JP3155834B2 - Manufacturing method of water tank panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention has good molding workability,
The present invention relates to a method for producing a water tank panel capable of obtaining a molded article having excellent strength and appearance.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a water tank panel made of FRP, a thermosetting resin composition is cut to a cutting length of 80 m.
m or less, usually about 25 mm cut glass fiber (chopped strand, hereinafter referred to as CS) is contained as a reinforcing material, and a sheet molding compound (hereinafter, referred to as SMC) obtained by thickening, and another reinforcing base material. Are generally put into a mold, pressurized and heated to cure the thermosetting resin. Here, glass paper, glass fiber woven fabric, continuous glass fiber mat (continuous strand mat, hereinafter referred to as CSM) or the like is used as another reinforcing substrate.

Further, there is also known a method of forming a water tank panel using solely SMC using CS as a reinforcing material having a relatively long cutting length of 80 to 450 mm as disclosed in Japanese Patent Publication No. 63-6331. Have been.

Further, a method has recently been disclosed in which CSM, which is usually used in combination with SMC as a reinforcing substrate, and SMC in which a predetermined amount is previously contained in a thermosetting resin composition as a reinforcing material, have also been disclosed.

[0005] In the above, the CSM is obtained by depositing continuous glass fibers drawn from a glass spinning furnace, then spraying a secondary binder (mat binder) and heating the same in a heating furnace. Is melted, and the glass fibers are bonded together to form a mat shape.

[0006]

However, the above-mentioned conventional manufacturing method has the following problems.

First, in the case of using SMC using CS having a cutting length of 80 mm or less as a reinforcing material, the strength of the water tank panel alone is insufficient, so that glass paper, glass fiber woven fabric, CSM, etc. S for reinforcement substrate
It is necessary to put it into a molding die together with MC and perform pressure molding. Although the water tank panel obtained by this method has the required strength, glass paper, glass fiber woven cloth, CSM, etc. used as a reinforcing substrate are SM
Unlike the SMC, it does not flow when pressed and molded with the C sheet, so it needs to be cut to the same size as the molding die, and a process for that is necessary. In addition, the reinforcing base material easily appears as a glass pattern on the surface of the water tank panel, which may result in poor appearance. Further, depending on the flow of the SMC at the time of molding, the above-mentioned reinforcing base material is liable to be broken, and disadvantages such as a reduction in strength are liable to occur. Furthermore, the impregnation of these reinforcing base materials with the resin in the SMC must be performed within a short time during pressure molding, and in order to improve the compatibility between the resin and the reinforcing base materials. In the method, it is necessary to set the viscosity of the SMC after thickening to be low, and the workability at the time of molding operation is deteriorated, for example, the SMC sheet is soft and sticky.

Next, in an SMC using a relatively long CS having a cutting length of 80 to 450 mm, since the CS used as a reinforcing material is relatively rigid and has a long cutting length, the CS is uniformly dispersed without directionality. Difficult to get
In the MC, the orientation of the glass fiber tends to occur. For this reason, the strength of the molded product is often not only about 50 in the horizontal direction but 100 in the horizontal direction,
Depending on the orientation of the glass fibers, the molded product may be warped. For this reason, when a plurality of SMC sheets are stacked and supplied during pressure molding, in order to eliminate the directionality of strength and the warpage after molding, it is necessary to consider an overlapping pattern in consideration of the directionality.

Furthermore, the following problems also occur when using SMC containing CSM as a reinforcing material in advance. That is, in the CSM used as the reinforcing material, since the strands are fixed to each other by the secondary binder as described above, almost no flow can be expected during the pressure molding. Therefore, this SMC is basically required not only to be cut into the same size and shape as a molded product, but also to have a large curvature such as an edge portion and a flange portion of the molded product, and to reduce the thickness of the molded product. In places where there is a sudden change, the reinforcing material is easily broken by friction between the reinforcing material and the mold, and the strength is reduced. Therefore, when using this SMC,
The size of the moldable product is apt to be limited by the width of itself.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a water tank capable of obtaining a molded article having good molding workability, excellent strength and appearance. It is an object of the present invention to provide a method for manufacturing a panel for use.

[0011]

In order to achieve the above object, a method for manufacturing a water tank panel according to the present invention comprises the steps of: providing a non-directionally distributed continuous glass fiber; A sheet molding compound containing a 50 mm glass fiber cut product as a reinforcing material is stacked in a plurality of layers, put into a mold, and pressurized and heated to cure the resin.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

As the thermosetting resin suitable for the SMC used for manufacturing the water tank panel of the present invention, unsaturated polyester resin, vinyl ester resin, phenol resin, epoxy resin and the like are used. Resin and vinyl ester resin.

