JPH10180879A - Resin member, thermal welding method therefor, and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently heat a welding surface to certainly weld the same to a part to be welded thermally even in a thick-walled resin member. SOLUTION: A pouring port opening member 1 is constituted so that the welding surface 11a heated by infrared rays to be thermally welded to the outer surface of the upper part of a container is covered with an outer layer material 21 having a hue of which the brightness is lower than that of a part other than the welding surface 11a. In this case, the infrared absorbing ratio of the welding surface 11a becomes higher than that of the part other than the welding surface 11a and the welding surface can be efficiently heated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin member which is thermally welded to a portion to be welded, a method for welding the same, and a welding apparatus therefor.

[0002]

2. Description of the Related Art As a method of covering an opening portion of a container filled with a beverage with a lid material made of a thermoplastic resin and sticking the lid material to the container, a thin lid material is heated to form a container. A so-called heat sealing of pressing is known (see Japanese Patent Publication No. 5-36284 and Japanese Patent Publication No. 7-2485). In the heat sealing, the lid is pressed against the container by directly pressing the lid against the container while the lid is pressed against the container at a high temperature.

[0003]

On the other hand, when a thick resin member is thermally welded to a portion to be welded, the resin member is directly heated by setting the pressing portion to a high temperature state like heat sealing. However, it is necessary to press the resin member against the welded portion after heating the welding surface of the resin member abutting on the welded portion by blowing heated air or the like.

However, when heating the welding surface of the resin member as described above, it is difficult to limit the location where the heated air is blown to only the welding surface, and the resin member is heated as a whole. Efficiency gets worse.

When the resin member has a portion having a low durability against a high temperature state, such as a thin portion, the blowing temperature of the heated air must be set accordingly. It was possible that the temperature of the surface could not be raised quickly and sufficiently.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to efficiently heat a welding surface even of a thick resin member. An object of the present invention is to provide a resin member that can be reliably thermally welded to a welded portion and a method for thermally welding the resin member.

[0007]

According to a first aspect of the present invention, there is provided a resin member having a welding surface which is heated by infrared rays and is thermally welded to a portion to be welded. The welding surface is covered with an outer layer material having a color lower in brightness than portions other than the welding surface.

According to a second aspect of the present invention, there is provided the resin member according to the first aspect, wherein the outer layer material is a sheet-like resin material adhered on a welding surface.

According to a third aspect of the present invention, there is provided the resin member according to the first aspect, wherein the outer layer material is a paint applied on the welding surface.

According to a fourth aspect of the present invention, there is provided the resin member according to any one of the first to third aspects, wherein the portion to be welded is an outer surface of a container filled with a beverage. The resin member is a spout opening member that forms a spout of the beverage on the outer surface of the container.

According to a fifth aspect of the present invention, there is provided an outer layer material forming step of coating a welding surface of a resin member contacting a portion to be welded with an outer layer material having a color lower in brightness than portions other than the welding surface. A heating step of heating the resin member by infrared rays,
And a pressing step of pressing a welding surface of the resin member covered with the outer layer material and heated by infrared rays to a portion to be welded.

According to a sixth aspect of the present invention, there is provided a method for heat-welding a resin member according to the fifth aspect, wherein, in the heating step, the absorptivity to the outer layer material and the absorption to portions other than the welding surface of the resin member. It is characterized in that infrared rays having a wavelength whose difference from the rate is equal to or more than a predetermined value are used.

According to a seventh aspect of the present invention, there is provided a resin material coated with an outer layer material having a color having a lower brightness than a portion other than the welded surface, wherein the welded surface which is heated by infrared rays and thermally welded to the welded portion. A conveying mechanism for conveying the member, an infrared irradiation mechanism for irradiating the resin member conveyed by the conveying mechanism with infrared light, and the resin member in the state in which the outer layer material is in contact with the portion to be welded; And a pressing mechanism for pressing the welded portion.

According to the first to seventh aspects of the present invention, since the outer layer material has a color lower in brightness than the portion other than the welding surface, the infrared ray absorption rate of the outer layer material is reduced in the portion other than the welding surface. Higher than the absorption rate. Therefore, by irradiating the resin member with infrared rays from the welding surface side and heating, the welding surface of the resin member covered with the outer layer material is more efficiently heated to a high temperature state than the other portions. be able to.

Further, even when the resin member has a portion having a low durability against a high-temperature condition such as a thin portion, the welding surface is maintained without setting the low-resistance portion to a high-temperature condition. Can be sufficiently raised.

Further, since the welding surface can be efficiently heated even in a state where the resin member is moving with respect to the infrared rays, the infrared irradiation source is fixed and the resin member is transported by a simple structure. In addition, the welding surface can be efficiently and continuously heated.

