JP7583359B2 - Sheet material manufacturing apparatus and sheet material manufacturing method - Google Patents

Description

The present invention relates to a sheet material manufacturing apparatus and a sheet material manufacturing method.

Composite materials made by mixing synthetic resin with fiber reinforcement materials such as carbon fiber and glass fiber are called fiber-reinforced plastics (FRP) and are widely used in housing equipment, transportation equipment, industrial products, etc.

Patent Document 1 describes a manufacturing method and manufacturing device for SMC (sheet molding compound), a sheet-shaped molding material (hereinafter referred to as "sheet material") used to mold FRP. Specifically, the carrier film is unwound in sequence from a roll on which it is wound. A doctor blade (also called a "doctor knife") is used to apply a resin compound to a predetermined thickness onto the carrier film that is unwound and moved by a conveying section, reinforcing fiber material is supplied and deposited on the applied resin compound, another carrier film coated with the resin compound is layered to form a sheet material, the sheet material is pressed to impregnate the reinforcing fiber material with the resin compound, and the sheet material is sequentially wound up to manufacture an SMC roll.

JP 2004-099820 A

The manufacturing standard for SMC is set based on the weight per unit area of SMC (hereinafter sometimes referred to as "unit weight"). Therefore, a portion of the manufactured SMC roll is unwound, cut off, and the weight of the cut sample is measured to inspect whether or not it meets the manufacturing standard for SMC.

Normally, SMC rolls are inspected on a production lot basis, so when the rolls are changed over, a portion of the downstream end of the sheet material being wound onto the SMC roll is cut off and inspected. With this type of inspection, if the sheet material is determined to be defective, all of the sheet material on the most recently wound SMC roll is treated as defective.

Not only that, if production of the next SMC roll is underway while the SMC roll is being inspected, that SMC roll will also be deemed defective. If production of the next SMC roll is stopped while the SMC roll is being inspected, the operating rate of the manufacturing equipment will decrease.

In addition, because the manufacturing method involves winding the material onto a roll, it is difficult to monitor weight fluctuations over the entire length of the sheet material that makes up the SMC roll, due to the nature of sampling inspection using cut samples. In addition to the manufacturing method involving winding the material onto a roll, there is also a manufacturing method in which the material is folded and packed into a box shape, but this method also has the same problems as above.

Therefore, the challenge is to control the quality of SMC and other sheet materials over their entire length and improve manufacturing efficiency.

The weight of sheet materials such as SMC is mainly determined by the total weight of the resin compound, reinforcing fiber material, and carrier film that make up the sheet material. When the inventors analyzed the factors that cause the unit weight of the sheet material to deviate from the manufacturing standard value, they found that the largest factor was the fluctuation in the weight of the resin compound.

The resin compound is supplied from the supply section to the carrier film. The supplied resin compound is then applied by a doctor blade to ensure a uniform resin thickness.

However, it was found that even using a doctor blade, the variation in the thickness of the applied resin could not be contained, which resulted in fluctuations in the weight of the resin compound. As will be described in more detail later, the inventors found that the cause of this was deformation of the doctor blade.

Based on the above analysis, the inventor came up with the idea of converting the control value of unit weight, which is the manufacturing standard for the sheet material, to derive a target value for the resin thickness of the resin compound, and then performing feedback control of the resin thickness when applying the resin compound.

That is, the sheet material manufacturing apparatus of the present invention is
a first supply unit that supplies a first resin compound to a first carrier film;
a first doctor blade for applying the first resin compound so as to make the resin thickness uniform;
a first driving unit that moves the first doctor blade toward or away from the first carrier film that is disposed opposite the first doctor blade;
At least one first resin thickness measuring unit that repeatedly measures a resin thickness of the applied first resin compound with respect to the first carrier film that moves relatively;
a depositing section that supplies and deposits a reinforcing fiber material on the first carrier film to which the first resin compound has been applied;
a sheet material forming section for forming a sheet material by laminating a second carrier film coated with a second resin compound onto the first carrier film on which the reinforcing fiber material has been deposited;
a control unit that corrects a target value of the gap between the first carrier film and the first doctor blade, the target value being set based on the weight per unit area of the sheet material to be formed, based on measurement results repeatedly obtained by the first resin thickness measuring unit, and sends the corrected target value to the first driving unit to control the first driving unit;
Equipped with.

The sheet material manufacturing device sets a target value for the distance between the first carrier film and the first doctor blade, which is directly related to the resin thickness, based on the unit weight, which is the manufacturing standard for the sheet material to be formed. This makes it possible to obtain a resin thickness that matches the management value (predetermined numerical range) for the unit weight of the sheet material to be formed.

Furthermore, the target value is corrected based on the measurement results repeatedly obtained by the first resin thickness measuring unit, and the corrected target value is sent to the driving unit, so that fluctuations in the resin thickness can be suppressed by feedback control.

This makes it possible to suppress the weight fluctuation of the resin compound over the entire length of the sheet material, which is the largest factor in the weight fluctuation of the sheet material. As a result, the conformity rate of the unit weight of the manufactured sheet material, which is the manufacturing standard, improves. This reduces the defect rate and improves the manufacturing yield.

In addition, the above-mentioned control of resin thickness can be performed without stopping the sheet material manufacturing equipment, which is less likely to lead to a decrease in the operating rate of the sheet material manufacturing equipment.

The sheet material manufacturing apparatus includes a second supply unit that supplies the second resin compound to the second carrier film;
a second doctor blade for applying the second resin compound so as to make the resin thickness uniform;
a second driving unit that moves the second doctor blade toward or away from the second carrier film that is disposed opposite the second doctor blade;
The apparatus may further include at least one second resin thickness measuring unit that repeatedly measures the resin thickness of the applied second resin compound with respect to the second carrier film that moves relatively.

