JP3880830B2 - Heater device and stretching device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heater device including a plurality of heating elements, and a stretching device that includes the heater device and stretches in the conveying direction while feeding a sheet-like material.
[0002]
[Prior art]
BACKGROUND ART Sheets made of thermoplastic resins are widely used as photographic film and magnetic recording tape supports and packaging films.
[0003]
A sheet-like material made of this thermoplastic resin is formed by casting a molten thermoplastic resin while cooling, and then stretched in the conveying direction or the width direction of the sheet-like material to give the required strength. It has been done.
[0004]
Conventionally, a stretching apparatus that stretches the sheet-like material after the casting is formed in the conveying direction includes a heater unit for heating the sheet-like material, and a plurality of sheets that are easily heated and stretched. An extending portion having a rotating roll is provided.
[0005]
FIG. 1 is a diagram illustrating an example of a conventional stretching apparatus that stretches (longitudinally stretches) a sheet-like material in a conveyance direction.
[0006]
As described above, the stretching apparatus 1 shown in FIG. 1 includes the heater unit 12 and the stretching unit 30, and in FIG. 1, the sheet-like material 100 heated by the heater unit 12 is stretched by the stretching unit 30. The state of being done is shown.
[0007]
The heater unit 12 shown in FIG. 1 reflects the radiant heat radiated from the five elongated rod-shaped infrared sheathed heaters 121 and the infrared sheathed heater 121 in the direction opposite to the sheet-shaped material to direct it toward the sheet-shaped material. For this purpose, the reflector 122 is provided.
[0008]
In FIG. 1, five infrared sheathed heaters 121 are arranged in the width direction of the sheet-like object 100, arranged in the conveying direction of the sheet-like object 100, and further covered with the reflecting plate 122. It is shown. Note that these infrared sheathed heaters 121 are overheated by mutual radiant heat if the distance between the adjacent infrared sheathed heaters is too short, and therefore maintain a predetermined distance set according to the heater employed. Are arranged.
[0009]
The stretching unit 30 shown in FIG. 1 includes a stretching roll 31, a cooling roll 32, and two nip rolls 33. The stretching of the sheet-like material 100 by the stretching unit 30 is performed at a low speed while the stretching roll 31 and the nip roll 33 are sandwiched between the sheet-like material 100 and are arranged on the upstream side in the conveyance of the sheet-like material. The cooling roll 32 and the nip roll 33, which are disposed on the downstream side in the conveyance, are similarly rotated by rotating at high speed while sandwiching the sheet-like material.
[0010]
In recent years, there has been an urgent need to reduce production costs. Therefore, improvement in productivity is also demanded in the manufacture of the above-mentioned sheet-like material, and the above stretching process is applied to sheet-like materials that are conveyed at higher speeds. It is done against. In the stretching process for the sheet-like material under high-speed conveyance, it is necessary to raise the temperature of the sheet-like material that moves at high speed to a temperature at which the sheet-like material can be stretched before the stretching timing.
[0011]
Therefore, it is conceivable to raise the temperature of the sheet-like material conveyed at high speed by the stretching timing by arranging as many infrared sheathed heaters as the number of heat necessary in the conveying direction of the sheet-like material.
[0012]
[Problems to be solved by the invention]
FIG. 2 is a view showing a stretching apparatus provided with a heater unit in which a large number of the infrared sheathed heaters are arranged in the sheet-like material conveying direction.
[0013]
As shown in FIG. 2, according to the heater unit in which the infrared sheathed heaters for the number of sheets necessary for raising the temperature of the sheet-like material following the high-speed conveyance are arranged in the sheet-like material conveyance direction, the sheet is conveyed at high speed. The sheet can be heated to a temperature at which it can be stretched by the stretching timing.
[0014]
However, since the infrared sheathed heaters provided in this stretching apparatus are arranged at a predetermined interval so as not to overheat due to each other's radiant heat as described above, the heat radiation area of the heater part with respect to the sheet-like material is Wide range. That is, in this stretching apparatus, the temperature of the sheet-like material conveyed at high speed is gradually increased to a temperature at which it can be gradually stretched over a long distance. As described above, when the heating capability per unit area for the sheet-like material is low, the neck-in amount of the sheet-like material in stretching increases, and the physical property defect occurs in the sheet-like material after stretching. There is.