In the thermosetting resin composition of SMC, various fillers are mixed and used in various ratios with the thermosetting resin depending on the application, and the usual mixing ratio of these fillers is thermosetting. 150 parts by weight or less based on 100 parts by weight of the conductive resin. Examples of the filler include calcium carbonate, aluminum hydroxide, glass fine powder, glass balloon, and the like. Usually, calcium carbonate and aluminum hydroxide are used.

The thermosetting resin composition further contains a polymerization initiator, a release agent, a colorant, a low-shrinkage agent, a thickener and other known additives as required. These can be mixed and used according to a conventional method.

The continuous glass fiber, which is one of the reinforcing materials for SMC used in the production of the water tank panel of the present invention, has been conventionally used as a reinforcing base material in that the strands are not bonded by a mat binder or the like. It is different from the CSM used. As a result, continuous glass fibers and C dispersed uniformly and non-directionally in SMC were obtained.
S, or continuous glass fiber comrades, when manufacturing SMC,
They are entangled with each other by the flow at the time of pressure molding, whereby a molded product of a water tank panel having high strength and no directionality is obtained. In addition, as CS, from the workability at the time of SMC manufacture and the directionality of molding strength, the cutting length is 12 mm to 50 mm.
Is used.

[0017] SM of continuous glass fiber used as a reinforcing material
The content of C is preferably 5 to 55 wt%, more preferably 10 to 35 wt%, and the cutting length is 12 m.
The content of CS of m to 50 mm to SMC is preferably 5 to 55 wt%, more preferably 10 to 35 wt%.
In addition, it is appropriate to adjust the content of the glass fiber obtained by combining the continuous glass fiber and the CS so as to be 20 to 60 wt% with respect to the SMC.

In the above, the continuous glass fiber is 5 wt%
In the following, even if the content of CS is increased, the required water pressure resistance cannot be obtained when the water tank panel is formed,
If the amount is 5 wt% or less, the entanglement of CS and the continuous glass fiber is too small, so that the effect of improving the flowability by using CS is insufficient, and the flowability is higher than that of the conventional SMC consisting of only CS having a length of 25 mm. Properties are greatly reduced.

When the content of the continuous glass fiber is 55% by weight or more, the strength of the continuous glass fiber cannot be further improved. Easy to cause. On the other hand, when CS is 55% by weight or more, the conventional S which requires another reinforcing material is required.
A disadvantage similar to MC occurs. That is, when the total glass fiber content is set to an appropriate value, the amount of continuous glass fibers becomes relatively 5% or less, and the reinforcing effect of the continuous glass fibers does not appear.

Further, when the total glass fiber content of the continuous glass fiber and CS combined with the SMC is 20% by weight or less with respect to the SMC, the required water pressure resistance when the water tank panel is formed regardless of the composition of the glass fiber. Can not get. On the other hand, if the content is 60 wt% or more, it becomes difficult to impregnate the thermosetting resin composition paste during the production of SMC, and the unimpregnated portion may cause internal peeling of the molded product. .

The specifications of the glass fiber as the reinforcing material are as follows.
１６16 μm, preferably 9 to 13 μm, and Tex per strand is 10 to 10 in continuous glass fiber.
300 Tex, preferably 20-75 Tex, for CS 20-300 Tex, preferably 30-150.
Tex's are suitable.

In the above, if the filament diameter is less than 6 μm, the productivity of the glass fiber is low and the cost is high, which is not practical. On the other hand, if the thickness exceeds 16 μm, the rigidity of the filament increases, and the filament becomes brittle. Therefore, the filament is easily cut by the friction between the mold and the glass fiber during the pressure molding or between the glass fibers, which adversely affects the strength of the molded product. Easy to affect.

On the other hand, if the Tex per strand is smaller than the above, the number of strands with respect to the required glass content is large and bulky, and impregnation with the thermosetting resin composition paste tends to be difficult. On the other hand, if the Tex per strand is larger than the above, the strands are too thick and the glass fiber distribution in the SMC sheet tends to be uneven, and the strength of the molded product tends to be uneven.

The SMC sheet used in the method for manufacturing a water tank panel of the present invention can be manufactured by only partially changing a conventionally known SMC manufacturing apparatus. FIG. 1 is a schematic diagram showing an example of an SMC manufacturing apparatus used in the present invention.

