JP5225260B2 - Manufacturing apparatus and manufacturing method of long fiber reinforced thermoplastic resin strand - Google Patents

Description

  The present invention relates to a production apparatus and production method for long fiber reinforced thermoplastic resin strands, and more specifically, a production apparatus and production of long fiber reinforced thermoplastic resin strands that can satisfactorily impregnate a thermoplastic resin into a reinforcing fiber bundle. It is about the method.

Since fiber reinforced thermoplastic resin (FRTP) is light and high in strength, it is often used for exteriors of vehicles and ships. In particular, among fiber reinforced thermoplastic resins, long fiber reinforced thermoplastic resin (LFRTP) containing reinforced fibers having a long fiber length is excellent in impact resistance and rigidity. It has come to be used frequently.
A strand used for molding such a long fiber reinforced thermoplastic resin passes a reinforcing fiber bundle such as glass roving through a molten thermoplastic resin bath, and pulls the reinforcing fiber bundle out of the thermoplastic resin bath. The reinforcing fiber bundle is impregnated with a thermoplastic resin.

  However, when the melt viscosity of the molten thermoplastic resin is high, the resin may not be impregnated even inside the reinforcing fiber bundle in which a plurality of reinforcing fibers are bundled. In such a strand in which the resin is not sufficiently impregnated, the portion where the resin cannot be completely impregnated tends to remain as voids, and the reinforcing fiber is used when melting the strand or the pellet formed by cutting the strand into a predetermined length. May not be sufficiently dispersed, or air bubbles may enter the molded product, which greatly impairs the mechanical properties and appearance of the molded product.

  Therefore, for example, as in Patent Document 1, before the reinforcing fiber bundle is impregnated with a resin having a high melt viscosity, the resin having a low melt viscosity is impregnated with the resin having a low melt viscosity, and the inside of the reinforcing fiber bundle is once sufficiently impregnated with the resin. Then, a technique for manufacturing a strand by coating a resin having a high melt viscosity is proposed.

Japanese Patent No. 3774959

By the way, in Patent Document 1 described above, as a method of coating a plurality of resins having different melt viscosities successively on a reinforcing fiber bundle, for example, a coating method using an extruder and a die, a coating method using a roll or a bar, and the like Is listed.
However, the coating method of Patent Document 1 is merely an example of a method of coating a reinforcing fiber bundle with a resin, and a plurality of resins are used in any procedure using any coating apparatus in an actual site. Does not indicate whether the reinforcing fiber bundle should be continuously coated. In other words, it is difficult to say that it is difficult to coat the reinforcing fiber bundles one after another with a plurality of resins having different melt viscosities at the manufacturing site only by the disclosure of Patent Document 1.

  The present invention has been made in view of the above-mentioned problems, and is a method of actually manufacturing a strand having excellent dispersibility of reinforcing fibers and having no air bubbles by satisfactorily impregnating a thermoplastic resin inside the reinforcing fiber bundle. An object of the present invention is to provide an apparatus and a method for producing a long fiber reinforced thermoplastic resin strand that can be manufactured.

In order to solve the above problems, the apparatus for producing a long fiber reinforced thermoplastic resin strand of the present invention employs the following technical means.
That is, the long fiber reinforced thermoplastic resin strand manufacturing apparatus according to the present invention includes a first resin tank for storing a thermoplastic first resin impregnated in a reinforcing fiber bundle in a molten state, and the first resin tank. Prior to impregnation, a second resin tank that is impregnated in the reinforcing fiber bundle and stores in a molten state a second resin that is set lower in melt viscosity than the first resin, the first resin tank and the second resin tank The resin tank is separated by a partition, and the partition is provided with an outlet for extracting the reinforcing fiber bundle from the second resin tank to the first resin tank, and the outlet of the reinforcing fiber bundle from the second resin tank. The reinforcing fiber bundle impregnated with the second resin is impregnated with the first resin by being drawn out to the first resin tank via the first resin tank.

