JP2002187150A - Method for manufacturing moldings of fiber-reinforced thermoplastic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for regenerating and reusing a waste FRTP resin by which it is possible to obtain remoldings with especially an outstanding mechanical physical property such as an impact strength through controlling the cutting of a reinforcing fiber contained in the FRTP resin by forming the remoldings in a single way without passing through an extrusion step, and cut a molding material cost by virtue of the use of the waste FRTP resin and further, make the effective use of the resources. SOLUTION: This method for manufacturing the FRTP resin moldings is characterized by comprising the first step to accumulate small pieces of the fiber-reinforced thermoplastic resin (hereafter called 'FRTP') composed of a thermoplastic resin and the reinforcing fiber, in such a shape approximating to the final moldings, the second step to obtain a molten material by thermally melting the accumulated pieces and the third step to mold the molten material into the final moldings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a fiber-reinforced thermoplastic resin (hereinafter referred to as FRTP) molded article,
In particular, remnants generated when newly forming and processing FRTP, recycled materials of FRTP collected in the market (both are referred to as waste FRTP), or long fiber reinforcement in the form of wire, pellet, or tape A thermoplastic resin (hereinafter referred to as L-FRTP) base material is treated with the FRTP or LF
The present invention relates to a method for obtaining a high-strength reshaped body (a shaped body obtained by reshaping waste FRTP) or a shaped body made of an L-FRTP base material without shortening the fiber length of reinforcing fibers in RTP.

[0002]

2. Description of the Related Art As a method of recycling and using a thermoplastic resin, a molded product recovered from the market or a scrap of a molded product generated during production is pulverized and granulated, and then melted and extruded by an extrusion molding machine. It is known to obtain a molding material by kneading. For example, JP-A-6-270342 discloses that a thermoplastic resin, which is waste material, is pulverized and granulated, and a molded board is obtained by extrusion molding.

On the other hand, in the case of FRTP reinforced with natural fibers, organic fibers, inorganic fibers, etc., the moldings recovered from the market or the scraps of the moldings generated during production are crushed and granulated, and extruded by an extrusion molding machine. It is known that a molding material is obtained by melting and kneading the material into a sheet to obtain a molding material. The sheet molded from the recycled material is heated again to a temperature higher than the softening point of the thermoplastic resin, and stamped using a press or the like. Methods for molding are known.

[0004]

However, in the above-mentioned known method, the waste FRTP used as a molding material is pulverized, granulated, and kneaded by an extruder.
There was a problem that natural fibers, organic fibers, inorganic fibers, and the like as reinforcing materials in the TP were broken, and a sufficient reinforcing effect could not be obtained in the reshaped product. Further, passing through the extrusion step is disadvantageous in terms of facilities, space, investment and cost, and a simpler method of recycling waste FRTP is desired.

[0005] The present invention is particularly useful as a method for recycling waste FRTP, in which a reshaped body is formed by a simpler method without an extrusion step, whereby cutting of reinforcing fibers in the waste FRTP is suppressed. It is possible to obtain a re-formed body with excellent mechanical properties such as impact strength, and because waste FRTP is used, the cost of the obtained molding material can be reduced and resources can be used effectively. The purpose is to provide a method for recycling waste FRTP. Further, the present invention provides an L-FRT in the form of a wire, a pellet or a tape.
By using a P base material to form a molded body more simply and without an extrusion step, cutting of the reinforcing fibers in the L-FRTP base material is suppressed, and particularly, mechanical properties such as impact strength. It is an object of the present invention to provide a method for producing an L-FRTP molded article capable of obtaining a molded article excellent in quality.

[0006]

In order to achieve the above object, the present invention relates to an FR comprising a thermoplastic resin and a reinforcing fiber.
A first step of accumulating small pieces of TP into a shape close to the shape of the final molded body, a second step of heating and melting the aggregate to obtain a melt, and a second step of molding the melt into the shape of the final molded body. There is provided a method for producing an FRTP molded body, which comprises three steps. In the present invention, "accumulation" means to collect small pieces into a desired shape by scattering and / or depositing small pieces.

[0007]

Next, the present invention will be described in more detail with reference to preferred embodiments. (1) Embodiment relating to recycling of waste FRTP The raw material for forming the FRTP molded product obtained in the present invention is FRTP composed of a thermoplastic resin and a reinforcing fiber, and preferably has a predetermined shape when the FRTP is molded. Unnecessary fragments generated in the manufacturing process to obtain the product, and waste FRTP collected from the market. It is preferable that such waste FRTP is recovered from, for example, bumpers for vehicles, particularly automobiles, bumper reinforces, ceiling panels, interior parts of trunk rooms, and the like.

In the present invention, FRT which is a raw material for molding is used.
As P (especially waste FRTP), it is preferable to use one kind prepared under the same conditions, but it is also possible to use waste FRTPs prepared under different conditions. These waste FRTPs are thermoplastic resin moldings reinforced with reinforcing fibers such as natural fibers, organic fibers, and inorganic fibers,
The average fiber length of the reinforcing fibers in the waste FRTP is preferably 5 mm or more. When the average fiber length is less than 5 mm, the fibers are further shortened by pulverization of waste FRTP, so that the average fiber length of the fibers in the obtained FRTP reshaped product is shortened, and a reshaped product having sufficient mechanical strength is obtained. I can't get it.