Further, in the invention according to claim 6, since the difference between the absorptivity for the outer layer material and the absorptivity for the portion other than the welding surface is a predetermined value or more, the infrared ray is used.
It is possible to more efficiently heat only the welded surface while reliably preventing a portion other than the welded surface from becoming a high temperature state.

[0018]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the back side of a spout opening member as a resin member according to an embodiment of the present invention.
Is a plan view of the back side of the spout opening member of FIG. 1, FIG. 3 is a cross-sectional view of the spout opening member of FIG. 2, taken along the line III-III, and FIG. 4 is a state where the spout opening member of FIG. FIG. 5 is a perspective view showing a continuous heating state of the spout opening member.

As shown in FIG. 4, the resin member according to the present embodiment is heat-sealed to the upper outer surface (welded portion) 5 of a paper container 3 in which a beverage is hermetically sealed. This is a hard thick-walled spout opening member 1 that is adhered and forms an opening at a spout 7 for pouring the beverage inside the container 3. The outer surface of the container 3 is coated with a thermoplastic resin.

As shown in FIGS. 1 and 2, the spout opening member 1 includes an outer frame portion 11, a movable portion 13, and a connecting portion 15,
These are integrally formed of polyethylene (PE) which is a thermoplastic resin.

The outer frame portion 11 is formed in a substantially B shape in plan view. The back surface (lower surface) of the outer frame portion 11 becomes a welding surface 11 a that is heated by infrared rays and is thermally welded to the upper outer surface 5 of the container 3. The movable portion 13 is a rectangular plate slightly smaller than the inner periphery of the outer frame portion 11 so as to be housed inside the outer frame portion 11 and form a gap 17 between the movable portion 13 and the rectangular inner peripheral surface of the outer frame portion 11. It is formed in a body shape. The outer frame portion 11 and the movable portion 13 are connected by a connecting portion 15 extending from both ends in the width direction substantially at the center in the longitudinal direction of the movable portion 13 and reaching the rectangular inner peripheral surface of the outer frame portion 11. 15 through the outer frame portion 11
It is supported by. The connecting portion 15 is formed in a rod shape, and the movable portion 13 is inclined with respect to the outer frame portion 11 when the connecting portion 15 is twisted.

The welding surface 11 a of the spout opening member 1 is covered with an outer layer material 21. The outer layer material 21 is formed of a portion other than the welding surface 11a of the spout opening member 1 (for example, the movable portion 13).
And a thin sheet-shaped resin material having a color lower in brightness than the connection portion 15), and is attached to the welding surface 11a.
In the present embodiment, the spout opening member 1 itself is colored white with high brightness, and the outer layer material 21 is colored black with the lowest brightness. As the outer layer material 21, for example, a material obtained by forming a PE resin containing carbon black in a thin shape is used. Although the sheet-like resin material is used as the outer layer material 21, a paint may be applied to the welding surface 11a in a thin film instead, and the applied paint may be used as the outer layer material.

The reason why the outer layer material 21 is attached to the welding surface 11a is that the infrared absorption performance depends on the wavelength of the infrared light and the color of the object to be heated, and the lower the brightness, the higher the absorption. By coloring the welding surface 11a to a color (black) having a lower brightness than the color (white) of the other portions, only the portion of the spout opening member 1 that needs to be heated is
This is for raising the temperature accurately and in a short time.

The relationship between the wavelength of the infrared ray, the color of the object to be heated, and the infrared ray absorbing performance will be described in more detail below.

FIGS. 6 and 7 show the wavelengths of infrared rays (about 250
6 shows the case of a black surface using a PE resin containing carbon black, and FIG. 7 shows the case of a white surface using a PE resin containing no carbon black. Are respectively shown.

P on the black surface containing carbon black
As shown in FIG. 6, the infrared absorptivity of the E resin is as high as 90% or more regardless of the wavelength of infrared rays. On the other hand, as shown in FIG. 7, the infrared absorptivity of the PE resin on the white surface containing no carbon black is relatively high at 80% or more in a short infrared wavelength range, but sharply at a wavelength of about 400 nm. It decreases to 20% or less, becomes 1% or less at a wavelength near 1000 nm, and gradually increases to about 70% while repeatedly increasing and decreasing at a longer wavelength.

Therefore, the spout opening member 1 is formed of a white surface PE resin containing no carbon black, and the welding surface 11a of the spout opening member 1 is formed of an outer layer material 21 made of a black surface PE resin containing carbon black. When the spout opening member 1 is irradiated with infrared light having a wavelength of 400 nm or more from the welding surface 11a side, a larger amount of infrared light is absorbed by the outer layer material 21 than other portions, and the welding surface 11a is It will be heated to a higher temperature state.

