JPH056504B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a method of manufacturing a synthetic resin band used for packaging bands, etc. In order to grant
After forming minute chevron-shaped ribs, vertical linear ribs are formed.

(Conventional example) Synthetic resin bands, which are often used for packaging bands, are generally made by extruding raw resin from a slit in an extruder as a belt-like material, cooling it, and then applying tensile stress in the vertical direction. It is formed by stretching and then using an embossing roll to protrude ribs on both the front and back surfaces. FIG. 4 is a partial plan view of an example of a conventional band of this type manufactured in this manner, and the front and back surfaces of the band C are embossed to prevent the band C from vertically cracking. A large number of minute chevron-shaped ribs 9 are formed for this purpose. Note that this band C is in the form of a continuous belt in the vertical direction in FIG. This product has the effect of preventing vertical cracking of the band C by the chevron ribs 9, and the effect of preventing misalignment of the band C due to the upper and lower chevron ribs 9 fitting into each other when the bands C are overlapped. However, the strength of the hips in the vertical direction, which is necessary for automatic packaging, is not sufficient.
In addition, the flexibility in the width direction is not sufficient, so if you bend it along the vertical direction, it is likely to cause vertical cracks10, and if you hold it with your fingers when packing or transporting the packaged items, the flexibility in the width direction will increase. Because of its low flexibility, it hurts the hands and fingers, and if it is tightly fastened to an object to be packed, such as a cardboard box, it tends to dig into the object and damage it. Further, even when the embossing roll is pressed, the stretching force is not sufficiently and uniformly applied in the width direction, so there is a problem that vertical cracking tends to occur when force F in the width direction is applied.

(Object of the Invention) An object of the present invention is to provide a method for manufacturing a synthetic resin band that solves the problems of the conventional methods described above. That is, an object of the present invention is to provide a method for manufacturing a synthetic resin band that can sufficiently impart flexibility in the width direction and stiffness in the longitudinal direction.

(Summary of the Invention) The present invention forms microscopic chevron-shaped ribs by pressing a first embossing roll onto the front and back surfaces of a belt-shaped original fabric made of thermoplastic synthetic resin extruded through a slit of an extruder. After that, a second embossing roll is pressed to form a plurality of linear ribs in the vertical direction. With this configuration, the above-mentioned effect of the sharp chevron ribs is ensured, and the linear ribs provide stiffness in the vertical direction and flexibility in the width direction, and when embossing with each embossing roll, Appropriate stretching force is applied in the width direction to improve the prevention of vertical cracking.

(Example) Next, an example of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is an extruder, 2 is a hopper,
3 is a die, and the thermoplastic synthetic resin A put into the hopper 2 is sent to the die 3 while being melted inside the extruder 1, and extruded as a belt-shaped raw fabric B from the slit (not shown). . The thermoplastic synthetic resin A is, for example, polypropylene, polyethylene, ethylene vinyl acetate copolymer, polyester, or a mixed raw material thereof, and some blowing agents and fillers are mixed in as necessary to ensure softness. Ru. 4 is a cooling water tank, 5 is a stretching tank, and after the raw fabric B is cooled in the water tank 4, it is stretched in order to apply a tensile force in the vertical direction. 6 is an annealing relaxation tank for removing strain, and 7 is a second cooling water tank.

8a and 8b are first embossed balls provided at the rear of the stretching tank 5. Rolls 8a, 8b
A large number of minute irregularities are formed on the peripheral surface of the fabric B, and embossing is performed by pressing the rolls 8a and 8b against the front and back surfaces of the raw fabric B. FIG. 2 is a plan view of the original fabric B that has been embossed by the rolls 8a and 8b, and the original fabric B has a large number of minute chevron-shaped ribs 9 formed thereon. This original fabric B is the same as the conventional one shown in FIG. 4, and is in the form of a continuous belt in the vertical direction in the figure. In the figure, the intersection indicated by a triangle indicates the top of the chevron, and the intersection indicated by a circle indicates the bottom of the chevron. The chevron ribs 9 have the effect of preventing the band from vertically cracking, and also prevent the chevron ribs 9 from fitting into each other and shifting the position of the band when the bands are overlapped. In addition to the pyramidal shape, similar effects can be obtained by using a conical shape, a hemispherical shape, etc. as the chevron shape.

Following the embossing with the rolls 8a and 8b, embossing with the second embossing rolls 11a and 11b is performed. In this embodiment, the second rolls 11a and 11b are arranged at the rear of the water tank 7, but the rolls 8a and 8 are located in front of the relaxation tank 6.
It may be arranged immediately after b. roll 11a,
11b is formed with a plurality of concave grooves that go around its peripheral surface, and by pressing the rolls 11a and 11b, a plurality of longitudinal linear ribs 14 are provided on the front and back surfaces of the web B. A synthetic resin band C is completed. (See Figures 3a-e). In the figure,
The line labeled 14 is the valley line of the linear rib. Among the sectional views shown in FIGS. 3b to 3e, b and d are sectional views A-A and B-B when the linear rib 14 is formed at the solid line position in FIG. 3a, and c and e These are AA and CC sectional views when the linear rib 14 is shifted by half a pitch as shown by the chain line. Note that even if the rolls 8a, 8b, 11a, and 11b are pressed against the web B, the web B recovers elastically due to its own elasticity, so the ribs 9 do not necessarily have an acute angle as shown in the figure, but rather It has a round taste. In FIG. 1, 12 is a winding section.

By forming the ribs 14 in the longitudinal direction of the band C in this way, it is possible to give the band C strength in the longitudinal direction and flexibility in the width direction, which are necessary when packing with a packing machine or the like. Furthermore, if the chevron ribs 9 and the longitudinal ribs 14 are not formed simultaneously in one step but are formed in two steps as in this method, the rolls 8a, 8b and the rolls 11a, 11
B can be brought into sufficient pressure contact with the original fabric B and can be stretched uniformly and sufficiently in the width direction due to its volume exclusion effect in the width direction, so that it can sufficiently prevent warp cracking.

(Effects of the Invention) As explained above, in the present invention, the vertical linear rills 14 are formed after the minute chevron ribs 9 are formed, so the chevron ribs 9 have an effect of preventing vertical cracking. In addition to ensuring the effect of preventing positional shift when the bands C are overlapped, the linear ribs 14 can provide stiffness in the vertical direction and flexibility in the width direction. Also, first embossing rolls 8a, 8b and second embossing rolls 1a, 1
Since 1b is pressed against the raw fabric B in two stages, sufficient tensile strength can be imparted to the raw fabric B without causing undue stress.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention.
The figure is a side view during manufacturing, Figure 2 is a plan view of the belt-like original fabric, Figures 3 a, b, c, d, and e are plan views and cross-sectional views of the band, and Figure 4 is a plan view of the conventional one. It is. 1... Extruder, 8a, 8b... First embossing roll, 9... Chevron rib, 11a, 11b... Second embossing roll, 14... Linear rib, B...
Belt-shaped raw fabric, C...Synthetic resin band.

Claims (1)

[Claims] 1. After extruding through the slit of an extruder, a first embossing roll is pressed against the front and back surfaces of a belt-shaped raw fabric made of thermoplastic synthetic resin that is formed by stretching, and then microscopic chevron-shaped ribs are formed. A method for manufacturing a synthetic resin band, comprising forming a plurality of linear ribs in the vertical direction by pressing a second embossing roll.