JP2011161807A - Heating method of sheet and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve efficiency in heating a sheet of a fiber-reinforced resin to a temperature of a melting point or higher, and to avoid the occurrence of a deficit in the sheet at that time. <P>SOLUTION: A heater 10 for the sheet comprises an endless track 14, 16 which is a contact-type heating means, and an infrared irradiation lamp 34 as a noncontact-type heating means heating the sheet 12 exposed from the endless track 14, 16. Furthermore, a discharge nozzle 32 which is a hot-air supply means as an insulating means is arranged between the endless track 14, 16 and the infrared irradiation lamp 34. In this constitution, a length direction size (contact width) La of a part contacting with the sheet 12 in the endless track 14, 16 is preferably set so as to satisfy La&ge;V&times;t in advance when the carrier speed of the sheet 12 is V, and a theoretical time value in which the temperature distribution of a thickness direction in the sheet 12 contacting with the part becomes uniform is t. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a sheet body heating method and apparatus implemented when a sheet body made of fiber reinforced resin is heated.

  As is well known, the fiber reinforced resin contains fibers in a matrix resin, and is often supplied as a sheet. In order to obtain a molded body of a fiber reinforced resin having a desired shape, first, the sheet body is softened by subjecting the sheet body to heat treatment, and then the softened sheet body or the sheet body A predetermined forming process such as vacuum forming is performed on the laminated body obtained by laminating each other.

  As a heating apparatus for performing the heat treatment, for example, a device that employs contact heating described in Patent Document 1 can be cited. That is, the heating device includes a transport mechanism that sequentially feeds sheet bodies and a set of heating plates that sandwich the transported sheet bodies.

  When the sheet bodies to be conveyed are positioned between the heating plates spaced apart from each other, the heating plates approach each other and sandwich the sheet body. At this time, the sheet body contacts both the heating plates. At this time, heat is transferred from the heating plate to the sheet body, and as a result, the temperature of the sheet body, which is about room temperature, rapidly increases.

  In this case, the temperature after the sheet body is raised must be lower than the melting point of the resin as the matrix. This is because part of the molten resin adheres to the heating plate when heated above the melting point. Of course, in this case, a defect occurs in the sheet body. Therefore, problems such as a difference in weight for each sheet member and a sheet member having reduced strength and rigidity are caused.

  Further, in order to sandwich the sheet body between the heating plates and sufficiently heat it, it is necessary to stop the conveyance of the sheet body or reduce the conveyance speed. For this reason, it is not easy to increase the sheet conveying speed. In other words, it is difficult to process the sheet body at high speed.

  On the other hand, a heating apparatus that employs a non-contact heating method is also known. For example, in the heating apparatus described in Patent Document 2, a thermoplastic resin plate is heated by radiant heat. In this case, since the heat source is separated from the sheet body, there is an advantage that the molten resin does not adhere to the heat source even if the sheet body is heated to the melting point or higher of the resin.

Japanese Utility Model Publication No. 51-99765 Japanese Utility Model Publication No. 55-134218

  The non-contact type heating method has low heating efficiency. For this reason, in order to increase the temperature difference between before and after heating, it is necessary to arrange a large number of heat sources and increase the width of the heating region. Accordingly, the heating apparatus becomes larger and the capital investment increases. In general, the greater the temperature difference before and after heating, the more difficult it is to control the ultimate temperature with high accuracy, and the inconvenience that the sheet body is excessively heated has become apparent.

  The present invention has been made in order to solve the above-described problem, and even when the sheet body is conveyed at high speed, the sheet body can be efficiently heated, and there is a concern that the sheet body may be damaged. It aims at providing the heating method and apparatus of the sheet | seat body which can be wiped off.

In order to achieve the above object, the present invention is a sheet body heating method for heating a sheet body made of a fiber reinforced resin,
The sheet body to be conveyed is sandwiched by a sandwiching body that rotates and heated together with the sandwiched body, and heated to less than the melting point of the resin contained in the sheet body;
Heating the sheet exposed from the sandwich body to a temperature equal to or higher than the melting point of the resin by non-contact heating means;
It is characterized by having.

Further, the present invention is a sheet body heating device for heating a sheet body made of fiber reinforced resin,
A transport mechanism for transporting the sheet body;
A sandwiching body for sandwiching the conveyed sheet body while rotating;
Heating means for heating the sheet body sandwiched between the sandwich bodies together with the sandwich body;
Non-contact heating means for reheating the sheet body exposed from the sandwich body;
It is characterized by having.