At each wavelength, a difference in infrared absorptivity between a black surface PE resin containing carbon black and a white surface PE resin not containing carbon black is determined, and the difference in the absorptivity is not less than a desired value. By irradiating infrared rays having a wavelength such that only the welding surface 11a can be heated more efficiently. For example, in order for the difference between the two absorptivity to be 80% or more, the wavelength is set to 600 n.
An infrared ray having a wavelength of m to 1400 nm may be used.

FIG. 8 shows the infrared absorptance at each wavelength of infrared when the surface of the PE resin not containing carbon black is colored with a black paint.
Even when a coating material is applied to the welding surface 11a in the form of a thin film and the applied coating material is used as an outer layer material, the infrared absorption rate is
Since it is as high as 90% or more regardless of the wavelength of infrared rays, the same effect as in the case where the outer layer material 21 made of PE resin having a black surface containing carbon black is attached can be obtained.

Next, a description will be given of a method and a welding device for thermally welding the spout opening member 1 to the upper outer surface 5. Such a heat welding method includes an outer layer member forming step, a heating step, and a pressing step. The welding apparatus includes a conveyor 27 as a transport mechanism, a heater 23 as an infrared irradiation source, and a pressing jig 25 as a pressing mechanism. It is configured.

In the outer layer material forming step, the outer layer material 21 is attached to the welding surface 11a of the spout opening member 1. As a result, the welding surface 11a is covered with the outer layer material 21.

In the heating step, as shown in FIG. 3, an infrared ray having a wavelength of 400 nm or more is emitted to the welding surface 11a side of the spout opening member 1 by a heater 23 which is a source of infrared rays. Thereby, the welding surface 11a covered with the outer layer material 21 is heated more efficiently than the other portions, and is brought into a high temperature state. At this time, the wavelength is adjusted so that the difference in absorptivity between the outer layer material 21 and the other portions is 80% or more.
If infrared light of 00 nm to 1400 nm is used, the welding surface 1
Only 1a can be heated more efficiently.

Further, even when the spout opening member 1 is moving with respect to the infrared rays, the welding surface 11a can be efficiently heated, and as shown in FIG. The welding surface 11a of each spout opening member 1 is formed by a simple structure in which a conveyor 27 that continuously conveys and a fixed heater 23 that irradiates infrared rays to the spout opening member 1 that is being conveyed are provided. Heating can be performed efficiently and continuously.

In the pressing step, as shown in FIG. 4, the spout opening member 1 is placed on the container 3 so that the outer layer material 21 heated by infrared rays comes into contact with the upper outer surface 5, and the pressing jig 25 As a result, the spout opening member 1 is pressed from above. Thereby, the welding surface 11a heated to a high temperature state is
Surface 1 which is pressed against the upper outer surface 5 of the
1 a is welded to the resin coated on the upper outer surface 5.

When the one end 13a of the movable portion 13 of the spout opening member 1 that is heat-welded to the upper outer surface 5 of the container 3 is pulled up with a fingertip or the like, the movable portion 13 tilts around the connecting portion 15, The opposite side 13 b of the movable part 13 descends and breaks through the upper outer surface 5, and a spout 7 is formed in the upper part of the container 3.

As described above, according to the present embodiment, since the outer layer material 21 is black having a lower brightness than the portion other than the welding surface 11a, the infrared absorptivity of the outer layer material 21 is lower than that of the welding surface 11a. Is higher than the absorption rate of the portion.
Therefore, by irradiating infrared rays to the spout opening member 1 from the welding surface 11a side and heating, the welding surface 11a of the spout opening member 1 covered with the outer layer material 21 is more efficiently processed than the other portions. It can be heated to a high temperature state quickly.

Further, the connecting portion 15 formed of a thin rod-shaped body and having low durability against high temperatures as compared with other portions is sufficiently heated to a temperature suitable for welding without bringing the connecting portion 15 into a high temperature state. be able to.

Further, even when the spout opening member 1 is moving with respect to infrared rays, the welding surface 11a can be efficiently heated, so the heater 23 is fixed and the spout opening member 1 is moved by the conveyor 27. With the simple structure of transport, the welding surface 11a can be efficiently and continuously heated.

Further, since the outer layer material 21 is black, which has the lowest lightness, portions other than the welding surface 11a need only be non-black, which is versatile.

Further, by using an infrared ray having a wavelength at which the difference between the absorptivity for the outer layer material 21 and the absorptivity for the portion other than the welding surface 11a is equal to or greater than a predetermined value, the portion other than the welding surface 11a becomes a high temperature state. , And only the welding surface 11a can be more efficiently heated.

