twist is not maintained. The pelletizer 13 was cut into pellets and tried to be pelletized. Except for this point, the same apparatus as in Example 1 was used, and the manufacture and operation of the apparatus were performed in the same manner. Then, the ratio of the number of pellets out of the range of 8 ± 1.5 mm was obtained in the same manner as in Example 1, and the number of times trouble occurred was obtained and evaluated in the same manner as in Example 1. .

(Comparative Example 2)
In Comparative Example 2, the twist holding means 12 was not provided. Then, instead of the twist holding means 12, a metal tube (length: 100 mm) of 5 mmφ was provided in front of the pelletizer 13. That is, a tube-shaped guide having a diameter of 5 mmφ and a length of 100 mm was installed as a strand guide. Except for this point, the same apparatus as in Example 1 was used, and the manufacture and operation of the apparatus were performed in the same manner. Then, the ratio of the number of pellets out of the range of 8 ± 1.5 mm was obtained in the same manner as in Example 1, and the number of times trouble occurred was obtained and evaluated in the same manner as in Example 1. .

[Results in Example 1 and Comparative Examples 1 and 2]
Table 2 shows the results in the case of Example 1, Comparative Example 1 and Comparative Example 2. As can be seen from Table 2, the ratio of the number of pellets outside the range of 8 ± 1.5 mm (pellets outside the specified range) is 56% in the case of Comparative Example 1. The comparative example 2 is a little smaller than the comparative example 1, but it is still 22%. On the other hand, in the case of Example 1, it is only 2% and is very small.

  In the case of Comparative Example 1, the number of troubles occurred is 118 times. In the case of Comparative Example 2, it is much less than that of Comparative Example 1, but there are still 42 times. On the other hand, in the case of Example 1, no trouble occurs and the number of troubles is 0, which is extremely small.

  These results indicate that the case of Example 1 of the present invention is extremely excellent in continuous operability as compared with the case of Comparative Example 1 and Comparative Example 2. That is, in the case of Example 1 of the present invention, the lengths of the pellets are unlikely to be uneven, and there is no occurrence of troubles such as the strands being detached from the guide and being unable to be pelletized, so the operation is stopped halfway. It is less necessary and has excellent continuous operation.

(Example a)
1 and 2 show an outline of a production apparatus for a long fiber reinforced thermoplastic resin strand according to Example a. FIG. 1 is a top view. FIG. 2 is an enlarged side sectional view showing a main part of the apparatus shown in FIG.

  In the above apparatus, the resin impregnation roller (impregnation roller) is a roller configured by inserting the shaft shown in FIG. 3 into the tube shown in FIG. 4 (though not having a through hole). A roller is used which is rotatably supported around the axis. As shown in FIGS. 1 and 2, the resin impregnating roller is disposed in a thermoplastic resin bath container (crosshead). That is, the axial direction of the roller intersects with the traveling track of the reinforcing fiber bundle at right angles, and the reinforcing fiber bundle travels in contact with the outer peripheral surface of the roller tube. These rollers (five pieces) are arranged in the thermoplastic resin bath container so that the reinforcing fiber bundles pass zigzag alternately up and down. A means (not shown) for taking out the resin-impregnated fiber bundle is provided on the downstream side of the thermoplastic resin bath container. The roller shaft is rotatably supported by a bearing. The diameter of the roller is 10 mm.

As the thermoplastic resin, the following polypropylene resin was used. That is, maleic anhydride-modified polypropylene resin (Sanyo Kasei Co., Ltd.) was added to 100 parts by mass of homopolypropylene resin having a density of 0.91 g / cm ³ , MER (230 ° C., 2.16 kgf): 60 g / 10 min, melting point (DSC method): 165 ° C. A resin pellet was prepared by blending 5 parts by mass of Kogyo Co., Ltd., trade name “Yumex 1001”, acid value: 26 mg KOH / g, density: 0.95 g / cm ³ , molecular weight: 40,000 (weight average molecular weight by GPC method). The resin pellet was heated to 270 ° C. and melted.

  As the reinforcing fiber, roving of 1200 tex E-glass fiber treated with an emulsion of maleic anhydride modified PP after glass fiber having an average diameter of 17 μm was surface-treated with γ-aminopropyltriethoxysilane was used.

  Using the above apparatus, the following long fiber reinforced thermoplastic resin strands were produced. That is, the polypropylene resin melted at 270 ° C. by an extruder was introduced into a thermoplastic resin bath container. The glass fiber rovings that are under tension are aligned and bundled into a molten polypropylene resin in a thermoplastic resin bath container, brought into contact with the outer peripheral surface of the tube of the resin impregnating roller and run while this roller. The top and bottom were alternately zigzag. Thereby, the glass fiber bundle (bundle of glass fiber roving) was impregnated with the polypropylene resin. Then, the resin-impregnated fiber bundle was pulled out from the outlet nozzle of the thermoplastic resin bath container to obtain a long fiber reinforced thermoplastic resin (polypropylene resin) strand. Furthermore, this strand was cut into 8 mm long pellets with a pelletizer and pelletized.

  At this time, the drawing speed of the resin-impregnated fiber bundle was 30 m / min. Then, the continuous operation time until the operation of the apparatus was stopped due to the trouble (strand production was stopped) was obtained and evaluated. However, if continuous operation was possible for 120 hours, the operation was interrupted and the continuous operation time was set to 120 hours or more.

