JPH03124592A - Fluororesin lined container and manufacture thereof - Google Patents

Abstract

PURPOSE:To increase the strength of a liner in the axial and circumferential directions and prevent the breakage of welded parts by a method wherein the outer peripheral surface of the liner containing a joint between fluororesin made upper and lower liner bodies is reinforced with an annularly-shaped strip formed thereon. CONSTITUTION:An upper liner body 1 having nozzle mounting holes 1a, a lower liner body 2 and nozzle liners 11 are formed of fluororesin on a separate basis. The nozzle liner 11 is inserted in the hole 1a of the upper liner body 1 and welded thereto at a weld part 11a. The upper and lower fluororesin liner bodies 1 and 2 are assembled into an integral form by welding together the lower end face of the upper liner and the upper end face of the lower liner using a heat sealable fluororesin therebetween. A surface treating part 14 is formed on the outer peripheral surface of a liner 5 including the weld part 12 by metallic sodium treating method and FRP made annularly-shaped strip 13 is attached to this surface treating part with an adhesive agent to bring the liner 5 to completion. The liner 5 is inserted into an outer can body 6 and a flare is formed at a nozzle part 7 to complete a container.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a fluororesin-lined container whose inner surface is lined with a fluororesin and a method for manufacturing the same.

Technical background of the invention Among fluororesins such as polytetrafluoroethylene (PTFE) and heat-melting fluororesins such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), PTFE has excellent heat resistance and chemical resistance. It is particularly excellent in terms of chemical properties and non-adhesive properties. Therefore, PTF
E is widely used as a lining material to protect the internal surfaces of tanks and containers for storing or transporting corrosive liquids.

By the way, fluororesins such as PTFE have high melt viscosity and poor fluidity even when melted, so injection molding,
It cannot be molded by extrusion molding or the like. Therefore, molded articles made of PTFE or the like are manufactured by compressing the powder under pressure to produce a preform, and then firing this preform.

Conventionally, a fluororesin-lined container having a fluororesin liner on its inner surface is manufactured by joining together the liner upper body, liner lower body, etc. that have been manufactured separately in this way, and then attaching the liner to a metal liner. It was manufactured by placing the container inside a container body made of plastic or glass fiber reinforced plastic (FRP).

Here, a conventional method for manufacturing a fluororesin lined container will be explained with reference to FIGS. 6 and 7.

First, a liner upper body 1 made of fluororesin and provided with an opening 1a for inserting a nozzle, a liner lower body 2 provided on the circumference of the lower body of the container, and a cylinder inserted into the opening 1a. A liner neck 3 having a shape is formed respectively. Next, the liner neck 3 is fused into the opening 1a of the liner upper body 1, and the liner neck 3 is fused along the entire circumference of the weld line 4 between the lower end surface of the liner upper body 1 and the upper end surface of the liner lower body 2. They are butt-fused together to form a liner 5 in which the two parts 1 and 2 are integrated, and then this liner 5 is installed inside the exterior can body 6, and the nozzle part 7 is flared to form a container.

Here, the above-mentioned liner upper body 1 and liner lower body 2 are butt-fused by placing heating jigs 10 and 10 inside and outside of the liner 5, sandwiching the joint between the upper body 1 and the lower body 2. ,
By using these heating jigs 10, 10, the joint portion is heated to PTFE.
temperature of 327°C or higher, which is the melting point of
The liner upper body 1 and the liner lower body 2 are fused and integrated while heating to 350° C. and applying a pressure of about 1 to 5 kg/a1.

However, when performing such fusion bonding, it is necessary to place one heating jig 10 inside the liner 5, so the nozzle diameter, that is, the fluororesin liner upper body 1 has to be taken in and out. There was a problem in that the inner diameter of the liner neck 3 to be installed in the opening la of the liner was severely restricted and could not be made very small.

Therefore, without using such fusion bonding, the fluororesin liner upper body 1 and the fluororesin liner lower body 2 are bonded by PF.
A method of welding using A may also be considered.

However, welding using PFA does not allow a sufficiently strong joint to be obtained and there is a risk that the liner 5 may be damaged at the weld, so that it cannot be put to practical use at present.

That is, in a fluororesin lined container, since the liner 5 is a molded liner, there is generally a gap between the molded liner and the outer can body 6, and the liner 5 is a molded liner.
When internal pressure is applied, the weld expands and contracts by the amount of this gap, and the stress generated at this time causes the welded part, which lacks strength, to break.