In this apparatus, the above-mentioned thermosetting resin composition pastes 2 and 4 are charged into the resin tanks 1 and 3, and the resin pastes 2 and 4 supplied from the resin tanks 1 and 3 are heated by doctor knives 5 and 7. A continuous glass drawn out of the cake 14 on the resin layer applied on the inner surface of one of the thermoplastic films 8 by forming a resin layer by applying the resin film on the inner surface of a plastic film (for example, polyethylene film or the like) 6, 8. The fibers 16 are uniformly distributed in the non-direction by the strand supply device 15 including two rolls rotating in opposite directions.

Further, the CS 9 obtained by cutting the roving 10 with the roving cutter 11 is sprayed on the resin layer of the thermoplastic film 8 from above the continuous glass fiber 16, and then the two thermoplastic films 6 are cut. , The inner surfaces on which the resin layers of 8 are formed are overlapped with each other, the glass fiber reinforced material is impregnated with the resin paste by the defoaming / impregnating roll 12, mixed, and then wound up by the winding roll 13 and aged.
Obtain the SMC used in the present invention.

The order in which the continuous glass fibers 16 and CS 9 are sprayed and dispersed may be the order described above, or may be reversed, or two or more layers may be simultaneously or alternately stacked and dispersed. As a method of forming a resin layer by the thermoplastic resin composition pastes 2 and 4 on the inner surfaces of the thermoplastic films 6 and 8, curtain coating, shower coating and spraying may be used in addition to the method using the doctor knives 5 and 7 described above. Can be used.

In the production of the SMC, the two rolls used for the supply device of the continuous glass fiber 16 may be ordinary rubber rolls, but it is preferable that at least one of the rolls is made of metal or hard plastic without slipping on the strand. It is preferable from the viewpoint of pulling out, and more preferably, a metal or hard plastic roll having a groove or a projection in the longitudinal direction is used.

As a method of supplying the continuous glass fiber 16, the following method is also conceivable. That is,
By two small rolls rotating in opposite directions,
While supplying the continuous glass fibers, the supply device is reciprocated in the width direction of the SMC manufacturing device, or the plurality of the supply devices are arranged in the width direction of the SMC manufacturing device to spray the continuous glass fibers on the resin layer. It is a way to make it. In this case, it is preferable that at least one of the rolls is made of metal or hard plastic in order to pull out the strand without slipping. More preferably, the roll having a groove or a protrusion in the longitudinal direction of the metal or hard plastic roll is used. Good to use.

Further, as another method, the nozzle is reciprocated in the width direction of the SMC manufacturing apparatus while blowing continuous glass fiber from the nozzle together with the high-speed air flow, or a plurality of nozzles are moved in the width direction of the SMC manufacturing apparatus. A continuous glass fiber may be sprayed on the resin paste by providing a nozzle.

According to the method described above, the continuous glass fiber and the CS are appropriately entangled with each other and are dispersed without any direction.
Can be obtained. The fluidity of the thus obtained SMC during continuous pressure molding of continuous glass fibers and CS is good, and as a result, a molded product of a water tank panel having high strength and good appearance without directivity is obtained.

Next, continuous glass fiber and CS were used as reinforcing materials.
A method for forming a water tank panel using the SMC containing

FIG. 2 shows an example of a water tank panel.
(A) is a plan view, and (b) is a cross-sectional view along the AA arrow line. The water tank panel 21 has a square shape as a whole, a central portion 22 bulging outward in a truncated pyramid shape, and a peripheral portion is bent outward to form a flange portion 23.
It has become. The water pressure acts as indicated by arrow P from inside the tank. As shown in FIG. 3, the water tank panel 21 has a large tank formed by abutting the flange portions 23 of the adjacent water tank panels 21 with rubber packing 24 therebetween and connecting them with bolts 25. Used to assemble.

In forming the water tank panel,
First, the SMC containing continuous glass fiber and CS as a reinforcing material is cut into a size substantially equal to the upper surface of the male die of the mold for the water tank panel, and the cut SMCs are stacked in a required number. And place it on the top of the male mold. The number of SMCs to be superimposed at this time may be appropriately selected depending on the thickness, strength, and the like required for the target water tank panel. Further, the size of the SMC that cuts the SMC is sufficient to substantially cover the upper surface of the male mold, and it is not necessary to cover the side surface corresponding to the flange portion.