(Example b)
In example b, the roller impregnated with resin is a roller constructed by inserting the shaft shown in FIG. 3 into the pipe shown in FIG. 4 (five through holes (through holes) are provided). A roller supported rotatably around the shaft was used. In other words, a tube having five through holes was used as a tube constituting the roller. Except for this point, the same apparatus as in Example a was used, and the manufacture and operation of the apparatus were performed in the same manner. Then, the continuous operation time was obtained and evaluated in the same manner as in Example a. The diameter of the through hole is 1 mm.

(Comparative Example A)
In Comparative Example A, the roller shown in FIG. 5 was used as the resin-impregnated roller. In other words, a structure in which the roller is integrated with the shaft was used. Except for this point, the same apparatus as in Example a was used, and the manufacture and operation of the apparatus were performed in the same manner. Then, the continuous operation time was obtained and evaluated in the same manner as in Example a.

[Examples a and b, results of Comparative Example A]
Table 1 shows the continuous operation time in the case of Example a, Example b and Comparative Example i. As can be seen from Table 1, the continuous operation time in the case of Comparative Example A is 26 hours. In contrast, the continuous operation time in Example a is 49 hours, which is extremely long. Furthermore, the continuous operation time in the case of example b is 120 hours or more, which is extremely long. Thus, in the case of Example a, the continuous operability is extremely excellent, and in the case of Example b, the continuous operability is extremely excellent.

  In the above example a, the roll used is a system in which the tube is rotatably supported around the shaft and is rotatable, and the shaft is rotatably supported by the bearing and is rotatable. When the fixed shaft type was used, the continuous operation time was slightly shorter, but the continuous operation time was longer than in the case of Comparative Example A, and the continuous operation property was excellent. In the roll of Example b, when the shaft was fixed, the continuous operation time was 120 hours or more, and the continuous operation was extremely excellent.

It is a schematic diagram which shows the outline | summary of the manufacturing apparatus of the long fiber reinforced thermoplastic resin strand which concerns on the example a. It is a schematic diagram which shows the outline | summary of the principal part of the manufacturing apparatus of the long fiber reinforced thermoplastic resin strand which concerns on the example a. It is a schematic diagram which shows the outline | summary of the axis | shaft for the rollers for resin impregnation concerning the example a. It is a schematic diagram which shows the outline | summary of the pipe | tube for resin impregnation rollers concerning Example b. It is a schematic diagram which shows the outline | summary of the roller for resin impregnation concerning the comparative example i. It is a schematic diagram which shows the outline | summary of the manufacturing apparatus of the long fiber reinforced thermoplastic resin strand which concerns on Example 1 of this invention.

Explanation of symbols

1-reinforcing fiber, 2-molten thermoplastic resin, 4-bobbin of reinforcing fiber,
5-Thermoplastic resin bath container, 6-Extruder, 7-Screw, 8-Roller for resin impregnation,
11a, 11b--roller assembly (take-off and twisting machine), 12--twisting means, 13--cutting machine (pelletizer).

Claims (4)

  A reinforcing fiber bundle is introduced into the molten thermoplastic resin in the thermoplastic resin bath container, the thermoplastic fiber is impregnated with the reinforcing fiber bundle, and the resin-impregnated fiber bundle is discharged from the outlet nozzle of the thermoplastic resin bath container. A long fiber reinforced thermoplastic resin strand production apparatus that twists the resin-impregnated fiber bundle with a twister and cuts and pellets the long fiber reinforced thermoplastic resin strands obtained by cutting with a cutting machine. A means for twisting a long fiber reinforced thermoplastic resin strand in the same direction as twisting by the twisting machine and maintaining the twist imparted by the twisting machine is provided between the twisting machine and the cutting machine. An apparatus for producing a long fiber reinforced thermoplastic resin strand.   2. The long fiber reinforcement according to claim 1, wherein the twist keeping means is a roller set arranged so as to be opposed to each other with a long fiber reinforced thermoplastic resin strand interposed therebetween, and the roller sets are arranged by shifting the angles of the roller shafts. Equipment for producing thermoplastic resin strands.   The apparatus for producing a long fiber reinforced thermoplastic resin strand according to claim 1 or 2, wherein the means for keeping the twist is provided at a position close to a cutting machine between the twisting machine and the cutting machine. A method for producing a long fiber reinforced thermoplastic resin strand using the long fiber reinforced thermoplastic resin strand production apparatus according to any one of claims 1 to 3, wherein the molten thermoplastic in a thermoplastic resin bath container A reinforcing fiber bundle is introduced into the resin, the thermoplastic fiber is impregnated into the reinforcing fiber bundle, the resin-impregnated fiber bundle is taken out from an outlet nozzle of the thermoplastic resin bath container, and the resin-impregnated fiber bundle is drawn by a twister. Twist the long fiber reinforced thermoplastic resin strand obtained by this, by means of keeping the twist provided between the twister and the cutting machine, twist in the same direction as the twist by the twister, A method for producing a long fiber reinforced thermoplastic resin strand, characterized in that the twist imparted by the twister is maintained, and thereafter the long fiber reinforced thermoplastic resin strand is cut by a cutting machine.

Images