[0015]
In view of the above circumstances, the present invention is a heater device in which the heat amount per unit area of the heat radiation region is increased as compared with the conventional one while ensuring a predetermined interval set between the heating elements of the heating elements employed. An object of the present invention is to provide a stretching apparatus that is equipped with such a heater device and has an increased temperature raising capability per unit area with respect to a sheet-like material.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the heater device of the present invention comprises:
A plurality of arranged heating elements, and a reflector that has openings in a heat radiation direction, covers the plurality of heating elements, and reflects radiant heat from the heating elements toward the openings, The heating elements are arranged in two stages on the upper and lower sides and in a staggered manner.
[0017]
In the heater device according to the present invention, the heating elements are arranged in two stages on the upper and lower sides and in a staggered manner, so as to secure a predetermined interval set between the heating elements that are employed, and per unit area of the heat radiation region. It is possible to increase the number of heating elements. For this reason, according to the heater device of the present invention, it is possible to increase the amount of heat per unit area of the heat radiation region as compared with the conventional one while ensuring a predetermined interval between the heating elements.
[0018]
In addition, the stretching apparatus of the present invention for achieving the above object
In a stretching apparatus for stretching the sheet material in the conveying direction of the sheet material while conveying the sheet material,
A plurality of arranged heating elements, and a reflector that has openings in a heat radiation direction, covers the plurality of heating elements, and reflects radiant heat from the heating elements toward the openings, The heating element is provided with a heater device arranged in a staggered manner in two upper and lower stages,
This heater device is provided at a position where the opening faces the sheet-like material being stretched.
[0019]
Since the stretching device of the present invention is provided with a heater device in which the amount of heat per unit area of the heat radiation region is increased as compared with the prior art while ensuring a predetermined interval between the heating elements, the stretching device of the present invention Then, the amount of heat applied per unit area of the sheet-like material to be conveyed can be increased as compared with the conventional case. As a result, the amount of heat necessary for stretching can be given to the sheet by heating at a shorter distance than in the conventional direction in the transport direction, and the neck-in amount can be reduced in the stretching apparatus of the present invention. Therefore, according to the stretching apparatus of the present invention, it is possible to obtain a sheet-like material having better physical properties than before.
[0020]
Here, the stretching device of the present invention includes a temperature control unit that controls the temperature independently by dividing the plurality of heating elements provided in the heater device into at least an upper heating element and a lower heating element. It is preferable to become.
[0021]
In the stretching apparatus of the present invention, the temperature of the upper heating element close to the reflector and the lower heating element away from the reflector can be controlled separately, so that the temperature of the upper heating element is reduced to the lower heating element. By lowering the temperature below the body temperature, it is possible to prevent deterioration of the upper heating element due to overheating due to heat generated between the reflector and the upper heating element.
[0022]
In addition, it is also preferable that the heater device provided in the stretching apparatus of the present invention is disposed above and below the sheet material so as to sandwich the sheet material being stretched from above and below.
[0023]
By doing in this way, the calorie | heat amount irradiated per unit area of the sheet-like material conveyed can be raised more reliably.
[0024]
Here, each of the plurality of heating elements of the heater device provided in the stretching device of the present invention is a rod-like member extending in the width direction of the sheet-like material, and the diameter of each of the plurality of heating elements is D. In a preferred embodiment, the plurality of heating elements are arranged at positions where the distance between the axes of adjacent heating elements is 1.5D or more and 3D or less.
[0025]
In this way, it is possible to more reliably prevent deterioration of the heating element due to overheating, which occurs because the heating element is too close, and to efficiently raise the temperature of the sheet-like material.
[0026]
Further, the plurality of heating elements of the heater device provided in the stretching device of the present invention are supported by respective predetermined support tools, and the support tool for supporting the plurality of heating elements is the sheet-like shape. It is also a preferred embodiment that the arrangement is oblique with respect to the conveyance direction of the object.
[0027]
By doing in this way, from the support body which supports the heating element, which is given to the sheet-like object when the support tool supporting the heating element is arranged in parallel with the conveyance direction of the sheet-like object It is possible to disperse the influence caused by the partial temperature decrease of the heating element due to the heat radiation.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0029]
First, the heater device of the present invention will be described.
[0030]
FIG. 3 is an external perspective view of an embodiment of the heater device of the present invention. 3 that are the same as those shown in FIG. 1 and FIG. 2 have the same reference numerals as those shown in FIG. 1 and FIG. .
[0031]
The heater device 20 shown in FIG. 3 includes seven infrared sheathed heaters 121 and a reflective cover 202 that reflects the radiant heat from the infrared sheathed heaters 121 toward the sheet-like object 100 (see FIG. 4) being conveyed. Is provided. The infrared sheathed heater 121 is arranged in a staggered manner in two upper and lower stages, and a support member (see FIG. 6) to be described later is attached to the reflective cover 202 to support the infrared sheathed heater 121. Yes. In addition, illustration about the power supply of the heater apparatus 20 is abbreviate | omitted.
