JPH09142456A - Pouring-out port for paper container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent pin holes from generating at a thinner part of the pouring- out port and at the base root part between the pouring-out port outer periphery and a flange part by a method wherein for the pouring-out port being ultrasonic- welded to a paper container main body, the radius of the tip of a groove at the thinner part, the opening angle and the opening width of the groove, are respectively specified. SOLUTION: A pouring-out port B is inserted in a pouring-out port attaching hole of a paper container A for liquid, from the inside, and welded by ultrasonic waves, and of which the sealing part can be unsealed by pulling a pull ring 5. For such a pouring-out port B, the tip 2a of a groove 2 on a thinner part 6 is formed into a curved surface of which the radius is 0.08-0.2mm. Also, the opening angle 2b of the groove 2 is specified in a range of 30-50 deg., and the opening width 2c of the groove 2 is specified in a range of 0.65-1.25mm. By doing so, when the pouring-out port B is welded to the paper container main body A with ultrasonic waves, pin holes and cut on the thinner part 6, or the base root part 4 between a pouring-out port outer periphery 3 and a flange part 1, can be prevented from generating, and the quality of an obtained product can be improved, and a speed up of the production can be done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid paper container, which is inserted into a spout attachment hole from the inside and ultrasonically welded,
The present invention relates to a spout for pulling a sealing portion with a pull ring to open the sealing portion.

[0002]

2. Description of the Related Art Conventionally, there are two types of spouts in a paper container, which are attached by inserting them into the mounting holes of the spout of the paper container from the inside and those attached from the outside. There is a type and a type that opens by pushing the inside plug.

In addition, especially when the contents are foods such as alcohols, oils, and long-term preserved products, spouts have been attached. However, as the demand for paper containers has increased, it has become necessary to reduce the manufacturing process and cost, and the use of a spout with an inner stopper for opening, which is composed of several parts, has started to be shunned. Therefore, more and more places are using spouts that are attached from the inside and that pull the pull ring to open the bag.However, this type of spout usually welds to the paper container by ultrasonic waves, so it is possible to use a thin wall for opening. It was often seen that sound waves generated pinholes. In order to deal with this, by providing a part for absorbing ultrasonic waves in the spout, a spout that prevents pinholes in thin-walled parts (Actual No. 63-16
No. 9429, Japanese Utility Model Publication No. 3-17028, etc.) have been developed. However, there are drawbacks that the shape of the ultrasonic wave absorbing portion is extra as a function of the spout, or that it is difficult to achieve the effect only by providing a similar shape.

In ultrasonic welding, electric vibration is converted into mechanical vibration, and by applying pressure, strong frictional heat is generated to weld the plastic. Usually, the welding of the spout is performed at a frequency of 20 kHz. (Vibrates 20,000 times per second) or 4
A frequency of 0 kHz (vibrates 40,000 times per second) is used to melt the plastic. Generally, when molding and filling a paper container, the spout is welded to the paper container by ultrasonic waves, but the ultrasonic conditions differ due to the difference in the filling destination or the filling machine, and pouring in places where welding is performed with strong energy. It was often observed that the root portion between the outer peripheral portion of the mouth and the flange portion was melted or a hole was formed and the contents leaked. This was because there was a problem with the shape of the spout and the structure was not able to withstand ultrasonic vibration.

[0005]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a thin portion of the spout or a root portion of the spout outer peripheral portion and the flange when the spout is welded to a paper container by ultrasonic waves. It is to develop a spout that can prevent the occurrence of pinholes.

[0006]

Means for Solving the Problems The present inventors have found that a thin wall portion having a specific structure can provide a spout for a paper container that can solve the above problems, and as a result of further studies,
The present invention has been completed.

That is, according to the present invention, in the spout for ultrasonically welding to the main body of the paper container, the radius of the tip of the groove of the thin portion is a curved surface of 0.08 to 0.2 mm, and the opening angle of the groove of the thin portion is It is a spout for a paper container, which is 30 to 50 ° and the opening width of the groove of the thin portion is 0.65 to 1.25 mm.

The spout for a paper container of the present invention will be described in detail below with reference to the drawings. First, FIG. 1 is a drawing showing a cross section of the paper container spout of the present invention, and FIG. 2 is an drawing showing an enlarged cross section of the groove 2 of FIG. According to the present invention, in the spout B which is ultrasonically welded to the paper container body A, the radius of the tip 2a of the groove 2 of the thin portion 6 is a curved surface of 0.08 to 0.2 mm, and the opening angle of the groove 2 is 2b is 30 to 50 °, and the opening width 2c of the groove 2 is 0.65 to 1.25 mm.

The paper container spout B of the present invention is formed by injection-molding a thermoplastic resin, and examples of the resin as a raw material thereof include polyethylene, polypropylene, polyester, polyamide, and ethylene-vinyl alcohol copolymer. Examples include coalescence. The paper container A referred to here is
The same kind of thermoplastic resin as the spout is provided on the inner surface of the container, and the flange portion 1 of the spout and the resin on the inner surface of the container are welded by ultrasonic waves.

The radius of the tip portion 2a of the groove 2 of the thin portion 6 at the spout B must be a curved surface of 0.08 to 0.2 mm, preferably 0.10 to 0.18 mm. . When the radius of the tip portion 2a of the groove 2 is less than 0.08 mm, the tip portion is sharpened, the vibration of ultrasonic waves is easily concentrated, and a pinhole is generated. Further, when the radius of the tip 2a of the groove 2 exceeds 0.2 mm, the area of the thin portion 6 becomes large and stress is not concentrated when the pull ring 5 is pulled, which makes unsealing difficult, which is not preferable.

In the conventional groove of the thin wall portion at the spout, as shown in FIG. 4, the tip 2a has a corner instead of a curved surface, so that ultrasonic vibration is concentrated and pinholes cannot be avoided. .

The opening angle 2b of the groove 2 in the thin portion 6 of the spout B must be 30 to 50 °, preferably 35 to 45 °. When the opening angle 2b is less than 30 °, the tip 2a is sharp and vibration of ultrasonic waves is concentrated to easily cause a pinhole, and when it exceeds 50 °, the radius of the tip 2a is 0.08 mm. However, the area of the thin portion 6 becomes large, stress is not concentrated even when the pull ring 5 is pulled, and opening is difficult.

Further, the groove 2 in the thin portion 6 of the spout B
The opening width 2c of 2 is required to be 0.65 to 1.25 mm, and preferably 0.80 mm to 1.10 mm.
It is. When the opening width 2c does not reach 0.65 mm, the tip 2a of the groove 2 is sharpened when the opening angle 2b is around 30 °, and the ultrasonic waves are likely to be concentrated.
In the vicinity of 50 °, the groove 2 becomes shallower and the thin portion 6 becomes thicker, resulting in unsealing failure. The opening width 2c is 1.25
If it exceeds mm, even if the radius of the tip 2a is 0.08 mm, the area of the thin portion 6 is widened and it becomes difficult to concentrate stress.
It is not preferable because the opening becomes difficult.

As described above, in the spout of the present invention which is ultrasonically welded to the main body of the paper container, the radius of the tip portion, the opening angle and the opening width of the groove of the thin portion may be in the above ranges. Not only that, but the specific range to be indispensable is determined by the close correlation of the tip radius of the groove of the thin portion, the opening angle, and the opening width, and the excellent effect of the present invention is thereby obtained. The effect is demonstrated.

Although FIG. 3 is an enlarged cross-sectional view of the root portion 4 of the spout portion 3 and the flange portion 1 in FIG. 1, the paper container spout according to the present invention is the spout portion 3.
It is desirable that the wall thickness 4a of the root portion 4 between the outer peripheral surface of and the flange portion 1 is 1.5 mm or more, and preferably 1.7 mm or more. If it is less than 1.5 mm, if the ultrasonic energy is excessively applied for welding, the resin of the root portion 4 may melt and flow out, and a hole may be opened and the contents may leak.

In the paper container spout B of the present invention, when the paper container main body A is ultrasonically welded, a pinhole or a break in the thin portion 6, the spout outer peripheral portion 3 and the base portion 4 of the flange portion 1 is formed. It is possible to prevent this, and it is possible to improve the quality of the obtained product and speed up the production.

