JP2001287232A - Method and apparatus for continuously producing resin molding containing aggregate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for continuously producing a resin molding containing aggregate which can stably and continuously produce the molding in which the aggregate is packed so that the aggregate particles are brought into contact with each other even when a crushed fiber-reinforced plastic molding, wood powder, etc. are used as the aggregate and an apparatus for the method. SOLUTION: In the method in which a molding material in which the aggregate is highly packed in a liquid thermosetting resin composition is cured in turn in a continuously moving mold to mold the molding continuously, a material supply process in which the molding material is supplied on an endless belt and a continuously compacting process in which the supplied molding material, while being conveyed toward the moving mold on the endless belt, is compressed gradually and continuously to be compacted to the thickness of the molding to be obtained at the inlet of the mold are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous production method and a continuous production apparatus for a resin molded product in which a liquid thermosetting resin composition is highly filled with an aggregate.

[0002]

2. Description of the Related Art On a surface of a core layer made of a foamed thermosetting resin in which an aggregate is dispersed, a surface layer made of a foamed thermosetting resin in which reinforcing fibers are dispersed substantially parallel to the longitudinal direction is laminated. Composite materials have already been proposed (Japanese Unexamined Patent Publication No. 5-1).
38797). In the case of this composite material, in order to increase the nailing performance and the compressive strength, it is necessary to increase the packing density of the aggregate until the aggregate constituting the core layer and the aggregate are partially in contact with each other.

As a method for continuously producing a material in which an aggregate is filled in a foamed resin, for example, a method disclosed in Japanese Patent Application Laid-Open No. 54-34376 has been proposed. However, according to this method, it is impossible to increase the packing density of the aggregates to such an extent that the aggregates contact each other at a part thereof.

The inventor of the present invention has proposed a lower endless belt forming a material supply section and a mold bottom of a continuously moving mold, and an upper endless belt forming a mold ceiling of a continuously moving mold. A manufacturing apparatus is provided, and a molding material in which the liquid thermosetting resin composition is highly filled with aggregate is supplied onto the material supply unit, and after being supplied to the material supply unit, continuously in the continuous moving mold. The thermosetting resin in the molding material fed into the mold was thermoset in a continuously moving mold to continuously mold the molded article. Also, after the molding material is supplied onto the material supply section and before entering the continuous molding die, the aggregates are pressed with a press plate or the like to ensure that they contact each other, increasing the static friction resistance of the material. This ensures that the endless belt can be compacted.

[0005] However, in order to reduce the cost of an aggregate-containing resin molded product, when a pulverized plastic molded product containing reinforcing fibers such as glass fiber, which is generated as waste, wood powder, or the like is used, Even if the pre-compression is performed, there is a problem that the molded material once compressed returns to the original state due to the elasticity of the aggregate and the like, and a molded product having a desired packing density of the aggregate cannot be obtained.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems, and the present invention solves the above-mentioned problems even when a pulverized plastic molded article containing reinforcing fibers or wood powder is used as an aggregate. It is an object of the present invention to provide a continuous production method and a continuous production apparatus for an aggregate-containing resin molded product capable of stably and continuously producing a highly-filled resin molded product until the resin molded products come into contact with each other.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, a method for continuously producing an aggregate-containing resin molded product according to the present invention is characterized in that the liquid thermosetting resin composition is highly filled with the aggregate. In a continuous production method of an aggregate-containing resin molded product in which a molding material is subjected to a curing reaction sequentially in a continuous moving mold to continuously mold the molded product, a material supply step of supplying the molding material on an endless belt; The molding material supplied to the endless belt is gradually and continuously compressed from above on the endless belt while being conveyed in the direction of the continuous moving mold by the endless belt, and the thickness of the molded product to be obtained at the entrance of the continuous moving mold is reduced. And a continuous consolidation step of making the consolidation state to the extent possible.

According to a second aspect of the present invention, there is provided a continuous consolidation step in which at least the upper surface of the molding material is pre-consolidated by pressing means provided between the material supply step and the continuous consolidation step. It is preferable to have.