[0032]
FIG. 4 is an external view of the infrared sheathed heater shown in FIG.
[0033]
The infrared sheathed heater 121 shown in FIG. 4 is one in which a nichrome wire is placed inside an incoloy 800 that is an alloy having an outer diameter of 20 mm, and magnesium oxide (MgO) that is an insulating material is filled between the nichrome wire and the incoloy 800. is there. Note that boron nitride (BN) may be filled instead of magnesium oxide.
[0034]
Moreover, the infrared sheathed heater 121 shown in FIG. 4 is comprised by the edge part 121a, the center part 121b, and the terminal part 121c.
[0035]
FIG. 5 is a side view of the heater device shown in FIG. 3.
[0036]
FIG. 5 shows a total of seven infrared sheathed heaters 121 arranged in a zigzag pattern with three on the upper stage and four on the lower stage, a reflective cover 202 covering these infrared sheathed heaters 121, and a sheet being conveyed. A shape 100 is also shown. 5 indicates the conveying direction of the sheet-like object 100, and the infrared sheathed heater 121 shown in FIG. 5 extends in the width direction of the sheet-like object 100.
[0037]
5 also shows a side surface portion 202a of the reflective cover 202. The side surface portion 202a has a diameter slightly longer than the diameter of the infrared sheathed heater 121 for supporting the end portion of the infrared sheathed heater 121. The hole 202b which has is provided. The end portion 121a of the infrared sheathed heater is supported by the hole 202b, and the central portion 121b of the infrared sheathed heater is supported by the upper surface 202c of the reflective cover 202 by a support (see FIG. 7).
[0038]
In the heater device 20 of this embodiment shown in FIG. 5, when the diameter of the infrared sheathed heater 121 is 20 mm (corresponding to D in the present invention), the distance between the adjacent infrared sheathed heaters 121 is 40 mm (2D). The closest distance of the infrared sheathed heater 121 to the reflective cover 202 is 30 mm (1.5 D), and the distance from the lower end of the infrared sheathed heater arranged on the lower side of the heater device 20 to the upper surface of the sheet-like object 100 is 25 mm. The watt density of the infrared sheathed heater is 6 W / cm ² , the total length of the infrared sheathed heater is 920 mm, and the applied voltage to the nichrome wire is 200V.
[0039]
FIG. 6 is a view of the heater device shown in FIG. 3 as seen from above through the reflective cover of the heater device.
[0040]
FIG. 6 shows a state in which the end portion 121 a of the infrared sheathed heater is inserted into the side surface portion 202 a of the reflective cover 202 and the central portion 121 b of the infrared sheathed heater is supported by the support 300.
[0041]
The support 300 shown in FIG. 6 has physical properties that occur in the sheet-like material due to the difference in the distance between the infrared sheathed heater 121 and the sheet-like material 100 in the width direction of the sheet-like material. This is to prevent unevenness.
[0042]
Further, FIG. 6 shows a state in which the support 300 for supporting the central portion 121b of the infrared sheathed heater is arranged obliquely with respect to the sheet conveying direction.
[0043]
FIG. 7 is an enlarged view showing a state in which the infrared sheathed heater is supported by the support.
[0044]
FIG. 7 shows an infrared sheathed heater 121 in which most of the outer periphery is captured by the support tool 300 except for the lower end.
[0045]
As shown in FIG. 6, the support tool 300 is arranged obliquely with respect to the conveyance direction of the sheet-like material, so that the support tool 300 is arranged in a straight line along the conveyance direction of the sheet-like material. The influence of the partial temperature decrease of the infrared sheathed heater due to the heat radiation of the support 300 is dispersed on the sheet-like material. That is, the temperature of the portion of these infrared sheathed heaters captured by the support tool 300 is lowered, and in this heater device 20, the support tool 300 is arranged in a straight line along the sheet-like material conveyance direction. If this is the case, the heater device 20 has a region that is cooler than the surroundings along the conveying direction of the sheet-like material. Therefore, even if the sheet-like material heated by the heater device having a part of the low temperature region as described above is stretched, good physical properties cannot be obtained. On the other hand, when the support tool 300 is arranged obliquely with respect to the conveying direction of the sheet-like material, a portion where the temperature is lowered by being captured by the support tool 300 is dispersed in the entire heater device. Therefore, the influence on the sheet-like material can be reduced.
