JPH0679741A - Water tank panel manufacturing method - Google Patents

Abstract

PURPOSE:To manufacture a better-looking molded panel product without a directional strength by stacking a first SMC which contains continuous glass fiber dispersed in a random direction over a second SMC which contains a 12 to 50mm long-glass fiber cutting dispersed in a random direction, and heating the SMCs in a die under pressure for curing the resin. CONSTITUTION:Thermally curable resin composition bases 2, 4 are charged in resin tanks 1, 3 and supplied, and then are applied to the inner surface of thermally curable films 6, 8 using doctor knives 5, 7. In addition, continuous glass fiber 9 drawn from a cake 13 is dispersed uniformly cover a resin layer in a random direction, using a strand feeder 10 consisting of two rolls. Next, the inner surfaces of the films 6, 8 are stacked over the other and the glass fiber 9 is impregnated with paste by a defoaming/impregnating roll 11 to obtain the first SMC. Further, the first SMC is stacked over the second SMC containing a glass fiber cutting as a reinforcing material, and these SMCs are charged into the die. Finally the SMCs are heated under pressure into a better-looking molded panel product.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention has good molding workability,
The present invention relates to a method for producing a panel for a water tank, which enables to obtain a molded product having excellent strength and appearance.

[0002]

2. Description of the Related Art Conventionally, as a method of molding an FRP water tank panel, a thermosetting resin composition has a cutting length of 80 m.
The sheet molding compound (hereinafter referred to as SMC) obtained by thickening the glass fiber cutting material (chopped strand, hereinafter referred to as CS) having a size of m or less, usually around 25 mm, as a reinforcing material and other reinforcing base material A method in which the thermosetting resins are cured by superposing them into a mold, applying pressure and heating, is generally widely used. Here, as other reinforcing base materials, glass paper, glass fiber woven cloth, continuous glass fiber mat (continuous strand mat, hereinafter referred to as CSM), and the like are used.

There is also known a method for molding a panel for a water tank by using SMC alone, which is made of a relatively long CS having a cutting length of 80 to 450 mm as a reinforcing material, as disclosed in Japanese Patent Publication No. 63-6331. Has been.

Furthermore, as a recently published method, usually,
CS used in combination with SMC as a reinforcing substrate
A method using SMC in which a predetermined amount of M is contained in a thermosetting resin composition as a reinforcing material is also known.

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

[0006]

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

[0007] First, when SMC having a cutting length of 80 mm or less as a reinforcing material is used as a reinforcing material, it is insufficient in strength as a panel for a water tank, so in order to compensate for it, glass paper, woven glass fiber cloth, CSM, etc. Reinforcing base material of S
It is necessary to put it in a molding die together with the MC for pressure molding. Although the water tank panel obtained by this method has a required strength, the glass paper, glass fiber woven cloth, CSM, etc. used as a reinforcing base material is SM
Unlike the SMC, it does not flow when it is pressure-molded by overlapping it with the C sheet. Therefore, it is necessary to cut it into almost the same size as the molding die, and a process therefor is required. Further, the reinforcing base material is likely to appear as a glass pattern on the surface of the water tank panel, resulting in poor appearance. Further, depending on how the SMC flows during molding, the reinforcing base material is liable to break, which rather causes a problem such as a decrease in strength. Further, the impregnation of the reinforcing base material and the resin in the SMC must be done within a short time during pressure molding, in order to improve the familiarity between the resin and the reinforcing base material. It is necessary to set the viscosity of the SMC after thickening to be low, and the SMC sheet is soft and tends to become sticky.

Next, in the SMC using CS having a relatively long cutting length of 80 to 450 mm, since CS used as a reinforcing material is relatively rigid and the cutting length is long, it is uniformly dispersed without directionality. It ’s difficult and you can get S
The orientation of glass fibers is liable to occur in MC. Therefore, the strength of the molded product is often about 50 in the horizontal direction with respect to 100 in the vertical direction of the line, and
Depending on the orientation of the glass fibers, warpage may occur in the molded product. For this reason, when a plurality of SMC sheets are superposed on each other at the time of pressure molding, in order to eliminate the directionality of strength and the warpage after molding, it is necessary to consider the superposition pattern in consideration of the directionality.