The control unit may modify the target value of the gap between the second carrier film and the second doctor blade, which is set based on the weight per unit area of the sheet material to be formed, based on the measurement results repeatedly obtained by the second resin thickness measurement unit, and send the modified target value to the second drive unit to control the second drive unit.

The first resin thickness measuring unit may include a plurality of sensors arranged in the width direction of the first carrier film. The second resin thickness measuring unit may include a plurality of sensors arranged in the width direction of the second carrier film. This allows the width direction thickness of the carrier film to be optimized, further improving the compliance rate of the manufactured sheet material with manufacturing standards.

The correction of the target value in the control unit includes weighting the measurement results of the multiple sensors. When weighting, the weight value for the measurement result of the sensor that is located closest to the center position of the width direction of the first carrier film (or the second carrier film) among the multiple sensors may be set to be larger than the weight values for the measurement results of the other sensors.

The thickness of the first resin compound at the widthwise center of the first carrier film has a greater effect on the weight of the manufactured sheet material than the thickness of the first resin compound at the widthwise ends of the first carrier film. Therefore, when correcting the target value, the weighting value of the thickness result of the resin compound at the widthwise center of the first carrier film is set to be greater than the weighting value of the thickness result of the first resin compound at the widthwise ends of the first carrier film. This allows further optimization of the widthwise thickness of the first carrier film, bringing the weight of the first resin compound closer to the optimal value and further improving the manufacturing standard compliance rate.

The resin thickness of the second resin compound at the widthwise center of the second carrier film has a greater effect on the weight of the manufactured sheet material than the resin thickness of the second resin compound at the widthwise end of the second carrier film. The above-mentioned application control of the first resin compound is similarly applied to the application control of the second resin compound applied to the second carrier film. In other words, when correcting the target value, the weight value of the thickness result of the resin compound at the widthwise center of the second carrier film is set to be greater than the weight value of the thickness result of the second resin compound at the widthwise end of the second carrier film. This allows further optimization of the widthwise thickness of the second carrier film, bringing the weight of the second resin compound closer to the optimal value and further improving the manufacturing standard compliance rate.

The control unit may modify the target value based on at least one of the temperature, specific gravity, viscosity, and amount of accumulated liquid of the first resin compound or the second resin compound, and the moving speed of the first carrier film or the second carrier film. This further reduces the change in the thickness of the resin to be applied, further suppresses the weight fluctuation of the first resin compound or the second resin compound, and further improves the manufacturing standard compliance rate of the manufactured sheet material.

an impregnation section that presses the sheet material to impregnate the resin compound between the reinforcing fiber materials;
a sheet thickness measuring unit that measures the thickness of the sheet material after impregnation;
At least one of the deposition amount of the reinforcing fiber material and the force with which the sheet material is pressed in the impregnation section may be adjusted based on the measurement results of the sheet thickness measurement section.

This adjusts the amount of reinforcing fiber material deposited, which is one of the factors that cause weight fluctuations in the sheet material, and further improves the compliance rate of the manufactured sheet material with manufacturing standards. In addition, by adjusting the force pressing the sheet material, the impregnation rate of the first resin compound and the second resin compound into the reinforcing fiber material and the air content are adjusted, improving the compliance rate of the sheet material with manufacturing standards other than weight, such as its thickness.

The sheet material manufacturing method of the present invention includes the steps of:
a first resin compound application step of supplying a first resin compound onto a first carrier film and applying the first resin compound to the first carrier film with a first doctor blade so as to make the resin thickness of the first resin compound uniform;
a resin thickness measuring step of the first resin compound, in which a resin thickness of the applied first resin compound is repeatedly measured with respect to the first carrier film moving relatively;
a depositing step of supplying and depositing a reinforcing fiber material on the first carrier film coated with the first resin compound;
A sheet material forming step of laminating a second carrier film coated with a second resin compound onto the first carrier film on which the reinforcing fiber material has been deposited to form a sheet material,
In the coating step of the first resin compound, a target value of the gap between the first carrier film and the first doctor blade is set based on a weight per unit area of the sheet material to be formed, the target value is repeatedly corrected based on the resin thickness of the first resin compound which is repeatedly measured, and the gap between the first carrier film and the first doctor blade is adjusted according to the corrected target value.
Be prepared to do so.

The sheet material manufacturing method includes a second resin compound application step of supplying the second resin compound to the second carrier film and applying the second resin compound to the second carrier film with a second doctor blade so as to make the resin thickness of the second resin compound uniform;
a resin thickness measuring step of the second resin compound, in which a resin thickness of the applied second resin compound is repeatedly measured with respect to the second carrier film moving relatively;
In the application step of the second resin compound, a target value for the distance between the second carrier film and the second doctor blade may be set based on the weight per unit area of the sheet material to be formed, and the target value may be repeatedly revised based on repeatedly measured resin thicknesses of the second resin compound, and the distance between the second carrier film and the second doctor blade may be adjusted according to the revised target value.

In at least one of the resin thickness measuring steps, the resin thickness is measured at a plurality of positions aligned in a width direction of the first carrier film or the second carrier film,
In at least one of the application steps, when correcting the target value, the measurement results at each of the multiple positions may be weighted, and when the weighting is performed, a weight value for the measurement result at the measurement position closest to the widthwise center of the first carrier film or the second carrier film among the measurement results at the multiple positions may be set to be greater than the weight values for the measurement results at other measurement positions.