Next, the superposed SMCs are pressed and heated by the female mold paired with the male mold. At this time, the SMC also flows to the side of the male mold, and the side (flange) of the molded product is formed. In this manner, a water tank panel having a flange on the periphery can be obtained. The temperature, molding pressure, time and the like of the mold at the time of molding are appropriately determined depending on the structure of the molded article, but are usually 100 to 180 ° C and 30 to 150 ° C.
kg / cm ² , within a range of ² to 20 minutes.
30-150 ° C, 30-100 kg, 3-10 minutes.

The water tank panel thus obtained has a cross-section in which continuous glass fibers and CS are appropriately entangled, dispersed without directionality, and formed in a layered form. The molded article has high strength and good appearance. Becomes

[0037]

According to the method for manufacturing a water tank panel of the present invention,
SMC containing both continuous glass fiber and CS as a reinforcing material is put into a mold by stacking multiple layers and pressing,
Since the heating is performed, it is possible to obtain a molded product containing the continuous glass fiber and CS in a layered state and appropriately entangled.

As described above, since not only CS but also continuous glass fibers are contained, the water pressure resistance required for a water tank panel is provided. Further, since the continuous glass fiber and CS are dispersed in a non-directional manner, strength without directivity can be obtained.

Further, the continuous glass fibers contained in the SMC are not bound by a secondary binder (mat binder) or the like, and are also entangled with CS more appropriately than at the time of manufacturing the SMC. The fluidity during molding is extremely excellent, and there are few restrictions on the shape when cutting SMC before molding. Furthermore, due to the fluidity during molding, continuous glass fibers are less likely to appear on the surface of the molded product, and a good appearance is obtained.

Therefore, as in the conventional method, the SMC
In addition to using glass paper, glass fiber woven fabric, CSM, or other reinforcing base materials, or examining the molding conditions in detail, there is no directionality in strength, and a molded panel product for water tanks with improved appearance. Can be obtained.

[0041]

【Example】

Example 1 Te per one strand with a filament diameter of 11 μm
x is a continuous glass fiber of 30 Tex and a filament diameter of 1
A CS having a cut length of 25 mm and a Tex of 72 μm per strand at 3 μm, and 12 w
tMC of 20% by weight and a glass fiber content of 32% by weight (weight per unit area of 3.1%).
kg / m ² ).

After cutting the SMC into a size of 1000 mm × 980 mm, four SMCs were put into a molding die and the molding temperature was 135/140 ° C. (male / female type) and the molding pressure was 47 kg / cm. Press and heat at ^{2 for} 4 minutes, 1000
A water tank panel of mm × 1000 mm was manufactured. The water pressure resistance was measured using this panel. Table 1 shows the results.

Example 2 The same continuous glass fiber and CS as in Example 1 were used for S
An SMC (weight per unit area: 3.1 kg / m ² ) having a glass fiber content of 32 wt% was prepared by being contained at 20 wt% and 12 wt% in MC.

After cutting the SMC into a size of 1000 mm × 980 mm, four SMCs were stacked and put into a molding die, and the same conditions as in Example 1 were applied to a 1000 mm × 1000 mm.
mm water tank panels were produced. The water pressure resistance was measured using this panel. Table 1 shows the results.

Example 3 A filament diameter of 11 μm and Te per strand
x is a continuous glass fiber of 30 Tex and a filament diameter of 1
3 μm, Tex per strand is 72 Tex
Of the cut length of 25 mm in each SMC
SMC with a glass fiber content of 40 wt% (weight per unit area: 3.20 wt%, 20 wt%).
1 kg / m ² ).

After cutting the SMC into a size of 1000 mm × 980 mm, four SMCs were put into a molding die, and the same conditions as those in Example 1 were used.
mm water tank panels were produced. The water pressure resistance was measured using this panel. Table 1 shows the results.

Example 4 A filament having a diameter of 13 μm and a T
ex is a continuous glass fiber of 48 Tex, a filament diameter of 13 μm, and Tex per strand is 72 Te.
x of CS with a cutting length of 25 mm are respectively inserted into the SMC.
An SMC (weight of 3.2 kg / m ² per unit area) having a glass fiber content of 40 wt% was prepared by containing 5 wt% and 15 wt%.

After cutting the SMC into a size of 1000 mm × 980 mm, four SMCs were stacked and put into a molding die.
mm water tank panels were produced. The water pressure resistance was measured using this panel. Table 1 shows the results.

COMPARATIVE EXAMPLE 1 A filament diameter of 13 μm and Te per strand
SMC containing 32 wt% of CS having a cut length of 25 mm and x of 72 Tex (weight per unit area: 3.9 kg / m ² )
made.

