JPH0955287A - Heater device for and melting heat-weldable resin-made tubular part by heating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To melt the end surface of a resin-made tubular part in a short time and at low temparature, thereby reduce energy consumption quantity needed for melting. SOLUTION: This heater device is used when a pair of resin-made pipes (2 and 4) to be connected are faced with each other, the facing end surfaces of the pipes are heated and melted respectively, and then both the resin-made pipes are relatively neared to be welded. Also, this device is provided with radiators (10e and 10f) composed of; a material capable of radiating, at high emissivity, far infrared rays including a wavelength region, having a relatively high absorption coefficient in an absorption spectrum of the resin-made pipes to be connected; and a heating element (10a) for heating the radiators to radiate given far infrared rays. In a preferable example, the resin-made pipes are composed of fluor-resin such as PTFE, FET, PFA, ETFE, CTFE, and PVDF, etc., or a high grade engineering plastic-made pipe, and the radiator is composed of a ceramic-made thin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pair of resin-made tubular parts to be connected to each other, and heats and melts the opposing end faces respectively, and thereafter, the two resin-made tubular parts are relatively brought close to each other for welding. The heater device used when performing, especially PTFE, FEP, PFA, ETFE, CTFE,
The present invention relates to a heater device used in a welding device for welding pipe materials made of a fluorine-based resin such as PVDF or a resin made of high-class engineering plastic such as PPS, by butting them together.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for higher quality resins in the fields of chemicals, food, semiconductor industry, biotechnology, chemical industry, housing, and gas due to their chemical resistance and cleanliness. For example, polyfluoroalkoxy, poly Fluorine resins such as vinylidene fluoride and super engineering plastics such as polyphenylene sulfide (PPS) and polyether ether ketone have come to be used as piping materials.

As a method of constructing the pipe, it has been common to process the end surface of the pipe material into flare and make a flange connection, or use a fitting to make a connection.

However, this construction method has problems that the construction is expensive, there is a risk of liquid leakage, and it is difficult to maintain cleanliness.

In order to solve this problem, attention has been paid to a construction method by welding a piping material made of a thermoplastic resin, and some welding devices have been developed.

For example, as disclosed in Japanese Patent Laid-Open No. 4-229231, particularly in an apparatus for butt welding plastic tubular parts, a chuck device for holding the parts in the axial direction does not come into contact with the end portion of the parts by heat rays. There is a heating device for heating the heating element, the heating device including a heating element of a metal plate which is electrically heatable and is covered with a ceramic coating layer.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The heating device shown in Japanese Patent No. 29231 is a heating element of a metal plate that can be electrically heated and is coated with a ceramic coating layer. The ceramic coating layer in the present invention was provided with the intention of uniform radiation of heat energy in combination with the lower metal plate having good heat conductivity.

Therefore, attention is paid to the absorption spectrum due to the difference in the material of the resin-made tubular parts to be bonded, let alone the material capable of emitting far infrared rays including the wavelength region having a relatively high absorptance in such absorption spectrum. Was not disclosed.

Therefore, the above-mentioned Japanese Patent Laid-Open No. 4-229231
The heating device disclosed in Japanese Patent Laid-Open Publication No. 2003-123242 cannot heat at a low temperature, which is not specified in the Japanese Patent Publication, and the energy consumption for that is high.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to obtain far infrared rays including a wavelength region having a relatively high absorptance in the absorption spectrum of a resin tubular part to be bonded. By selecting a material capable of radiating as the radiator, the end face of the resin tubular component can be melted in a short time and at a low temperature, and thus the energy consumption required for the resin can be reduced by heat welding. It is an object of the present invention to provide a heater device that heats and melts a tubular part made of metal.

[0011]

SUMMARY OF THE INVENTION According to the present invention, a pair of resin tubular parts to be connected are opposed to each other, and the opposing end faces are respectively heated and melted, and then both resin tubular parts are brought relatively close to each other. A heater device used when welding by welding, and a radiator made of a material capable of emitting far infrared rays having a high emissivity including a wavelength region having a relatively high absorptance in an absorption spectrum of a resin tubular part to be connected. The present invention relates to a heater device for heating and melting a heat-weldable resin tubular part, which is configured to include a heating element that heats a radiator to emit a predetermined far infrared ray.