In this embodiment, the spout opening member 1 is used.
Is made of PE, but other resin materials may be used as long as they are compatible with each other.

Although the spout opening member 1 is white and the outer layer material 21 is black, if the outer layer material 21 is colored so as to have lower brightness than the surface of the spout opening member 1,
The combination can be freely set. In this case, the relationship between the wavelength of the infrared ray and the absorptance changes depending on the material and the color of the infrared irradiation surface, so that an infrared ray having an optimal wavelength may be used according to the material and the color.

[0044]

As described above, according to the first to seventh aspects of the present invention, since the infrared ray absorption rate of the outer layer material is higher than that of the portion other than the welding surface, the resin material is made of resin. By irradiating the member with infrared rays from the welding surface side and heating it, the welding surface covered with the outer layer material of the resin member is more efficiently heated than the other parts, and quickly brought to a high temperature state. Can be.

Further, even when the resin member has a portion having a low durability against a high temperature condition such as a thin portion, the welding surface is not changed to the low durability portion without the high temperature condition. Can be sufficiently raised.

In addition, since the welding surface can be efficiently heated even when the resin member is moving with respect to the infrared rays, a simple structure in which the infrared irradiation source is fixed and the resin member is conveyed. Thereby, the welding surface can be efficiently and continuously heated.

According to the sixth aspect of the present invention, the infrared ray having a wavelength at which the difference between the absorptivity for the outer layer material and the absorptivity for portions other than the welded surface is equal to or more than a predetermined value is used. It is possible to more efficiently heat only the welding surface while reliably preventing the other parts from being in a high temperature state.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a back side of a spout opening member as a resin member according to an embodiment of the present invention.

FIG. 2 is a plan view of the back side of the spout opening member of FIG. 1;

FIG. 3 is a sectional view of the spout opening member of FIG. 2 taken along the line III-III.

FIG. 4 is a perspective view showing a state in which the spout opening member of FIG. 1 is attached to a container.

FIG. 5 is a perspective view showing a continuous heating state of the spout opening member.

FIG. 6 shows the relationship between each wavelength of infrared rays and infrared absorptivity in the case of a black surface using a PE resin containing carbon black.

FIG. 7 shows the relationship between each wavelength of infrared rays and infrared absorptivity in the case of a white surface using a PE resin containing no carbon black.

FIG. 8 shows the relationship between each wavelength of infrared rays and infrared absorptivity when the surface of a PE resin containing no carbon black is colored with a black paint.

[Explanation of symbols]

 Reference Signs List 1 spout opening member (resin-made member) 3 container 5 upper outer surface (welded portion) 7 spout 11a welding surface 21 outer layer material 23 heater (infrared radiation source) 25 pressing jig (pressing mechanism) 27 conveyor (transporting mechanism) )

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeo Katsumata 6-12 Kioicho, Chiyoda-ku, Tokyo Inside Tetra Pak Co., Ltd.

Claims (7)

[Claims] 1. A resin member having a welding surface which is heated by infrared rays and thermally welded to a portion to be welded, wherein said welding surface has a color lower in brightness than portions other than the welding surface. A resin member characterized by being coated with: 2. The resin member according to claim 1, wherein the outer layer material is a sheet-like resin material adhered on the welding surface. 3. The resin member according to claim 1, wherein the outer layer material is a paint applied on the welding surface. 4. The resin member according to claim 1, wherein the portion to be welded is an outer surface of a container filled with a beverage, and the resin member is A spout opening member for forming a spout of the beverage on an outer surface of the container. 5. An outer layer material forming step of covering a welding surface of a resin member abutting on a portion to be welded with an outer layer material having a color lower in brightness than portions other than the welding surface; And a pressing step of pressing a welding surface of the resin member covered with the outer layer material and heated by the infrared rays to the welded portion. Welding method. 6. The method for heat-welding a resin member according to claim 5, wherein, in the heating step, a difference between an absorptivity for the outer layer material and an absorptivity for a portion other than a welding surface of the resin member. A method for heat-welding a resin member, wherein infrared rays having a wavelength of which is not less than a predetermined value are used. 7. A transport mechanism for transporting a resin member in which a welding surface heated by infrared rays and thermally welded to a welded portion is coated with an outer layer material having a color lower in brightness than portions other than the welded surface. An infrared irradiation source that irradiates the resin member conveyed by the conveyance mechanism with infrared light, and a pressing mechanism that presses the resin member against the welded portion while the outer layer material is in contact with the welded portion. A heat welding device for a resin member, comprising: