JPS63203564A - Cord for bundling - 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 relates to a tying string, and more specifically, the present invention relates to a tying string, and more specifically, the tying string [1] is hard to loosen, and the fibers do not become frayed or fluffy, and can be used, for example, in an automatic tying machine. This invention relates to a binding string suitable for binding corrugated pole boxes, old words, etc.

[Conventional technology and its problems] Conventionally, strings used for wrapping or binding corrugated pole boxes, archaic boxes, etc. have often been made of stretched resin, such as high-density polyethylene. Resin, polypropylene resin, etc. are used.

However, high-density polyethylene resin is too soft as a material for strings, so the knots in high-density polyethylene resin strings tend to loosen. They had to tie it together and make multiple knots to distribute the force applied to a single knot.

On the other hand, although strings made of polypropylene resin have strong knots, the fibers tend to fray and become fluffy.For example, when used in an automatic tying machine, the frayed fibers may get tangled in the string guiding part of the automatic tying machine. However, the disadvantage is that the strings may not be drawn out smoothly, which may easily cause the automatic tying machine to malfunction.

[Means for solving the above problems] The purpose of this IN+ is to solve the problems that conventional tying strings had, and to prevent the knots from loosening and the fibers from fraying and becoming loose. It is to provide Yuihigawa Himo.

In order to achieve this objective, the inventor has made extensive studies and found that a string made by stretching a composition made by blending polypropylene and high-density polyethylene in a specific ratio can have loose knots and fibers. This invention was achieved by discovering that there is no fraying.

That is, the outline of the present invention for solving the above-mentioned problems is to create a composition in which stretchable polypropylene and stretchable high-density polyethylene are blended in a weight ratio of polypropylene/high-density polyethylene = 90/10 to 50,150. This is a binding string characterized by being stretched.

The polypropylene may be obtained by a conventionally known manufacturing method in which propylene obtained by fractionating petroleum graphing gas or natural gas is polymerized using a Ziegler-type catalyst such as alkyl aluminum and titanium chloride. Alternatively, it may be obtained by a manufacturing method other than known methods.

As the polypropylene, Melt Index (
MI) from 0.5 to 10 (g/lo min) preferably from 1 to
4 (g/lo min), particularly preferably about 2 (g/10 min), and a density of 0.910 (g/cm3) is preferred.

When MI is outside the above range, moldability may deteriorate.

There are no particular restrictions on the manufacturing method for the high-density polyethylene, such as the nu Pout method, the Ziegler method,
It may be manufactured by conventionally known manufacturing methods such as the Pb1llips method and the 5 standard method.

The high density polyethylene has an MI of 0.2 to 2.
0 (g/10 min), preferably 0.05-L (g/10 min), preferably 0.05-L (g/10 min)
IQ minute) and its density is 0.947 to 0.9
60 (g/cm3) is desirable.

When MI is outside the above range, moldability may deteriorate.

The binding string of the present invention is made by stretching a composition containing the polypropylene and the high-density polyethylene in a weight ratio of polypropylene/high-density polyethylene = 90/10 to 50,150.

If the blending ratio of polypropylene in the composition is greater than 0.8, the fibers of the string formed by stretching this composition will fray and become fluffy, and for example, when used in an automatic tying machine, This fluff may get tangled with the string guiding part of the automatic tying machine, or the string may not be drawn out smoothly.

On the other hand, the blending ratio of polypropylene in the composition is 0.5
If it is smaller, the knot tends to loosen and may not be able to function as a binding string.

The stretching ratio of the composition is preferably 3 to 10 times,
Particularly preferred is 5 to 7 times.

When the stretching ratio exceeds 10 times, it may become easy to break during stretching. On the other hand, if the stretching ratio is less than 3 times, the strength of the resulting string may decrease.

There is no particular restriction on the thickness of the tying string of the present invention, and it is possible to obtain 70% of the performance as a tying string at the thickness of a normal string, that is, 25 to 45 microns. It can be suitably used.

[Effects of the Invention] The binding string of the present invention is made by stretching a composition made by blending high-density polyethylene and polypropylene in a specific ratio, so it is different from conventional strings made only of high-density polyethylene resin. There is no problem of the knots loosening easily, as in the case of conventional strings made only of polypropylene resin, and there is no problem of the fibers fraying and becoming fluffy, as with conventional strings made only of polypropylene resin.

Therefore, according to the present invention, it is possible to solve the problems that conventional strings had and to provide a tying string suitable for use in, for example, an automatic tying machine.

[Examples] Next, Examples and Comparative Examples of the present invention will be shown to explain the present invention in more detail.

(Examples 1 to 5) The blending ratio of polypropylene and high-density polyethylene was the first
A knot having a loop diameter of 1 cm was tied using an automatic tying machine using string made of the composition shown in the table.

Next, hold the string 5cm to the left of the knot (point A) and 5cm to the right of the knot at point 21 (point B), and hold it to the left and right.
The length between AH and AH was measured after the knot was pulled with a force of 100 kg to examine the elongation of the knot and its suitability for automatic knot-tying machines.

The results are shown in Table 1.

(Comparative Example 1) The elongation of the knot and its suitability for an automatic tying machine were examined in the same manner as in Examples 1 to 5, except that a string made only of polypropylene resin was used.

The results are shown in Table 1.

As is clear from Table 1, although the string made only of polypropylene resin does not stretch at the knot, the fibers are so fluffy and tangled that they are not suitable for use in automatic tying machines.

(Comparative Example 2) In the same manner as in Comparative Example 1, except that a string made only of high-density polyethylene resin was used instead of the string made only of polypropylene resin, the knot II was stretched and applied to an automatic tying machine in the same manner as in Comparative Example 1. We investigated the suitability of

The results are shown in Table 1.

As is clear from Table 1, although strings made only of high-density polyethylene resin have some suitability for automatic tying machines, the knots tend to elongate considerably, making it difficult to securely tie heavy items with one wrap. It is not possible.

The suitability for automatic tying machines was evaluated as follows.

0: There is no fluff or tangle of fibers.

O: There is almost no fluff or tangle of fibers.

Δ: Woven fibers are slightly fluffy.

X: Fibers are severely fluffed and tangled.

(hereinafter referred to as margin)

Claims (1)

[Claims] (1) A bundle characterized by stretching a composition in which stretchable polypropylene and stretchable high-density polyethylene are blended in a weight ratio of polypropylene/high-density polyethylene = 90/10 to 50/50. String for use.