In a preferred embodiment of the present invention, the resin tubular component is PTFE, FEP, PFA, ETFE, C.
It is made of a fluorine resin such as TFE or PVDF or a high-grade engineering plastic such as PPS, and the radiator is composed of a thin ceramic layer.

In another preferred embodiment of the present invention, the heating element is arranged to heat the surface of the radiator from 250 ° C to less than 580 ° C.

In still another preferred embodiment of the present invention, the resin tubular component is made of PFA or PVDF,
The radiator is made of a material capable of emitting far infrared rays having an emissivity of 0.5 or more, preferably 0.6 or more in a wavelength region of 6 to 10 μm, which has a relatively high absorptance in the absorption spectrum of PFA or PVDF. , Or the resin tubular part is P
A material which is made of PS and whose radiator can emit far infrared rays having an emissivity of 0.5 or more in wavelength regions 2.5 to 3.5 μm and 6 to 13 μm, which have relatively high absorptance in the absorption spectrum of PPS. Consists of.

According to a second aspect of the present invention, a pair of fluororesin-made or high-grade engineering plastic tubular parts to be connected are made to face each other, and the opposite end faces are respectively heated and melted. It is a heater device used when welding tubular parts relatively close to each other, and the emissivity of far infrared rays in a wavelength region having a relatively high absorptance in the absorption spectrum of the resin tubular parts to be connected is 0. A thin radiator made of a material having a temperature of 5 or more, preferably 0.6 or more, and a surface of the radiator having a temperature of 250 to 580 °
The heat of substantially the same amount as that of each of the pair of resin tubular parts, each of which is configured to include a heating element that heats the heating element to a temperature less than that and causes the radiator to emit a predetermined far infrared ray in the temperature range. The present invention relates to a heater device that emits energy.

According to a third aspect of the present invention, a pair of fluororesin-made or high-grade engineering plastic tubular parts to be connected are opposed to each other, and the opposite end faces are respectively heated and melted. A heater device used when welding tubular parts relatively close to each other, which is a far-infrared transparent glass plate having first and second flat surfaces, and an outer surface of the first and second glass plates. The laminated ceramic thin radiator has a far-infrared emissivity of 0.5 or more in a wavelength region having a relatively high absorptance in an absorption spectrum of a resin tubular part to be connected, preferably 0. A radiator made of a material of 6 or more, and an electrically heatable heater element interposed between both glass plates, wherein the surface of the radiator is heated to 250 ° C to less than 580 ° C. A heater element that causes the radiator to emit a predetermined far infrared ray in a range of degrees, and is built up at a position that surrounds at least the heater element of both glass plates and at a height slightly higher than the thickness of the heater element. Further, the present invention relates to a heater device that radiates substantially the same amount of heat energy to each of a pair of resin tubular parts configured by including a built-up portion made of a glass material that can be welded to the glass plate.

[0017]

According to the heater device of the present invention, when the heating element is heated to heat the radiator to a predetermined temperature, the absorption coefficient of the resin tubular parts to be connected is relatively high. It emits far-infrared rays including the wavelength region with high emissivity. Since the resin tubular part is heated by far infrared rays including the wavelength region with high absorptivity, even if the temperature of the radiator is lower than that of the conventional heating device, it reaches the melting temperature in a short time and melts. start. Further, once the radiator reaches a predetermined temperature, it continues to emit a predetermined far infrared ray without continuously heating it by the heating element. Since these properties and the temperature of the radiator may be lower than those of the conventional ones, the energy required to melt the end surface of the resin tubular component is small.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A heater device according to the present invention will be described in detail below with reference to FIGS.

1 (a) to 1 (c) are schematic perspective views showing respective steps of thermally welding a resin pipe using the heater device of the present invention.

The welding of the heat-weldable resin pipe is carried out as follows.