[0046]
In the heater device of the present embodiment described above, the number of infrared sheathed heaters per unit area of the heat radiation area is increased more than before while more reliably preventing overheating due to mutual radiation heat of the infrared sheathed heaters. Therefore, according to the heater device of the present embodiment, it is possible to increase the amount of heat per area of the heat radiation region as compared with the conventional one while ensuring a predetermined interval between the infrared sheathed heaters.
[0047]
In the heater device of the present embodiment, a case where an elongated sheathed infrared sheathed heater is used is described as an example. However, the heater device of the present invention is not limited to this, and a heating element that radiates heat is vertically moved. What is necessary is just to arrange | position at 2 steps | paragraphs and zigzag form, and when the diameter of an infrared sheathed heater is set to D, although the distance between the adjacent infrared sheathed heaters is 2D, the heater apparatus of this invention Is not limited to this.
[0048]
Furthermore, in the heater device of the present embodiment, the infrared sheathed heater is supported by a support member attached to the reflective cover, but is not limited thereto, and is supported by a support member attached to other than the reflective cover. It is also possible that they are not supported by these supports. The shape of the support is not limited to the shape described in this embodiment, and a plate having a hole in a thin punching plate may be used obliquely.
[0049]
In addition, here, the heater device of the present embodiment has been described as an example provided in a stretching device, but the heater device of the present invention is not limited to this and may be used alone. Or even if it is provided in things other than the stretching apparatus, the effect of the present invention is not denied.
[0050]
Next, the stretching apparatus of the present invention will be described.
[0051]
FIG. 8 is an external perspective view of an embodiment of the stretching apparatus of the present invention.
[0052]
The stretching device 50 shown in FIG. 8 includes the heater device 20 shown in FIG. 3, the stretching portion 30 shown in FIG. 1, the auxiliary heater device 25 disposed at a position facing the heater device 20 with the sheet-like material interposed therebetween, and the heater device. The temperature controller 60 is disposed between the power source 20 and a power source (not shown) and controls the temperature of the heater device 20. In addition, illustration of the power supply of the heater apparatus 20 and the auxiliary heater apparatus 25 is abbreviate | omitted, and the difference between the auxiliary heater apparatus 25 and the heater apparatus 20 is only the difference in the number of infrared sheathed heaters.
[0053]
FIG. 9 is a side view of the heater device and a front view of the temperature controller shown in FIG.
[0054]
The seven infrared sheathed heaters 121 shown in FIG. 9 are divided into three control areas A, B, and C, and are controlled by the temperature controller 60. Of the seven infrared sheathed heaters shown in FIG. 9, the upper three belonging to the control area A are connected to the terminal 62 of the temperature controller 60, and the lower one belonging to the upstream control area C in the sheet conveyance direction. Are connected to the terminal 61 of the temperature controller 60. Further, the remaining two lower stages (the right side in FIG. 9) belonging to the control region B on the downstream side in the sheet conveyance direction are connected to the terminal 63 of the temperature controller 60.
[0055]
In this way, by dividing the upper side control and the lower side control of the infrared sheathed heaters arranged in a staggered manner in two upper and lower stages, the temperature of the sheathed heater belonging to the upper stage and the seeds belonging to the lower stage are divided. The temperature of the heater can be made different. Thus, by setting the temperature of the upper sheathed heater that is likely to generate heat between itself and the reflective cover 202 to be lower than that of the lower sheathed heater, deterioration of the infrared sheathed heater due to overheating can be prevented.
[0056]
In addition, since the lower-stage infrared sheathed heater is divided and controlled on the upstream side and the downstream side in the conveyance direction of the sheet-like material, the temperature of the sheet-like material can be raised immediately before the stretching timing. It is possible to obtain a sheet-like material having better physical properties than the case where the side temperature control is performed collectively.
[0057]
In addition, since it is as having mentioned above about the heater apparatus 20 and the extending | stretching part 30 of the extending | stretching apparatus shown in FIG. 8, duplication description is abbreviate | omitted.
[0058]
In addition, the function of the auxiliary heater device 25 of the stretching device 50 shown in FIG.
[0059]
In the stretching apparatus 50 of the present embodiment described above, the amount of heat applied per unit area of the sheet-like material to be conveyed by the heater device 20 which is an embodiment of the heater apparatus of the present invention described above is larger than in the past. Can be up. For this reason, since the amount of heat necessary for stretching can be applied to the sheet-like material by heating at a shorter distance than before, the amount of neck-in can be reduced. Therefore, according to the stretching apparatus of the present embodiment, a sheet-like material having better physical properties than before can be obtained.