In this way, when the reinforcing fiber bundle is pulled out from the second resin tank to the first resin tank via the outlet, the reinforcing fiber bundle is rapidly, directly and continuously without contacting the outside air (air). Therefore, the impregnation treatment with the thermoplastic resin is continued. That is, the reinforcing fiber bundle enters the first resin tank before the second resin impregnated in the reinforcing fiber bundle in the second resin tank is solidified.
When the reinforcing fiber bundle passes through the first resin tank, the first resin impregnated in the first resin tank is replaced with the second resin impregnated in the second resin tank, or the second resin tank is impregnated. The resin and the first resin are mixed and laminated, and as a result, the first resin to be impregnated easily penetrates into the reinforcing fiber bundle (up to the core). As described above, in the present invention, the thermoplastic resin is surely and satisfactorily impregnated into the reinforcing fiber bundle, and the dispersibility of the reinforcing fiber is excellent, and the air quality is not included. The apparatus which can manufacture the strand and pellet of this can be provided as what is concrete and realizable.

Moreover, if it is an above-mentioned apparatus structure, while providing the partition with respect to the resin tank which stores the thermoplastic resin to impregnate and partitioning into the 1st resin tank and the 2nd resin tank, for this partition, Since it can be carried out only by providing an outlet for extracting the reinforcing fiber bundle from the second resin tank, there is no concern that the equipment configuration becomes complicated or the manufacturing cost increases.
The outlet is formed with a diameter that allows the reinforcing fiber bundles to be pushed out and bubbles to be pushed out when the reinforcing fiber bundles are drawn from the second resin tank to the first resin tank. Is preferred.

  In this way, when the reinforcing fiber bundle is drawn from the second resin tank to the first resin tank via the outlet, the reinforcing fiber bundle is squeezed and air bubbles are pushed out. Not only the second resin but also the first resin is sufficiently soaked into the inside of the bundle of reinforcing fibers so as to spread. Therefore, a portion that cannot be completely impregnated with the resin does not remain as a void, which is more effective.

In addition, it is preferable that the said partition is comprised with the heat insulation member which suppresses the heat transfer between tanks, and the said 1st resin tank and the 2nd resin tank can hold | maintain resin at a mutually different temperature.
By doing this, the same type of resin can be used as the first resin and the second resin having different melt viscosities by changing the holding temperature of the first resin tank and the holding temperature of the second resin tank, A variety of fiber reinforced thermoplastic resin pellets can be produced using various types of resins.

Further, the method for producing a long fiber reinforced thermoplastic resin strand of the present invention is a method for producing a long fiber reinforced thermoplastic resin strand for producing a long fiber reinforced thermoplastic resin strand using the above-described production apparatus. The first resin tank and the second resin tank are separated using a partition wall, and an outlet through which the reinforcing fiber bundle can pass is formed in the partition wall, and the reinforcing fiber impregnated with the second resin in the second resin tank is formed. The reinforcing fiber bundle impregnated with the second resin is impregnated with the first resin by directly pulling the bundle through the outlet and into the first resin tank.
The most preferable embodiment of the long fiber reinforced thermoplastic resin strand production apparatus of the present invention is a first resin tank for storing a thermoplastic first resin impregnated in a reinforcing fiber bundle in a molten state, and the first resin. Prior to impregnation in the tank, a second resin tank for storing the second resin impregnated in the reinforcing fiber bundle and having a melt viscosity set lower than that of the first resin in a molten state, the first resin tank And the second resin tank are separated by a partition, and the partition is provided with an outlet for extracting the reinforcing fiber bundle from the second resin tank to the first resin tank, and the reinforcing fiber bundle is connected to the second resin tank. The reinforcing resin bundle impregnated with the second resin is impregnated with the first resin by being pulled out from the first resin tank through the outlet, and the outlet is connected to the second resin tank from the second resin tank. 1 When the reinforcing fiber bundle is pulled out into one resin tank It squeezes the fiber bundle is formed by a diameter which allows extrusion bubble, the inside diameter of the draw-out opening is substantially the same as the diameter of the reinforcing fiber bundle.
Moreover, the other preferable form of the manufacturing apparatus of the long fiber reinforced thermoplastic resin strand of this invention is the 1st resin tank which stores the thermoplastic 1st resin impregnated in a reinforced fiber bundle in a molten state, The said 1st Prior to impregnation in the resin tank, a second resin tank for storing the second resin impregnated in the reinforcing fiber bundle and having a melt viscosity set lower than that of the first resin in a molten state. The tank and the second resin tank are separated from each other by a partition wall, and the partition wall is provided with an outlet for extracting the reinforcing fiber bundle from the second resin tank to the first resin tank. The reinforcing resin bundle impregnated with the second resin is impregnated with the first resin by pulling it out from the tank via the outlet port, and the partition moves heat between the tanks. The first resin tank and the second resin tank. Fat bath so as to be capable of retaining the resin at different temperatures.