Here, the average fiber length refers to the waste F used.
Resin is burned off from five samples obtained by arbitrarily cutting out RTP, and the fiber length of 200 fibers arbitrarily selected from each sample is measured to determine the average fiber length of one sample. You can ask. When a plurality of types of waste FRTPs are used, the average fiber length of each different waste FRTP is determined, and the average fiber length is determined from the mixture ratio.

In the preliminary step of pulverizing the waste FRTP to obtain small pieces in the present invention, the form of the small pieces is not particularly limited, and the pulverized form may be any of square, round, spherical, rod, and the like. . In particular, the waste FRT is so arranged that the average length of the longest part in the small piece is 3 to 100 mm.
P is preferably pulverized, and more preferably, the average length of the longest part in the small piece is 4 to 50 mm. When the average length of the longest portion is less than 3 mm, the reinforcing effect of the fiber in the FRTP re-formed body is inferior, which is not preferable. When the average length of the longest portion exceeds 100 mm, it becomes difficult to handle small pieces of waste FRTP. Not preferred.

The method of pulverization for obtaining the small pieces is not particularly limited, and an apparatus for pulverizing a general plastic molded article or an apparatus having a cutter or a slitter can be used. At this time, it is more preferable to use an apparatus that does not promote the breakage of the fiber of the obtained small pieces, because the aggregate of the small pieces easily becomes bulky and the process is simplified.

[0012] The present invention also provides a method for manufacturing a waste FRTP, wherein the waste FRTP has a wire shape, a pellet shape or a tape shape.
-It is preferable to further mix a FRTP base material (new material). Here, L-FRTP is obtained by coating or impregnating a continuous reinforcing fiber with a thermoplastic resin, and can be used by continuously or cutting it. This increases the bulk of the small piece stack described below,
A heat source such as a high-temperature gas, which will be described later, is brought into contact with the aggregate, and the aggregate can be easily melted. Particularly, as an L-FRTP substrate, a wire having an average diameter of 0.1 to 1.5 mm, a reinforcing fiber content of 15 to 85% by mass, and an average length of 5 to 150 mm It is preferable to use This is particularly preferable because the aggregates tend to be bulky, the accumulated small pieces easily contact with a heat source such as a high-temperature gas, and the mechanical strength of the obtained reshaped body is improved.

[0013] In the practice of the present invention, the integrated product of the small pieces, or the bulk density of the mixed integrated products of the said and the small piece L-FRTP substrate and [rho _1, wherein the same pieces or small-piece, L
When the true density of -FRTP substrate was ρ _0, 1/10
It is preferable that 0 ≦ ρ ₁ / ρ ₀ ≦ 1/2. This makes it possible to have more voids in the aggregate of the same small pieces, and for example, a high-temperature gas as a heat source can easily contact the small pieces in the aggregate and melt the aggregate.

The small piece or the small piece and L-FRTP
Bulk density ρ when integrated with substrate ₁Is the capacity is measured
Containers such as measuring cylinders, beakers, etc.
Therefore, it is more than the length of the small pieces and the L-FRTP base material.
Use a small piece and L-FRT
To measure by collecting P base materials as randomly as possible
Can be. On the other hand, the true density of the small pieces and the L-FRTP substrate
ρ₀Is obtained by determining the theoretical density of the substrate used.
Can be Here, for example, a small piece and L-FRTP
In the case of two types of mixtures that are mixed with the substrate
Is the true density ρ by the following equation₀Is determined.

(Equation 1)

[0015] The waste FRTP small pieces may be a L-FRTP base material in the form of a wire, a pellet or a tape, or a sheet in which the base material is arranged randomly or in the same direction.
It is preferable to accumulate so as to be arranged on at least part of the surface or layer of the obtained FRTP reshaped product. Thereby, the surface strength of the obtained molded body is improved, so that it is preferably adopted. Particularly as the L-FRTP base material,
By using a wire-shaped material having the following characteristics, heating and melting are facilitated, and formability is improved. In addition, by arranging a small amount of the L-FRTP base material on the surface or layer of the obtained reshaped body, the surface strength is easily improved, and the mechanical strength of the whole reshaped body is further improved. It is particularly preferable because the weight of the molded body can be reduced. In this case, when a surface material is further arranged on a re-formed body to be described later, the L-FRTP base material is arranged between the re-formed body and the surface material.

The thermoplastic resin used for the L-FRTP substrate is not particularly limited, and a normal thermoplastic resin can be used. However, the same or the same resin as the resin used for the waste FRTP is used. Preferably, it is used.
The present invention provides the waste FRT, in addition to the waste FRTP pieces.
It is possible to contain a thermoplastic resin, a reinforcing fiber, a filler, a lightweight aggregate, or the like, which is the same as or different from P, and it is possible to appropriately mix the above materials depending on the intended use of the reshaped product. In this case, an additive such as talc may be added to the thermoplastic resin.