As shown in FIG. 1 (a), a pair of pipes 2 and 4 are each held by a clamp, and the heater device 10 of the present invention is inserted in the middle thereof. The distance between the heater surface of the heater device 10 and the end faces of the pipes 2 and 4 is made equal.

After being heated to a predetermined depth from the end faces of the pipes 2 and 4 to be in a molten state, the heater device 10 is pulled out as shown in FIG. 1 (b), and then, as shown in FIG. 1 (c).
As shown in FIG. 2, the pipes 2 and 4 are brought close to each other, but they are butted and connected. In the drawing, 2a and 4a represent the portions of the pipes 2 and 4 in a molten state.

The heater device 10 can be preheated to a predetermined temperature before it is inserted into the heating position between the pair of pipes 2 and 4, and when it is inserted into the heating position, the electricity is not supplied from the power source. It can be stopped.

Next, the heater device 10 according to the present invention will be described in detail with reference to FIGS. 2 and 3.

This heater device 10 is roughly composed of first and second flat infrared ray transmitting glass plates 10c and 10d.
And thin ceramic layers 10e and 10f respectively laminated on the outer surfaces of the first and second glass plates 10c and 10d,
An electrically heatable plate-shaped tungsten heater 10a interposed between both glass plates, and at a position surrounding at least the plate-shaped tungsten heater 10a of both glass plates and slightly higher than the thickness of the plate-shaped tungsten heater 10a. And a built-up portion 10b made of quartz glass that can be bonded to the glass plate that is built up by the height.

The ceramic layers 10e and 10f are made of a material capable of emitting far infrared rays having a high emissivity including a wavelength region having a relatively high absorptance in the absorption spectrum of the resin pipe to be connected.

FIG. 4 shows the relationship between the wavelength and the spectral emissivity when a typical metal is heated. And FIG. 5 is an infrared absorption spectrum of various resins.

As shown in FIG. 4, metal has an emissivity in the near infrared region of about 0.4 to 0.6, but the emissivity in the far infrared region is 0.3 or less. Is. However, when observing the infrared absorption spectra of various resins,
Generally, a polymeric material such as a resin has a high absorptance of far infrared rays having a wavelength of 6 μm or more and an extremely low absorptance of near infrared rays. This is the reason why it takes high temperature and time to heat the resin by the Nichrome (Ni-Cr) heating element or the iron / chromium / aluminum (Fe-Cr-Al) heating element. The energy required was also enormous.

According to the present invention, by selecting a material capable of emitting far infrared rays having a high emissivity including a wavelength region having a relatively high absorptance in the absorption spectrum of a resin pipe to be connected, as a radiator, It was made based on the finding that the end face of the resin pipe can be melted in a short time.

In recent years, PT has come to be widely used in medicine, food, semiconductor industry, biotechnology, chemical industry and the like.
FE, FEP, PFA, ETFE, CTFE, PVDF
The absorption spectra of fluorine-based resins such as PPS and high-grade engineering plastics such as PPS also have a high absorptivity in the far infrared region, and therefore it is preferable to use a radiator that can radiate such far infrared rays with a high emissivity.

FIG. 6 is an absorption spectrum diagram of PVDF. As can be seen from FIG.
At m, the absorptivity of far infrared rays is 0.5 or more. FIG. 7 shows an infrared spectral radiation output in the case where the ceramic layers 10e and 10f are made of CERASTATS BHA (trade name: distributor: Shima Trading Co., Ltd., Chuo-ku, Osaka City; manufacturer: Parker Co., Ltd., Higashi-ku, Osaka City). ing.
As a reference value, a blackbody furnace of 500 ° C is selected, and the surface temperatures of the ceramic layers 10e and 10f are 686 ° C and 500 ° C.
It measured with the Fourier-transform infrared spectrophotometer (FTIR) about each case of 300 degreeC and 250 degreeC.

