JPS6234623B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a synthetic resin binding band used for packing, wrapping vegetables, flower petals, etc., and a method for manufacturing the same.

(Prior Art) Conventionally, this type of binding band is disclosed in Japanese Utility Model Publication No. 52-6538, in which a large number of protrusions are formed in parallel to the short axis direction of a band-shaped body, and between the protrusions there is a A binding band is described in which a groove is formed into which a protrusion is fitted.

(Problems to be Solved by the Invention) However, when binding the binding band,
By arranging the surfaces on which the protrusions are formed at both ends of the band to face each other, and fitting the protrusions on one end into the grooves on the other end, and the protrusions on the other end into the grooves on the one end, respectively. They will be united. Therefore, when tensile stress is applied to the band after bundling, stress is applied to the mating part in the direction of peeling off, causing the fitted protrusions to come out of the grooves, and the innermost protrusion Since each of the protrusions separates individually, the tensile strength becomes approximately equal to the separation force of the individual protrusions, and there is a drawback that the tensile strength does not increase significantly even if the number of fitted protrusions increases.
Furthermore, the binding band is manufactured by extruding plastic or the like from a mold having a cross-sectional shape equal to that of the binding band, and then cutting it to an appropriate width, which has the disadvantage that only a predetermined length can be obtained.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned drawbacks of conventional products. One to several rows of protrusions are arranged in parallel at equal intervals, and a large number of through holes are bored between the protrusions in the thickness direction of the strip, and the length of the through holes is made to be slightly larger or equal to the length of the protrusions. A synthetic resin binding band and a crystalline thermoplastic resin material are molded into a synthetic resin band-like body having one to a plurality of protrusions on one side using an extrusion molding machine,
The stretched strip is once rapidly cooled and stretched to form a stretched strip, and then a pair of upper and lower molds are formed, each having the same shape as the upper and lower surfaces of the stretched strip. However, the stretched synthetic resin strip is introduced into a punching device in which protrusions are formed on the other mold, and the ridges of the stretched strip are penetrated in the thickness direction of the strip, and the punched portions are transparent. This method consists of manufacturing a synthetic resin binding band characterized by continuously drilling through holes in which the lengths of the holes and the lengths of the protrusions in the non-punched portions are approximately equal.

(Function) When both ends of the synthetic resin binding band are overlapped, the protrusions arranged in parallel at regular intervals are fitted into the through holes formed between the protrusions as shown in FIG. By making the length of the through hole slightly larger or equal to the length of the projection, the projections fitted into the through hole are bound together so that they do not come off. The tensile strength of the binding portion is adjusted by the shapes of the protrusions and through holes and the number of fittings.

A synthetic resin band having one or more protrusions on one side is molded, and a punching device is used to continuously punch through holes in the protrusions, and the desired length of the band is cut. can get.

(Example) In the drawings, 1 is a stretched band made of synthetic resin, 2 is an extrusion molding machine, 3 is a cooling tank, 4 is a pinch roll, and 5 is a stretched strip made of synthetic resin.
6 is a heating stretching tank, 6 is a stretching roll, 7 is a punching device, and 8 is a winding machine. Note that 9 in the figure is a distortion removing device.

The stretched synthetic resin strip 1 is made of a thermoplastic resin, and in particular, resins such as polypropylene, polyethylene, polyester, and polyamide, which increase tensile strength by stretching, are preferably used. The stretched strip 1 is obtained by heating and melting the above-mentioned thermoplastic resin in an extrusion molding machine 2 and passing through the discharge port 2 of a die 21.
2 is extruded into a strip 1' having a predetermined cross-sectional shape, and then cooled once in a cooling tank 3 and reheated in a heated stretching tank 5, with at least one pair of pinch rolls 4 provided before and after the extrusion molding. stretching roll 6
It is manufactured by stretching 1.5 to 10 times in the length direction between the two. Note that when a through hole 12 is punched in the stretched strip 1 by the punching device 7 described later, if there is a risk of cracks occurring at the edge of the through hole 12, rubber, ethylene-vinyl acetate, etc. may be added to the resin. It may be softened by mixing a copolymer resin, a low molecular weight olefin resin, etc., or adding a plasticizer, a blowing agent, a filler such as calcium carbonate, etc. as appropriate.

One to three protrusions 11'' are integrally formed on one surface of the stretched synthetic resin strip 1 over the entire length in the longitudinal direction. The grooves 23 are integrally formed on one surface of the strip 1', and by stretching the strip 1',
It has a predetermined cross-sectional shape. Note that the height of the protrusion 11'' is equal to or greater than the thickness of the strip 1'.The protrusion 11'' has a large number of through holes 12 bored along the protrusion 11''. The length of the through hole 12 is approximately equal to the length of the projection 11.If the four corners of the through hole 12 are slightly chamfered, the four corners of the projection 11 The ribs stand out, protrusion 1
1 and the through hole 12 are firm, which is preferable. The through holes 12 are formed by continuously punching out the stretched synthetic resin strip 1 by a punching device 7 after stretching. The punching device 7 includes, for example, a pair of upper and lower punching dies 71 and 72, each of which has a concave portion in which the stretched synthetic resin strip 1 is sandwiched, and one of the punching dies 71 has a through hole. 1
A punching hole 74 corresponding to the hole 12 is formed in the other punching die 72, and a protrusion 75 corresponding to the through hole 12 is projected from the other punching die 72. By tightening the pair of punching dies 71 and 72, the synthetic resin sandwiched between them is formed. A through hole 12 is bored in the stretched strip 1. If the above-mentioned punching dies 71 and 72 cannot keep up with the manufacturing speed of the stretched synthetic resin strip 1, a pair of rotating rolls each having a punching protrusion 75 and a punching hole 74 along the outer peripheral wall may be used. It is okay to have
Alternatively, the manufacturing process of the stretched synthetic resin strip 1 and the punching process of the through holes 12 may be performed as separate processes. When punching the through hole 12 with the punching device 7, the through hole 1
If there is a risk of cracks occurring at the edges of the synthetic resin stretched strip 1, it is advisable to take measures to prevent the cracks, such as heating and softening the stretched synthetic resin strip 1.

The strain removing device 9 removes distortions such as torsion caused during extrusion molding or heating stretching of the stretched strip 1, and usually uses hot water heated to around the softening temperature of the stretched strip. It is stored. Note that it is preferable that the stretched strip 1 heated and softened by the strain removing device 9 be guided to the punching device 7 before it cools down, since this will prevent cracks from forming at the edges of the through holes 12 when the through holes 12 are bored.

The synthetic resin binding band manufactured in this way is continuously wound up by a winding machine 8. During winding, the through hole 1 of the upper layer binding band is
2 is preferably prevented from getting stuck in the protrusion 11 of the lower binding band.

Next, examples of the present invention will be described.

First, the compositions shown in the following table were used as thermoplastic resin raw materials.

Polypropylene 100 parts by weight Polyethylene 60 〃 Azodicarbonamide 0.3 〃 Calcium stearate 0.4 〃 Pigment 0.35 〃 This resin raw material was screwed into a screw diameter of 60 m/m, L/D=
22 is heated and melted in the extruder 1, and the die 21 at the tip of the
A strip 1' was continuously extruded from the material. die 2
The discharge port 22 of No. 1 is a horizontally long slit with a width of 14 mm and a height of 0.5 mm, and two concave grooves 23, 23 with a width of 1.7 mm and a height of 1 mm are provided at a position of 3.5 mm from both ends, respectively, on the upper side of the oblong slit with a width of 14 mm and a height of 0.5 mm. Therefore, the cross-sectional dimension of the band 1' is made equal to the dimension of the die 21, and the protrusion 11' has 23 grooves.Then, the synthetic resin band 1' is heated to a water temperature of 20°C.
After being cooled once in a cooling tank 3, the strip 1' is guided to a heating stretching tank 5 containing hot water at 85 to 90°C, and pinch rolls 4 are provided before and after the heating stretching tank 5.
The circumferential speed ratio between the belt and the stretching roll 6 was set to 1:3, and the stretched belt-like body 1 made of synthetic resin was stretched three times in the length direction. Note that the shape of the stretched synthetic resin strip 1 has a width of 8.
mm, width 1mm, height 0.5mm on the top surface of the strip with a thickness of 0.3mm
Projections 11'', 11'' are formed at positions 2 mm from both ends, respectively.