The target value may be modified based on at least one of the temperature, specific gravity, viscosity, and amount of liquid pool of the first resin compound or the second resin compound, and the moving speed of the first carrier film or the second carrier film.

an impregnation step of pressing the sheet material to impregnate the resin compound between the reinforcing fiber materials;
a sheet thickness measuring step of measuring the thickness of the sheet material after impregnation;
The method may further include a sheet thickness adjustment step of adjusting at least one of the deposition amount of the reinforcing fiber material and the force with which the impregnation section presses the sheet material based on the sheet thickness measurement result.

This allows for quality control over the entire length of the sheet material, improving the efficiency of sheet material production.

1 is a schematic diagram of a sheet material manufacturing apparatus according to a first embodiment; FIG. 1 is a flow diagram of a method for manufacturing a sheet material. FIG. 2 is an enlarged side view of a first doctor blade and its surrounding area. FIG. 11 is a flow chart showing calculation and control of a control unit in a coating step. FIG. 2 is an enlarged perspective view showing a peripheral area including a first doctor blade. 4 is a block diagram of a first resin thickness measuring unit, a control unit, and a first driving unit. FIG. FIG. 6 is a view seen from the V1 direction in FIG. 5 . FIG. 6 is a schematic diagram of a sheet material manufacturing apparatus according to a second embodiment.

The embodiment will be described in detail with reference to the drawings. Note that each drawing is shown diagrammatically. In each drawing, the dimensional ratios in the drawing do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match.

In the following, each drawing will be described with reference to the XYZ coordinate system as appropriate. In the XYZ coordinate system, the horizontal plane is the XY plane, and the direction of gravity is the -Z direction. Note that in this specification, when a direction is expressed and a positive or negative direction is to be distinguished, it is described with a positive or negative sign, such as "+X direction" and "-X direction". When a direction is expressed without distinguishing between positive and negative directions, it is simply described as "X direction". In other words, in this specification, when it is simply described as "X direction", both the "+X direction" and the "-X direction" are included. The same applies to the Y direction and the Z direction.

First Embodiment
[Outline of sheet material manufacturing apparatus and sheet material manufacturing method]
Fig. 1 is a schematic diagram of a manufacturing apparatus 100 for SMC, which is a sheet material in which glass fibers are impregnated with a resin compound. An outline of one embodiment of the sheet material manufacturing apparatus will be described with reference to Fig. 1.

As shown in FIG. 1, the sheet material manufacturing apparatus 100 has a plurality of supply sections (6, 16) that respectively supply the resin compounds (4, 14), a plurality of doctor blades (5, 15), a deposition section 8, a sheet material forming section 21, an impregnation section 18, and a conveyor belt 3. The carrier film (2, 12) onto which the resin compounds (4, 14) are applied is set in the sheet material manufacturing apparatus 100 in the form of a rolled unwinding roll (1, 11). The carrier film (2, 12) is then used by being pulled out little by little while the two unwinding rolls (1, 11) are rotating.

The carrier films (2, 12) are both made of a thermoplastic resin film such as polyethylene or polypropylene. The thickness of the carrier films (2, 12) is, for example, 10 to 50 μm. The width of the carrier films (2, 12) is, for example, 0.5 to 1.5 m. The first carrier film 2 and the second carrier film 12 may be made of the same material or different materials. The first carrier film 2 and the second carrier film 12 may be made of the same thickness or different thicknesses.

The conveyor belt 3 is a conveyor that supports the first carrier film 2 and the sheet material 10 from below and conveys them in the +X direction in the figure. The conveyor belt 3 is driven by a rotating roller 31. The rotation speed of the roller 31 can be changed by a control unit described below. This allows the movement speed of the first carrier film 2 and the sheet material 10 to be changed. Appropriate guide rollers are arranged inside the annular conveyor belt 3 to move the conveyor belt 3 smoothly.

The conveying belt 3 may have openings or may be composed of multiple belts as appropriate. The conveying mechanism for the first carrier film 2 and the sheet material 10 is not limited to a belt-shaped conveyor, and various conveying mechanisms may be used.

In addition to FIG. 1, an outline of one embodiment of a sheet material manufacturing apparatus and a sheet material manufacturing method will be described with reference to FIG. 2. FIG. 2 is a flow diagram of the sheet material manufacturing method. The sheet material manufacturing method includes a coating step S1, a deposition step S2, a sheet material forming step S3, and an impregnation step S4.

In the application step S1, the resin compound (4, 14) is supplied from the supply section (6, 16) onto the moving carrier film (2, 12). Then, the doctor blade (5, 15) is used to make the resin thickness of the supplied resin compound (4, 14) uniform. In this way, the resin compound (4, 14) is applied onto the carrier film (2, 12). Details of the doctor blade (5, 15) will be described later.

The resin compound (4, 14) may be a paste-like mixture with a viscosity of about 30 to 600 poise, made by mixing, for example, a thermosetting resin such as unsaturated polyester resin or vinyl ester resin as the main component with a filler, thickener, curing catalyst, internal mold release agent, shrinkage reducing agent, colorant, etc. as appropriate. The resin to be applied may be, for example, 0.5 to 2.0 mm thick. The first resin compound 4 and the second resin compound 14 may have the same components and the same amounts of components, or the first resin compound 4 and the second resin compound 14 may have different components or amounts of components.

In the deposition step S2, in the deposition section 8, reinforcing fiber material 9 is deposited on the first resin compound 4 applied to the first carrier film 2. Details will be described with reference to FIG. 1. The reinforcing fiber material 9 is formed by cutting multiple bundles of glass strands 7 into pieces of about 1 inch using a cutting device. The cut pieces of reinforcing fiber material 9 are then sprinkled and supplied onto the first resin compound 4 applied to the first carrier film 2 so as to be uniformly dispersed. This causes the reinforcing fiber material 9 to be deposited on the first resin compound 4.