  If the apparatus and method for producing a long fiber reinforced thermoplastic resin strand according to the present invention are used, a strand that is excellent in dispersibility of the reinforcing fiber and has no air bubbles can be obtained by satisfactorily impregnating the thermoplastic fiber inside the reinforcing fiber bundle. Pellets can actually be produced.

It is the side view which showed typically the manufacturing process of the long fiber reinforced thermoplastic resin strand. It is the A section enlarged view of FIG. It is sectional drawing which showed a mode that molten resin impregnated the reinforced fiber bundle, Comprising: (a) is made to correspond to the BB sectional drawing of FIG. 2, (b) is CC sectional drawing of FIG. Corresponding.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG.1 and FIG.2 has shown typically the manufacturing apparatus 1 of the long fiber reinforced thermoplastic resin strand which concerns on this invention.
The manufacturing apparatus 1 collects 2000 to 3000 long fibers (filaments) such as glass fibers to form a string-like bundle having an outer diameter of about 1 to 2 mm, and polypropylene (PP) inside and outside the string-like bundle. A reinforcing fiber bundle 2 (strand) that is a source of pellets is produced by impregnating and applying a sizing agent such as.

  The manufacturing apparatus 1 includes a stock unit 5 that holds one or more (three in the illustrated example) wound bodies 4 in a state in which the reinforcing fiber bundle 2 before the sizing agent is applied is wound around the bobbin 3. The feed portion 6 for continuously feeding the reinforcing fiber bundle 2 from the stock portion 5 and the resin impregnation in which the reinforcing fiber bundle 2 sent out by the feed portion 6 is impregnated with a thermoplastic molten resin 7 (a sizing agent is applied). Part 8. Furthermore, the manufacturing apparatus 1 includes a post-processing unit 10 that appropriately performs processing on the long fiber reinforced resin strand 9 taken out from the resin-impregnated unit 8.

The post-processing unit 10 includes, for example, a water tank 12 that cools the long fiber reinforced resin strand 9 and promotes curing of the impregnated resin, a twist roller device 13 that twists the long fiber reinforced resin strand 9, and a long fiber. A pelletizer 14 for cutting the reinforced resin strand 9 into a predetermined length is included.
The resin impregnated portion 8 provided in the manufacturing apparatus 1 has a long cylindrical shape facing the transfer direction of the reinforcing fiber bundle 2, and a thermoplastic molten resin 7 is stored in the resin impregnated portion 8. As the reinforcing fiber bundle 2 passes through the cylindrical resin impregnated portion 8, the thermoplastic molten resin 7 is impregnated and applied.