On the other hand, the continuous manufacturing apparatus according to the present invention is provided with a material supply section in which a molding material in which a liquid thermosetting resin composition is filled with an aggregate is supplied from above, and is located behind the material supply section. A lower endless belt having a lower mold part constituting a lower surface side of a continuous moving mold for continuously molding the molding material supplied to the material supply unit; and a lower end belt provided to face the lower mold part. An upper mold part constituting the upper surface side of the continuous moving mold, and a distance between the upper mold part and the lower mold part, which is provided behind the material supply part, is gradually reduced to a distance between the upper mold part and the lower mold part. And an upper endless belt having a tapered portion for gradually consolidating the molding material continuously conveyed from the material supply unit to the lower endless belt.

In the present invention, the liquid thermosetting resin composition may be a liquid thermosetting resin alone or, if necessary, a catalyst, a foaming agent, a foam stabilizer, a foaming aid, and the like. , Colorant, UV absorber, antioxidant, crosslinker,
Stabilizers, plasticizers, flame retardants and the like may be added.

The above-mentioned liquid thermosetting resin is not particularly restricted but includes, for example, polyurethane resin, phenol resin, unsaturated polyester resin, epoxy resin, vinyl ester resin and the like. The foaming agent is not particularly limited, and examples thereof include a pyrolytic foaming agent, a solvent-type foaming agent such as chlorofluorocarbon, and by-products such as a decomposition gas generated when the thermosetting resin reacts.

The aggregate is not particularly limited. For example, inorganic and organic granules, sludge dry granules, reinforcing fibers,
A fiber reinforced resin pulverized product and the like can be mentioned. These aggregates may be used alone or as a mixture of two or more. Examples of the inorganic powder include rock powder, glass powder, calcium silicate, cement concrete pulverized material, amorphous particles such as silica sand, inorganic short fiber powders such as sericite and wollastonite, and vermiculite. And inorganic powder having a relatively small particle size such as calcium carbonate, fly ash, etc., and inorganic powder having bubbles such as pearlite, expanded shale, and hollow powder of fly ash.

Examples of the organic particles include pulverized plastic products such as PVC pipes and PET bottles. As the sludge dry powder, there is a constant temperature dry solid content of sludge generated from a sludge treatment plant.

Examples of the reinforcing fibers include inorganic fibers such as glass fibers, organic fibers, and metal fibers. Examples of the crushed fiber reinforced resin include a crushed fiber reinforced plastic (FRP) and a crushed fiber reinforced hard urethane foam.

In the present invention, the state of the aggregate being highly filled (high-pressure dense state) means a state in which the aggregate particles are in contact with each other.
The volume filling rate of the aggregate differs depending on the shape, particle size, particle size distribution, and the like of the selected aggregate. For example, in the case of silica sand,
About 60% by volume is preferable. If it is considered that the silica sand particles are perfectly spherical, the filling rate is preferably about 50 to 75% by volume.

The method for calculating the aggregate filling rate is not particularly limited. For example, in the case of a solid body such as silica sand, the calculation method is based on the true specific gravity, or the hollow body such as a philia ash balloon or the expanded shale. In the case of a foam, it is calculated by the apparent specific gravity, that is, the total specific gravity including voids inherent in the aggregate. Further, in the case of a FRP pulverized product or the like, a specific method is conceivable in which the specific gravity differs depending on the site when viewed microscopically, but the specific gravity of the composite is used as a representative value macroscopically.

The molding material is first obtained by mixing the liquid thermosetting resin composition and the aggregate, but the mixing method is not particularly limited. Examples thereof include a method using a batch mixer such as a continuous mixer and a mixer / kneader.

When a clay mixing machine is used, a biaxial type has a self-cleaning property and is excellent in continuous stability. When a batch mixer is used, a feeder for continuously supplying the mixture to the material supply unit and, if necessary, a container for temporarily storing the mixture are required. The molding material obtained by the above mixing method comprises a liquid thermosetting resin composition, an aggregate, and a void.