In the sheet material forming step S3, in the sheet material forming section 21, a second carrier film 12 coated with a second resin compound 14 is bonded to a first carrier film 2 coated with a first resin compound 4 and having a reinforcing fiber material 9 deposited thereon. When bonding, the two carrier films (2, 12) are laminated so that the resin compounds (4, 14) coated on both carrier films (2, 12) are positioned on the inside of both carrier films (2, 12). This forms the sheet material 10 (see FIG. 1).

In the impregnation step S4, the sheet material 10 is pressed in the impregnation section 18 to impregnate the resin compound (4, 14) between the reinforcing fiber material 9. This allows the resin compound (4, 14) to impregnate between the reinforcing fiber material 9 and expels air bubbles (air) present in the sheet material 10. There are no particular limitations on the structure of the impregnation section 18, and various configurations can be adopted. The sheet material 10 that has passed through the impregnation section 18 is wound up to form a winding roll 20.

[Doctor Blade]
A description will be given of a plurality of doctor blades (5, 15). Fig. 3 is an enlarged side view showing one embodiment of the first doctor blade 5 for applying to the first carrier film 2 and its surrounding area in the sheet material manufacturing apparatus 100. The following description will be given for the application mechanism of the first resin compound 4 (i.e., the first supply unit 6, the first doctor blade 5, and the first resin thickness measuring unit (44, 45)), but unless otherwise specified, the following description can also be applied to the application mechanism of the second resin compound 14 (i.e., the second supply unit 16, the second doctor blade 15, and the second resin thickness measuring unit).

As shown in FIG. 3, a puddle of the first resin compound 4 is formed on the upstream side (-X side) of the first doctor blade 5 in the moving direction of the first carrier film 2. As the first carrier film 2 moves relative to the first doctor blade 5 (in FIG. 3, the first carrier film 2 moves in the +X direction relative to the stationary first doctor blade 5), the first resin compound 4 flows out from the puddle in the +X direction through the gap d1 between the first doctor blade 5 and the first carrier film 2. As a result, the first resin compound 4 is applied onto the surface of the first carrier film 2 with a resin thickness corresponding to the gap d1. In other words, the resin thickness is mainly influenced by the gap d1 between the first doctor blade 5 and the first carrier film 2.

The first doctor blade 5 has a plate shape with a small thickness in the X direction. The width (dimension in the Y direction) of the first doctor blade 5 is longer than the width of the first carrier film 2 (e.g., 1 m or more).

While the first resin compound 4 is being applied, the first supply unit 6 supplies the first resin compound 4 to the puddle so that the amount of the first resin compound 4 in the puddle is maintained as constant as possible.

The sheet material manufacturing apparatus 100 further includes a first drive unit 43 that moves the first doctor blade 5 toward or away from the first carrier film 2, a first resin thickness measurement unit (44, 45) that repeatedly measures the thickness of the applied first resin compound 4, and a control unit 70.

[Drive unit]
In this embodiment, a cylinder driven by an AC servo motor is used as the first drive unit 43 that moves the first doctor blade 5 toward or away from the first carrier film 2. However, the first drive unit 43 is not limited to this, and various drive sources and drive control methods can be applied. It is preferable that the first drive unit 43 moves the first doctor blade 5 toward or away from the surface of the first carrier film 2 in parallel.

[Resin thickness measurement unit]
An embodiment of the resin thickness measuring unit will be described with reference to Fig. 3. In this embodiment, a laser distance measuring sensor capable of measuring the distance to the detected object is used as the first resin thickness measuring unit (44, 45). The laser distance measuring sensor 44 is disposed on the upper side (+Z side) of the first carrier film 2 where the first resin compound 4 is applied, and the laser distance measuring sensor 45 is disposed on the lower side (-Z side) where the first resin compound 4 is not applied.

The laser length measuring sensor 44 arranged on the upper side projects a laser toward the upper surface of the applied first resin compound 4 and receives the laser reflected from the upper surface to measure the distance from the laser length measuring sensor 44 to the upper surface of the first resin compound 4. The laser length measuring sensor 45 arranged on the lower side projects a laser from an opening portion where there is no conveyor belt 3 (not shown in FIG. 3), passes through the first carrier film 2, and then receives the laser reflected from the contact surface (lower surface of the first resin compound 4) of the applied first resin compound 4 with the first carrier film 2 to measure the distance from the laser length measuring sensor 45 to the contact surface. The control unit 70 subtracts the sum of the distances measured by the laser length measuring sensors (44, 45) from the gap in the Z direction between the laser length measuring sensors (44, 45) to obtain the resin thickness of the applied first resin compound 4.

If the projected laser does not pass through the first carrier film 2, the control unit 70 measures the distance to the rear surface of the first carrier film 2. Then, the sum of the distances measured by the laser length measuring sensors (44, 45) and the thickness of the first carrier film 2 are subtracted from the gap between the laser length measuring sensors (44, 45) to obtain the thickness of the applied first resin compound 4.

The measurement of the thickness of the first resin compound 4 by the laser length measuring sensors (44, 45) is performed repeatedly over time with respect to the first carrier film 2, which moves relatively. This allows for continuous detection of changes in the thickness of the resin that is sequentially applied to the first carrier film 2. With regard to the relative movement, in this embodiment, the first carrier film 2 and the first resin compound 4 are moved in the +X direction with respect to the stationary laser length measuring sensors (44, 45). However, it is also possible to move the laser length measuring sensors (44, 45).