  An inlet hole 27 that can pass through the reinforcing fiber bundle 2 is formed at the inlet of the resin impregnated portion 8 (upstream in the transfer direction of the reinforcing fiber bundle 2). The reinforcing fiber bundle 2 is formed through the inlet hole 27. Enters the resin impregnated portion 8. A die nozzle 11 is provided at the outlet of the resin impregnated portion 8, and the long fiber reinforced resin strand 9 to be taken out is shaped into a predetermined cross-sectional diameter (thickness). A transport roll is provided between the outlet and the inlet in the resin impregnated portion 8, and the reinforcing fiber bundle 2 is transferred from the outlet to the inlet while being wound around the transport roll.

  Furthermore, in the long fiber reinforced thermoplastic resin strand manufacturing apparatus 1 according to the present invention, as shown in an enlarged view in FIG. 2, the resin impregnated portion 8 has a second resin tank 15 and a first resin tank 16. It is said that. With respect to the feeding direction of the reinforcing fiber bundle 2, the second resin tank 15 is disposed on the upstream side, and the first resin tank 16 is disposed on the downstream side. Therefore, the reinforcing fiber bundle 2 passes through the first resin tank 16 after passing through the second resin tank 15.

  The second resin tank 15 stores the second thermoplastic resin 7a in a molten state, and the first resin tank 16 stores the first thermoplastic resin 7b in a molten state. Specifically, the second resin tank 15 is provided with a second resin supply port 25a through which the thermoplastic second resin 7a is supplied, and the second resin supply port 25a has the second resin supply port 25a. A delivery device 26a for delivering the second resin 7a is provided. The first resin tank 16 is provided with a first resin supply port 25b to which a thermoplastic first resin 7b is supplied. The first resin supply port 25b has a first resin 7b connected to the first resin supply port 25b. Is provided.

The second resin 7a in the second resin tank 15 and the first resin 7b in the first resin tank 16 have a melt viscosity of the second resin 7a of the first resin 7b by, for example, different types of resins. The relationship is set to be lower than the melt viscosity.
As a method for making the melt viscosity of the second resin 7a lower than the melt viscosity of the first resin 7b, the second resin 7a has a thermoplastic resin of a kind in which the melt viscosity is lower than that of the resin of the first resin 7b even at the same melting temperature. Resin may be used, and if the temperature in the second resin tank 15 (resin storage temperature) is higher than that in the first resin tank 16, the melt viscosity can be changed even with the same kind of thermoplastic resin. . For example, even if the thermoplastic resin is the same PP, if the second resin 7a has a low molecular weight and the first resin 7b has a high molecular weight, the melt viscosity of the second resin 7a is less than that of the first resin 7b. It can be lower than the melt viscosity.

  Now, in this embodiment, by providing the partition 20 which divides the said resin impregnation 8 into the upstream and the downstream in the inside of the resin impregnation part 8 formed in the cylinder shape, the second resin tank 15 and the first resin are provided. The tank 16 is provided adjacently. That is, the second resin tank 15 and the first resin tank 16 are directly provided without any gap between the two tanks. In addition, it is good also as a structure which connects the two tanks, and makes the wall formed between the connection into the partition 20, or as a structure which partitions the inside of the tank into two tanks by providing the partition 20 in one tank. Also good. In this case, the partition wall 20 that separates the second resin tank 15 and the first resin tank 16 is formed of a heat insulating member that suppresses heat transfer between the two tanks, and the second resin tank 15 and the first resin tank 16 are formed. However, it is preferable that the molten resin can be held at different temperatures.

  The partition wall 20 is provided with an outlet 21 for communicating between the two tanks. Therefore, the reinforcing fiber bundle 2 in the second resin tank 15 can be extracted into the first resin tank 16 through the outlet 21. The position where the outlet 21 is provided is a depth range in which the molten resin (second resin 7a, first resin 7b) is stored in each of the second resin tank 15 and the first resin tank 16. It is necessary to be inside. However, the position of the outlet 21 may be any position of the partition wall 20 as long as the molten resin is always filled in both the second resin tank 15 and the first resin tank 16.