  In the present invention, the “sheet body exposed from the clamping body” includes not only the case where the entire sheet body is exposed from the clamping body but also the case where a part of the sheet body is exposed from the clamping body. To do.

  That is, in the present invention, after the sheet body is heated to below the melting point by the sandwiching body that is a contact heating means, the sheet body is heated to the melting point or more by the non-contact heating means. For this reason, it is avoided that the resin contained in the sheet body is heated and melted by the sandwiching body and adheres to the sandwiching body, that is, a defect occurs in the sheet body.

  In addition, in this case, the temperature rise of the sheet by the non-contact heating means is small. This is because the sheet member is preferably heated to the vicinity of the melting point while being sandwiched between the sandwich members.

  Therefore, even if the non-contact heating means is small, the sheet body can be heated quickly. For this reason, it is avoided that the heating apparatus for sheet bodies enlarges, and a capital investment is avoided from rising. And since a sheet | seat body is heated rapidly, it is possible to process a sheet | seat body at high speed. In other words, the heating efficiency of the sheet body is improved.

  In addition, as a suitable example of a non-contact heating means, an infrared irradiation means or a hot air supply means is mentioned. Of course, you may use both together.

  Here, for example, when a lead wire or the like for energizing the non-contact heating means interferes with the sandwiching body, the sandwiching body and the non-contact heating means may be separated to some extent. In this case, when there is a concern that the temperature of the sheet body is excessively lowered, a heat retaining unit for retaining the sheet body may be provided between the sandwiching body and the non-contact heating unit.

  In any case, it is preferable to adopt an endless track including at least one set of rollers and a belt that is stretched over the one set of rollers and contacts the sheet body as each of the sandwiching bodies. . In this case, since the sheet body is sufficiently preheated, it becomes easy to make the temperature in the thickness direction from the lower end surface of the sheet body toward the upper end surface substantially uniform.

Furthermore, when the theoretical time value at which the temperature distribution in the thickness direction of the sheet body is uniform is t, the sheet body is conveyed so that the contact time t _real when the sandwiching body contacts the sheet body is equal to or greater than the theoretical time value t. It is preferable to set the speed V. For this purpose, the following formula (1) is established between the conveyance speed V and the theoretical time value t, where L is the contact width dimension of the portion that contacts the sheet body in the sandwiching body. The contact width dimension L and the conveyance speed V may be set.
L ≧ V × t (1)

  Here, the theoretical time value t is obtained as follows.

If q1 is the amount of heat transmitted from the belt and q2 is the amount of heat received by the sheet body, q1 = q2. Here, q1 is obtained by partially differentiating the temperature difference before and after heating with time. That is, the following formula (2) is established.
q1 = δT / δt (2)

On the other hand, q2 is obtained by multiplying the temperature change in the thickness direction of the sheet body by second-order partial differentiation with respect to the thickness direction dimension x, and the temperature diffusivity α of the sheet body. That is, the following formula (3) is established.
q2 = α (δ ² T / δx ² ) (3)

  Note that α = (λ / ρ) Cp, where λ, ρ, and Cp are the thermal conductivity, density, and constant pressure specific heat capacity of the sheet body, respectively. Since these values are known, the value of α is uniquely determined.

As described above, since q1 = q2, the following equation (4) is derived.
δT / δt = α (δ ² T / δx ² ) (4)

  Based on this equation (4), the theoretical time value t at which the temperature from the lower end surface to the upper end surface of the sheet body is uniform regardless of the part can be obtained.

Therefore, if the time t _real when the sheet body is in contact with the sandwiching body is equal to or greater than the theoretical time value t, the temperature along the thickness direction of the sheet body (from the lower end surface to the upper end surface) can be made substantially the same regardless of the part. .

The following relational expression (5) is established between the contact width dimension L, the sheet conveying speed V, and the contact time t _real .
L = V × t _real (5)

From this equation (5), by setting t _real to be equal to or greater than the theoretical time value t, that is, satisfying the above equation (1), the temperature from the lower end surface to the upper end surface of the sheet body is related to the part. It can be seen that they can be substantially identical.