[Control unit]
The control unit 70 corrects the target value of the distance d1 between the first carrier film 2 and the first doctor blade 5 based on the measurement results repeatedly obtained by the first resin thickness measuring unit (44, 45) so as to maintain the resin thickness at a constant value. Then, the control unit 70 sends an instruction signal corresponding to the corrected target value to the first driving unit 43.

The control of the control unit 70 in the application step S1 will be described in detail with reference to FIG. 4. FIG. 4 is a flow diagram of the calculation and control of the control unit 70 in the application step S1. The following description will be about the application step in the application mechanism of the first resin compound 4, but unless otherwise specified, the following description can also be applied to the application step in the application mechanism of the second resin compound 14.

First, we will explain how to set the target value for the gap between the first carrier film 2 and the first doctor blade 5 before starting application. First, the unit weight of the sheet material 10 to be manufactured, which is the manufacturing standard value (control value), is obtained (step S11). The control value may be input into the control unit 70 by the production staff, or may be selected by the production staff from a product-specific control value table stored in a storage medium in the control unit 70.

Next, the obtained control value of the unit weight of the sheet material 10 is converted to calculate the unit weight of the first resin compound 4 (step S12). Specifically, the unit weight of the carrier film (2, 12) and the unit weight of the reinforcing fiber material 9 contained in the sheet material 10 constituting the unit weight are subtracted from the unit weight of the sheet material 10 (manufacturing standard value) to calculate the unit weight of the resin compound (4, 14). The calculated unit weight of the resin compound (4, 14) is distributed to the resin application amount of the first resin compound 4 and the resin application amount of the second resin compound 14 in the desired ratio.

The unit weight of each of the distributed resin compounds (4, 14) is the target weight to be applied. In the case of applying the first resin compound 4, the target value of the gap between the first doctor blade 5 and the first carrier film 2 is calculated, and the first driving unit 43 is driven according to the calculated target value to adjust the gap between them (step S13). To calculate the target gap, specifically, the weight of the first resin compound 4 calculated in step S12 is converted to the volume of the first resin compound 4 using the weight-volume conversion coefficient of the first resin compound 4 to be applied. Then, the weight is divided by the average width (average dimension in the Y direction) and average length (average dimension in the X direction) of the applied first resin compound 4 to obtain a resin thickness that satisfies the target value of the unit weight of the first resin compound 4. In this way, the manufacturing standard value (control value) of the sheet material is converted to obtain the resin thickness, and the target value of the gap d1 between the first carrier film 2 and the first doctor blade 5 to obtain this resin thickness is set.

The weight-volume conversion coefficient of the first resin compound 4 varies depending on the density inherent to the resin compound, as well as on temperature expansion and the amount of air contained in the resin, which vary depending on various factors such as the resin selected, the environmental temperature at which it is applied, and the application speed. Therefore, the weight-volume conversion coefficient of the first resin compound 4 may be varied depending on these various factors.

In this way, by setting the target value of the distance d1 between the first carrier film 2 and the first doctor blade 5 before coating begins based on the manufacturing standard value of the sheet material 10 being formed, the manufacturing standard conformity rate of the manufactured sheet material 10 is improved.

Then, application is started (step S14). Until application is completed, the resin thickness of the applied first resin compound 4 is repeatedly measured (step S15). If there is a deviation between the measured resin thickness and the target resin thickness (if Y), the process returns to step S13, and the distance between the first doctor blade 5 and the first carrier film 2 is calculated again to correct the target value. Then, the first drive unit 43 is driven according to the corrected target value to adjust the distance between the two. If there is no deviation between the measured resin thickness and the target value or the deviation is negligibly small (if N), the process returns to step S14 and application is continued without correcting the target distance between the first carrier film 2 and the first doctor blade 5.

In this way, the control unit 70 repeatedly corrects the target value of the gap between the first carrier film 2 and the first doctor blade 5 based on the measurement results repeatedly obtained by the resin thickness measurement unit (44, 45), and repeatedly sends the corrected target value to the first drive unit 43. As a result, the measurement results of the resin thickness are fed back to the target value of the gap d1 between the first carrier film 2 and the first doctor blade 5, making it possible to suppress fluctuations in the resin thickness.

The first resin thickness measuring unit (44, 45) can be positioned near the downstream side of the first doctor blade 5 (for example, within 1 m, preferably within 0.5 m, and more preferably within 0.2 m in the +X direction from the first doctor blade 5), thereby suppressing the time delay that occurs in feedback control.

When the length of the applied first carrier film 2 exceeds a predetermined value (e.g., the total length of one roll of sheet material 10), application of the first resin compound 4 is terminated (step S16).

In this embodiment, a PLC (Programmable Logic Controller) is used for the control unit 70 that performs the above-mentioned calculations and control. However, other sequencers, microcomputer boards, or general-purpose computers may also be used for the control unit 70.

[Control of resin thickness in the width direction of the carrier film]
5 is an enlarged perspective view showing a peripheral region including the first doctor blade 5. However, the first supply unit 6 of the first resin compound 4 is omitted from the drawing. As shown in FIG. 5, three sensors (44a, 44b, 44c) are arranged side by side in the width direction as a first resin thickness measuring unit 44 on the upper side (+Z side) of the first carrier film 2 where the resin is applied. Although only a part of them is shown in FIG. 5, three sensors (45a, 45b, 45c) are also arranged side by side in the width direction as a first resin thickness measuring unit 45 on the lower side (-Z side) of the first carrier film 2 where the resin is not applied.