  The outlet 21 allows the reinforcing fiber bundle 2 to pass from the second resin tank 15 to the first resin tank 16 but restricts the movement (intrusion) of the resin between the first resin tank 16 and the second resin tank 15. It is supposed to be large. That is, the inner diameter of the outlet 21 is substantially the same as the diameter of the reinforcing fiber bundle 2. Note that the outlet 21 may be formed with a diameter that allows the reinforcing fiber bundle 2 to be squeezed out to allow bubbles to be pushed out during passage. However, the size of the diameter of the outlet 21 specifically depends on the thickness and tensile strength of the reinforcing fiber bundle 2, the feeding speed of the reinforcing fiber bundle 2, the viscosity of the second resin 7a, and the like. For example, in the case of the reinforcing fiber bundle 2 having an outer diameter of 1 mmφ, the outlet 21 may be formed with a diameter of about 1 mmφ to 3 mmφ.

Hereinafter, the production process of the long fiber reinforced thermoplastic resin strand by the production apparatus 1 of the present invention having such a configuration, in other words, the production method of the long fiber reinforced thermoplastic resin strand of the present invention will be described. To do.
First, the feed unit 6 continuously pulls out the reinforcing fiber bundle 2 from one or a plurality of wound bodies 4 held in the stock unit 5 of the manufacturing apparatus 1, and the reinforcing fiber bundle 2 is drawn into the entrance of the resin impregnated unit 8. It is fed into the resin impregnated portion 8 through the hole 27. In the resin impregnated portion 8, the reinforcing fiber bundle 2 first passes through the second resin tank 15, and then passes through the first resin tank 16 via the outlet 21 of the partition wall 20. Since the reinforcing fiber bundle 2 is continuously fed out by the feed unit 6, the reinforcing fiber bundle 2 that has passed through the second resin tank 15 is continuously impregnated with the second resin 7a and impregnated with the second resin 7a. The reinforcing fiber bundle 2 passes through the outlet 21 and is then impregnated in the first resin 7b of the second resin tank 16.

As a result, the reinforcing fiber bundle 2 is impregnated with the low-viscosity second resin 7a in the second resin tank 15 (see FIG. 3A), and is higher than the second resin 7a in the first resin tank 16. The first resin 7b having a viscosity is impregnated and covers around the fiber bundle (see FIG. 3B).
And it is taken out from the die nozzle 11 provided in the 1st resin tank 16 as the long fiber reinforced resin strand 9 which has predetermined cross-sectional diameter (thickness), and this long fiber reinforced resin strand 9 is the water tank 12 in the post-processing part 10. In this way, it is subjected to cooling, twisting by the twisting roller device 13, cutting by a predetermined length by the pelletizer 14, and the like, and finally it is produced as a long fiber reinforced thermoplastic resin pellet 30.

  In this manufacturing process, when the reinforcing fiber bundle 2 is pulled out from the second resin tank 15 to the first resin tank 16 through the outlet 21 in the resin impregnated portion 8, the reinforcing fiber bundle 2 is exposed to the outside air (air). The thermoplastic resin impregnation process is continued quickly, directly and continuously without contact with the resin. That is, the reinforcing fiber bundle 2 enters the first resin tank 16 before the second resin 7a impregnated in the reinforcing fiber bundle 2 in the second resin tank 15 is solidified.

When the reinforcing fiber bundle 2 passes through the first resin tank 16, the first resin 7 b impregnated in the first resin tank 16 with respect to the second resin 7 a impregnated in the second resin tank 15 is As a result, the second resin 7a and the first resin 7b are mixed and laminated, and as a result, the first resin 7b to be impregnated easily penetrates into the reinforcing fiber bundle 2 (to the core).
Moreover, even if the reinforcing fiber bundle 2 contains air bubbles in the second resin tank 15, the ladder 21 is pulled out by the outlet 21 when the reinforcing fiber bundle 2 is drawn from the second resin tank 15 to the first resin tank 16. Therefore, the bubbles are pushed out of the fiber bundle, and not only the second resin 7a but also the first resin 7b are sufficiently soaked into the reinforcing fiber bundle 2 and spread.