  According to the present invention, a sheet body made of a fiber reinforced resin is first heated to below the melting point with a sandwich body that is a contact-type heating means, and then the melting point or higher by non-contact heating means such as infrared irradiation means or hot air supply means. To heat up. For this reason, it is avoided that the resin contained in the sheet body melts and adheres to the sandwiching body, and as a result, the occurrence of defects in the sheet body is avoided.

  Moreover, since the temperature rise of the sheet body heated by the non-contact heating means is small, the sheet body can be quickly heated even if the non-contact heating means is small. For this reason, while improving the heating efficiency of a sheet | seat body, it can avoid that the heating apparatus for sheet | seat bodies enlarges or a capital investment rises.

It is a principal part schematic side view of the heating apparatus for sheet bodies which concerns on embodiment of this invention. It is a principal part schematic side view of the clamping body which the heating apparatus for sheet bodies which concerns on another embodiment comprises. It is a graph which shows an example of the time-dependent change of the temperature along the thickness direction of a specific sheet | seat body. It is a chart which shows various conditions and evaluation results in Examples 1-20. It is a graph which shows the various conditions and evaluation result in Examples 21-38. It is a graph which shows the various conditions and evaluation result in Examples 39-48. It is a chart which shows various conditions and evaluation results in comparative examples 1-9. It is a graph which shows the various conditions and evaluation result in Examples 49-58.

  Hereinafter, the sheet body heating method according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments in relation to an apparatus for carrying out the method.

  FIG. 1 is a schematic side view of a main part of a sheet body heating apparatus (hereinafter also simply referred to as a heating apparatus) 10 according to the present embodiment. In the heating device 10, endless tracks 14 and 16 are employed as a sandwiching body for sandwiching the sheet body 12.

  The sheet body 12 is sent out by a transport mechanism (not shown) and transported along the arrow Y direction. This transport mechanism is a well-known one attached to this type of heating device 10, and therefore illustration and detailed description thereof are omitted. In FIG. 1, the thickness direction of the sheet body 12, that is, the side end surface is shown.

  In this case, the endless tracks 14 and 16 have a driving roller 18a whose rotating shaft is connected to a rotational driving source (not shown), a driven roller 20a, and a footwear plate 22a (which is stretched over the driving roller 18a and the driven roller 20a). Belt).

  The crawler plate 22a is formed by arranging a plurality of blocks 24a in parallel. A connecting piece 26a is bridged between adjacent blocks 24a and 24a. The connecting piece 26a is supported by the blocks 24a and 24a via the support pins 28a and 28a.

  The remaining one endless track 16 is configured in the same manner as the endless track 14. Accordingly, the same reference numerals are given to the same components, and the subscript a is replaced with b, and the detailed description is omitted. Needless to say, the drive roller 18a and the drive roller 18b are driven to rotate synchronously.

  The crawler plate 22a rotates (rotates) along the arrow X1, while the crawler plate 22b rotates (rotates) along the arrow X2. In the process, a portion of the shoe plate 22a that faces the lower end surface of the sheet body 12 and a portion of the shoe plate 22b that faces the upper end surface of the sheet body 12 are in contact with the lower end surface and the upper end surface.

Here, when the dimension in the length direction of the part is La, the value of La is the theoretical time value at which the conveyance speed V of the sheet body 12 and the temperature distribution in the thickness direction of the sheet body 12 in contact with the part are uniform. T is preferably set in advance so as to satisfy the following expression (6). The reason for this will be described later.
La ≧ V × t (6)

  Discharge nozzles 30a and 30b for discharging hot air generated by a hot air generation source (for example, a heater) between the driving roller 18a and the driven roller 20a and between the driving roller 18b and the driven roller 20b, respectively. Are arranged respectively. The driving rollers 18a and 18b and the driven rollers 20a and 20b are heated by receiving heat from the hot air discharged from the discharge nozzles 30a and 30b.

  The blocks 24a and 24b, and the entire footwear plates 22a and 22b, are indirect by receiving heat directly from the hot air or from the driving rollers 18a and 18b and the driven rollers 20a and 20b whose temperatures have increased as described above. Heated to a predetermined temperature. Of course, the crawler plates 22a and 22b are set to substantially the same temperature.

  The sheet body 12 inserted in the clearance between the endless tracks 14 and 16 moves along the arrow Y direction. On the downstream side in the arrow Y direction, from the side close to the endless tracks 14, 16, the discharge nozzle 32 (heat insulating means) for discharging hot air toward the sheet body 12, and the sheet body 12 are irradiated with infrared rays. An infrared irradiation lamp 34 (non-contact heating means) is provided.