Figure 6 is a block diagram showing a simplified signal transmission flow of the first resin thickness measuring unit (44, 45), the control unit 70, and the first driving unit (43a, 43b). As shown in Figure 6, the three sensors (44a, 44b, 44c) arranged on the upper side (+Z side) and the three sensors (45a, 45b, 45c) arranged on the lower side (-Z side) are connected to the control unit 70. The six sensors (44a, 44b, 44c, 45a, 45b, 45c) send signals received by the light to the control unit 70. The control unit 70 calculates the thickness of each of the resin at three positions aligned in the width direction of the carrier film from the six sensors, and controls the first driving unit (43a, 43b) of the first doctor blade 5 based on the calculated thickness.

The advantage of arranging multiple sensors side by side in the width direction will be explained with reference to FIG. 7. FIG. 7 is a schematic diagram viewed from the V1 direction in FIG. 5. As described above, the inventors have discovered that the first doctor blade 5 deforms when the first resin compound 4 is applied. In FIG. 7, the first doctor blade 5 is bent, particularly in the center part in the width direction, and deformed in a convex shape in the -Z direction.

Such deformation occurs due to thermal deformation of the first doctor blade 5 or stress deformation caused by being pressed by the resin compound, which occurs depending on the temperature, specific gravity, amount of liquid pooled, and supply position of the resin compound, as well as the moving speed of the carrier film, and deformation due to the weight of the first doctor blade 5.

When the first doctor blade 5 is deformed as shown in FIG. 7, the distance d2 between the first carrier film 2 and the first doctor blade 5 at the center in the width direction becomes narrower than the distances (d3, d4) between the first carrier film 2 and the first doctor blade 5 at the ends in the width direction. Therefore, the thickness of the resin applied by the first doctor blade 5 at the center in the width direction becomes thinner than the thickness of the resin applied at the center in the width direction.

As described above, the thickness of the first resin compound 4 at the widthwise center of the first carrier film 2 has a greater effect on the weight of the manufactured sheet material 10 than the thickness of the first resin compound 4 at the widthwise ends of the first carrier film 2. Therefore, in this embodiment, the resin thickness at the widthwise center is adjusted with priority over the resin thickness at the widthwise ends.

To adjust the resin thickness at the widthwise center with priority over the resin thickness at the widthwise ends, the target value is modified based on a weighted average dt obtained by weighting the measurement results at multiple positions. The weighting is set so that, among the measurement results at the multiple positions, the weight value of the measurement result at the position closest to the widthwise center of the first carrier film 2 is greater than the weight values of the measurement results at other positions.

For example, the weight value of the distance d2 between the first carrier film 2 and the first doctor blade 5 at the widthwise center is set to W2. The weight value of the distance d3 between the first carrier film 2 and the first doctor blade 5 at the widthwise end is set to W3, and the weight value of the distance d4 between the first carrier film 2 and the first doctor blade 5 at the widthwise end is set to W4. The weight value W2 at the widthwise center is set to a value greater than the weight values (W3, W4).

Then, the weighted average dt of the distance between the first carrier film 2 and the entire first doctor blade 5 is expressed as follows:

The deviation between the weighted average dt and the target value of the resin thickness is added to the target value of the gap between the first carrier film 2 and the first doctor blade 5 to reflect the deviation. Then, the drive units (43a, 43b) are driven according to the reflected target value.

In addition, when there is a misalignment between the distance d3 on the -Y side and the distance d4 on the +Y side regarding the distance (d3, d4) between the first carrier film 2 and the first doctor blade 5 at the widthwise end, the drive amount of the first drive unit 43b on the -Y side and the drive amount of the first drive unit 43a on the +Y side may be made different in order to reduce the misalignment (i.e., so that the blade tip of the first doctor blade 5 is parallel to the first carrier film 2).

<Modification of the first embodiment>
As a modification of the first embodiment, a feedforward control of the distance d1 between the first doctor blade 5 and the first carrier film 2 will be described. The following description will be given of the control in the coating step of the first resin compound 4, but the following description can also be applied to the control in the coating step of the second resin compound 14.

As mentioned above, the resin thickness is mainly, but not only, affected by the distance d1 between the first doctor blade 5 and the first carrier film 2. In other words, the resin thickness also varies with the deformation of the doctor blade. This variation is caused by disturbances such as the temperature, specific gravity, viscosity, and amount of accumulated liquid of the first resin compound 4, as well as the moving speed of the first carrier film 2. The above-mentioned feedback control aims to keep the resin thickness constant by adjusting the distance d1 between the first carrier film 2 and the first doctor blade 5 to compensate for the variation in resin thickness caused by these disturbances.

In this modified example, disturbances such as the temperature, specific gravity, viscosity, and amount of accumulated liquid of the first resin compound 4, as well as the moving speed of the first carrier film 2, are measured, and a change in resin thickness based on the change in the measured disturbance is predicted, and feedforward control is performed to correct the distance d1 between the first carrier film 2 and the first doctor blade 5 in advance. This prediction is performed by the control unit 70. The control unit 70 has a calculation algorithm for making the prediction stored in a storage medium.

This feedforward control can be used in combination with the feedback control described above. This can further reduce the change in the thickness of the resin being applied, thereby further suppressing the weight fluctuation of the first resin compound 4.

Second Embodiment
A second embodiment of the sheet material manufacturing apparatus will be described with reference to Fig. 8. Matters other than those described below are the same as those in the first embodiment, and therefore descriptions thereof will be omitted.