In the continuous consolidation step, the molding material comprising the liquid thermosetting resin composition, the aggregate, and the voids is filled with the inlet of the continuous moving mold from just before the continuous moving mold so as to have a predetermined aggregate filling rate. Continuously reduce the gap of the molding material until
That is, the cross-sectional area is reduced. Then, for example, after the molding material is supplied onto the endless belt at the upstream portion of the line, while the molding material is being conveyed to the continuously moving mold on the downstream side by the endless belt, the entrance of the continuously moving mold is located above the endless belt. In order to gradually reduce the distance from the endless belt toward the endless belt, a method of gradually compressing the upper endless belt as continuous consolidation means provided facing the endless belt for conveying the molding material is used.

In order to continuously reduce the cross-sectional area of the molding material, that is, to achieve compaction, first, it is assumed that the height of the insertion opening of the upper endless belt is higher than the height of the molding material before compaction. It is necessary that the upper endless belt is inclined and changes to the cross-sectional height (product thickness) of the continuously moving mold entrance. Further, instead of using the endless belt as described above, the continuous consolidation means can be performed by a plurality of rollers or the like which are continuously arranged so that the distance between the endless belt and the lower endless belt is gradually reduced. . Further, the upper endless belt may be provided so that the space between the upper endless belt and the lower endless belt gradually narrows at a constant inclination angle toward the continuous moving mold entrance, or the inclination angle is changed stepwise, It may be possible to compress the cross-sectional shape at the entrance of the continuous moving mold. That is, it is preferable that it can be changed so as to correspond to various molding materials.

Further, the press device used in the pre-consolidation step of the second aspect is not particularly limited, but for example, an intermittent press system, a roll system, an endless belt system, or the like can be used. From the viewpoint of uniformity in the line direction, a roll system and an endless belt system are preferred.

In the continuous moving mold, at least the mold bottom surface and the ceiling surface are formed by an endless belt, and if the endless belt moves in the moving direction of the molded product,
Although not particularly limited, if the cross section of the molded product is a square, it is preferable that both side surfaces of the mold are also formed by an endless belt. The material of the endless belt used in the continuous moving mold is not particularly limited as long as it has heat resistance and does not inhibit the curing reaction, and examples thereof include steel and resin.

The endless belt used in the present invention includes:
Although not particularly limited, an endless belt system using a continuous belt belt or a slat conveyor system in which a number of slats are connected may be used. Endless belt method,
The material of the belt-shaped belt and the slats in the slat conveyor system is not particularly limited, but is preferably a high-strength metal such as steel, stainless steel, or aluminum.
When a slat conveyor is used, the slat exhibits an intermittent behavior. However, by shortening the slat length in the line direction, it is possible to approach a continuous consolidation state. In addition, in the slat conveyor system, it is easy to give an irregular shape in the longitudinal direction.

In the manufacturing apparatus of the present invention, a heating mechanism for accelerating a curing reaction of a molding material after consolidation is provided at a portion where an endless belt forms a continuously moving mold, and a reaction heat of a cured body thereafter is removed. Cooling mechanism can be provided. Although the heating and cooling mechanism is not particularly limited, a method of controlling the temperature by applying heat, warm or cold air to the belt and the slat from the back surface side can be used. In the case of a slat conveyor system, a method of controlling the temperature by using a slat as a jacket system may also be used. As a driving method of the endless belt constituting the continuous moving mold, it is most preferable to provide a driving means on the endless belt itself, but a take-up machine may be provided downstream in the traveling direction. However, in order to apply a driving force to the mold using a take-off machine at the start of production, it is necessary to use a driving force transmitting member such as a base material.

When a foaming resin such as a urethane resin is used, it is preferable that a structure is provided at a front portion in a die traveling direction in which a dam plate required at the start of production can be installed. That is, at the start of production, this dam plate is installed in the front part in the traveling direction, and the introduced molding material leaks from the mold exit side.
It is preferable to prevent the occurrence of (foaming deformation), and at the time when foaming and curing are completed, remove the dam plate and draw the molded product into the take-off machine.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows one embodiment of a continuous apparatus for producing a resin molded product of the present invention.

As shown in FIG. 1, the manufacturing apparatus A includes a molding material supply device 1, a lower endless belt 2, an upper endless belt 3, a pair of side endless belts (not shown), Machine 4.