FIG. 8 shows the ceramic layers 10e, 10e.
It is a figure which shows the correlation of the surface temperature of f, and the temperature of the tungsten heater 10a. The actual measured values serving as the basis for this figure were as follows. That is, the ceramic layers 10e, 1
The surface temperature of 0f (measured by infrared radiation thermometer) is 68
The temperature of the tungsten heater 10a in each case of 6 ° C., 500 ° C., 400 ° C., 300 ° C. and 250 ° C. (measured by a sensor installed in the heater) is 50, respectively.
It was 0 degreeC, 400 degreeC, 297 degreeC, 221 degreeC, and 192 degreeC.

As is apparent from FIG. 7, the ceramic layer 1
6 μm when the surface temperature of 0e and 10f is 500 ° C or lower
The absolute value of the radiated energy is not so large in the wavelength region exceeding. Therefore, if the emissivity of the far-infrared radiator in such a wavelength range is low, for example, 0.5 or less, if the object to be heated has a high absorptivity in such a wavelength range, it will be efficient. It will not be converted into heat energy. Conversely, if a material having a high emissivity of the far infrared radiator in such a wavelength range, a processing method, or the like is adopted, the object can be heated at a low surface temperature and in a short time.

In the case of the PVDF shown in FIG. 6, since the wavelength range where the absorptance is 0.5 or more is 6 to 10 μm, by selecting a material having a high emissivity in this wavelength range as the radiator, Can be heated efficiently and in a short time.

FIG. 9 is an absorption spectrum of PFA. As can be seen from FIG. 9, as in the case of PVDF, the absorptivity of far infrared rays is 0.5 or more in the wavelength range of 6 to 10 μm. . Therefore, by selecting a material having a high emissivity in this wavelength region as the radiator, the PFA pipe can be efficiently heated in a short time.

FIG. 10 is an absorption spectrum diagram of PPS. As can be seen from FIG. 10, in the case of PPS, the absorption coefficient becomes 0 intermittently in the wavelength range of 2.5 to 3.5 μm and 6 to 13 μm. .5 or more. Therefore, by selecting a material having a high emissivity in this wavelength region as the radiator, the PPS pipe can be efficiently heated in a short time.

As is clear from the above description, focusing on the region where the absorption rate of the object to be heated is higher,
If a material having a high emissivity in such a region is selected as the radiator, more efficient heating is possible. For example, PF
In the case of A and PVDF, since the wavelength region where the emissivity is 0.6 or more is 6.8 to 9.2 μm and 7.2 to 8.8 μm, the emissivity in such a wavelength region is particularly high. By selecting the materials as radiators, they can be heated efficiently and in a short time.

The ceramic layers 10e and 10f are made of the above-mentioned ceramics BHA and have a surface temperature of 500.
Table 1 shows the temperature changes with time at the end faces of the PFA, PVDF and PPS pipes in the case of ° C.

[0039]

[Table 1] As shown in Table 1, in all cases, the temperature drop at the end face of the pipe is gentle. This is because the heater device continues to emit far infrared rays even after the power is turned off. Also during this time, the melting progresses from the end face of the pipe to the inside, and the pipe can be melted to a predetermined melting depth.

Ceramics are widely used as far-infrared radiators because they generally have a large emissivity in the far-infrared region and are excellent in heat resistance.

However, the infrared radiation characteristics of each ceramic are closely related to the electron arrangement and the resistivity of the metal elements forming the ceramics, and depend on the processing method and the material combination method.

FIG. 11 shows the spectral emissivity of II-IV group metal oxide ceramics. As shown in FIG. 11, for example, alumina (Al ₂ O ₃ ) contains 10 to 20 μm.
The far infrared ray emissivity of m is not necessarily high, and it is not suitable when the wavelength region having a relatively high absorptance is 10 to 20 μm in the absorption spectrum of the resin pipe to be connected.

Generally, a composite of several kinds of materials is
In many cases, the physical properties of the raw materials to be composited are combined, and the infrared radiation characteristics have the same tendency. Knowing these tendencies, it becomes possible to select the optimum material that emits infrared rays in a wavelength region having a relatively high absorptance in the absorption spectrum of the resin pipe to be connected with a high emissivity.