Further, when using SMC containing CSM as a reinforcing material in advance, there are the following problems. 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 pressure molding. For this reason, this SMC is basically required to be cut into almost the same size and shape as the molded product, as well as where the edge and flange of the molded product have large curvatures and the molded product has a large thickness. In places where there is a sudden change, the reinforcing material is likely to break due to the friction between the reinforcing material and the mold, and the strength decreases. Therefore, when using this SMC,
The size of a molded product that can be molded is likely to be limited by its width.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is a water tank which has a good workability in molding and has a good strength and appearance. An object of the present invention is to provide a method for manufacturing a display panel.

[0011]

In order to achieve the above object, a method for producing a water tank panel according to the present invention comprises a first SMC in which continuous glass fibers are non-directionally dispersed and contained as a reinforcing material, and a cutting length. The second SMC in which CS of 12 mm to 50 mm is dispersed and contained in a non-directional manner is superposed at least one layer each, put into a mold, and pressurized and heated to cure the resin.

The present invention will be described in more detail below with reference to preferred embodiments.

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

In the thermosetting resin composition of SMC, various fillers are mixed with the thermosetting resin in various proportions depending on the application, and the usual mixing ratio of these fillers is thermosetting. 150 parts by weight or less relative to 100 parts by weight of the organic resin. Examples of the filler include calcium carbonate, aluminum hydroxide, fine glass powder, glass balloons, etc., but calcium carbonate and aluminum hydroxide are usually used.

In addition to the above, the thermosetting resin composition may appropriately contain a polymerization initiator, a release agent, a coloring agent, a low-shrinking agent, a thickener, and other known additives, if necessary. They can be mixed and used according to a conventional method.

The filament diameter of the continuous glass fiber used in the first SMC is preferably 6 to 16 μm, more preferably 9 to 13 μm, and Tex per strand is Tex.
Is preferably 10 to 100 Tex, more preferably 2
It is 0 to 75 Tex. In addition, continuous glass fiber SMC
Is preferably 20 to 60 wt%, more preferably 30 to 45 wt%.

The filament diameter of CS used in the second SMC is preferably 6 to 16 μm, more preferably 9 to 13 μm, and Tex per strand is 2
0-300 Tex, more preferably 30-150 Tex
Is. The content ratio of CS to SMC is preferably 20 to 60 wt%, more preferably 30 to 45 wt%.
%. As the CS, one having a cutting length of 12 mm to 50 mm is used, and preferably one having a cutting length of 20 to 30 mm, from the viewpoint of workability during SMC production and directionality of molding strength.

In the above, if the glass fiber content in the first and second SMCs is less than 20 wt%, the required water pressure strength can be obtained even if the structure of the glass fibers used and the structure of the superposition of the first and second SMCs are devised. Can't get On the other hand, if it exceeds 60 wt%, it becomes difficult to impregnate the thermosetting resin composition paste at the time of SMC production, and internal exfoliation of the molded product may occur due to the impregnated end portion. Not.

If the filament diameter of the glass fiber used in the first and second SMCs is less than 6 μm, the productivity of the glass fiber is low and the cost is high, which is not realistic. Again 1
If it exceeds 6 μm, the filament becomes more rigid and brittle, so that the filament is likely to be broken by friction between the mold and the glass fiber or between glass fibers during pressure molding, which adversely affects the strength of the molded product. Cheap.

Further, the Tex of the glass fiber strands used in the first and second SMCs is Te per 1 strand.
When x is smaller than the above, the number of strands with respect to the required glass content becomes large and becomes bulky,
Impregnation of the thermosetting resin composition paste tends to be difficult. If the Tex per strand is larger than the above value, the strand is too thick and the glass fiber distribution in the SMC sheet is likely to be non-uniform, which causes unevenness in the strength of the molded product.

