JPH02120025A - Method and thermowelding jig for heat-sealing transmitting filter to resin molding - Google Patents

Abstract

PURPOSE:To tightly weld a transmitting filter without developing breakage, separation and the like by a method wherein a projection, which is made of the same stock as that of an annular spacer, is provided on the upper edge face of the annular spacer so as to weld a transmitting filter to the upper edge face of the spacer under the condition that the filter is sagged downwards by the air flowing out of a thermowelding jig. CONSTITUTION:A projection 1a, which is made of the same stock as that of an annular spacer 1, is provided on the upper edge face of the annular spacer 1. A transmitting filter 2 is heat-sealed to the upper edge of the annular spacer 1 by automatically pressing it with a thermowelding jig 3. At that time, the transmitting filter 2 is forcibly sagged downwards by the air flowing out of the thermowelding jig 3 so as to check the easy upward sagging deformation, separation and the like of the transmitting filter with the approach of the thermowelding jig 3 under heat. The projection 1a protects the transmitting filter 2 from being excessively pressed by serving as the buffering material for the annular spacer 1 during the instant, in which the projection is melted by the heat of the thermowelding jig 3 and at the same time and, after melting, increases the sealing strength between both the transmitting filter and the annular spacer by serving as the welding reinforcing material.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is to weld and secure a transmission filter (object to be adhered), which is mainly used in non-adjustable gas lighters, to an annular spacer (molded object) of a predetermined shape. The present invention relates to a method for heat-sealing a transmission filter to a resin molded product and a heat-sealing jig for heat-sealing.

(Prior Art) In a non-adjustable lighter with a built-in transmission filter, the flame length is determined in advance by the area and transmittance of the transmission filter.

As a mounting means for such a transmission filter, for example, it is fixed in advance to the end face of an annular spacer made of a synthetic resin material by thermocompression bonding, ultrasonic welding, or impulse welding, and is assembled at a predetermined position within the valve. 63-5
(See No. 5864).

Conventionally, as a method of thermocompression bonding a transmission filter, which is an adhered object, to the upper end surface of an annular spacer, which is a resin molded object,
For example, there is a so-called heat sealing method in which a transmission filter is placed on the upper end surface of an annular spacer and then a heat bonding jig is pressed from above to fuse the spacer upper end surface and the transmission filter.

(Problem to be solved by the invention) However, in the above heat sealing method,
Since the transmission filter is very thin, it is easy to tear due to the heat and pressure applied with such a heat bonding jig.In particular, if the heat bonding jig is simply pressed against the top surface of the transmission filter, the filter will be damaged by the heat. Since the filter loosens and curls upward, there are problems such as peeling of the edge of the transmission filter and poor adhesion due to wrinkles.

Furthermore, the gas permeation area of the permeation filter fluctuates, making the gas flow rate unstable, resulting in the problem that a stable flame length cannot be obtained.

The present invention has been made in view of these problems, and provides a resin molded product for a transmission filter that allows the transmission filter to be tightly welded to the upper end of the annular spacer without causing tearing or peeling of the transmission filter. It is an object of the present invention to provide a heat sealing method, and also to provide a heat sealing jig suitable for carrying out this heat sealing method.

(Means and operations for solving the problem) In order to solve the above-mentioned conventional problems and achieve the intended purpose, the present invention has the following features:
A first step of supplying and arranging a transmission filter made of the same material on the upper end surface of an annular spacer made of a synthetic resin material, and a second step of welding the transmission filter to the upper end surface of the annular spacer by pressing a heat bonding jig from above. In the method for heat sealing a transmission filter, the method comprises the steps of:
During or before the step, a projection made of the same material is attached to the upper end surface of the annular spacer.

The present invention also provides a method of heat-sealing a transmission filter to a resin molded product, in which air is flowed out from inside the heat-bonding jig to loosen the transmission filter downward and weld it to the upper end surface of the spacer during the second step.

On the other hand, the heat sealing jig according to the present invention for carrying out this method includes a columnar body having an air inflow hole opened on the side surface and an air flow path communicating with the air inflow hole opened at the lower end; The heat body is removably fitted to the tip of the columnar body and has an air outflow path coaxially communicating with the air flow path, and the heat body has a protruding tip extending coaxially. A tip heating member with the air outflow passage opened, a first ring member bonded to the rear end surface of the tip heating member, and a second ring member bonded to the rear end surface of the first ring member.
It is characterized by comprising a ring member and a removable tubular member that is fitted into the air outflow path of the tip heating member so that its tip projects.

The present invention will be explained in more detail below.

The object of the present invention is mainly a transmission filter used in gas lighters, but is not limited to this, and also applies to transmission filters used in non-adjustable valves, etc. be.

Further, as the transmission filter, a microporous polypropylene resin membrane is used, but the invention is not limited thereto.

Incidentally, as the material for such a transmission filter, it is preferable to use a resin of the same type as the synthetic resin of the annular spacer.

First, the first step of the one seat heel method will be explained.