  Therefore, voids due to poor impregnation of the molten resin do not remain in the reinforcing fiber bundle 2, and the thermoplastic fiber (first resin 7b) can be satisfactorily impregnated into the reinforcing fiber bundle 2, and the reinforcement A pellet 30 having excellent dispersibility of the fibers 23 (shown in FIG. 3) and free of bubbles can be produced. Moreover, since both the 2nd resin 7a of the 2nd resin tank 15 and the 1st resin 7b of the 1st resin tank 16 impregnate the reinforcing fiber bundle 2, the final resin content as the pellet 30 can be raised.

In addition, in this resin impregnation part 8, in order to improve the impregnation property and adhesiveness to the reinforcing fiber bundle 2, an additive (for example, maleic acid modified PP etc.) can be added. In this case, the additive only needs to be added to the second resin 7 a of the second resin tank 15. By doing in this way, there exists an advantage which can suppress the total amount of the additive to be used.
The present invention is not limited to the above-described embodiment, and can be appropriately changed according to the embodiment.

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2 Reinforcement fiber bundle 7a 2nd resin 7b 1st resin 15 1st resin tank 16 2nd resin tank 20 Partition 21 Exit 30 Pellets

Claims (3)

A first resin tank for storing the thermoplastic first resin impregnated in the reinforcing fiber bundle in a molten state; and the impregnated reinforcing fiber bundle prior to impregnation in the first resin tank and melted from the first resin. A second resin tank for storing the second resin having a low viscosity in a molten state;
The first resin tank and the second resin tank are separated by a partition, and the partition is provided with an outlet for extracting the reinforcing fiber bundle from the second resin tank to the first resin tank,
The reinforcing fiber bundle is configured to impregnate the first resin into the reinforcing fiber bundle impregnated with the second resin by pulling the reinforcing fiber bundle from the second resin tank to the first resin tank via the outlet .
The outlet is formed with a diameter that allows the reinforcing fiber bundle to be squeezed out to extrude bubbles when the reinforcing fiber bundle is drawn from the second resin tank to the first resin tank,
An apparatus for producing a long fiber reinforced thermoplastic resin strand, wherein an inner diameter of the outlet is substantially the same as a diameter of a reinforcing fiber bundle . A first resin tank for storing the thermoplastic first resin impregnated in the reinforcing fiber bundle in a molten state; and the impregnated reinforcing fiber bundle prior to impregnation in the first resin tank and melted from the first resin. A second resin tank for storing the second resin having a low viscosity in a molten state;
The first resin tank and the second resin tank are separated by a partition, and the partition is provided with an outlet for extracting the reinforcing fiber bundle from the second resin tank to the first resin tank,
The reinforcing fiber bundle is configured to impregnate the first resin into the reinforcing fiber bundle impregnated with the second resin by pulling the reinforcing fiber bundle from the second resin tank to the first resin tank via the outlet .
The partition wall is made of a heat insulating member that suppresses heat transfer between the tanks, and the first resin tank and the second resin tank can hold the resin at different temperatures. Item 2. An apparatus for producing a long fiber reinforced thermoplastic resin strand according to Item 1. Using the manufacturing apparatus according to claim 1 or 2, a method for producing a long fiber-reinforced thermoplastic resin strand to produce a long fiber-reinforced thermoplastic resin strands,
Separating the first resin tank and the second resin tank using a partition, and forming an outlet through which the reinforcing fiber bundle can pass through the partition,
The reinforcing fiber bundle impregnated with the second resin in the second resin tank is directly drawn out to the first resin tank via the outlet, so that the reinforcing fiber bundle impregnated with the second resin is impregnated with the first resin. A process for producing a long fiber reinforced thermoplastic resin strand, characterized by comprising:

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