[0060]
In the stretching apparatus 50 of the present embodiment, the case where the sheet-like material is sandwiched and the heater devices are arranged to face each other has been described as an example. However, the stretching apparatus of the present invention is not limited to this, and either The heater device may be disposed only on one side, and in the stretching device 50 of the present embodiment, the infrared sheathed heater provided in the heater device is divided into an upper stage and a lower stage, and each independently. Furthermore, the lower stage has been described with an example in which the temperature is separately controlled separately on the upstream side and the downstream side in the conveyance direction of the sheet-like material, but the stretching device of the present invention is not limited to this, and heat generation The body may be divided into an upper stage and a lower stage, and the temperature may be controlled independently of each other, or even if all the heating elements are heated uniformly and the temperature is not controlled. What the effect of is denied No.
[0061]
【The invention's effect】
As described above, according to the heater device of the present invention, it is possible to increase the amount of heat per area of the heat radiation region as compared with the conventional one while ensuring a predetermined interval between the heating elements.
[0062]
Further, according to the stretching apparatus of the present invention, the amount of neck-in at the time of stretching the sheet-like material can be reduced, so that a sheet-like material having uniform physical properties in the width direction can be obtained. The thickness can be controlled. Further, according to the stretching apparatus of the present invention, since the neck-in at the time of stretching the sheet-like material can be reduced, the control of the conveying speed of the sheet-like material is ensured, and the slip due to the speed difference between the roll and the sheet-like material is achieved. The mark can be eliminated from the sheet-like material. Furthermore, according to the stretching apparatus of the present invention, since the heating region for the sheet-like material can be made shorter than before, the stretching apparatus itself can be made compact by shortening the roll span.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a conventional stretching apparatus that stretches (longitudinal stretching) a sheet-like material in a conveyance direction.
FIG. 2 is a view showing a stretching apparatus provided with a heater unit in which a large number of the infrared sheathed heaters are arranged in the conveying direction of the sheet-like material.
FIG. 3 is an external perspective view of an embodiment of the heater device of the present invention.
4 is an external view of the infrared sheathed heater shown in FIG.
5 is a side view of the heater device shown in FIG. 3. FIG.
6 is a view of the heater device shown in FIG. 3 as seen from above through a reflective cover of the heater device.
FIG. 7 is an enlarged view of a state in which an infrared sheathed heater is supported by a support tool.
FIG. 8 is an external perspective view of an embodiment of the stretching apparatus of the present invention.
9 is a side view of the heater device and a front view of the temperature controller shown in FIG. 8. FIG.
[Explanation of symbols]
1, 10 Stretching device 12, 20, 22 Heater device 100 Sheet material 121 Infrared sheathed heater 121a End portion 121b Center portion 121c Terminal portion 122, 202 Reflective cover 202a Side surface portion 202b Hole 202c Top surface portion 25 Auxiliary heater device 30 Stretching portion 31 Drawing roll 32 Cooling roll 33 Nip roll 300 Supporting tool 60 Temperature controller 61, 62, 63 Terminal

Claims (5)

A plurality of arranged heating elements, and a reflector that has an opening in a heat radiation direction, covers the plurality of heating elements, and reflects radiant heat from the heating element toward the opening;
The plurality of heating elements are arranged in a staggered manner in two upper and lower stages, and the temperature of the heating element on the reflector side is set lower than the temperature of the heating element on the opening side. A heater device characterized by the above. In a stretching apparatus for stretching the sheet material in the conveying direction of the sheet material while conveying the sheet material,
A plurality of heating elements arranged, and a reflector that has openings in a radiation direction of heat, covers the plurality of heating elements, and reflects radiant heat from the heating elements toward the openings, A heating device is provided in two upper and lower stages and in a zigzag pattern, and a heater device in which the temperature of the heating element on the reflector side is set lower than the temperature of the heating element on the opening side is provided. ,
The stretching device, wherein the heater device is disposed at a position where the opening faces the sheet-like material being stretched. The stretching apparatus according to claim 2, further comprising a temperature control unit that divides the plurality of heating elements into an upstream side and a downstream side in a sheet conveyance direction and independently controls the temperature.   3. The stretching apparatus according to claim 2, wherein the heater device is disposed above and below the sheet material so as to sandwich the sheet material being stretched from above and below.   The plurality of heating elements provided in the heater device are each supported by a predetermined support, and the support for supporting the plurality of heating elements is oblique to the conveying direction of the sheet-like material. The stretching apparatus according to claim 2, wherein the stretching apparatus is arranged in a line.

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