[0017]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition, to confirm the pinhole generation rate and the hole generation rate at the root part 4a, use a dye penetrant flaw detection agent “Japan Red Check Liquid” (trade name, manufactured by Inspection Technology Laboratory Co., Ltd.) at the spout welded to the paper container. It was applied and confirmed by permeation of the liquid. In addition, the unsealing strength of the spout is measured by the tensile tester “Autograph AGS
-D "(manufactured by Shimadzu Corporation, trade name) at a head speed of 500 mm / min.

Example 1 Low density polyethylene was injection-molded to obtain a spout for a paper container. The spout had the following shape. ◎ Curved surface of the tip 2a of the groove 2 of the thin portion 6 having a radius of 0.12 mm ◎ The opening angle 2b of the groove 2 is 36 ° ◎ The opening width 2c of the groove 2 is 0.87 mm ◎ The wall thickness 4a of the root 4 is 1. 9 mm

This spout was welded to the main body of the paper container by ultrasonic welding machines "8400" and "920M" (both manufactured by Branson Co., Ltd.). The maximum output of these ultrasonic welding machines is 900 W for "8400" and 2000 W for "920M". The welding conditions of the spout welding machine "8400" are as follows: pressure is 300 kPa, peak power is 80
% (720W), "920M" welding conditions, pressure is 3
The power was 50 kPa and the peak power was 85% (1700 W). Table 2 shows the unsealing strength of the spout before welding, the pinhole generation rate of the spout welded to the paper container, and the hole generation rate of the root portion 4a.

Examples 2 and 3 and Comparative Examples 1 and 2 Low density polyethylene was injection-molded to obtain a spout for a paper container, and the shape of the spout was as shown in Table 1. These spouts were welded to the paper container body in the same manner as in Example 1. Table 2 shows the unsealing strength of the spout before welding, the pinhole generation rate of the spout welded to the paper container, and the hole generation rate of the root portion 4a.

[0021]

[Table 1]

[0022]

[Table 2]

In Comparative Example 1, since the tip 2a of the groove 2 has a corner, the shape is easy to open and the unsealing strength is low, but the pinhole generation rate of the spout and the hole generation of the root portion 4a are generated. The rate is extremely large, and the unsealing strength is high in Comparative Example 2 (unsealing with the pull ring 5 by hand gives an unsealing strength of 4 k
It is difficult to open with gf or more), ultrasonic welding machine "9
The rate of occurrence of holes in the root portion 4a by welding with "20 M" is considerably high. Compared to them, Examples 1 and 2,
It can be seen that No. 3 has a low unsealing strength and is good, and that both the pinhole generation rate at the spout and the hole generation rate at the root portion 4a are very good.

[0024]

EFFECTS OF THE INVENTION According to the present invention, it is possible to prevent the occurrence of pinholes and breaks in the thin-walled portion, the root portion of the periphery of the spout and the flange portion due to ultrasonic vibration, and to provide a spout that can be easily opened. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a paper container spout of the present invention.

FIG. 2 is an enlarged cross-sectional view of the groove 2 of FIG.

FIG. 3 is an enlarged cross-sectional view of a root portion 4 of the spout portion 3 and the flange portion 1 of FIG.

FIG. 4 is an enlarged sectional view of a groove 2 in a conventional spout.

[Explanation of symbols]

 A Paper container main body B Spout 1 Flange 2 Groove 2a Tip 2b Opening angle 2c Opening width 3 Pouring spout 4 Base part 4a Base part wall thickness 5 Pull ring 6 Thin part

Claims (2)

[Claims] 1. A spout for ultrasonically welding to a paper container body, wherein the radius of the tip of the groove of the thin portion is 0.08 to 0.2 mm.
The opening angle of the groove of the thin portion is 30 to 50 °, and the opening width of the groove of the thin portion is 0.65 to 1.25.
mm, a spout for a paper container. 2. The paper container spout according to claim 1, wherein the thickness of the root portion between the outer peripheral surface of the spout and the flange is 1.5 mm or more.