JPS5942613B2 - Manufacturing method of packing bands for heavy packaging - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing heavy-duty packaging and bands.

Traditionally, steel ties have been used to tie heavy packaged items together, but this has drawbacks such as rust and danger, and there is a need for a high-strength binding material to replace this. It had been. Then, so-called synthetic resin bands made by stretching polyester appeared, but these polyester bands had drawbacks such as high material cost, long stretching time and poor manufacturing efficiency, and poor heat weldability. Ta. The present invention was created in view of these problems, and provides a method for manufacturing a synthetic resin band for heavy packaging that is inexpensive in material cost, has high tensile strength, has low elongation at break, and has excellent heat weldability. The purpose is to

The first method of the present invention is to cool the original fabric extruded from an extruder using polypropylene as the main raw material, and then
As stage stretching, stretching is performed in a first stretching tank at a temperature of 800C to 110C to a stretching ratio of 4 to 8 times, and as two stage stretching, in a second stretching tank, a stretching ratio of 1.5 times or more is drawn at a temperature of 200C to 2800C. 1. A method for producing a heavy-duty packing ribbon, which comprises embossing a band that has been stretched to a total stretching ratio of 7 to 12 times.

'', and the second method is ``After cooling the original fabric extruded from an extruder using polypropylene as the main raw material,
As a first-stage stretching, the stretching is carried out in a first stretching tank at a temperature of 80'C to 1100C to a stretching ratio of 4 to 8 times, and as a second stage stretching, a stretching ratio of 1 is drawn at a temperature of 200'C to 280°C in a second stretching tank. ．．
Stretched to 5 times or more, and then stretched to a stretching ratio of 1.2 times or more at a temperature of 200°C to 300°C, which is higher than the 2nd stage stretching, in a third stretching tank as a 3rd stage stretching, and the total stretching ratio was 8 to 14. This is a manufacturing method of a packing band for heavy packaging, characterized in that it is made by subjecting a double stretched band to embossing. The method of the present invention will be described in detail below. As the main raw material, polypropylene or polypropylene blended with a copolymer of polypropylene and ethylene is used.

A small amount of filler or pigment such as calcium carbonate is added to these raw materials as necessary. A raw material mainly consisting of polypropylene is supplied from a hopper 1 to a commonly used extruder 2, heated and melted in the extruder 2 to about 220° C., and quantitatively extruded from a mold 3.

The raw material 4 extruded from the mold 3 is passed through the first
It is introduced into water tank 5 and cooled. The water temperature in the first water tank 5 is approximately 20
It is ℃. The raw fabric 4 once cooled in this first water tank is
A second take-up roll 8K is taken off from the first take-up roll 6 via the first stretching tank 7. In the first drawing tank 7, heating is carried out at 80°C to 110°C, and the rotational speed of the first take-up roll 6 and the second take-up roll 8 is adjusted to make the stretching ratio of the original fabric 4 to 8 times. . This stretching is called one-stage stretching. The stretched original fabric is hereinafter referred to as a band 19. The strip 19 stretched one step in this way is
It is introduced into the second stretching tank 9 from the second take-up roll 8 and taken up by the third take-up roll 10. In the second stretching tank 9, 200°C to 28°C
Stretch by heating to a temperature of 0°C. The stretching ratio is set to 1.5 times or more by adjusting the rotational speed of the second take-up roll 8 and the third take-up roll 10. This stretching is called two-stage stretching. The strip 19 stretched in two stages is introduced from the third take-up roll 10 into the third stretching tank 11 and taken up by the fourth take-up roll 12 .

In the third stretching tank 11, the temperature is 200°C, which is higher than that during the second stage stretching.
C. to 300.degree. C. and stretched to a stretching ratio of 1.2 times or more. This stretching ratio is also achieved by adjusting the rotation speeds of the third take-off port 10 and the fourth take-up roll 12. This stretching is called three-stage stretching. The three-stage stretched strip 19 is embossed with an embossing roll 13,
It is introduced into the annealing tank 14.

The band 19 annealed at a temperature of about 280° C. is introduced from the fifth take-up roll 15 into a cooling tank 16 and cooled, and then sent from a guide roll 17 to a winding drum 18 and wound up.

The process from extrusion by the extruder 2 to winding by the winding drum 18 is performed continuously. Note that stretching can be carried out up to two stages to produce a product. In addition, it is also possible to slit both ends of the raw fabric 4 on the first take-up roll 6 and stretch it in multiple stages to form a strip with a uniform cross-section. Even if a manufacturing method is adopted in which the belt is stretched in multiple stages after being made into a band, the stretching ratio is 4 to 8 times in one stage stretching, but 1.5 in two stage stretching.
The stretching ratio is 1.2 to 2 times, and the stretching ratio is gradually lowered.

In the case of two-stage stretching, the stretching ratio from the original fabric is 7 to 12 times, and in the case of three-stage stretching, the total stretching ratio is 8.
~14 times.

