JPH0679742A - Method for manufacturing water tank panel - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a water tank panel which demonstrates superior molding workability, excellent strength and has satisfactory appearance. CONSTITUTION:Continuous glass fiber 16 arranged in a random direction and a sheet molding compound containing 12 to 50mm long-glass cutting 9 dispersed in a random direction as a reinforcing material, are stacked over the other in layers. Further, these stacked materials are charged in a die and heated under pressure to cure the resin.

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 a molded product having excellent strength and appearance to be obtained.

[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.
A sheet molding compound (hereinafter referred to as SMC) obtained by thickening a glass fiber cut product (chopped strand, hereinafter referred to as CS) having a size of m or less, usually about 25 mm, as a reinforcing material, and another reinforcing base material. Generally, a method in which the thermosetting resin is cured by stacking the two and placing them in a mold and applying pressure and heat is 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.

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

[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. Therefore, when a plurality of SMC sheets are superposed and input at the time of pressure molding, in order to eliminate the directionality of strength and warpage after molding, it is necessary to consider a 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 tends to be limited by the width of itself.

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. The purpose 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 panel for a water tank according to the present invention comprises a non-directionally distributed continuous glass fiber and a non-directionally dispersed cutting length of 12 to 12. It is characterized in that a sheet molding compound containing a cut product of 50 mm of glass fiber as a reinforcing material is superposed in a plurality of layers, 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.

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 used as a reinforcing base material in the past in that the strands are not bonded to each other by a mat binder or the like. It is different from the CSM used. As a result, the continuous glass fibers and C, which are uniformly dispersed in the SMC without directivity
S, or continuous glass fiber comrades,
By the flow during pressure molding, they are entangled with each other, whereby a molded product of a water tank panel having high strength without directivity can be obtained. In addition, as the CS, a cutting length of 12 mm to 50 mm is taken from the workability at the time of manufacturing the SMC and the direction of the molding strength.
What is used.

SM of continuous glass fiber used as a reinforcing material
The content rate with respect to 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 with respect to SMC is preferably 5 to 55 wt%, more preferably 10 to 35 wt%.
Further, it is appropriate to adjust the content rate of the combined glass fibers of continuous glass fibers and CS to be 20 to 60 wt% with respect to 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 strength cannot be obtained when the panel for the water tank is molded.
If the amount is 5 wt% or less, the entanglement of CS and continuous glass fiber is too small, so the effect of improving the fluidity due to the combined use of CS becomes insufficient, and flow is greater than that of conventional SMC consisting of only CS with a length of 25 mm. Sex is greatly reduced.

When the content of continuous glass fibers is 55 wt% or more, further improvement in strength due to the continuous glass fibers cannot be obtained, but rather, the flow of SMC during pressure molding is hindered and the strength of the molded product at the flow end decreases. Easy to cause. On the other hand, if CS is 55 wt% or more, the conventional S
The same drawbacks as MC occur. That is, when the appropriate total glass fiber content is set, the continuous glass fiber amount becomes 5% or less, so that the reinforcing effect by the continuous glass fiber does not appear.

Furthermore, if the total glass fiber content of continuous glass fibers and CS is 20 wt% or less relative to SMC, the required water pressure resistance strength is obtained when the water tank panel is molded, regardless of the glass fiber structure. Can't get On the other hand, if it is 60 wt% or more, impregnation of the thermosetting resin composition paste becomes difficult during SMC production, and the unimpregnated part may cause internal peeling of the molded product, which may adversely affect the strength, which is not practical. .

As for the specification of the glass fiber as the reinforcing material, both the continuous glass fiber and CS have a filament diameter of 6
.About.16 .mu.m, preferably 9 to 13 .mu.m, and the Tex per strand is 10 for 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 glass fiber is low and the cost is high, which is not practical. On the other hand, if it exceeds 16 μm, the rigidity of the filament is increased and becomes brittle, so that the filament is likely to be cut by friction between the mold and the glass fiber or between the glass fibers during pressure molding, which adversely affects the strength of the molded product. Easy to exert.

On the other hand, when the Tex per strand is smaller than the above, the number of strands corresponding to the required glass content becomes large and bulky, and impregnation with the thermosetting resin composition paste tends to be difficult. When 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, resulting in uneven strength of the molded product.

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

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 heated by doctor knives 5 and 7. A continuous glass drawn from the cake 14 on the resin layer applied on the inner surface of one of the thermoplastic films 8 to form a resin layer by applying the resin layer on the inner surface of the plastic film (eg, polyethylene film) 6. The fibers 16 are non-directionally evenly distributed by a strand supply device 15 consisting of two rolls rotating in opposite directions.

Further, CS9 obtained by cutting the roving 10 with the roving cutter 11 is sprinkled on the resin layer of the thermoplastic film 8 from above the continuous glass fiber 16, and then the above-mentioned two thermoplastic films 6 , 8 inner layers on which the resin layers are formed are overlapped, the glass fiber reinforced material is impregnated with the resin paste by the defoaming / impregnating roll 12, and mixed, and then wound by the winding roll 13 and aged,
The SMC used in the present invention is obtained.

The continuous glass fibers 16 and CS9 may be dispersed and dispersed in the order described above or vice versa, or two or more layers may be simultaneously or alternately superposed and dispersed. Further, 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, in addition to the method using the doctor knives 5 and 7 described above, curtain coating, shower coating and spraying. Can be used.

The two rolls used in the apparatus for supplying the continuous glass fiber 16 during the SMC production may be ordinary rubber rolls, but at least one of them may be made of metal or hard plastic without slipping the strands. It is preferable for drawing out, and more preferably, a metal or hard plastic roll having a groove or a protrusion in the longitudinal direction is used.

Further, as the method for supplying the continuous glass fiber 16, the following method can be considered. That is,
With two small rolls that rotate in opposite directions,
While supplying the continuous glass fibers, the supply device is reciprocated in the width direction of the SMC manufacturing device, or a plurality of the supply devices are arranged in the width direction of the SMC manufacturing device to spread the continuous glass fibers on the resin layer. It is a method to let. 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 spread in the width direction of the SMC manufacturing apparatus. You may provide a nozzle and sprinkle a continuous glass fiber on resin paste.

By the above method, SMC in which continuous glass fibers and CS are appropriately entangled and dispersed without directionality
Can be obtained. The SMC thus obtained has good fluidity of the continuous glass fiber and CS in pressure molding, and as a result, a molded article for a water tank panel having no directionality, high strength and good appearance is obtained.

Next, continuous glass fiber and CS were used as reinforcements.
A method for forming a water tank panel using the above SMC containing and 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 SMC containing continuous glass fiber and CS as a reinforcing material is cut into substantially the same size as the upper surface of the male mold of the molding die 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. At this time, the number of SMCs to be superposed 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 to be cut is sufficient to cover almost 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.

In the water tank panel thus obtained, in its cross section, continuous glass fibers and CS are appropriately entangled, dispersed without directionality and in a layered form, and a molded product having high strength and good appearance. Becomes

[0037]

According to the method for manufacturing a water tank panel of the present invention,
Multiple layers of SMC containing both continuous glass fiber and CS as a reinforcing material are placed in a mold and pressed,
Since heating is performed, it is possible to obtain a molded product in which continuous glass fibers and CS are layered and appropriately entangled and contained.

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

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

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.

[0041]

【Example】

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

After cutting this SMC into a size of 1000 mm × 980 mm, four sheets of the SMC are stacked and placed in a molding die, and the molding temperature is 135/140 ° C. (male / female) and the molding pressure is 47 kg / cm. Pressurize and heat at ^{2 for} 4 minutes, 1000
A panel for a water tank of mm × 1000 mm was manufactured. The water pressure resistance strength was measured using this panel. The results are shown in Table 1.

Example 2 The same continuous glass fiber and CS as in Example 1 were mixed with S
20 wt% and 12 wt% were contained in MC to make SMC (weight per unit area 3.1 kg / m ² ) having a glass fiber content of 32 wt%.

After cutting this SMC into a size of 1000 mm × 980 mm, four sheets of the SMC are stacked and placed in a molding die, and 1000 mm × 1000 under the same conditions as in Example 1.
mm water tank panels were 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
x is 30 Tex continuous glass fiber and filament diameter 1
Tex per strand of 3 μm is 72 Tex
The cutting length of 25 mm and the CS of 20
SMC with a glass fiber content of 40 wt% (weight per unit area: 3.
1 kg / m ² ).

After cutting the SMC into a size of 1000 mm × 980 mm, four sheets of the SMC are stacked and placed in a molding die, and 1000 mm × 1000 under the same conditions as in Example 1.
mm water tank panels were manufactured. The water pressure resistance strength was measured using this panel. The results are shown in Table 1.

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

After cutting the SMC into a size of 1000 mm × 980 mm, four sheets of the SMC were stacked and placed in a molding die, and 1000 mm × 1000 under the same conditions as in Example 1.
mm water tank panels were manufactured. 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
SMC containing 32 wt% of CS having a cutting length of 25 mm, where x is 72 Tex (weight per unit area 3.9 kg / m ² ).
made.

Three pieces of this SMC cut into 1000 mm × 980 mm and CSM (weight per unit area 30
0 g / m ² ) cut into 1050 mm × 1050 mm, and 1 piece of glass fiber woven cloth (weight per unit area 200 g / m ² ) cut into 1050 mm × 1050 mm are overlapped to form molding metal. Example 1
A water tank panel 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 2 Te per strand of 13 μm filament diameter
x is 72Tex, 32w only for CS with a cutting length of 25mm
SMC containing t% (weight per unit area 4 kg / m
² ) made.

After cutting this SMC into 1000 mm × 980 mm, three sheets were stacked and put into a molding die, and a water tank panel 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.

[0053]

[Table 1]

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

[0055]

As described above, according to the method for manufacturing a water tank panel of the present invention, molding is performed using SMC containing CS and CS which are non-directionally dispersed continuous glass fibers. Therefore, it is possible to obtain a water tank panel that has sufficient water pressure resistance strength required for a water tank panel, has no directionality in strength, and has a good appearance. The continuous glass fiber contained in SMC is CS
Since it is not bonded with a secondary binder like M, it has excellent fluidity during pressure molding, and there are few restrictions on the shape during SMC cutting before molding. Therefore, S
A water tank panel can be easily manufactured by using only SMC without using a reinforcing base material in addition to MC or requiring detailed examination of the molding conditions of SMC, 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 an 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]

 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 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 continuous glass fiber which is non-directionally distributed,
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 is put into a mold by superposing a plurality of layers.
A method for manufacturing a water tank panel, which comprises pressurizing and heating to cure the resin. 2. The content of the continuous glass fiber is 5 to 55 wt% with respect to the entire sheet molding compound.
%, The content of the cut glass fiber material is 5 to 55 wt% with respect to 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 wt% with respect to the entire molding compound,
A sheet molding compound is used.
A method for manufacturing the water tank panel described. 3. The continuous glass fiber has a filament diameter of 6 to 16 μm and a Tex of 10 per strand.
A sheet molding compound having a filament diameter of 6 to 16 μm and a Tex of 20 to 300 Tex per strand is used for the water tank. Panel manufacturing method.