  In addition, a hot air reaches | attains the range shown as Lb in FIG. That is, the temperature of the part between the hot air reach ranges Lb is held.

  Moreover, the infrared rays irradiated from the infrared irradiation lamp 34 are incident on a range indicated by Lc in FIG. That is, infrared rays can raise the temperature of the site | part between infrared incident width Lc.

  The heating apparatus 10 according to the present embodiment is basically configured as described above. Next, the function and effect will be described in relation to the heating method according to the present embodiment.

  First, the driving rollers 18a and 18b constituting the endless tracks 14 and 16 are rotationally driven, and the crawler plates 22a and 22b rotate in accordance with this, and the driven rollers 20a and 20b start rotating. Further, hot air is discharged from the discharge nozzles 30a and 30b, whereby the driving rollers 18a and 18b, the driven rollers 20a and 20b, and the footwear plates 22a and 22b are heated to increase the temperature. Accordingly, the portions of the sheet body 12 that are in contact with the crawler plates 22a and 22b are heated by receiving heat from the crawler plates 22a and 22b, whereby the temperature rises.

  The temperature rise of the sheet body 12 is suppressed to be less than the melting point of the resin that is the matrix of the sheet body 12. In other words, the temperature of the footwear plates 22a and 22b is set to a temperature that does not raise the temperature of the sheet body 12 above the melting point.

  Therefore, melting of the resin contained in the sheet body 12 is avoided. For this reason, it can prevent that the defect | deletion arises in the sheet | seat body 12 resulting from melted resin adhering to the footwear 22a, 22b.

In this case, the length direction dimension (in other words, the length of the heating region) La of the portion that contacts the sheet body 12 in the footwear 22a, 22b is V, the conveyance speed of the sheet body 12 is V, and the sheet that is in contact with the portion When the theoretical time value at which the temperature distribution in the thickness direction of the body 12 is uniform is t, it is preferably set so as to satisfy the following formula (6).
La ≧ V × t (6)

La is obtained as the product of the conveyance speed V of the sheet body 12 and the time t _real when the sheet body 12 contacts the endless tracks 14 and 16. From this and the above equation (5), the time t _real when the sheet body 12 contacts the portion is set to be equal to or longer than the theoretical time value t determined by thermal analysis, so that the upper end surface from the lower end surface of the sheet body 12 is obtained. The temperature up to can be made substantially uniform regardless of the part.

For example, the matrix is a nylon-6,6 resin having a melting point of 261 ° C. and a crystallization temperature of 220 ° C., a carbon fiber ratio of 58 wt%, a thickness of 0.25 mm, a density of 1450 kg / m ³ , and a constant pressure specific heat capacity of 1230 J / (Kg · K), when the sheet body 12 having a thermal conductivity λ of 0.7 J / (m · second · K) is brought into contact with the footwear 22a and 22b whose temperature Ta is set to 250 ° C. The theoretical time value at which the temperature along the thickness direction of the sheet body 12 becomes uniform at 250 ° C. according to the formulas (2) to (4) is 0.14 seconds (described later).

  In this case, when the conveyance speed V of the sheet 12 is 2.5 m / min, 10 m / min, 20 m / min, and 50 m / min, La calculated from the above equation (6) is 5. It becomes 8 mm or more, 23.3 mm or more, 46.7 mm or more, and 116.7 mm or more.

  By setting the length La of the heating region to an appropriate value obtained in this way, the sheet body 12 is sufficiently heated up to the middle part in the thickness direction. Therefore, variation in temperature along the thickness direction is suppressed. In addition, by setting the dimensions, it is possible to sufficiently heat the sheet body 12 even when the sheet body 12 is conveyed at a high speed.

There are irregularities on the actual surface of the sheet body 12. For this reason, there is a concern that the contact between the surface of the sheet body 12 and the shoe plates 22a and 22b becomes insufficient. Therefore, it may be preferable to set the value of La sufficiently larger than the product of V and t _real .

  A part of the sheet body 12 heated in this way is exposed from the crawler plates 22a and 22b. Hot air discharged from the discharge nozzle 32 comes into contact with the exposed portion.