The sheet material manufacturing apparatus 200 shown in FIG. 8 has a sheet thickness measuring section 51 downstream (+X side) of the impregnation section 18. The sheet thickness measuring section 51 can use laser length measuring sensors (51a, 51b) like the resin thickness measuring section. It measures the thickness of the sheet material 10. Based on the measurement results of the sheet thickness measuring section 51, at least one of the force with which the sheet material 10 is pressed in the impregnation section 18 and the amount of reinforcing fiber material 9 added is adjusted to reduce the deviation from the target value of the thickness of the sheet material 10.

When making the adjustment, if the resin thicknesses of the first resin compound 4 and the second resin compound 14 on the carrier film (2, 12) are known as measured by the respective resin thickness measuring units, the variation in these resin thicknesses can be subtracted from the variation in the thickness of the sheet material 10. This improves the measurement accuracy. In this way, the force (impregnated state) pressing the sheet material 10 or the amount of reinforcing fiber material 9 added can be optimized to achieve a sheet thickness that meets the manufacturing standards.

<Modification of the second embodiment>
As a modification of the second embodiment, an additional sheet thickness measuring section may be disposed between the sheet material forming section 21 and the impregnation section 18 (section P1 shown in FIG. 8). By comparing the measurement results of the sheet thickness measuring section disposed in section P1 with the measurement results of the sheet thickness measuring sections (51, 52), it is possible to distinguish whether the deviation of the thickness of the sheet material 10 from the target value is due to an excess or deficiency of the force pressing the sheet material 10, or due to an excess or deficiency of the input amount of the reinforcing fiber material 9. This allows the sheet thickness to be made more compliant with the manufacturing standards.

Above, each embodiment of the sheet material manufacturing apparatus and their modified examples have been described. The present invention is not limited to the above-described embodiments, and the above-described embodiments and modified examples can be combined or various improvements or modifications can be made to the above-described embodiments and modified examples without departing from the spirit of the present invention. Examples of improvements or modifications are shown below.

The application mechanism and application step of the first resin compound 4 described in the above embodiment may be applied only to the application mechanism and application step of the second resin compound 14, and may not be applied to the application mechanism and application step of the first resin compound 4.

In the above embodiment, one doctor blade is provided for one carrier film, but two or more doctor blades may be provided for one carrier film.

The types of sensors used in the resin thickness measuring unit or sheet thickness measuring unit and the methods of using them described above are just examples, and other types of sensors or methods of using the sensors may be adopted. For example, to measure the thickness, length measuring sensors were provided on both the front and back sides and light was projected onto them, but it is also possible to measure the resin thickness by providing a length measuring sensor only on the front side and measuring the distance to the coated portion and the distance to the uncoated portion.

The control unit does not have to be integrated into the sheet material manufacturing apparatus. For example, only the control unit that controls the doctor blade drive unit and the resin thickness measurement unit may exist independently, and control the sheet material manufacturing apparatus in cooperation with the control units of other units (such as the deposition unit and the sheet material forming unit) used in the SMC manufacturing process. Different control units may be used for the coating mechanism that coats the first carrier film 2 and the coating mechanism that coats the second carrier film 12, or the same control unit may be shared.

In order to prioritize adjustment of the resin thickness at the center in the width direction over the resin thickness at the ends in the width direction, each measurement result was weighted to find a weighted average, but finding a weighted average is not essential, and an arithmetic average of each measurement result may also be found. Also, instead of the control unit calculating the target values and performing various calculations, a person may calculate the target values and perform various calculations and input the calculated target values and calculation results to the control unit.

In the above embodiment, an example was shown in which the resin compound application mechanism and the sheet material manufacturing device were applied to the manufacture of SMC, but in addition to the above-mentioned SMC, the sheet material to be manufactured can also be applied to the manufacture of prepreg, which is formed by impregnating a resin compound such as epoxy resin between carbon fibers, which are reinforcing fiber materials. There are no particular restrictions on the constituent materials of the sheet material, such as the resin compound, reinforcing fiber material, and carrier film, as long as they are used in the manufacture of SMC and prepreg.

Reference Signs List 1, 11: Unwinding roll 2: First carrier film 3: Conveyor belt 4: First resin compound 5: First doctor blade 6: First supply section 7: Glass strand 8: Deposition section 9: Reinforcing fiber material 10: Sheet material 12: Second carrier film 14: Second resin compound 15: Second doctor blade 16: Second supply section 18: Impregnation section 20: Take-up roll 21: Sheet material forming section 31: Roller 43 (for driving the conveyor belt): First drive section 44, 45 (for driving the first doctor blade): First resin thickness measuring section (laser length measuring sensor)
51a, 51b: Sheet thickness measuring unit (laser length measuring sensor)
70: Control unit 100, 200: Sheet material manufacturing device

Claims (11)