It is preferable that the small pieces are integrated so as to provide a gap for sufficiently bringing the small pieces into contact with a heat source to be described later to melt the small pieces. The heat source is not particularly limited, but a surface on which the small pieces of FRTP are to be accumulated (accumulation surface) and / or the upper surface of the aggregate, and if necessary, a heating plate for the mold, which is used as a heat source, or a high-temperature gas (hot air Is also preferably used. When the above-mentioned heating plate is used, the temperature is preferably set to a temperature equal to or higher than the melting point of the thermoplastic resin using the heating plate. For example, in the case of polypropylene, the temperature is preferably 150 ° C. or higher,
C. is more preferable. Hereinafter, an example using a high-temperature gas will be described. The method for accumulating the small pieces so that the high-temperature gas can be contacted, by using the small pieces described above, a bulky aggregate can be easily obtained by accumulating according to a normal method. It is preferable to uniformly accumulate a fixed amount at a time so as to accumulate three-dimensionally in the non-direction as much as possible. In this case, although it depends on the obtained re-formed body, in order to sufficiently obtain the bulky aggregate, it is necessary to accumulate the small pieces by using a preforming mold in which the small pieces can maintain their bulk. preferable.

At this time, assuming that the bulk density when the small pieces of waste FRTP are accumulated is ρ ₁ and the true density of the small pieces is ρ ₀ , 1/100 ≦ ρ ₁ / ρ ₀ ≦ 1/2 It is preferable to accumulate so that it is possible to have more voids in the aggregate of the same small piece, and it is possible for the hot gas to easily contact the aggregate and melt the aggregate. Become.

In the present invention, as a first step, the small pieces are
It is characterized in that it is integrated into a shape that is the same as or similar to the shape of the target final molded body. The same or similar shape as the shape of the final molded body can be usually observed visually or the like, but is preferably represented by a parting line of a molding die used for the molded body. It is preferable to integrate in the same or similar shape as the line. Further, in the present invention, it is preferable that the projected area of the aggregate in which the small pieces are accumulated or the area of the accumulated portion when the small pieces are accumulated is 50% or more of the projected area of the final molded body. FIG. 1 shows an FRT having a bottom plate 12 having two rectangular holes 11 and a curved rib 13 on one side thereof.
1 shows an example of a P compact 10. When molding a molded body having such a shape by the method of the present invention, the small pieces are accumulated in a mold 20 as shown in FIG.

The inner shape of the mold 20 shown in FIG. 2 is similar to the outer shape of the molded body 10 shown in FIG. That is, since the mold 20 includes three side plates 21, 22 and 23 and one side curved plate 24, the form 20 has rectangular parallelepiped cores 25 and 26 (although these cores are not indispensable) at substantially the center. A fine mesh 27 is provided on the bottom surface (this mesh is not essential). It is not essential that the cores 25 and 26 are fixed to the mesh 27, and the cores 25 and 26 may be simply placed on the mesh 27 and easily replaced with another core (not shown).

In the present invention, as shown in FIG. 3, the small pieces are dispersed and accumulated in the preforming mold 20 as described above. After the accumulation of the small pieces is completed, the melting step, which is the second step, may be performed as it is (FIG. 3), or the second step may be performed at another location by moving the aggregate. Good (see FIG. 4). In FIG. 3, a breathable web 34 moving in the direction of arrow X is arranged on a punching metal 33 having a large number of holes 32, 32,. The mold 20 is placed thereon, and the small pieces 35 are accumulated in the mold 20 in an appropriate amount. When the air-permeable web or the like is used below the mold 20, the mesh 27 need not be provided.
In this state, the hot air 31 at a temperature at which the aggregate softens and melts is passed through the bulky aggregate 35 from below, and the aggregate 35 is softened and melted, and its shape is similar to that of the final molded body 10 shown in FIG. Shape. The aggregate 35 thus softened and melted.
Is taken out of the mold frame 20 and transferred to the next third step, the final molding step (see FIG. 4).

In the final molding step, the molten preform 35 is inserted into a press molding die capable of forming a cavity corresponding to the outer shape of the molded body shown in FIG.
The molded body shown in FIG. 1 is obtained by press molding. The mold 20 is not provided with a shape corresponding to the rib 13 of the molded body shown in FIG. 1, but the rib 13 is easily formed by the preform flowing in the mold during press molding. You.

After the molten material (preformed material) 35 is taken out, small pieces may be accumulated in the same mold as described above, or the same or unshown same or not provided provided downstream of the web 34. It is also possible to move a different mold together with the web 34 to a predetermined position, accumulate the small pieces in the other mold, perform melting and preforming in the same manner as described above, and similarly move to the final molding step.