Of the SMC sheets used in the method for producing a water tank panel of the present invention, the second SMC containing CS.
What was manufactured by the conventionally well-known method and apparatus can be used for this.

The first SM containing continuous glass fibers
C can be manufactured using a manufacturing apparatus as shown in FIG. 1, for example. In this apparatus, the resin tanks 1 and 3 are charged with the above-mentioned thermosetting resin composition pastes 2 and 4, and the resin pastes 2 and 4 supplied from the resin tanks 1 and 3 are made into thermoplastic films ( (For example, polyethylene film, etc.) 6 and 8 are coated on the inner surfaces to form a resin layer, and the continuous glass fiber 9 drawn from the cake 13 is placed on the resin layer applied on the inner surface of one thermoplastic film 8. A strand supply device 10 composed of two rolls rotating in opposite directions disperse the particles uniformly in a non-direction. Then, the above-mentioned two thermoplastic films 6 and 8
The inner surfaces of the rolls are overlapped with each other, and the continuous glass fiber is impregnated with the resin paste by the defoaming / impregnating roll 11, and the winding roll 1
The obtained SMC of the present invention is obtained by winding and aging by 2.

In the above SMC manufacturing apparatus, the two rolls used in the continuous glass fiber feeding device may be ordinary rubber rolls, but if at least one of them is made of metal or hard plastic, the strand can be pulled out without slipping. It is preferable to use a metal or hard plastic roll having grooves or protrusions in the longitudinal direction.

In addition to the above, the following method can be considered as a method for supplying continuous glass fibers. That is, while supplying continuous glass fibers by two small rolls rotating in opposite directions, the supplying device is reciprocated in the width direction of the SMC manufacturing apparatus. Alternatively, it is a method of disposing continuous glass fibers on the resin layer by arranging a plurality of the supply devices in the width direction of the SMC manufacturing device. In this case, the roll is preferably made of metal or hard plastic, at least one of which is preferable for pulling out the strand without slipping, and more preferably a roll having a groove or a protrusion in the longitudinal direction of the metal or hard plastic roll. Good to use.

Further, as another method, the nozzle is reciprocated in the width direction of the SMC manufacturing apparatus while the continuous glass fibers are blown out from the nozzle together with the high-speed air flow, or a plurality of the glass fibers are blown in the width direction of the SMC manufacturing apparatus. You may provide a nozzle and sprinkle a continuous glass fiber on resin paste.

Next, a method of molding a water tank panel using the first and second SMCs will be described.

FIG. 2 shows an example of a water tank panel,
(A) is a top view, (b) is sectional drawing which followed the AA arrow line. The water tank panel 21 has a square shape as a whole, a central portion 22 bulges outward in a truncated pyramid shape, and a peripheral edge portion is bent outward to form a flange portion 23.
Has become. The water pressure acts from the inside of the tank as indicated by arrow P. As shown in FIG. 3, the water tank panel 21 has a rubber tank 24 interposed therebetween, the flange portions 23 of adjacent water tank panels 21 are abutted against each other, and the water tank panel 21 is connected by a bolt 25. Used to assemble.

When molding this water tank panel,
First, the first SM containing continuous glass fiber as a reinforcing material
C and the second SMC containing CS as a reinforcing material were cut into substantially the same size as the upper surface of the male die of the molding die for the water tank panel, and after laminating the required number of each, the male die Place on top. In this case, the number of each of the first and second SMCs and the overlapping structure may be appropriately selected depending on the thickness, strength and the like required for the intended water tank panel. Further, the size of the SMC cut 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 pressurized and heated by the female die paired with the male die. At this time, the SMC also flows into the side surface of the male mold, and the side surface (flange portion) of the molded product is formed. In this way, a water tank panel having a flange portion on the periphery can be obtained. The mold temperature, molding pressure, time, etc. during molding are appropriately determined depending on the structure of the molded product, but are usually 100 to 180 ° C., 30 to 150.
The range is ² to 20 minutes, generally 1
30 to 150 ° C., 30 to 100 kg, and 3 to 10 minutes.