The molding material supply device 1 includes an aggregate silo 11
, A resin tank 12, an aggregate feeder 13, a resin supply pump 14, and a continuous mixer (hereinafter simply referred to as “mixer”) 15. And the aggregate silo 11
A fixed amount of the aggregate in the container is supplied to the mixer 15 via the aggregate feeder 13, and a fixed amount of the liquid thermosetting resin in the resin tank 12 is supplied to the mixer 15 via the resin supply pump 14. After uniformly mixing the aggregate and the liquid thermosetting resin into a molding material, the mixture is continuously supplied to the lower endless belt 2 from the discharge port of the mixer 15. In addition, the mixer 15 rotates its shaft (not shown) simultaneously with the supply of the aggregate and the resin, and starts mixing.

The lower endless belt 2 includes a material supply section 21 and
It has a consolidating section 22 and a lower mold section 23 that forms the bottom surface of a continuously moving mold 7 that continuously molds the molding material 6 supplied to the material supply section 21.

The upper endless belt 3 is provided so as to face the lower mold part 23, and is provided behind the upper mold part 31 constituting the ceiling surface of the continuously moving mold 7 and the material supply part 21. The distance from the lower endless belt 2 gradually decreases until it reaches the distance between the upper mold part 31 and the lower mold part 23, and is continuously conveyed from the material supply unit 21 to the lower endless belt 2. And a taper portion 22 for gradually consolidating the coming molding material 6 with the lower endless belt 2.

The tapered portion 22 can be arbitrarily changed in angle so that the molding material 6 does not stay in the tapered portion 22 at the time of consolidation described later.
The side endless belt forms a side wall surface of the continuously moving mold 7.

The continuous moving mold 7 formed by the upper endless belt 3, the lower endless belt 2, and the side endless belt includes an insertion area, a foaming area, a hardening area, and a cooling area. The cutting machine 4 cuts a long molded product 8 formed by the continuous moving mold 7 and continuously discharged into a product 81 of a predetermined size.

The manufacturing apparatus A is configured as described above, and the material supply section 21 of the lower endless belt 2 is supplied from the mixer 15.
When the molding material 6 supplied to the lower endless belt 2 is conveyed by the lower endless belt 2 at the tapered portion 22 of the upper endless belt 3, the thickness thereof gradually decreases between the lower endless belt 2 and the tapered portion 22. Can be That is, the molding material 6 is compacted, and finally the molding material 6 is compacted to the cross-sectional shape of the inlet of the continuously moving mold 7, that is, the cross-sectional dimension of the molded product 8 to be obtained.

The molding material 6 thus compacted
However, when the liquid thermosetting resin composition enters the continuous moving mold 7, the liquid thermosetting resin composition undergoes a polymerization reaction to form a molded article 8. Then, the molded article 8 whose temperature has risen due to the heat generated during the polymerization reaction is introduced into a cooling zone and cooled to a required temperature. As described above, according to the manufacturing method using the manufacturing apparatus A, the molding material supply unit 21
Is supplied between the tapered portion 22 of the upper endless belt 3 and the lower endless belt 2 provided immediately before the continuous moving die 7 in advance.
Due to the frictional resistance between the molding material 6 and the molding material 6, the molding material 6 is bitten in the direction of the continuously moving mold 7 and gradually compacted,
While maintaining this compacted state, the liquid thermosetting resin composition in the molding material 6 is introduced into the continuously moving mold 7 and thermally cured to obtain a molded product 8.

Therefore, it is possible to continuously and stably produce a resin molded product highly filled with aggregate.

FIG. 2 shows another embodiment of the manufacturing apparatus according to the present invention. As shown in FIG. 2, this manufacturing apparatus B is provided with a press device 5 for pre-consolidation behind a material supply unit 21 and in front of a tapered portion 22, and a take-up machine behind a continuously moving mold 7. 9 is the same as the above-mentioned manufacturing apparatus A, except that 9 is provided.

The manufacturing apparatus B is configured as described above. The material supply unit 21 of the lower endless belt 2 is supplied from the mixer 15.
Is first pre-consolidated by the press device 5, and at least the upper surface of the molding material 6 is densified. After that, when the lower endless belt 2 conveys the tape at the tapered portion 22 of the upper endless belt 3, the taper of the tapered portion 22 causes the lower endless belt 2 to convey to the lower endless belt 2.
The thickness of the molding material 6 is gradually reduced to further consolidate, and finally the molding material 6 is consolidated to the cross-sectional shape of the inlet of the continuously moving mold 7, that is, the cross-sectional dimension of the molded product 8 to be obtained. Then, after the continuous moving mold 7 similarly forms the long molded product 8, the take-off machine 9 takes the long molded product 8 at a constant speed.

As described above, according to the manufacturing method using the manufacturing apparatus B, the molding material 6 supplied to the molding material supply section 21 is pre-consolidated by the press device 5, so that it is slippery. Even in the case of a molding material (having a small coefficient of static friction), a resin molded product filled with aggregate is continuously and stably manufactured without loosening the taper angle of the tapered portion 22 and without increasing the entire length of the tapered portion 22. be able to.

That is, as in the case where there is a large gap between the aggregate of the molding material 6 supplied from the mixer 15 and the liquid thermosetting resin composition, the molding material is slippery (has a small static friction coefficient). In the case of (2), unless the taper angle of the tapered portion 22 is not loosened, the tapered portion 22 and the lower endless belt 2
However, if the taper angle of the tapered portion 22 is reduced, the overall length of the tapered portion 22 must be increased. Therefore, the overall length of the manufacturing apparatus is also increased, and there is a problem in cost. However, this manufacturing apparatus B
As described above, if the upper surface of the molding material 6 is densified by performing pre-consolidation to increase the coefficient of static friction, the taper angle of the tapered portion 22 is steep, that is, the entire length of the tapered portion 22. Even if the length is shortened, it becomes possible to continuously and stably produce a resin molded product in which the aggregate is filled.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the side endless belt is provided, but the side endless belt may be omitted. In the above embodiment, the upper, lower, and side endless belts are slat conveyor belts.
A steel belt or a resin belt may be used as long as it can withstand the temperature during molding.

Further, a tapered portion may be provided on the side endless belt. Further, in the above-described embodiment, the lower mold part of the continuous moving mold and the material supply unit 21 are constituted only by the lower endless belt 2.
The endless belt forming the mold 1 and the endless belt forming the mold bottom surface may be formed separately.

[0042]

Examples of the present invention will be described below. Example 1 A resin molded product was manufactured using the manufacturing apparatus A shown in FIG. 1 under the following manufacturing conditions.

[Manufacturing conditions] Liquid thermosetting resin composition (hard urethane resin) → 100 parts by weight of polyether polyol (hydroxyl value: 390) with foaming, 110 parts by weight of polymethylene polyphenyl polyisocyanate, foam stabilizer Liquid thermosetting resin composition composed of 0.5 parts by weight of silicone oil agent for use and 0.3 parts by weight of water 0.05 parts by weight of dibutyltin laurate as a reaction catalyst Aggregate: No. 7 silica sand Aggregate filling rate in molding material ... 55% by volume Line speed ... 1m / min Taper angle of taper section ... 10 ° Temperature distribution of continuously moving mold ... Insertion area = room temperature, foaming area = 5
0 ° C, Curing range = 80 ° C, Cooling range = Room temperature Molded product cross-section dimensions: width 200mm, height 100mm

Example 2 A resin molded product was manufactured using the manufacturing apparatus B shown in FIG. 2 under the following manufacturing conditions.

[Manufacturing conditions] 110 parts by weight of polymethylene polyphenyl polyisocyanate, 100 parts by weight of polyether polyol (hydroxyl value: 390), silicone oil for foam control, based on 100 parts by weight of foamable thermosetting resin composition (hard urethane resin) Foaming thermosetting resin composition comprising 0.5 part by weight of an agent, 0.3 part by weight of water, and 0.05 part by weight of dibutyltin laurate as a reaction catalyst Aggregate: No. 3 silica sand, No. 7 silica Bone in molding material Material filling rate: No. 3 = 52% by volume, No. 7 =
13% by volume Line speed: 1 m / min Pre-press: Yes Taper angle of taper part: 30 ° Temperature distribution of continuously moving mold: Insertion area = room temperature, foaming area = 5
0 ° C, Curing area: 80 ° C, Cooling area = Room temperature Molded product cross-section dimensions: width 200mm, height 100mm

Comparative Example 1 A molded product was manufactured in the same manner as in Example 1 except that the taper angle of the tapered portion was 0 °, ie, the tapered portion was eliminated.