Although the above description has been made with reference to the mold shown in FIG. 2, the shape of the mold is not limited to the shape shown in the figure, but is naturally determined as appropriate according to the shape of the final molded product. It is. Further, in FIG. 3, a punched metal through which hot air is passed is shown, but hot air may be passed from above the stack 35 to below. Furthermore, in order to make the passage of hot air good, it is possible to arrange holes such as punching metal only in the accumulation portion.

At the time of the preforming, as shown in FIG. 3 or FIG. 4, it is preferable that the heating atmosphere of the integrated material is sealed to minimize the loss of heat energy. In the example shown in FIG. 3, the heating atmosphere is formed by the cylindrical body 36. However, when a cylindrical body is used as the heating atmosphere, various shapes such as a circular section, a square section, and a multi-sided irregular shape may be employed. it can. The size of the tubular body is not particularly limited, but preferably has an inner diameter equal to or larger than the size of the mold 20 (in the case of a square, the length of the inner short side). Also,
The tubular body needs to have a structure capable of contacting the high-temperature gas with the aggregate, and preferably has an inlet 37 and an exhaust port 38 for bringing the high-temperature gas into contact with the aggregate.

In this case, the arrangement of the cylindrical body is not particularly limited, and it is preferable to adopt a structure in which an inlet and an exhaust port are provided above and below the cylindrical body in order to contact the high-temperature gas. For example, in addition to the above-described punched metal at the lower portion of the cylindrical body, a mesh of metal or the like may be used, and a high-temperature gas may be blown from there, or conversely, a high-temperature gas may be blown from the upper portion of the cylindrical body. The air may be exhausted through a mesh such as a punching metal or metal at the lower part of the body. Further, a slit or the like may be provided in the lower part of the cylindrical body instead of the punching metal or the like.

In the present invention, on the mesh 27 of the mold, when the mesh 27 is not used, a woven or non-woven fabric made of an organic fiber, an inorganic fiber or a natural fiber is passed through a punched metal or a wire mesh. It is preferable that small pieces are accumulated on the surface material having the property, and that the woven or nonwoven fabric is arranged on the surface after the small pieces are accumulated. This makes it possible to easily handle the aggregate that has been softened and melted by heating, thereby improving the surface properties and providing design of the obtained reshaped product. At this time, it is preferable that the nonwoven fabric or woven fabric used is made of a material having a higher softening point than the thermoplastic resin having the lowest softening point among the thermoplastic resins constituting the small pieces.

A preferred example of preparing a pre-formed body in the above is a) a method in which small pieces are accumulated in a mold using a mold as described above, and then a high-temperature gas is blown into the aggregate by hot air. However, in addition, b) after accumulating the small pieces in the mold, introducing the aggregate together with the mold, preferably in an atmosphere in which the high-temperature gas stays, and distributing the high-temperature gas into the aggregate. (B) a method of introducing small pieces accumulated in a mold into a high-temperature gas atmosphere, causing the high-temperature gas to substantially pass through and contact the aggregate to melt the aggregate, and (d) a top surface of the aggregate. There is a method in which a heating plate is provided on the lower surface or the side surface and the aggregate is heated and melted.

The above-mentioned method can be appropriately selected depending on the desired reshaped product. However, when the reshaped product is a discontinuous material and can be directly formed, the batch method a) is preferably used. For example, for the formation of a continuous product such as a sheet shape or a long shape, the above-mentioned b), c) and d) are used.
Is preferably employed.

The wind speed in the method (a) or (b), in which a high-temperature gas is blown, is not particularly limited because it depends on the shape of the cylindrical body or the like forming the heating atmosphere to be used and the shape and size of the aggregate. It is preferable to increase the wind speed within a range in which the air does not blow off, and 0.3 to 10 m / s, and more preferably 0.5 to 10 m / s.
-5 m / s is more preferable. By bringing the high-temperature gas into contact with the aggregate in this way, the resin in the aggregate is melted,
A method of obtaining a preformed melt by reducing the bulk by its own weight of the aggregate or by reducing the bulk by pressing from the outside is suitably employed.

However, the preform obtained by its own weight of the aggregate is bulky and has a large surface area, so that the preform is easy to handle when it is transferred to a molding machine. In order to make it difficult to be cooled, it is preferable to prepare a preform pressed at a low pressure. The pressing force at this time is preferably set to 0.1~1.5kgf / cm ^2. In addition, since the entire preform is heated before pressing and the preform is flexible, there is no breakage or breakage of the reinforcing fibers in the small pieces constituting the preform even when pressed. A relatively dense preform can be obtained.
As a result, the mechanical strength of the finally obtained reshaped body does not decrease, and the surface appearance can be improved.

When the pressing is performed, it is preferable to close the introduction port and the exhaust port and to shut off the high-temperature gas in order to avoid excessive heating. In addition, it is preferable to use a plunger or the like for the pressing, and it is more preferable to use a heating plunger having a pressing surface having a shape similar to the surface shape of the preformed product so as not to lower the temperature of the preformed product. The preform pressed by the plunger in this manner may be in a dense state without any voids, or may be pressed to an extent that it can be handled, and may have some voids.