  The temperature of the hot air is set to such an extent that the temperature of the sheet body 12 is maintained. Preferably, the temperature of the blocks 24a and 24b is Ta, the temperature of the sheet body 12 at the boundary (position A) between La and Lb is T1, and the temperature of the sheet body 12 at the boundary (position B) between Lb and Lc is T2. Ta × 0.9 ≦ T1 and Ta × 0.9 ≦ T2 are compatible temperatures. Thereby, it can avoid that the temperature of the sheet | seat body 12 falls, and as a result, temperature distribution arises inside this sheet | seat body 12. FIG. It is more preferable that Ta × 0.95 ≦ T1 and Ta × 0.95 ≦ T2 are satisfied, and it is most preferable that Ta = T1 = T2. In the above, it goes without saying that T1 and T2 are less than the melting point of the resin contained in the sheet body 12.

  The sheet body 12 is further conveyed along the arrow Y direction and reaches a position facing the infrared irradiation lamp 34. When the infrared rays are incident at this position, the sheet body 12 is heated to a temperature T3 equal to or higher than the melting point of the resin included in the sheet body 12 and reaches the position C.

  Since the sheet body 12 is preheated by the crawler plates 22a and 22b, the temperature rise of the sheet body 12 due to this heating is relatively small. For this reason, since it becomes possible to control the final reached temperature of the sheet | seat body 12 with high precision, the concern which overheats the sheet | seat body 12 can be wiped off.

  Moreover, although the infrared irradiation lamp 34 is a non-contact heating means, since the temperature rise width of the sheet body 12 is small, the sheet body 12 can be heated quickly. For this reason, it is not necessary to provide many infrared irradiation lamps 34. Therefore, since the heating apparatus 10 is prevented from increasing in size, it is also possible to avoid an increase in capital investment.

  As described above, according to the present embodiment, the sheet body 12 can be efficiently heated to the melting temperature of the resin or higher. In addition, the concern that the sheet body 12 is damaged during the heating process is eliminated.

  In the above-described embodiment, the discharge nozzle 32 that discharges hot air is disposed between the endless tracks 14 and 16 and the infrared irradiation lamp 34. However, the sheet body 12 exposed from the endless tracks 14 and 16 is used. If it is possible to reach the infrared irradiation lamp 34 while being maintained in a heat retaining state, the discharge nozzle 32 (heat retaining means) may be omitted. The means for heating the endless tracks 14 and 16 may be a heater instead of hot air.

  The non-contact heating means is not particularly limited to the infrared irradiation lamp 34, and may be a discharge nozzle that discharges hot air. In this case, when the discharge nozzle 32 (heat retaining means) is provided, hot air having a temperature higher than that of hot air discharged from the discharge nozzle 32 may be discharged from the discharge nozzle which is a non-contact type heating means.

  The heat retaining means is not particularly limited to the discharge nozzle that discharges hot air, and may be a heating lamp that emits heating light.

  Furthermore, a heater may be embedded in the crawler plates 22a and 22b, and the endless tracks 14 and 16 may be heated by the heater. You may make it combine a hot air and a heater.

  Furthermore, in the endless tracks 14 and 16, endless rings may be adopted instead of the crawler plates 22a and 22b.

  In addition, in this embodiment, the endless tracks 14 and 16 are employed as the sandwiching body, but a pair of heating rollers 40a and 40b as shown in FIG. 2 may be employed as the sandwiching body. In this case, the contact width dimension in which the heating rollers 40a and 40b contact the sheet body 12 is Ld in FIG.

[Examples 1 to 48, Comparative Examples 1 to 9]
A fiber reinforced resin having a matrix of a nylon-6,6 resin having a melting point of 261 ° C. and a crystallization temperature of 220 ° C. and a carbon fiber ratio of 58% by weight was selected as the sheet body 12. The thickness x, density ρ, constant pressure specific heat capacity Cp, and thermal conductivity λ of the sheet body 12 are 0.25 mm, 1450 kg / m ³ , 1230 J / (kg · K), and 0.7 J / (m · Second · K).

  The center of the sheet body 12 in the thickness direction (that is, the portion having a dimension along the thickness direction of 0.125 mm) is defined as a zero node, and the distance from the zero node to the upper end surface is virtually divided every 0.0125 mm. 1 node to 10th node. The tenth node is the upper end surface.