In the present invention, as a pre-process, the melting temperature is approximately 70°C to 320°C.
An annular spacer (molded object) 1 of a predetermined size can be obtained by injection molding a molded object base made of a thermoplastic synthetic resin material, such as polypropylene, which is kept at a temperature of about 0.degree. It also has a conveyance mechanism (not shown) that sequentially sends them out to one process while arranging them in parallel.

The annular spacer 1 that has been sent out has a protrusion 1a made of the same material (polypropylene resin) mechanically attached to the upper end surface of the annular spacer 1, and a thickness of approximately 25 mm is then attached to the upper end surface of the annular spacer 1 by a filter transfer mechanism (not shown). A long transmission filter 2 of about 100 microns is supplied and arranged.

The projections 1a serve as a crushing margin and a buffer material to stabilize the welding and retention of the transmission filter 2 in the next step, and increase the sealing strength.

Furthermore, the material of the protrusion 1a is a synthetic resin material (polypropylene resin in this embodiment) of the annular spacer 1.
It is necessary to use a resin material that is compatible with the above, and is melted by the melting heat of the heat bonding jig 3, which will be described later, to firmly bond the two together.

Therefore, in the instant until the protrusion 1a protruding from the upper end surface of the annular spacer 1 is melted by heating with the heat bonding jig 3, which will be described later, the annular spacer acts as a buffering material to protect the transmission filter 2. In addition to protecting against excessive pressure, it serves as an adhesive reinforcement after melting, increasing the strength of the seal between the two.

Incidentally, the projection 1a may be integrally attached in advance at the time of injection molding of the annular spacer 1.

Next, the second step will be explained.

The annular spacer 1 obtained in the first step, that is, the annular spacer 1 with the elongated transmission filter 2 arranged on the upper end surface, is trimmed from above using a special press machine, and at the same time, a heat bonding jig 3, which will be described later, is automatically pressed. The transmission filter 2 is heat-sealed to the upper end of the annular spacer 1.

At this time, air is forced out from inside the heat bonding jig 3 to forcibly loosen the transmission filter 2 downward, and the heat bonding jig 3
This prevents the transmission filter 2 from being easily loosened upward and peeled off due to the approach of heating.

As shown enlarged in FIGS. 5 to 8, the heat sealing jig 3 has an air inflow hole 3a on the side surface and an air flow path 31a communicating with the air inflow hole 3a at the lower end. A released columnar body 3A made of stainless steel (SUS) and a heat body that is removably fitted to the tip of the columnar body 3A and opens an air outlet passage 3b coaxially communicating with the air flow passage 31a. It consists of 3B.

The heat body 3B also includes a tip heat member 31b made of copper whose tip protrudes and has an air outflow path 3b opened in the coaxial direction, and a first heat member made of Teflon with the same diameter joined to the rear end surface of the tip heat member 31b. The ring member 32b and a second ring member 33b of the same diameter made of stainless steel joined to the rear end surface of the first ring member 32b are fitted so that the tip of the tip heat member 31b protrudes from the air outflow path 3b. The heat member 31b is electrically heated by a tubular member 34b made of inserted carbon steel (545C) or polished steel bar (trade name DR).

The fusing temperature of such a heat bonding jig 3 is 180 to 195°C.
(195° C. when using a Teflon sheet) and welding time is preferably about 0.8 seconds.

Note that even if the copper heat member 31b is heated to a high temperature, only the carbon steel tubular member 34b is heated to a predetermined temperature; In addition, because the columnar body 3A is made of stainless steel, no heat is transferred at high temperatures.

On the other hand, as a means to prevent upward peeling or tearing of the peripheral edge of the transmission filter 2, as shown in FIG. A synthetic resin film 4 having a high melting temperature, such as Teflon or polyester, may be coated to prevent upward relaxation and deformation as the heat bonding jig 3 approaches the heating.

On the other hand, by laminating a polypropylene nonwoven fabric with a thickness of 75 microns on the upper surface of the transmission filter 2, a constant gas flow rate is ensured, and a stable flame length is obtained without being affected by gas pressure fluctuations. .

At that time, the material of the transmission filter 2 is, for example, a maximum pore diameter of 0.4 x 0.04 microns, a porosity of 45%,
A microporous film made of polypropylene having a thickness of 25 microns is preferred.

The present invention will be explained below with reference to Examples.

(Example 1) After attaching a protrusion 1a made of the same material to the upper end surface of an annular spacer 1 made of polypropylene resin and installing a transmission filter 2 which is a microporous polypropylene resin membrane, the temperature was set at 180° C. from above. When the heat bonding jig 3 was pressed against the transmission filter 2 for 0.8 seconds while letting the air flow out of the tubular member 34b through the air inflow hole 3a and loosening the transmission filter 2 downward, the obtained result was obtained. All of the molded products that were molded had good sealing, and the peeling of the transmission filter 2 was not possible as in the conventional method.
No defective products were found due to damage.

(Example 2) After attaching a protrusion 1a made of the same material to the upper end surface of an annular spacer 1 molded from polypropylene resin and installing a transmission filter 2 which is a microporous polypropylene resin membrane, a polyester resin film 4 is further placed on the upper surface thereof. was coated, and a heat bonding jig 3 set at 180° C. was pressed from above for 0.8 seconds.