Further, the temperature of the high-temperature gas varies depending on the thermoplastic resin contained in the small pieces, but is higher than the softening point of the thermoplastic resin having the lowest softening point among the types of thermoplastic resins in the small pieces used. And a temperature lower than the decomposition temperature. If the temperature of the high-temperature gas is lower than the softening point of the resin, the resin cannot be melted, which is not preferable. On the other hand, if the temperature of the high-temperature gas is higher than the decomposition temperature, the resin deteriorates, which is not preferable.

For heating the small pieces accumulated in the mold, in addition to the high-temperature gas (hot air), heating from the upper and lower surfaces or the lower surface by a hot plate press, heating by far infrared rays, or accumulation in a high-temperature bath. Although it is possible to obtain a target preform in any method, such as heating by arranging objects, heating by hot air is preferable in terms of production efficiency and production cost, and the hot air is a heater and a blower. It can be obtained by a combined device or the like.

The high-temperature gas preferably used in the present invention is not particularly limited, and includes air, inert gas, and reducing gas. Of these, air and / or inert gas are preferably used. Waste FR used
If the thermoplastic resin in the TP does not significantly affect the strength and appearance of the obtained remolded body due to oxidative deterioration due to heat or the like, the use of air is advantageous in terms of cost, and in the case where the influence is exerted. It is preferable to use an inert gas or a reducing gas alone or as a mixture. The inert gas mentioned here includes a gas of a rare gas element or a gas such as N ₂ or CO ₂ which is chemically inert. Further, a reducing gas may be added to these gases to prevent oxidation.

Further, in the method of the present invention, in order to prepare a preform with almost no shearing force applied to the aggregate, the residual average fiber length of the reinforcing fibers in the obtained preform is determined by the fiber length in the small piece. Is maintained at the average length. That is, the residual average fiber length of the reinforcing fibers in the preform is preferably at least 95%, more preferably at least 97%, of the average fiber length in the small pieces. This prevents breakage of the reinforcing fibers in the preformed product, suppresses a decrease in fluidity due to bulky expansion of the fibers when shearing force is applied, or suppresses the occurrence of resin deterioration due to entrainment of air, resulting in remolding. It will not reduce the mechanical strength of the body.

Next, the method of molding the preform in the third step is not particularly limited, but a preferred molding method is press molding. For example, in the method (a) of blowing a high-temperature gas into a preform using the above-described mold, the preform formed as described above is taken out, and is moved by, for example, a hand, a conveyor, or a robot. It is preferable to supply to a mold. These supply methods can be appropriately selected in consideration of the fluidity of the thermoplastic resin in the preform, the solidification time, and the surface appearance of the reshaped product.

The conditions for press-molding the preform supplied to the molding die are appropriately selected in consideration of the fluidity of the thermoplastic resin in the preform used, the solidification time, and the surface appearance of the reshaped product. Although good, generally, press molding conditions such as stamping molding usually used for a thermoplastic resin or the like can be employed. That is, it is preferable that the mold is heated by a heater or the like, and the temperature is lower than the softening point of the thermoplastic resin in the pre-molded product, as long as it is in accordance with the mold temperature when molding a normal thermoplastic resin. Good. Further, the pressing pressure is preferably from 40 to 300 kgf / cm ² .

According to the present invention, it is possible to obtain a final re-formed body by the third step. However, the pre-formed material (hereinafter, referred to as a sheet-like material) once formed into a desired shape by the third step. Molding material).
In this case, the molding material such as a sheet-like material is cut to a predetermined size as necessary, and heated to a temperature equal to or higher than the softening point of the thermoplastic resin in the small pieces in a far-infrared heating furnace or a hot-air circulation type high-temperature tank, Furthermore, by transferring this into a mold having a predetermined shape adjusted to a temperature control or room temperature state below the softening point of the thermoplastic resin and pressing it with a press, the thermoplastic resin in the softened molten state is The solidification is promoted, and a reshaped body having a predetermined shape can be obtained.

[0040] In the remolded article thus obtained, the average fiber length of the reinforcing fibers remaining in the remolded article is maintained at the average fiber length in the state of the small pieces. That is, the remaining average fiber length of the reinforcing fibers of the reshaped body is 95% of the average fiber length of the small pieces.
% Or more, whereby the mechanical strength of the obtained reshaped product does not decrease and a reshaped product with particularly good impact strength can be obtained.

(2) An embodiment in which the small pieces of FRTP are L-FRTP base material in the form of wire, pellet or tape. In this embodiment, instead of the waste FRTP, the L-
Except for using the FRTP substrate alone, the waste FRTP
Is substantially the same as the embodiment using. In this case (in the case of using L-FRTP alone), it is preferable to use the wire material. As a result, the aggregate can be made bulky, and the plasticity by passing hot air is excellent, and the uniformity of the reinforcing fibers in the obtained molded body is improved, and the mechanical strength is improved. The body is obtained. In addition,
An example of the method of the present invention is shown schematically in FIG. 4 (first embodiment) and FIG. 5 (second embodiment) to facilitate understanding of the present invention.

[0042]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Example 1 As a waste FRTP, a scrap of an automobile ceiling plate made of polypropylene as a thermoplastic resin, an average fiber length of 50 mm, and a glass content of 40% by mass was used.
It was pulverized to about m square to obtain a small piece (hereinafter referred to as A-1 material) having an average length of the longest part of 7 mm. Ρ ₁ / ρ ₀ when the small pieces were deposited was 0.1. At this time, a nonwoven fabric of PET and a resin film for ventilation prevention were adhered to the surface material of the automobile ceiling panel as a skin material as a surface material, and these were pulverized without being removed. Next, as shown in FIG. 3, a predetermined amount of this small piece was uniformly dispersed in a mold 20 placed on a punching metal 32 and a web (wire mesh) 34 to form a deposit. Further, a wire mesh was placed on the sediment so that the sediment was not scattered. At this time, the wire mesh was placed without applying pressure in order not to reduce the bulk density of the deposit.

Next, hot air at 200 ° C. heated by air was passed through the entire surface of the deposit uniformly distributed in the mold 20 from below the punching metal for 30 seconds. The flow rate of the hot air at this time was 2 m / sec. The hot air passed through the voids of the sediment and brought into contact with the small pieces to soften and melt the entire sediment to obtain a preform 35 as shown in FIG. The preform was placed in a press mold having a cavity corresponding to the outer surface of the formed body of FIG. 1 set at a surface temperature of 40 ° C., and pressed at 60 kgf / cm ^{2 with} a hydraulic press at a pressure of 60 kgf / cm ^2.
Pressed for 0 seconds, width 450mm, length 900mm, bottom plate thickness 3mm, two rectangular holes (100mm x 200m
m) and a molded body having a rib height of 100 mm as shown in FIG. 1 was prepared. A test piece was cut out from a flat portion on the bottom surface of the molded body, and various physical properties were measured. Table 1 shows the results.
The physical properties were calculated from the average value of TD / MD of the test piece (the same applies to the following examples).

Example 2 A glass fiber content of 40% by mass comprising a polypropylene resin and glass fibers, an average diameter of a cross section of 1 mm and a length of 20 mm
A wire having a substantially circular cross-sectional shape was prepared as B-1 material. Next, the mixture was obtained by mixing the mass ratio of A-1 material (same as in Example 1): B-1 material = 50: 50. Incidentally, ρ ₁ / ρ ₀ when the mixture was sprayed was 0.07. A molded article was prepared in the same manner as in Example 1 in a state in which both of the mixture were uniformly dispersed, and a test piece was cut out from a flat portion on the bottom surface of the molded article, and various physical properties were measured. Table 1 shows the results.

Example 3 A glass fiber content of 60% by mass consisting of a polypropylene resin and glass fibers, an average cross-sectional diameter of 0.7 mm and a length of 20 mm
A wire having a substantially circular cross section having a cross section of mm was prepared as a B-2 material. Next, the mass ratio was changed to A-1 material (Example 1).
Same as above): B-2 material = 50: 50 to obtain a mixture. Incidentally, ρ ₁ / ρ ₀ when the mixture was sprayed was 0.08. A molded article was prepared in the same process as in Example 1 in a state where both of the mixture were uniformly dispersed, and a test piece was cut out from a flat portion on the bottom surface of the molded article, and various physical properties were measured. Table 1 shows the results.

Example 4 A scrap of an automobile bumper made of polypropylene and talc was pulverized by a pulverizer into a piece of about 5 mm square to obtain a small piece having a longest portion having an average length of 7 mm (hereinafter referred to as A-2 material). Next, the mass ratio was changed to A-1 material (same as in Example 1): A-2 material = 7.
Mixing at 0:30 gave a mixture. Note that ρ ₁ / ρ ₀ when the mixture was sprayed was 0.2. A molded article was prepared in the same process as in Example 1 in a state where both of the mixture were uniformly dispersed, and a test piece was cut out from a flat portion on the bottom surface of the molded article, and various physical properties were measured. Table 1 shows the results.

Example 5 The glass content of polypropylene and glass fiber was 7
A wire having a cross section of approximately 5% by mass, an average diameter of the cross section of 0.5 mm, and a length of 30 mm and having a substantially circular shape was prepared as a B-3 material. Next, the mass ratio was changed to A-1 material (the same as in Example 1): B
-3 material = 90: 10, 5% by mass of B-3 material was evenly scattered on the surface, 90% by mass of A-1 material was scattered uniformly, and 5% of the remaining B-3 material was further scattered thereon. A molded body was prepared in the same process as in Example 1 with the mass% dispersed uniformly,
A test piece was cut out from a flat portion on the bottom surface of the molded body, and various physical properties were measured. Table 1 shows the results.

Example 6 A mixture was prepared by mixing the above A-1 material and the same B-3 material as used in Example 5 and mixing them at a mass ratio of A-1 material: B-3 material = 90: 10. did. On the other hand, a non-woven fabric made of 20 g / m ² of polyethylene terephthalate was placed on the wire mesh, and then the B-3 material was evenly sprayed thereon, and the mixture was evenly sprayed thereon. Then
The B-3 material was evenly sprayed on the mixture so that the mass ratio of A-1 and B-3 in the whole was 80:20. Further, a molded article was formed in the same process as in Example 1 with the nonwoven fabric disposed thereon. A test piece was cut out from a flat portion on the bottom surface of the molded body, and various physical properties were measured. Table 1 shows the results.

Examples 7 to 9 In Example 1, except that only the material B-1 (Example 7), the material B-2 (Example 8) and the material B-3 (Example 9) were used. A molded article was obtained in the same manner as in Example 1. A test piece was cut out from a flat portion on the bottom surface of these molded bodies, and various physical properties were measured. Table 1 shows the results.

Comparative Example 1 The same small piece A-1 as in Example 1 was melt-kneaded with an extruder and granulated to obtain a C material. Next, the granulated product was mixed with a commercially available virgin polypropylene resin pellet (D material) at a mass ratio of C material: D material = 15: 85, and extruded in a sheet with an extruder and a slit die. 0
A sheet having a thickness of mm was prepared. The sheet was reheated by far infrared rays to obtain a softened melt. Further, a molded article was prepared from the melt in the same process as in Example 1, and a test piece was cut out from a flat portion on the bottom surface of the molded article, and various physical properties were measured. Table 1 shows the results.

Comparative Example 2 The same granulated product (material C) as in Comparative Example 1 was mixed with a commercially available virgin polypropylene resin pellet (material D) in a mass ratio of C.
The mixture was mixed at a ratio of 70:30 for the material: D material, and extruded with an extruder and a slit die to form a 2.0 mm thick sheet. The sheet was reheated by far infrared rays to obtain a softened melt. Further, a molded article was prepared from the melt in the same process as in Example 1, and a test piece was cut out from a flat portion on the bottom surface of the molded article, and various physical properties were measured. Table 1 shows the results. In Table 1, the low-temperature falling ball impact (m
m) is a free fall height (mm) when a 525 g steel ball was dropped in a state where the test piece reached -40 ° C. in an atmosphere of -40 ° C. and the test piece was broken. It is.

[0052]

[0053]

As shown in Examples 1 to 9, by obtaining a molded article by the method of the present invention, the fiber length of the small pieces of waste FRTP or the fiber length of the L-FRTP base material is not impaired. A reshaped body (formed body) is obtained. As a result, the reshaped body (formed body) maintains particularly high impact resistance. In addition, since the reshaped product (formed product) can be obtained while maintaining the value inherent in the small piece or the value of the L-FRTP base material also in the glass content, the bending of the reformed product (formed product) The strength and flexural modulus were also improved as compared with Comparative Examples 1 and 2.

In Comparative Examples 1 and 2, since the extruder melts and kneads, the destruction of the fibers in the small pieces is promoted, and the tendency is remarkable by increasing the proportion of the small pieces as in Comparative Example 2; Although the proportion of reinforcing fibers in the body increased, no improvement in impact strength was observed. Further, as in Examples 2, 3, 5 and 6, the wire-shaped L-FR
By mixing the TP base material into small pieces or arranging them on the surface, the physical properties of the reshaped product are significantly improved.

Further, in the present invention, since the aggregate is softened and melted in the mold, the flow distance of the melt during the final molding can be shortened, and therefore, it is easy to produce a thin molded article. Further, the pressure used at the time of final molding can be reduced. Further, since the fibers are not localized in the molded article and the dispersion is uniform, a molded article having a uniform strength can be obtained. Further, even if the obtained final molded body has a complicated shape such as having holes, finishing after molding is easy, and as a result, the yield of the material is improved.

Further, as compared with the conventional method of manufacturing a molded article from a sheet, cutting of the sheet is not required, and no scrap is generated. In addition, there is no need to prepare sheets of various sizes, and storage problems are reduced. In addition, it is not necessary to insert a plurality of sheets into the mold at the time of final molding, so that the preformed body can be easily inserted into the mold. Further, when waste FRTP and L-FRTP base material are used in combination, many L-FRTs are required where strength is required.
Depositing a P base material has various advantages, such as preventing excess quality.

[0058]

As described above, in particular, as a method of recycling waste FRTP, small pieces of waste FRTP or LF
By accumulating the RTP base material in a mold with a gap and heating and melting it with a high-temperature gas or the like, it is a simple process and impairs the fiber length of small pieces or fibers in the L-FRTP base material. Thus, a reshaped product (formed product) can be obtained. Furthermore, L-FR is used as a reinforcing material by this method.
The TP base material can be easily mixed, and the mixing can easily improve various physical properties of the reshaped body. It is noteworthy that this process does not go through the extrusion process conventionally used for molding recycled materials, and it is possible to improve the physical properties of the remolded product while obtaining a reshaped product from waste FRTP at low cost. Is meant.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a shape of an example of a molded article obtained by a method of the present invention.

FIG. 2 is a diagram schematically illustrating a mold used in the method of the present invention.

FIG. 3 is a diagram schematically illustrating an example of the method of the present invention.

FIG. 4 is a diagram schematically illustrating an embodiment of the method of the present invention.

FIG. 5 schematically illustrates another embodiment of the method of the present invention.

[Description of Signs] 10: Molded body 11: Hole 12: Bottom plate 13: Rib 20: Formwork 21, 22, 23: Side plate 24: Curved side plate 25, 26: Core 27: Mesh 31: Hot air 32: Hole 33: Punching metal 34: Web 35: Stack 36: Tubular body 37: Hot air inlet 38: Hot air outlet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsuaki Ohno 3-6-3 Kanda Kajicho, Chiyoda-ku, Tokyo Asahi Fiberglass Co., Ltd. (72) Inventor Yuji Yoji 3-6-6 Kanda Kajicho, Chiyoda-ku, Tokyo 3. Asahi Fiberglass Co., Ltd. (72) Inventor Akira Sunohara 10-1 Amanuma, Hiratsuka-shi, Kanagawa Nissan Shatai Co., Ltd. F-term in the formula company (reference) 4F204 AA11 AA24 AA50 AD04 AD16 FA01 FB01 FE17 FF01 FF05 FN15

Claims (16)

[Claims] 1. A first step of accumulating small pieces of a fiber-reinforced thermoplastic resin (hereinafter, referred to as FRTP) comprising a thermoplastic resin and reinforcing fibers into a shape close to the shape of a final molded body, and heating and melting the aggregate. A method for producing a FRTP molded body, comprising: a second step of obtaining a melt and a third step of molding the melt into a shape of a final molded body. 2. The method according to claim 1, wherein the projected area (from above or below) of the aggregate of the small pieces is 50% or more of the projected area of the final molded body. 3. The method according to claim 1, wherein the second step is a step of bringing a high-temperature gas into contact with the aggregate and heating and melting the same.
3. The method for producing an FRTP molded article according to 1.). 4. The method according to claim 1, wherein, in the second step, the aggregate is heated and melted using a heating plate on a surface on which the small pieces of FRTP are accumulated and / or an upper surface of the aggregate to obtain a melt. Production method of FRTP molded article 5. The method according to claim 1, wherein an average fiber length of the reinforcing fibers in the FRTP is 5 mm or more. 6. The method according to claim 1, wherein the small pieces of FRTP are unnecessary pieces generated when molding the FRTP into a predetermined shape or crushed small pieces of waste FRTP collected from the market. 13. The method for producing a FRTP molded article according to the above item. 7. The FR according to claim 6, wherein the FRTP is pulverized so that the longest portion of the small piece is 3 to 100 mm.
A method for producing a TP molded body. 8. A long fiber reinforced thermoplastic resin (hereinafter referred to as L-FRTP) base material in the form of a wire, a pellet or a tape is mixed into the small pieces of the FRTP.
6. The method for producing an FRTP molded article according to any one of items 1 to 5. 9. An L-FRTP base material in the form of a wire, a pellet or a tape, or a sheet in which the base material is arranged randomly or in the same direction as the small piece of the FRTP,
The method for producing a FRTP molded body according to any one of claims 1 to 8, wherein the FRTP molded body is integrated so as to be arranged on at least a part of a surface or a layer of the obtained FRTP molded body. 10. The FRTP molded article according to claim 1, wherein the small piece of FRTP is a base material of a long fiber reinforced thermoplastic resin (hereinafter referred to as L-FRTP) in a wire, pellet or tape form. Production method. 11. The wire-shaped L-FRTP base material has a wire shape having an average diameter of 0.1 to 1.5 mm, a reinforcing fiber content of 15 to 85% by mass, and an average length. The FRTP according to any one of claims 8 to 10, which is 5 to 150 mm.
A method for producing a molded article. 12. A woven or non-woven fabric made of organic fibers, inorganic fibers or natural fibers is arranged before the FRTP pieces are accumulated, and the small pieces are formed on the woven or non-woven fabric in the shape of a final molded article. Claims 1 to 3
12. The method for producing an FRTP molded article according to any one of items 11 to 11. 13. The method according to claim 1, wherein after accumulating the FRTP pieces, a woven or non-woven fabric made of organic fibers, inorganic fibers or natural fibers is arranged on the accumulation. Production method of FRTP molded article 14. The woven or non-woven fabric comprising the organic fiber, inorganic fiber or natural fiber has a softening point higher than the softening point of the thermoplastic resin having the lowest softening point among the thermoplastic resins in the FRTP. A method for producing a FRTP molded article according to claim 12. 15. When the bulk density of the aggregate of the small pieces of FRTP is ρ ₁ and the true density of the small pieces is ρ ₀ , 1/100 ≦ ρ ₁ / ρ ₀ ≦ 1/2. A method for producing the FRTP molded article according to any one of claims 1 to 14. 16. The FRTP obtained in the third step
The molded product is a sheet-like material, and after the sheet-like material is further heated and melted to obtain a melt, the melt is molded, and the FRTP molded body according to any one of claims 1 to 15 is molded. Production method.