Purpose of the Invention The present invention aims to solve the problems associated with the prior art as described above, and provides a liner in which the welded portion between the liner upper body and the liner lower body has sufficient strength for practical use. An object of the present invention is to provide a fluororesin-lined container and a method for manufacturing the same.

Summary of the Invention The fluororesin lined container according to the present invention includes a liner formed by welding the lower end surface of a fluororesin liner upper body and the upper end surface of a fluororesin liner lower body with a heat-melting fluororesin, and The liner is characterized in that it is provided with a reinforcing annular band adhered to the outer peripheral surfaces of the upper body and the lower body including the welded portions.

In addition, the method for manufacturing a fluororesin lined container according to the present invention involves separately molding a fluororesin liner upper body and a fluororesin liner lower body, and abutting the two at their end faces and welding them together using a heat-fusible fluororesin. After that, a reinforcing annular band made of, for example, FRP is adhered to the peripheral area including the welded part to form a liner, and this liner is installed inside the outer can body.

According to the present invention having the above configuration, the outer circumferential surface of the liner including the joint between the fluororesin liner upper body and the fluororesin liner lower body is reinforced by the annular band wrapped here, so that the liner axis Moreover, the strength in the circumferential direction is increased, and damage to the welded portion can be prevented as much as possible even when internal pressure is applied.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be explained below based on a first embodiment and FIGS. 1 to 3. FIG.

The container according to the present invention has a fluororesin liner upper body 1 and a fluororesin liner lower body 2 integrally butted together, and the above-mentioned It is mainly composed of a liner 5 constructed by welding a nozzle liner 11 made of fluororesin, an exterior can body 6 in which this liner 5 is mounted, and a nozzle part 7.

Here, the above-mentioned butt joint between the above-mentioned liner upper body 1 and the liner lower body 2 is performed by welding with a hot-melt fluororesin along the welding line 4 of this joint part.
2 are integrated, and then an annular band 13 made of, for example, FRP is bonded to the outer peripheral surface including the welded portion 12 for reinforcement.

In this way, by covering the outer peripheral surfaces of the fluororesin liner upper body 1 and the fluororesin liner lower body 2, including the welded parts 12, with the annular band 13, and reinforcing the liner 5,
The strength of the liner 5 in the axial and circumferential directions is increased, and damage to the welded portion 12 when internal pressure is applied can be prevented as much as possible. Furthermore, since the liner upper body 1 and the liner lower body 2 can be joined without using a heating jig, the inner diameters of the through hole 1a and the nozzle liner 11 can be made smaller, as shown in FIG.

The above container is manufactured as follows.

First, a liner upper body 1, a liner lower body 2, and a nozzle liner 11 each having a through hole 1a for inserting a nozzle are separately formed in advance from a fluororesin such as PTFE.

Then, the nozzle liner 11 is inserted into the through hole 1a of the fluororesin liner upper body 1 and welded at the welded portion 11a.

Next, welding is performed between the lower end surface of the fluororesin liner upper body 1 and the upper end surface of the fluororesin liner lower body 2 using a heat-melting fluororesin such as PFA to integrate the two parts 1.2. do. At this time, as shown in FIG. 2, a V-shaped notch is formed on the outer periphery between the lower end surface of the fluororesin liner upper body 1 and the upper end surface of the fluororesin liner lower body °2. It is desirable to do so.

Then, a surface treated portion 14 is formed on the outer peripheral surface of the liner 5 including the welded portion 12 welded as described above by a metal sodium treatment method, a sputtering etching method, a plasma etching method, etc., and an adhesive is applied to this surface treated portion 14. The liner 5 is constructed by bonding the FRP annular band 13 using the following. The adhesive may be any conventional adhesive, such as a curable resin adhesive such as an epoxy adhesive, a room temperature curable adhesive such as a rubber adhesive, or a silicone heat-resistant adhesive. Note that this annular band 13 only needs to be annular at the time it is adhered to the outer peripheral surface of the liner 5, and even if it has a complete annular shape before adhesion, it is not necessary to adhere the annular band 13 into several pieces. It may also be configured in a ring shape.

The liner 5 thus completed is inserted into the outer can body 6, and the nozzle portion 7 is flared to complete the container.

Note that instead of the above surface treatment, the above liner upper body 1
At the stage where the liner lower body 2 is a preformed body obtained by pressing and compressing fluororesin powder, the following treatment may be performed on the outer circumferential surface including the joint portion.