The stretching temperature was 8'C to 110°C for the 1st stage stretching, 20'C to 28'C for the 2nd stage stretching, and 200°C to 30°C for the 3rd stage stretching.
At 0'C, the temperature is gradually increased as the stretching progresses from the first stage to the second stage and then to the third stage.

Next, specific examples of the method for manufacturing the synthetic resin band of the present invention will be shown.

The physical properties of the two-stage stretched band and the three-stage stretched band obtained by the method of the present invention will be compared with the physical properties of the single-stage stretched band.

Further, the tensile strength and elongation of the steel band, the two-stage stretched band of the method of the present invention, the three-stage stretched band, and the ordinary one-stage stretched band are expressed as SS curves as shown in the following graph.

As can be seen from these physical property tables and S-S curves, the width, thickness, and weight are similar to those of ordinary packaging bands, but the tensile strength is 390.8K9 in the case of two-stage stretching, and 390.8K9 in the case of three-stage stretching. In the case of 31330K9, it is comparable to the case of banded iron, and is suitable for packing heavy items, and the elongation at break is 11.2% in two-stage stretching, which is only slightly lower than that of banded iron. In three-stage stretching, it was 8.5%, a little less than twice as much, and was sufficiently suitable for heavy-duty packaging.

Moreover, the welding strength was 272K9 in the case of two-stage stretching and 313Kg in the case of three-stage stretching, making it suitable as a packing band for heavy-duty packaging. In addition, unlike polyester, polypropylene has extremely good stretchability and can be stretched at a stretch ratio of 4 to 8 times at once.Moreover, even when stretched at once, it does not cause uneven stretching, cracks, or cross-sectional shape. was completed. Furthermore, even if each stretching temperature was set to a considerably high temperature, the strip could be heated uniformly and quickly, and manufacturing efficiency could be improved. Since it is a band for heavy packaging, the thickness of the band is 0.6m77! ~1.4m77! This is quite thick, and there is a risk that temperature will not be transmitted uniformly to this thick strip and uniform stretching will not be possible. There are no such concerns with the invention method. If thicker bands were stretched all at once, the molecular orientation would not be uniform and the tensile strength would be low. However, as in the method of the present invention, polypropylene is used as the main raw material, and one-stage stretching is performed at a stretch ratio of 4 to 8 times. Furthermore, since the film was stretched in two or three stages under certain conditions, it was possible to obtain a band with well-ordered molecular orientation and high tensile strength. In addition to the three-stage stretching described above, it is also possible to produce a band stretched in four or five stages. In the present invention, after the original fabric extruded from the extruder using polypropylene as the main raw material is once cooled, it is drawn in a first drawing tank at a temperature of 8'C to 110C at a stretching ratio of 4 to 8 times. The strip was stretched to a stretching ratio of 1.5 times or more at a temperature of 200° C. to 28° C. in a second stretching tank as a two-stage stretching process, and then stretched to a total stretching ratio of about 7 to 12 times. A manufacturing method in which embossing is applied to the film, or after cooling the original fabric extruded from an extruder using polypropylene as the main raw material, it is stretched to 8'C in the first stretching tank as a first-stage stretching process.
Stretching to a stretching ratio of 4 to 8 times at a temperature of ~11'C, stretching to a stretching ratio of 1.5 times or more at a temperature of 200 ° C to 280 ° C in a second stretching tank as a 2-stage stretching, and 3-stage stretching In the third drawing tank, the temperature is 200'C to 30°C, which is higher than that during the second drawing.
By using a manufacturing method that involves embossing a band that has been stretched to a stretching ratio of 1.2 times or more at 0°C and a total stretching ratio of about 8 to 14 times, a band suitable as a packing band for heavy-duty packaging has been created. Obtained.

In other words, although it is consumed in large quantities for heavy-duty packaging, it can be provided at low cost because its main material is polypropylene, and it has sufficient tensile strength to be used for heavy-duty packaging. Moreover, the elongation at break was suitable for use as a packing band for heavy-duty packaging, and the welding strength was also suitable for use as a packing band for heavy-duty packaging.

[Brief explanation of the drawing]

The drawings are schematic diagrams showing the manufacturing process of the method of the present invention.

Claims (1)

[Claims] 1. After once cooling the original fabric extruded from an extruder using polypropylene as the main raw material, it is drawn in a first drawing tank at a temperature of 80°C to 110°C at a stretching ratio of 4 to 3 times. Stretched and heated at 200°C to 230°C in a second stretching tank as two-stage stretching.
A method for producing a packing band for heavy-duty packaging, characterized in that the band is stretched to a stretching ratio of 1.5 times or more at a temperature of °C and embossed to a total stretching ratio of 7 to 12 times. 2 After once cooling the original fabric extruded from an extruder using polypropylene as the main raw material, it is stretched in a first stretching tank at a temperature of 80°C to 110°C to a stretching ratio of 4 to 8 times, and then a second stage stretching is performed. 200℃~280℃ in the second drawing tank as
Stretched to a stretching ratio of 1.5 times or more at a temperature of
A method for producing a packing band for heavy-duty packaging, characterized in that the band is stretched at a stretching ratio of 1.2 times or more at a temperature of .degree. C. to 300.degree.