a first supply unit that supplies a first resin compound to a first carrier film;
a first doctor blade for applying the first resin compound so as to make the resin thickness uniform;
a first driving unit that moves the first doctor blade toward or away from the first carrier film that is disposed opposite the first doctor blade;
At least one first resin thickness measuring unit that repeatedly measures a resin thickness of the applied first resin compound with respect to the first carrier film that moves relatively;
a depositing section that supplies and deposits a reinforcing fiber material on the first carrier film to which the first resin compound has been applied;
a sheet material forming section for forming a sheet material by laminating a second carrier film coated with a second resin compound onto the first carrier film on which the reinforcing fiber material has been deposited;
a control unit that corrects a target value of the gap between the first carrier film and the first doctor blade, the target value being set based on the weight per unit area of the sheet material to be formed, based on measurement results repeatedly obtained by the first resin thickness measuring unit, and sends the corrected target value to the first driving unit to control the first driving unit ;
the first resin thickness measuring unit includes a plurality of sensors arranged in a width direction of the first carrier film,
A sheet material manufacturing apparatus, characterized in that the correction of the target value in the control unit includes weighting the measurement results of the multiple sensors, and when weighting, a weight value for the measurement result of a sensor among the multiple sensors that is located at a position closest to the widthwise center position of the first carrier film is set to be greater than the weight values for the measurement results of other sensors . a second supply section that supplies the second resin compound to the second carrier film;
a second doctor blade for applying the second resin compound so as to make the resin thickness uniform;
a second driving unit that moves the second doctor blade toward or away from the second carrier film that is disposed opposite the second doctor blade;
At least one second resin thickness measuring unit that repeatedly measures a resin thickness of the applied second resin compound with respect to the second carrier film that moves relatively,
The sheet material manufacturing apparatus of claim 1, characterized in that the control unit corrects a target value of the distance between the second carrier film and the second doctor blade, which is set based on the weight per unit area of the sheet material to be formed, based on measurement results repeatedly obtained by the second resin thickness measuring unit, and sends the corrected target value to the second driving unit to control the second driving unit. The sheet material manufacturing apparatus according to claim 2 , wherein the second resin thickness measuring unit includes a plurality of sensors arranged in a width direction of the second carrier film. The sheet material manufacturing apparatus of claim 3, characterized in that the correction of the target value in the control unit includes weighting the measurement results of a plurality of sensors arranged in the width direction of the second carrier film , and when weighting, a weight value for the measurement result of a sensor arranged in a position closest to the width direction center position of the second carrier film among the plurality of sensors arranged in the width direction of the second carrier film is set to be larger than the weight values for the measurement results of other sensors. The sheet material manufacturing device according to any one of claims 1 to 4, wherein the control unit modifies the target value based on at least one of the temperature, specific gravity, viscosity, and amount of liquid pool of the first resin compound or the second resin compound, and the moving speed of the first carrier film or the second carrier film. an impregnation section that presses the sheet material to impregnate the resin compound between the reinforcing fiber materials;
a sheet thickness measuring unit that measures the thickness of the sheet material after impregnation;
At least one of the deposition amount of the reinforcing fiber material and the force of the impregnation unit pressing the sheet material is adjusted based on the measurement result of the sheet thickness measurement unit.
6. The sheet material manufacturing apparatus according to claim 1, wherein the sheet material manufacturing apparatus comprises: a first resin compound application step of supplying a first resin compound onto a first carrier film and applying the first resin compound to the first carrier film with a first doctor blade so as to make the resin thickness of the first resin compound uniform;
a resin thickness measuring step of the first resin compound, in which a resin thickness of the applied first resin compound is repeatedly measured with respect to the first carrier film moving relatively;
a depositing step of supplying and depositing a reinforcing fiber material on the first carrier film coated with the first resin compound;
A sheet material forming step of laminating a second carrier film coated with a second resin compound onto the first carrier film on which the reinforcing fiber material has been deposited to form a sheet material,
In the coating step of the first resin compound, a target value of a gap between the first carrier film and the first doctor blade is set based on a weight per unit area of the sheet material to be formed, the target value is repeatedly corrected based on repeatedly measured resin thicknesses of the first resin compound, and the gap between the first carrier film and the first doctor blade is adjusted according to the corrected target value ;
In the resin thickness measuring step of the first resin compound, the resin thickness is measured at a plurality of positions aligned in a width direction of the first carrier film,
A sheet material manufacturing method, characterized in that in the application step of the first resin compound, when correcting the target value, the measurement results of each of the multiple positions are weighted, and when weighting, a weight value for the measurement result at the measurement position closest to the widthwise center of the first carrier film among the measurement results at the multiple positions is set to be larger than the weight values for the measurement results at other measurement positions . a coating step of the second resin compound, which comprises supplying the second resin compound to the second carrier film and coating the second resin compound on the second carrier film with a second doctor blade so as to make the resin thickness of the second resin compound uniform;
a resin thickness measuring step of the second resin compound, in which a resin thickness of the applied second resin compound is repeatedly measured with respect to the second carrier film moving relatively;
8. The sheet material manufacturing method of claim 7, characterized in that, in the applying step of the second resin compound, a target value of the distance between the second carrier film and the second doctor blade is set based on the weight per unit area of the sheet material to be formed, the target value is repeatedly corrected based on the resin thickness of the second resin compound which is repeatedly measured, and the distance between the second carrier film and the second doctor blade is adjusted according to the corrected target value. In the resin thickness measuring step of the second resin compound , the resin thickness is measured at a plurality of positions aligned in a width direction of the second carrier film,
The sheet material manufacturing method of claim 8, characterized in that in the application step of the second resin compound , when correcting the target value, the measurement results of each of the multiple positions are weighted, and when the weighting is performed , a weight value for the measurement result at the measurement position closest to the widthwise center of the second carrier film among the measurement results at the multiple positions is set to be larger than the weight values for the measurement results at other measurement positions. The sheet material manufacturing method according to any one of claims 7 to 9, wherein the target value is corrected based on at least one of the temperature, specific gravity, viscosity, and amount of liquid pool of the first resin compound or the second resin compound, and the moving speed of the first carrier film or the second carrier film. an impregnation step of pressing the sheet material to impregnate the resin compound between the reinforcing fiber materials;
a sheet thickness measuring step of measuring the thickness of the sheet material after impregnation;
The sheet material manufacturing method according to any one of claims 7 to 10, further comprising a sheet thickness adjustment step of adjusting at least one of the deposition amount of the reinforcing fiber material and the force with which the sheet material is pressed in the impregnation section based on the measurement result of the thickness of the sheet material.