That is, the outer circumference of the upper end of the PTFE preform of the liner upper body 1 and the outer circumference of the upper end of the lower liner body 2 are coated with a heat-melting fluororesin dispersion such as PFA, or a tape-shaped or sheet-shaped dispersion is applied. After adhering the hot-melt fluororesin film, these preforms are fired. As a result, as shown in FIG. 4, an adhesive layer 15 of heat-fusible fluororesin is formed on the outer peripheral surfaces of the fluororesin liner upper body 1 and the fluororesin liner lower body 2, thereby increasing the welding strength of the welded portion. At the same time, the strength of the FRP ring-shaped belt 13 is increased.

Furthermore, as shown in FIG. 5, a reinforcing glass cloth is placed on the heat-fusible fluororesin dispersion or the heat-fusible fluororesin film (the heat-fusible fluororesin layer 15) to be fired together with the unfired PTFE. 16 are stacked,
By firing the unfired PTFE, bonding them together by thermocompression, and adhering the annular band 13 thereon, the annular band 13 can be more firmly adhered to the liner via the glass cloth. At the same time, the reinforcement strength can also be increased.

In the above-mentioned examples, PTFE was used as the fluororesin liner, but the present invention is not limited to this. PFA, which is a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, FEP, which is a copolymer with propylene,
Alternatively, a heat-melting fluororesin such as EPH, which is a copolymer of tetrafluoroethylene, hexafluoropropylene, and perfluoroalkyl vinyl ether, can be widely used.

Effects of the Invention According to the fluororesin-lined container and the manufacturing method thereof according to the present invention, the outer circumferential surface of the liner including the joint between the fluororesin liner upper body and the fluororesin liner lower body is covered with an annular band member wrapped therein. This increases the strength of the liner in the axial and circumferential directions, and even when internal pressure is applied, it is possible to prevent this welded portion from breaking as much as possible.

Further, according to the fluororesin lined container and the manufacturing method thereof according to the present invention, the fluororesin liner upper body and the fluororesin liner lower body can be welded with sufficient strength, so no heating jig is required. Yes, it is possible to install small diameter nozzles.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, in which FIG. 1 is a sectional view of a container, FIG. 2 is a sectional view of a liner molded body, and FIG.
The figure is an enlarged view of part A in Figure 2, Figures 4 and 5 are views corresponding to Figure 3 showing different embodiments, Figures 6 and 7 are conventional examples, and Figure 6 is the Figure 7 is a diagram equivalent to Figure 2. DESCRIPTION OF SYMBOLS 1... Fluorine resin liner upper body, 1a... Through hole, 2... Fluorine resin liner lower body, 4... Welding line, 5... Liner 6... Exterior can body, 11 ...
Nozzle liner, 12... Welded part, 13... Annular band, 14... Surface treated part, 15... Heat-fusible fluororesin layer, 16... Glass cloth.

Claims (6)

[Claims] (1) A liner is provided by welding a lower end surface of a fluororesin liner upper body and an upper end surface of a fluororesin liner lower body with a heat-melting fluororesin, and the liner is connected to the upper body and the lower body. A fluororesin-lined container characterized in that a reinforcing annular band is provided on the outer peripheral surface including the welded portion of the container. (2) The fluororesin upper liner body and the fluororesin lower liner body are molded separately, and after they are butted together at their end faces and welded with heat-fusible fluororesin, the surrounding area including this welded part is reinforced. A method for manufacturing a fluororesin-lined container, comprising: forming a liner by adhering an annular band for use in the container, and mounting the liner inside an outer can body. (3) The above-mentioned liner upper body and the above-mentioned liner lower body are manufactured by firing a preformed body obtained by pressurizing and compressing fluororesin powder, and the former preformed body contains heat-fusible fluorine on the outer peripheral surface on the joint side. 2. The fluororesin-lined container according to claim 1, wherein the container is coated with a dispersion made of resin powder. (4) The above-mentioned liner upper body and the above-mentioned liner lower body are manufactured by firing a preformed body obtained by pressurizing and compressing fluororesin powder, and the former preformed body contains heat-fusible fluorine on the outer peripheral surface on the joint side. The fluororesin-lined container according to claim 1, characterized in that a resin film is laminated thereon. (5) The liner upper body and the liner lower body are made of a heat-fusible fluororesin, and a dispersion made of a heat-fusible fluororesin powder is applied to the outer circumferential surface of the joint side. The fluororesin lined container according to claim 1. (6) The fluororesin-lined container according to any one of claims 3 to 5, wherein a cloth is further laminated on the outer circumferential surface of the joint between the liner upper body and the liner lower body.