In the illustrated preferred embodiment of the present invention, the infrared transmissive glass plate is made of quartz glass, but any infrared transmissive glass plate may be used, such as calcium aluminate. Alternatively, germanate glass and arsenic sulfide glass may be used.

Inside the heater device 10, which is the first and second glass plates 10c and 10d, the built-up portion 10 is also provided.
As a part of b, a plurality of ridges (having a height of approximately 0.2 mm) 10e at predetermined intervals are formed by padding. A plate-shaped tungsten heater 10a is arranged between the plurality of ridges 10e. As a result, the first and second glass plates 10c and 10d are supported by the plurality of ridges 10e even in the central portion, so that the heater device 1
Even if a force is applied to the center portion of 0, the possibility of breakage such as cracking is reduced.

In the heater device 10 of the present invention, the quartz glass is melted and the padding portion 10b and the plurality of ridges 10g are padded on one glass plate 10d, and the plate-shaped tungsten heater 10a is provided before they solidify. Can be produced easily and in a short time by placing the other glass plate 10c thereon.

At the center of the heater device 10, a temperature sensor 12 such as a thermocouple is arranged. The temperature of the tungsten heater 10a during melting is determined by the temperature sensor 12
Thus, the temperature is controlled and set to an appropriate temperature with reference to FIG.

The other pipe 4 melted by the heater device 10 is moved to the one pipe 2 side melted by the heater device 10 to weld the two pipes 2, 4 to each other.

Ceramic layer 10 in heater device 10
e, 10f and the cut end faces of the pipes 2, 4 are not in contact with each other, and it is optimal to provide an interval of approximately 1 to 10 mm, preferably 1.5 to 2.5 mm. If it is too close, the end faces of the pipes 2 and 4 may come into contact with the heater device 10 due to expansion of the pipes 2 and 4 at the time of heating, while on the other hand, the temperature of the heater device 10 must be raised if it is far away. The time at this time is about 5 to 150 seconds, and the stable radiation heat causes the pipe 2,
The end surface of No. 4 is melted uniformly.

[0050]

According to the heater device of the present invention, the end surface of the resin tubular part to be directly connected by the heating element is not heated and melted, but the absorptance is relatively high in the absorption spectrum of such a resin tubular part. It is characterized by using a radiator that emits far infrared rays with a high emissivity including a high wavelength region of.

That is, the heating element is heated, whereby
When the radiator is heated to a predetermined temperature, far infrared rays including a wavelength region having a relatively high absorptance in the absorption spectrum of the resin tubular parts to be connected are radiated with a high emissivity.

Since the resin tubular part is heated by the far infrared rays including the wavelength region having a high absorptivity, even if the temperature of the radiator is lower than that of the conventional heating device, the melting temperature can be shortened in a short time. It has the effect of reaching and melting. Therefore, there is an effect that the energy required to melt the end surface of the resin tubular component can be small.

Further, once the radiator reaches a predetermined temperature, a predetermined far-infrared ray is continuously emitted even if it is not continuously heated by the heating element. Therefore, the heating element is preheated and the resin to be connected is connected. When the end surface of the tubular component is melted by heating, the heat generation of the heating element can be stopped. As a result, the energy required to melt the end surface of the resin tubular component can be further reduced, and the time required for heating and melting can be shortened.

[Brief description of drawings]

1A to 1C are schematic external perspective views showing respective steps of thermally welding a resin pipe using the heater device of the present invention.

FIG. 2 is a cross-sectional view of an embodiment of the heater device according to the present invention.

3 is a vertical cross-sectional view of the heater device of FIG.

FIG. 4 shows the relationship between wavelength and spectral emissivity when a typical metal is heated.

FIG. 5 is an infrared absorption spectrum of various resins.

FIG. 6 is an absorption spectrum diagram of PVDF.

FIG. 7 shows infrared spectral radiation output when Celastaz BHA is used as a ceramic layer.

FIG. 8 is a diagram showing a correlation between the surface temperature of the ceramic layer of the heater device and the temperature of the tungsten heater.

FIG. 9 is an absorption spectrum diagram of PFA.

