JPS61192A - Method of sealing fill opening of plastic vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides a method for filling a plastic container with contents.
The present invention relates to a method of sealing the filling port so that it cannot be easily opened.

(Prior Art) Conventional methods for sealing the filling opening of a plastic container after filling it with contents to prevent easy opening include (1) riveting and (2) gluing. The riveted method (ii) means that the cap is screwed onto the filling opening of a plastic container, and a rivet is inserted into the side of the cap so as to penetrate through the wall of the filling opening to prevent the cap from loosening. The adhesion method (2) is one in which a sealing member made of thermoplastic plastic is adhered to the filling opening of the container using high frequency or ultrasonic waves.

(Problems to be Solved by the Invention) However, in the riveting of the prior art (2), there is a risk of leakage of the contents from the rivet hole or corrosion of the rivet, and the cost of the rivet parts increases. Since rivet driving work is required, there are problems in terms of sealing performance, product price, and workability. Furthermore, in the case of prior art (2), which uses adhesive, there is a risk of leakage if the contents are liquid, and high-frequency or ultrasonic bonding equipment is expensive, and the work is not easy. I have a similar problem.

The present invention provides a method for sealing a filling port of a plastic container.
This solves the problems of the prior art, namely the possibility of poor sealing, increased product prices, and poor work efficiency. (Means for Solving the Problems) In order to solve these problems, the present invention seals the filling opening of a plastic container by the following five means. That is, an inner frame made of a cylindrical thermoplastic plastic having a threaded part on the inner periphery fixed to the filling opening of the plastic container main body, and a threaded part on the outer periphery that is screwed together with a slight deviation from the threaded part of the cough inner frame. 1. A stopper made of thermoplastic plastic provided on the plate is screwed on by high-speed rotation. The plug was fused to the inner frame by the frictional heat generated during the threaded connection, thereby sealing the filling opening of the plastic container.

The present invention will be explained below using the accompanying drawings.

Fig. 1 is a perspective view of the container body and the stopper before sealing, Fig. 2 is a sectional view taken along the cutting frame line A-A and B-B in Fig. 1,
FIG. 3 is a sectional view of the container after being sealed.

The container body 1 is made of a thermoplastic such as polyethylene and is obtained by blow molding. A filling port 2 for filling the contents is opened in the upper part of the container body 1, and an inner frame 3 shown in FIG. 4 is fixed to the filling port 2.

The middle frame 3 is made of a cylindrical thermoplastic plastic having a threaded portion 3a on the inner periphery, and film-like protrusions 3b and unevenness 3G having a thickness of 10 to 1000 microns are formed on the outer periphery. The middle frame 3 is set in a blow mold when blow molding the container body 1, and the film-like protrusions 3b are melted by the heat during blow molding, so that the inner frame 3 is inserted into the filling port 2 at the same time as the container body 1 is molded. Welded and uneven 3C
Engagement and fixation is also performed. The reason why the container body 1 and the inner frame 3 are made as separate parts is because it is difficult to manufacture a hollow product with a threaded part on the inner periphery on a factory scale by blow molding.
Moreover, the obtained product is expensive, and the reason why the film-like projections 3b are fused and fixed by melting is to prevent leakage even when the contents stored in the container body 1 are liquid. It is. Therefore, if the content is powder or granules, the outer periphery of the inner frame may be made only in an uneven shape and may be engaged and fixed to the filling port of the container body during blow molding, or the filling port of the container body may be fixed after blow molding. It may be fitted to

The plug body 4 is made of thermoplastic plastic, and has a threaded portion 4a on its outer periphery that is screwed into the threaded portion 3a of the inner frame 3 with a slight deviation.
It has a recess 4b for inserting an electric screwdriver in the center of the upper surface. Since the threaded portion 3a of the inner frame 3 and the threaded portion 4a of the plug body 4 are formed so as to be screwed together with a slight deviation as described above, the screwed state is not smooth and there is some resistance. It is something. Note that as the thermoplastic plastic forming the inner frame 3 and the plug body 4, a hard type such as hard vinyl chloride resin is used.

After filling the container body 1 with the contents, the stopper 4 is screwed and fixed to the inner frame 3 by high speed rotation to seal the container filling opening. (Function) Since the screw parts 4a and 3a are formed so that the plug body 4 and the middle frame 3 are screwed together with a slight deviation, the plug body 4 is rotated at high speed and screwed into the middle frame 3. At this time, frictional heat is generated in the threaded portion, and this frictional heat melts the threaded portions 4a and 3a.
The plug body 4 and the middle frame 3 are fused together.

(Effects of the Invention) The present invention involves screwing a stopper made of thermoplastic plastic into an inner frame made of thermoplastic plastic fixed to the filling opening of a plastic container main body by high-speed rotation, and using frictional heat generated at that time to stop the stopper. The body and inner frame are fused together, and the filling opening is sealed to prevent easy opening. Therefore, it is sealed by both screwing and fusion, and there is no risk of leakage even with liquid contents. In addition, the inner frame and the stopper are cheaper than conventionally used rivet parts, which is advantageous in terms of product price. Furthermore, in terms of workability, it is only necessary to screw the plug into the inner frame using a high-speed rotating fastener such as an electric screwdriver, which is very quick and efficient. Additionally, high speed rotating fasteners have the advantage of being incomparably cheaper than high frequency or ultrasonic bonding devices.

[Brief explanation of the drawing]

The drawings relate to the present invention; FIG. 1 is a perspective view of the container body and stopper before sealing, and FIG. 82 is taken along cutting lines A-A and B in FIG.
3 is a longitudinal sectional view of the container after being sealed, and FIG. 4 is a perspective view of the inner frame. DESCRIPTION OF SYMBOLS 1... Container body, 2... Filling port, 3... Middle frame, 3a... Threaded part, 3b... Film-like projection, 4... Stopper, 4a...
Threaded part patent applicant Inoue MCP Co., Ltd. Figure 1
Figure 2 Figure 3

Claims (1)

[Claims] An inner frame made of cylindrical thermoplastic plastic with a threaded part on the inner periphery is fixed to the filling opening of the plastic container body.
A plug made of thermoplastic plastic with a threaded part on its outer periphery that is slightly misaligned and screwed into the threaded part of the inner frame is screwed on by high-speed rotation, and the plug is closed by the frictional heat generated at the time of screwing in the threaded part. A method for sealing a filling opening of a plastic container, characterized by fusing the body to the inner frame.