All of the molded products obtained had good sealing, and no defective products due to peeling or damage of the transmission filter 2 as in the prior art were observed.

(Comparative Example 1) After attaching a protrusion 1a made of the same material to the upper end surface of an annular spacer 1 made of polypropylene resin and installing a transmission filter 2 which is a microporous polypropylene resin membrane, the temperature was set at 180° C. from above. The heat bonding jig 3 was pressed for 0.8 seconds.

Note that air was not blown out from the air outlet path 3b of the heat bonding jig 3.

Among the obtained products (100 products), there were some defective products (15 products) such as poor adhesion due to peeling of the edge of the transmission filter 2 or wrinkles, although it was only partially present.

(Effects of the Invention) According to the method of the present invention, even when a heat bonding jig is pressurized to a very thin transmission filter, it takes only an instant for the protrusion provided on the upper end surface of the annular spacer to melt.

Since such protrusions act as a buffer between the annular spacer and protect the transmission filter, the filter is prevented from tearing due to excessive pressure, and the sealing strength is increased, making it possible to firmly bond the two.

Moreover, even if a heat bonding jig is simply pressed onto the top surface of the transmission filter, the filter is forcibly loosened downward by air pressure. It does not curl up in the direction, and has the effect of preventing edge peeling of the transmission filter and poor adhesion due to wrinkles.

Furthermore, after placing the transmission filter on the upper end surface of the annular spacer, if a synthetic resin film having a high melting temperature, such as Teflon or polyester, is further coated on the upper surface, the transmission filter can be moved downward by air pressure. It is possible to prevent upward relaxation deformation of the heat bonding jig as it approaches heating without forcibly loosening the jig, and
By using it together with air pressure, further relaxation and deformation prevention effects can be obtained.

On the other hand, the heat bonding jig according to the present invention is suitable for performing such a seat heel method.

In addition, the structure is simple, making it suitable for mass production.

It has excellent advantages such as being able to be supplied to consumers at a low price, and implementing the present invention has enormous practical value.

[Brief explanation of the drawing]

The drawing shows a simplified process exploded view of the method of the present invention.
Figure 2 is a simplified explanatory diagram showing the first process, Figure 2 is a simplified explanatory diagram showing the second process, Figure 3 is a vertical sectional view showing the molded product, and Figure 4 is a simplified explanatory diagram showing the second process showing another example. A simplified explanatory diagram, FIG. 5 is a plan view of the heat sealing jig used in this example,
FIG. 6 is a front view of the same, FIG. 7 is a longitudinal sectional side view of the same, and FIG. 8 is an exploded view of the same. 1... Annular spacer 18... Protrusion 2... Transmission filter 3... Heat bonding jig 3A... Body part
3a... Air inflow hole 3B... Heat body
3b...Air outflow path 31b...Tip heating member 33b...Second ring member 4...Synthetic resin film 32b...First ring member 34b...Tubular member Fig. 2 Fig. 5 Figure 6Figure 4

Claims (7)

[Claims] (1) A first step of supplying and arranging a transmission filter made of the same material on the upper end surface of an annular spacer made of a synthetic resin material, and then welding the transmission filter to the upper end surface of the annular spacer by pressing a heat bonding jig from above. In the heat-sealing method for a transmission filter, the method includes a second step in which a protrusion made of the same material is attached to the upper end surface of the annular spacer during or before the first step, and a projection made of the same material is attached in the second step. . A method for heat sealing a transmission filter onto a resin molded product, characterized in that the transmission filter is welded to the upper end surface of a spacer while loosening the transmission filter downward by causing air to flow out from within the heat bonding jig. (2) A first step of supplying and arranging a transmission filter made of the same material on the upper end surface of an annular spacer made of a synthetic resin material, and then welding the transmission filter to the upper end surface of the annular spacer by pressing a heat bonding jig from above. In the heat-sealing method for a transmission filter, the second step includes attaching a protrusion made of the same material to the upper end surface of the annular spacer during or before the first step;
2. The method of heat-sealing a transmission filter to a resin molded product according to claim 1, wherein during the step, the upper surface of the transmission filter is covered with a synthetic resin film having a high melting temperature and the heat-sealing jig is pressed. (3) A columnar body with an air inflow hole opened on the side surface and an air flow path communicating with the air inflow hole opened at the lower end; It consists of a heating body with an air outflow path that communicates with the flow path.
Further, the heating body includes a tip heating member having a protruding tip and opening the air outflow passage in the coaxial direction, a first ring member joined to a rear end surface of the tip heating member, and further the first ring. A heat-sealing heat-sealing device comprising a second ring member joined to the rear end surface of the member, and a removable tubular member fitted so that the tip thereof protrudes into the air outflow path of the tip heat member. Wearing jig. (4) The heat sealing jig according to claim 3, wherein the columnar body is made of stainless steel. (5) The heat sealing jig according to claim 3, wherein the tip heating member is made of copper. (6) The heat sealing jig according to claim 3, wherein the first ring member is made of Teflon, and the second ring member is made of stainless steel. (7) The heat-sealing jig according to claim 3, wherein the tubular member is made of carbon steel.