The aggregate filling rate, compressive strength, and the presence or absence of stagnation of the molding material in the tapered portion in the molded articles obtained in Examples 1 and 2 and Comparative Example 1 were evaluated. The results are shown in Table 1. The filling rate of the aggregate in the molded article was calculated by baking the molded article in a muffle furnace to remove the organic component, and then measuring the weight of the remaining inorganic substance, that is, the aggregate component. In addition, the presence or absence of the stagnation of the molding material was observed by visually observing the vicinity of the tapered portion and observing the consolidation.
The continuous operation was performed for about 3 hours. Compressive strength is JIS K
It was measured using the method of 2101.

[0048]

[Table 1]

Table 1 clearly shows that the production method of the present invention can stably obtain a molded product having the same aggregate filling ratio as the aggregate filling ratio in the molding material. In addition, when the preliminary consolidation step is provided as in the second embodiment, the molding material can be smoothly conveyed to the continuously moving mold even though the taper angle of the tapered portion is steeply increased. I understand.

[0050]

According to the continuous production method and the continuous production apparatus for an aggregate-containing resin molded product of the present invention, as described above, a molding in which a small amount of a liquid thermosetting resin composition and a large amount of an aggregate are mixed. Even if it is a material, it is possible to continuously consolidate without causing stagnation, and it is possible to continuously and stably produce a resin molded product highly filled with aggregate. In addition, discarded granules of fiber-reinforced plastic molded products, wood powder, and the like can be used as aggregates, and the production cost of molded products can be reduced.

Further, according to the present invention, even when the properties (static friction coefficient, etc.) of the molding material change, the taper angle of the tapered portion does not need to be reduced, that is, without increasing the size of the apparatus. In addition, it is possible to continuously and stably produce a resin molded product filled with an aggregate at a high packing density.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating one embodiment of a continuous production apparatus for an aggregate-containing resin molded product according to the present invention.

FIG. 2 is an explanatory view illustrating another embodiment of the continuous production apparatus for an aggregate-containing resin molded product according to the present invention.

[Explanation of symbols]

 A, B continuous manufacturing apparatus 2 lower endless belt 21 material supply section 23 lower mold section 3 upper endless belt 31 upper mold section 32 taper section

Claims (3)

[Claims] 1. A method for continuously producing an aggregate-containing resin molded product, wherein a molding material in which a liquid thermosetting resin composition is highly filled with an aggregate is subjected to a curing reaction sequentially by a continuous moving mold to continuously mold the molded product. A material supply step of supplying the molding material onto the endless belt, and gradually and continuously from above on the endless belt while conveying the molding material supplied on the endless belt in the direction of the continuous moving mold by the endless belt. A continuous consolidation step of subjecting the molded article to a state of compacting until the thickness of the molded article to be obtained at the entrance of the continuous moving mold is obtained. Production method. 2. A pre-consolidation step for pre-consolidating at least the upper surface of a molding material by a pressing means provided between the material supply step and the continuous consolidation step.
4. The continuous production method for a resin molded article containing an aggregate according to item 1. 3. A material supply section to which a molding material in which an aggregate is filled in a liquid thermosetting resin composition is supplied from above, and a molding material located behind the material supply section and supplied to the material supply section. A lower endless belt having a lower mold part constituting a lower surface side of a continuous moving mold for continuously molding, and provided so as to face the lower mold part, and an upper surface side of the continuous moving mold is provided. The upper mold part to be configured, provided behind the material supply part, the distance between the lower endless belt gradually decreases to the distance between the upper mold part and the lower mold part, and continuously from the material supply part. An apparatus for continuously manufacturing a resin molded product highly filled with an aggregate, comprising an upper endless belt having a tapered portion for gradually consolidating a conveyed molding material between the lower endless belt.