FIG. 10 is an absorption spectrum diagram of PPS.

FIG. 11 is a spectral emissivity of Group II-IV metal oxide ceramics.

[Explanation of symbols]

 2, 4 pipe 10 heater device 10a tungsten heater 10b built-up portion 10c, 10d glass plate 10e, 10f ceramic layer 10g ridge

Claims (7)

[Claims] 1. A pair of resin tubular parts to be connected are made to face each other, and the facing end faces are respectively heated and melted,
After that, the heater device is used when welding the two resin tubular parts relatively close to each other, and the heater device includes a long range including a wavelength region having a relatively high absorptance in the absorption spectrum of the resin tubular parts to be connected. A radiator made of a material capable of radiating infrared rays with a high emissivity, and a heating element for heating the radiator to emit a predetermined far infrared ray, and a pair of resin tubular parts each of which is configured to include: A heater device that radiates almost the same amount of heat energy. 2. A heater device for heating and melting a heat-weldable resin tubular component according to claim 1, wherein the resin tubular component is PTFE, FEP, PFA, E.
Fluorinated resin such as TFE, CTFE, PVDF or PPS
A heater device made of a high-grade engineering plastic such as, and the radiator is composed of a thin ceramic layer. 3. A heater device for heating and melting a heat-weldable resin tubular component according to claim 2, wherein the heating element has a surface of the radiator from 250 ° C. to 580 ° C.
A heater device configured to heat below ℃. 4. A heater device for heating and melting a heat-weldable resin tubular part according to claim 2, wherein the resin tubular part is made of PFA or PVDF.
The radiator is made of a material capable of emitting far infrared rays having an emissivity of 0.5 or more, preferably 0.6 or more in a wavelength range of 6 to 10 μm, which has a relatively high absorptance in the absorption spectrum of PFA or PVDF. A heater device characterized by the following. 5. A heater device for heating and melting a heat-weldable resin tubular component according to claim 2, wherein the resin tubular component is made of PPS, and the radiator is A heater made of a material capable of emitting far infrared rays having an emissivity of 0.5 or more in wavelength regions 2.5 to 3.5 μm and 6 to 13 μm, which have relatively high absorptance in the absorption spectrum of PPS. apparatus. 6. A pair of fluororesin resin or high-grade engineering plastic tubular parts to be connected are made to face each other, and the opposite end faces are respectively heated and melted, and then both resin tubular parts are brought relatively close to each other. A heater device used for fusion welding, wherein the emissivity of far infrared rays in a wavelength region having a relatively high absorptance in the absorption spectrum of the resin tubular parts to be connected is 0.5 or more, preferably 0. A thin radiator made of a material having a thickness of 0.6 or more, and the surface of the radiator is heated to 250 ° C. to less than 580 ° C., and the radiator emits predetermined far infrared rays in the temperature range. A heater device that radiates approximately the same amount of heat energy to each of a pair of resin tubular parts configured by including a heating element. 7. A pair of fluororesin-made or high-grade engineering plastic tubular parts to be connected are made to face each other, and the opposite end faces are respectively heated and melted, and then the two resin-made tubular parts are brought relatively close to each other. A heater device used for welding by means of: a far-infrared transparent glass plate having first and second flat surfaces; and a ceramic plate laminated on the outer surface of the first and second glass plates. A material that is a thin radiator and has a far infrared ray emissivity of 0.5 or more, preferably 0.6 or more in a wavelength region having a relatively high absorptance in the absorption spectrum of the resin tubular parts to be connected. And an electrically heatable heater element interposed between the glass plates, wherein the radiator has a surface of 250 ° C. to 5 ° C.
A heater element which is heated to less than 80 ° C. and causes the radiator to emit a predetermined far infrared ray in the temperature range, and at a position surrounding at least the heater element of both the glass plates and the heater An approximately equal amount for each of a pair of resin tubular parts made up of a built-up portion made of a glass material that can be welded to the glass plate, which is built up by a height slightly higher than the thickness of the element, and a pair of resin tubular parts. A heater device that radiates the heat energy of.