  And in the sheet | seat body 12 which contacts the footwear 22a, 22b by which temperature Ta was set to 250 degreeC, the time-dependent change of the temperature in each of a zero node-a 10th node is calculated | required according to said Formula (2)-(4). It was. The results are shown in FIG. From FIG. 3, the temperature at which the temperatures of the zero node to the tenth node are the same, in other words, the theoretical time value at which the temperature along the thickness direction of the sheet body 12 is uniform at 250 ° C. is 0.14 seconds. I understand.

  The sheet body 12 has various conditions in the heating device 10 having a configuration conforming to the heating device 10 shown in FIG. 1 except that the discharge nozzle 32 is not provided, that is, the heat retaining means is not provided. Heated under. However, the distance between the end point of La and the start point of Lc (for convenience, Lb) was 50 mm.

Specifically, the time t _real when the endless tracks 14 and 16 contact the sheet body 12 was changed by variously changing the value of La in FIG. The temperature T1 of the sheet body 12 at the boundary between La and Lb (position A), the temperature T2 of the sheet body 12 at the boundary (position B) between Lb and Lc, and the temperature T3 of the sheet body 12 at the end point (position C) of Lc. Was measured. Each is made into Examples 1-10, and an evaluation result is shown in FIG. In addition, P in FIG. 4 shows the output per unit length of the infrared irradiation lamp 34, and the same applies to the following drawings.

  In this evaluation, regarding T1, a case where Ta × 0.95 ≦ T1 ≦ Ta is determined as good (◯), and a case where Ta × 0.9 ≦ T1 ≦ Ta × 0.95 is determined (Δ) ), T1 <Ta × 0.9 is determined to be unacceptable (×), and T2 is similarly determined as Ta × 0.95 ≦ T2 ≦ Ta when the determination is good (◯), Ta × 0 The case where .9 ≦ T2 ≦ Ta × 0.95 was determined as acceptable (Δ), and the case where T2 <Ta × 0.9 was determined as unacceptable (x).

  Further, regarding T3, a case where the melting point was equal to or higher than the melting point was evaluated as good (◯), and a case where the melting point was lower than the melting point was determined as unacceptable (X).

  Furthermore, the case where the defect | deletion did not arise in the sheet | seat body 12 was set as the good determination ((circle)), and the case where it occurred was set as the impossibility determination (x).

  Separately, the sheet body 12 having the same specifications as described above was heated under various conditions by the heating apparatus 10 shown in FIG. However, the hot air arrival width Lb was 50 mm. Each is made into Examples 11-48, and the evaluation result is shown in FIGS.

  4 to 6, when the conveyance speed of the sheet body 12 is 2.5 m / min (Examples 1 to 10), the endless tracks 14 and 16 and the infrared irradiation lamp 34 sufficiently increase the temperature of the sheet body 12. Can be controlled, and the occurrence of defects in the sheet body 12 can be avoided. In addition, in the case of 10 m / min (Examples 11 to 20), or in the case of a higher speed of 20 m / min (Examples 21 to 21). 30) Further, in the case of a high speed of 50 m / min (Examples 31 to 38), the temperature of the sheet body 12 is increased by each of the endless tracks 14 and 16, the discharge nozzle 32 for supplying hot air, and the infrared irradiation lamp 34. It can be appreciated that it is possible to sufficiently control the occurrence of defects in the sheet body 12. Note that the reason why T1 is less than 250 ° C. even though La is not less than the length calculated by Equation (6) is that the surface of the sheet body 12 is not flat and has some unevenness as described above. It is inferred that

  For comparison, the sheet body 12 having various conveyance speeds was heated only by infrared irradiation by the infrared irradiation lamp 34. Each is designated as Comparative Examples 1 to 4.

  Furthermore, the sheet body 12 having various conveying speeds was heated only by contact heating with the endless tracks 14 and 16 heated to 250 ° C. Let each be the comparative examples 5-7.

  These Comparative Examples 1 to 7 were also evaluated in the same manner as described above. The results are shown in FIG. As shown in FIG. 7, in Comparative Examples 1 to 4, when the conveying speed of the sheet body 12 was set to 2.5 m / min, the melting point of the resin contained in the sheet body 12 could not be exceeded. On the other hand, in Comparative Examples 5 to 7, when the sheet body 12 was heated above the melting point of the resin, the sheet body 12 was damaged.

  From the above, it is clear that the sheet body 12 can be processed at high speed and the temperature of the sheet body 12 can be easily controlled by combining the contact-type heating means and the non-contact-type heating means that rotate.