Three pieces of this SMC cut to 1000 mm × 980 mm and a CSM (weight per unit area: 30
0g / m ² ) cut to 1050 mm × 1050 mm, and one sheet of glass fiber woven fabric (weight per unit area: 200 g / m ² ) cut to 1050 mm × 1050 mm. Example 1
A water tank panel was manufactured under the same conditions as described above. The water pressure resistance was measured using this panel. Table 1 shows the results.

Comparative Example 2 Te having a filament diameter of 13 μm per strand
x is 72Tex, cutting length 25mm CS only 32w
SMC containing t% (weight 4 kg / m per unit area)
² ) Made.

After cutting this SMC into 1000 mm × 980 mm, three SMCs were put into a molding die, and a water tank panel was manufactured under the same conditions as in Example 1.
The water pressure resistance was measured using this panel. Table 1 shows the results.

[0053]

[Table 1]

From the results shown in Table 1, the water tank panels of Examples 1 to 4 molded using SMC containing continuous glass fiber and CS as a reinforcing material are all sufficient for water tank panels. It can be seen that it has excellent water pressure resistance and good appearance. On the other hand, an SMC containing only CS is used as a reinforcing base material.
It can be seen that the water tank panel of Comparative Example 1 made by stacking the SM and the glass fiber woven fabric had sufficient water pressure resistance, but had poor appearance. In Comparative Example 1, C
The SM and glass woven fabric had to be cut to approximately the same size as the moldings. Further, it can be seen that the water tank panel of Comparative Example 2, which was made of only SMC containing only CS, had a good appearance but lacked the water pressure resistance.

[0055]

As described above, according to the method for manufacturing a water tank panel of the present invention, molding is performed using SMC containing continuous glass fibers and CS as reinforcing materials dispersed in a non-directional manner. Therefore, it is possible to obtain a water tank panel having a sufficient waterproof pressure strength required for a water tank panel, and having no directionality in the strength and having a good appearance. In addition, continuous glass fibers contained in SMC are CS
Since they are not bonded by a secondary bonding material as in M, they have excellent fluidity during pressure molding, and there are few restrictions on the shape when cutting SMC before molding. Therefore, S
A water tank panel can be easily manufactured using only the SMC without using a reinforcing base material other than the MC or requiring detailed examination of the molding conditions of the SMC, and significant simplification of the process can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an SMC manufacturing apparatus used in the present invention.

FIGS. 2A and 2B show an example of a water tank panel, wherein FIG. 2A is a plan view and FIG. 2B is a cross-sectional view taken along the line AA.

FIG. 3 is a partial sectional view showing a connection structure of a water tank panel.

[Explanation of symbols]

 Reference Signs List 1 resin tank 2 resin paste 3 resin tank 4 resin paste 5 doctor knife 6 thermoplastic film 7 doctor knife 8 thermoplastic film 9 chopped strand 10 roving 11 roving cutter 12 defoaming / impregnating roll 13 winding roll 14 cake 15 strand supply roll 16 Continuous glass fiber strand 21 Panel for water tank 22 Central part 23 Flange part

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ Identification code FIB29L 31:00 (56) References JP-A-6-79741 (JP, A) JP-A-59-24623 (JP, A) JP-A-59-178220 (JP, A) JP-A-54-148064 (JP, A) JP-A-58-18225 (JP, A) JP-A-1-156927 (JP, U) (58) Int.Cl. ⁷ , DB name) B29C 43/02-43/20 B29C 43/32-43/34 B29B 11/16 B29C 70/10

Claims (3)

(57) [Claims] 1. A continuous glass fiber which is non-directionally disposed,
A sheet molding compound containing, as a reinforcing material, a glass fiber cut product having a cutting length of 12 to 50 mm dispersed in a non-directional manner, and superimposing a plurality of layers into a mold,
A method for producing a water tank panel, wherein the resin is cured by pressurizing and heating. 2. The content of the continuous glass fiber is 5 to 55 wt% based on the whole sheet molding compound.
%, The content of the cut glass fiber material is 5 to 55 wt% based on the entire sheet molding compound, and the glass fiber content of the continuous glass fiber and the cut glass fiber material is a sheet. 20 to 60% by weight based on the whole molding compound,
Claim 1 using a sheet molding compound
A method for producing a water tank panel as described in the above. 3. The continuous glass fiber has a filament diameter of 6 to 16 μm and a Tex of 10 per strand.
3. The water tank according to claim 1, wherein the cut glass fiber is a sheet molding compound having a filament diameter of 6 to 16 μm and a Tex per strand of 20 to 300 Tex. 4. Panel manufacturing method.