The cross section of the water tank panel thus obtained has a structure in which continuous glass fibers and CS are appropriately entangled with each other and has a layered structure, and is a molded product having high strength and good appearance.

[0031]

According to the method for manufacturing a water tank panel of the present invention, a first SMC having continuous glass fiber as a reinforcing material, and CS
The second SMC, which is used as a reinforcing material, is superposed, charged into a mold, pressurized and heated, so that a continuous glass fiber and CS are appropriately entangled and a molded product containing a layer is obtained. To be

As described above, since not only CS but also continuous glass fibers are contained, the strength required as a panel for a water tank is provided. Moreover, since the continuous glass fibers are dispersed in a non-directional manner, strength without directivity can be obtained. Furthermore, since the continuous glass fiber is contained in the SMC in advance, a molded product having a good appearance can be obtained.

Further, since the continuous glass fiber contained in the first SMC is not bonded with a secondary binder (mat binder) or the like, it has excellent fluidity at the time of pressure molding and at the time of cutting SMC before molding. There are few restrictions on the shape.

Therefore, as in the conventional method, the SMC
In addition to the above, glass water, glass fiber woven cloth, CSM, and other reinforcing base materials are also used together, and there is no directionality in strength and the appearance of improved water tank panel moldings without detailed consideration of molding conditions. Can be obtained.

[0035]

【Example】

Example 1 Te per one strand with a filament diameter of 11 μm
Using continuous glass fiber having x of 30 Tex as a reinforcing material,
A first SMC (weight per unit area: 1.5 kg / m ² ) containing 32 wt% of this continuous glass fiber in SMC was manufactured. On the other hand, the filament diameter is 13 μm, the Tex per strand is 72 Tex, and the cutting length is 25 mm.
S was used as a reinforcing material, and 32% of this CS was added to SMC.
% Second SMC (weight per unit area 3.5 kg
/ M ² ) was produced.

After cutting the first SMC and the second SMC into a size of 1000 mm × 980 mm, respectively,
Using 3 sheets of SMC and 2 sheets of 2nd SMC, put them in a molding die by alternately stacking them in the order shown in Table 1, molding temperature 135/140 ° C (male / female mold), molding pressure 47 kg. /
Pressurize and heat at cm ^{2 for} 4 minutes, 1000mm × 1000
A water tank panel with a size of mm was manufactured. The water pressure resistance strength was measured using this panel. The results are shown in Table 1.

Example 2 The same first SMC and second SMC as in Example 1
Cut to a size of 0 mm x 980 mm and cut the first SMC into 4
One sheet of the second SMC is used, the sheets are stacked in the order shown in Table 1 and charged into a molding die, and the same conditions as in Example 1 are applied.
A water tank panel having a size of 000 mm × 1000 mm was manufactured. The water pressure resistance strength was measured using this panel. The results are shown in Table 1.

Example 3 Te per one strand with a filament diameter of 11 μm
Using continuous glass fiber having x of 30 Tex as a reinforcing material,
S containing 40 wt% of this continuous glass fiber in SMC
MC (weight per unit area 1.9 kg / m ² ) was produced. On the other hand, a CS having a filament diameter of 13 μm, a Tex per strand of 72 Tex, and a cutting length of 25 mm was used as a reinforcing material, and the second SMC containing 32 wt% of this CS in the SMC (weight per unit area: 3.5 kg / m
² ) manufactured.

After cutting the first SMC and the second SMC into a size of 1000 mm × 980 mm, respectively,
Example 3 Using three SMCs and two second SMCs, the layers were alternately stacked in the order shown in Table 1 and charged into a molding die.
A panel for a water tank having a size of 1000 mm × 1000 mm was manufactured under the same conditions as described above. The water pressure resistance strength was measured using this panel. The results are shown in Table 1.