[Comparative Examples 8 and 9]
Heating was performed after setting the time for the sheet body 12 to contact the endless tracks 14 and 16 to 0.12 seconds or 0.06 seconds, which is smaller than the theoretical time value t (0.14 seconds). Each is set as Comparative Examples 8 and 9, and the evaluation results are also shown in FIG.

  Here, in the embodiment 30 shown in FIG. 5, the time for the sheet body 12 to contact the endless tracks 14 and 16 is 0.15 seconds. Even in this case, sufficient temperature control was possible, but in Comparative Examples 8 and 9, T1 and T2 were low as shown in FIG. For this reason, the sheet body 12 may not rise in temperature beyond the melting point of the resin, and variations in the ultimate temperature are large.

[Examples 49 to 58]
Using the heating device 10 shown in FIG. 1, the sheet body 12 having the same specifications as described above was heated while repeating a cycle in which high-speed conveyance was continued for 10 seconds and then conveyance was stopped for 5 seconds. During conveyance, hot air was discharged from all of the discharge nozzles A to C and infrared rays were applied to the sheet body 12, while only infrared irradiation was stopped while conveyance was stopped. Each was made into Examples 49-58, and the evaluation result was shown in FIG.

  From FIG. 8, it can be seen that even when the high-speed conveyance and conveyance stop are repeated, it is possible to avoid the occurrence of defects in the sheet body 12 and to heat the sheet body 12 to the melting point or higher.

DESCRIPTION OF SYMBOLS 10 ... Sheet body heating device 12 ... Sheet body 14, 16 ... Endless track 18a, 18b ... Drive roller 20a, 20b ... Driven roller 22a, 22b ... Footwear 30a, 30b, 32 ... Discharge nozzle 34 ... Infrared irradiation lamp 40a, 40b ... Heating roller

Claims (10)

A sheet body heating method for heating a sheet body made of fiber reinforced resin,
The sheet body to be conveyed is sandwiched by a sandwiching body that rotates and heated together with the sandwiched body, and heated to less than the melting point of the resin contained in the sheet body;
Heating the sheet exposed from the sandwich body to a temperature equal to or higher than the melting point of the resin by non-contact heating means;
A method of heating a sheet body, comprising:   The heating method according to claim 1, wherein at least one of infrared irradiation means and hot air supply means is used as the non-contact heating means.   The heating method according to claim 1 or 2, wherein the sheet body is kept warm until the sheet body exposed from the sandwiching body reaches the non-contact heating means.   The heating method according to any one of claims 1 to 3, wherein the sandwiching body includes at least one set of rollers and a belt that is stretched over the one set of rollers and contacts the sheet body. A heating method for a sheet body, characterized by using an endless track. The heating method according to any one of claims 1 to 4, wherein when the theoretical time value at which the temperature distribution in the thickness direction of the sheet body is uniform is t, the nipping body contacts the sheet body. The sheet body heating method, wherein the sheet body conveyance speed is set so that the time t _real is equal to or greater than the theoretical time value t. A heating device for a sheet body for heating a sheet body made of fiber reinforced resin,
A transport mechanism for transporting the sheet body;
A sandwiching body for sandwiching the conveyed sheet body while rotating;
Heating means for heating the sheet body sandwiched between the sandwich bodies together with the sandwich body;
Non-contact heating means for reheating the sheet body exposed from the sandwich body;
A heating device for sheet bodies, comprising:   7. A heating apparatus for a sheet body according to claim 6, wherein said non-contact heating means is at least one of infrared irradiation means and hot air supply means.   The heating apparatus for a sheet body according to claim 6 or 7, further comprising a heat retaining means for retaining the sheet body before the sheet body exposed from the holding body reaches the non-contact heating means. apparatus.   9. The heating apparatus according to claim 6, wherein the sandwiching body includes at least one set of rollers and a belt that is stretched over the one set of rollers and contacts the sheet body. 10. A sheet body heating device characterized by an endless track. The heating device according to any one of claims 6 to 9, wherein a contact width dimension of a portion of the sandwiching body that contacts the sheet body is L, a conveyance speed of the sheet body is V, and the sandwiching body is contacted. When the theoretical time value at which the temperature distribution in the thickness direction of the sheet body is uniform is t, the following formula (1) is established between L, V, and t. .
L ≧ V × t (1)

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