Subsequently, the stretched belt-shaped body 1 made of synthetic resin is introduced into a water tank with a water temperature of 50°C using a strain removing device 9, and the stretched belt-shaped body 1 is
After removing the strain, it was introduced into a punching device 7, and a large number of through holes 12 were punched out at predetermined intervals in the thickness direction on the protrusions 11'', 11'' of the stretched strip 1 at equal intervals. . The punching device 7 includes a pair of upper and lower die rolls 7.
1,72, and grooves 73, 73 with a width of 1 mm and a depth of 1 mm corresponding to the protrusions 11'', 11'' of the stretched synthetic resin strip 1 are carved in the upper mold roll 71, and the grooves Width 1mm, length 8mm at the bottom of 73, 73
Punched holes 74 are drilled at 8mm intervals,
In addition, protrusions 75 each having a width of 1 mm, a length of 8 mm, and a height of 1 mm are protruded from a portion of the lower mold roll 72 opposite to the punched holes 74 of the upper mold roll 71 at intervals of 8 mm at their tips. Due to the meshing of the mold rolls 71 and 72, a through hole 12 with a length of 8 mm is formed continuously in the stretched strip 1 passing between them.
A synthetic resin binding band was obtained in which protrusions 11 were formed by perforating holes 11 at intervals of 8 mm and by dividing protrusions 11'' by the through holes 12.

(Effects of the Invention) As detailed above, in the synthetic resin binding band of the present invention, the protrusions formed on the stretched strip are divided by a large number of through holes to form protrusions, and the length of the through holes is Since the lengths of the protrusions are approximately equal, the band can be easily bound by simply overlapping both ends of the band and inserting the protrusion at the other end into the through hole at one end.

Further, in the band of the present invention, the protrusions are fitted into the through holes in the binding portion, so that the protrusions are retained by the through holes both in the longitudinal direction and the width direction of the band, making it difficult for the binding portion to come off.

Furthermore, since the band of the present invention has through-holes and protrusions arranged at equal intervals, the tensile strength of the bundled part can be increased by adjusting the length of the overlapping part at both ends, that is, the number of inserted through-holes and protrusions. It can be adjusted arbitrarily.

Furthermore, in the method for manufacturing a synthetic resin binding band of the present invention, a pair of upper and lower molds are provided, each having the same shape as the upper and lower surfaces of the stretched synthetic resin strip, and one mold is provided with a ridge portion of the stretched strip. Since the opposed punching holes continuously guide the stretched synthetic resin strip to a punching device in which a protrusion is formed on the other die, the through hole must be continuously punched in the protrusion portion of the stretched strip. In addition, the protrusions can be divided into protrusions by the through holes.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of the process of the manufacturing method of the present invention, Fig. 2 is a perspective view showing an example of a die used in the method of the present invention, and Fig. 3 is an example of a stretched band made of synthetic resin. 4 is a sectional view showing an example of a punching device used in the method of the present invention, FIG. 5 is a perspective view showing an example of a binding band made of the synthetic resin of the present invention, and FIG. 6 is a sectional view showing an example of a binding band made of the synthetic resin of the present invention. FIG. 7 is a partially cutaway plan view showing another example of a binding band manufactured by the manufacturer, and FIG. 7 is a cross-sectional view showing a method of binding the binding band of the present invention, in which A shows the band before binding and B shows the band after binding. 1...Stretched synthetic resin strip, 1'...Synthetic resin strip, 11...Protrusion, 11', 11''...Protrusion, 12
... through hole, 2 ... extrusion molding machine, 21 ... die, 22 ... discharge port, 23 ... groove, 3 ... cooling tank, 4 ... pinch roll, 5 ... heating stretching tank, 6 ... stretching roll, 7 ... punching device, 71...Upper mold roll, 72...Lower mold roll, 73...Groove, 74...Punching hole, 75...Protrusion, 8
... Winding machine, 9... Strain removal device.

Claims (1)

[Scope of Claims] 1. One to several rows of protrusions are arranged in parallel at equal intervals along the longitudinal direction on one side of a stretched synthetic resin strip, and a through hole penetrating the strip in the thickness direction is formed between the protrusions. A binding band made of synthetic resin having a plurality of holes, the length of which is slightly larger or equal to the length of the protrusions. 2 A crystalline thermoplastic resin material is molded into a synthetic resin band-like body having one or more protrusions on one side using an extrusion molding machine, and then rapidly cooled and stretched to form a stretched band-like body, and then the stretched band-like body is It consists of a pair of upper and lower molds with the same shape as the upper and lower surfaces, and one mold has a punching hole facing the protrusion of the stretched strip, and the other mold has a protrusion. A stretched strip made of synthetic resin is guided, and a transparent hole is inserted through the protrusion portion of the stretched strip in the thickness direction of the strip, and the length of the through hole in the punched portion is approximately equal to the length of the protrusion in the non-punched portion. A method for manufacturing a synthetic resin binding band, which comprises continuously drilling holes.