COMPARATIVE EXAMPLE 1 A filament having a diameter of 13 μm and Te per strand
SM with x of 72 Tex and a cutting length of 25 mm as a reinforcing material and containing 32 wt% of this CS in SMC
C (weight per unit area 3.9 kg / m ² ) was produced.

Three pieces of this SMC cut into 1000 mm × 980 mm and CSM (weight per unit area 30
Table 1 shows one piece obtained by cutting 0 g / m ² ) into 1050 mm × 1050 mm, and one piece obtained by further cutting a glass fiber woven cloth (weight per unit area 200 g / m ² ) into 1050 mm × 1050 mm. 1000 mm under the same conditions as in Example 1 after stacking in the above order and putting them in a molding die.
A water tank panel having a size of 1000 mm was manufactured. The water pressure resistance strength was measured using this panel. The results are shown in Table 1.

Comparative Example 2 Te per strand of 13 μm filament diameter
SM with x of 72 Tex and a cutting length of 25 mm as a reinforcing material and containing 32 wt% of this CS in SMC
C (weight per unit area 4 kg / m ² ) was produced.

Three pieces of this SMC cut into 1000 mm × 980 mm were piled up and put into a molding die, and a panel for a water tank having a size of 1000 mm × 1000 mm was manufactured under the same conditions as in Example 1. The water pressure resistance strength was measured using this panel. The results are shown in Table 1.

[0044]

[Table 1]

From the results shown in Table 1, the molded articles of Examples 1 to 3 in which the first SMC containing continuous glass fibers and the second SMC containing CS were used in combination were all sufficiently required as panels for water tanks. It can be seen that it has excellent water pressure resistance and has a good appearance. In contrast, SMC containing CS is used as a reinforcing base material for CSM.
It can be seen that the molded article of Comparative Example 1 in which the woven glass fiber and the woven glass fiber are stacked has a sufficient hydrostatic strength, but has a poor appearance. Further, in Comparative Example 1, the CSM and the glass fiber woven fabric had to be cut into almost the same size as the molded product. Further, it can be seen that the molded article of Comparative Example 2 using only SMC containing CS has a good appearance, but lacks in water pressure resistance strength.

[0046]

As described above, according to the method for producing a panel for a water tank of the present invention, the first SMC containing continuous glass fibers and the second SMC containing CS are used in combination, so that the water tank is It is possible to obtain a molded panel for a water tank which has sufficient water pressure resistance required for a water panel, has no directionality in strength, and has a good appearance.
Further, unlike the CSM, the continuous glass fibers in the first SMC are not bonded with a secondary binder, and thus have excellent fluidity during pressure molding, and there are few restrictions on the shape when the SMC is cut before molding. Therefore, as in the past, SMC
In addition to the above, a water tank panel can be obtained without using a reinforcing base material or detailed examination of the SMC molding conditions, and a great simplification of the process can be achieved.

[Brief description of drawings]

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

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 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 Continuous glass fiber strand 10 Strand supply roll 11 Defoaming / impregnating roll 12 Winding roll 13 Cake 21 Water tank Panel 22 Central part 23 Flange part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area B29L 7:00 4F 9:00 4F

Claims (3)

[Claims] 1. A first sheet molding compound in which continuous glass fibers are non-directionally dispersed and contained as a reinforcing material, and a second sheet in which glass fiber cut products having a cutting length of 12 mm to 50 mm are non-directionally dispersed and contained. A method for manufacturing a water tank panel, comprising at least one layer each of which is laminated with a molding compound, and the mixture is placed in a mold, and the resin is cured by pressurizing and heating. 2. The glass fiber content in the first and second sheet molding compounds is 20 to 60.
The method for producing a water tank panel according to claim 1, wherein the water tank panel has a wt%. 3. The continuous glass fiber used in the first sheet molding compound has a filament diameter of 6 to 6.
Tex per strand of 10 to 10 at 16 μm
0 Tex, the cut glass fiber used for the second sheet molding compound has a filament diameter of 6 to 16 μm and a Tex of 20 to 20 per strand.
The method for producing a water tank panel according to claim 1 or 2, which is 300 Tex.