JPS6297825A - Lateral stretching and heat treating of net-like body - Google Patents

Abstract

PURPOSE:To manufacture a favorable product at low cost by means of a simple device by a method wherein a pair of right and left discs with the same peripheral speed are bisymmetrically arranged so as to have a divergent orbit in the same plane or at the constant angle in order to laterally stretching a net-like body under heating atmosphere by means of the divergent orbit produced by the right and left discs by holding both the edges of the net-like body, which is introduced between the right and left discs, with the outer peripheral parts of the right and left discs. CONSTITUTION:A net-like body 11, which is past through a nip roller 9 and turn rollers 10 and 11, is led to a laterally stretching device or to the narrowest portion of two discs 13 and 13', which are arranged in an inverted V-shape. A large number of pins 14 and 14' are respectively planted along the circumferences of the discs 13 and 13' at pitches ranging from several milimeters to several tens of milimeters so as to hook the net-like body 11 by changing the position of the turn roller 12 in response to the width of the net-like body 11 to be laterally stretched in order to gradually laterally stretch the net-like body along the divergent inverted V-shape orbit or the discs 13 and 13'. The whole laterally stretching device is housed in a hot air chamber. The net-like body 11 is heated by hot air blown from between the two discs 13 and 13' to the outside out of the circumference of each disc. The hot air escaped outside is collected and circulated for reuse.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for transversely stretching and heat treating a mesh.

In recent years, nets made of thermoplastic resin have been used for simple packaging, reinforcing paper, and as insect and bird prevention nets in the A industry.In particular, nets made by stretching the fibers of the net are lightweight and lightweight. Because of its durability, it came to be consumed in large quantities in industry. The present application relates to a method of manufacturing a stretched mesh body using a simple H-position at low cost.

[Prior art and its problems]

Stretching and heat treatment of net-like bodies have been well known for a long time.
31459 etc. All of these employ a single tenter method as the horizontal stretching method. The single tenter type is a method used as a biaxial stretching device for film, and is an excellent method as it provides high quality, high-speed productivity, and can be heat treated, but the equipment cost is very high and the equipment is expensive. Since the floor space is large and the equipment is large, it is not suitable for high-mix, low-volume production. In the one-type tenter, grippers or pins are set up on a chain conveyor to grip both ends of the net-like body and stretch it along the laterally widening trajectory of the chain conveyor. Even if a fairly sturdy chain conveyor is used, the stretching tension will cause the chain to stretch over a long period of time, causing errors in the trajectory of the left and right chain conveyors. When stretching the mesh, looseness in the left and right tracks or in the chain will cause the mesh to be uneven. If a large chain conveyor is used to reduce the amount of loosening of the chain, the cost of the equipment will increase accordingly, and there will also be a lot of energy loss since such a lump of iron must be heated. One of the disadvantages of the tenter type is that the product gets dirty due to the oil from the Cheno.

[Means to solve the problem]

The present invention solves the above-mentioned problems with a simple device in the horizontal stretching and heat treatment of a net-like body formed by integrally bonding thermoplastic resin filaments substantially perpendicularly in the vertical and horizontal directions, thereby producing a good product at a low cost. It is made possible to manufacture.

As a means to solve the problems already mentioned, during horizontal stretching, a pair of left and right disks with the same circumferential speed are arranged symmetrically in the same plane or at a constant angle so that they have trajectories that widen toward the end. Then, the ends of the mesh introduced between the left and right disks are gripped by the outer peripheries of the left and right disks, and stretched in the horizontal direction along the divergent trajectory formed by the left and right disks in a heated field under air. If heat treatment is desired after horizontal stretching, continue to hold both ends of the net-like body until the end part of the disk is parallel to the end, or beyond that part until the part where the trajectory begins to narrow slightly. This makes it possible to perform foot width or shrink heat treatment.

Then, as a means for gripping both ends of the mesh, a groove for the belt is cut on the outer periphery of the disc, and a belt under tension is circulated into this groove, and the grooves between the belt and the disc (pulley) are used to circulate the belt under tension. We propose a stretching and heat treatment method in which both ends of the mesh are held in between. As another gripping method, we have invented a method for stretching and heat treating a net-like body, in which a large number of pins are planted around the outer periphery of the disk, and these pins hook and hold both ends of the net-like body. This horizontal stretching method and heat treatment method are made using extremely simple equipment, that is, two disks, and these disks are inexpensive and easy to manufacture. Moreover, belt bobbins, which are usually mass-produced in the market, can be used as they are, so they are very inexpensive. It is. Furthermore, since it is a disk, there is no problem of the chain extending like the one-type tenter mentioned above, and there is no worry about contamination of the chain with oil. Moreover, despite its simple configuration, the divergent trajectory created by the two disks initially consists of a portion that hardly expands, and is preheated here. Next, it is horizontally stretched in the slowly expanding section, and if necessary, it is heat treated in the next approximately parallel trajectory. Generally, the stretching of thermoplastic resin requires the following steps: a preheating step, a stretching step, and a heat treatment step, and each of these steps corresponds to each part of the aforementioned curved trajectory, which can be said to be ideal. Furthermore, since it has a simple mechanism, it is easy to adjust the position and opening angle of the disc and change the introduction and removal positions of the net-like material depending on the product width, stretching ratio, heat treatment, etc., making it easy to produce a wide variety of products in small quantities. Easy to adapt to.

As for heating, the overall device is simple, so there is little heat loss from the surface of the device, and in the commonly used hot air stretching, hot air is supplied through the mesh, allowing efficient heating with a small amount of hot air. Another feature of the present invention is that hot bath heating is also possible as a heating method, and this is possible due to the simple structure. However, there is no example of hot bath stretching being applied to a tenter-only method because the waves not only cause energy loss due to severe waves, but also prevent uniform stretching of the material to be stretched.

If hot bath stretching becomes possible, not only will the heat transfer rate be faster and uniform heating will be easier, but it will also be possible to dissolve various heating media, solvents, plasticizers, etc. can be applied to networks of various polymeric substances.

As a method for manufacturing a net-like body, there is a method of manufacturing a tubular net-like body as in US Pat. The ability to manufacture two sheets at the same time using a simple device like the present invention is an epoch-making invention that cannot be imitated by other methods.

Although heat treatment is not necessary in fields where the product is required to have shrinkability, thermal dimensional stability is generally required for the product, and the present invention is capable of producing either of these products. For products that require shrinkage, it is easy to take them out from the range of the disc's end-widening orbit and make them into products without heat treatment. The product is heat-treated for shrinkage by taking it out in the area where it shrinks a little beyond the area where it travels.

When stretching a net-like material, it is generally necessary to stretch it in the vertical direction as well, but in this method, care must be taken to ensure that the mesh does not become uneven. Generally, the film is stretched in such a way that it becomes smaller (this method is called proximity stretching in film stretching). In the horizontal stretching method of the present invention, stretching in the vertical direction is not limited to proximity stretching, but can be combined with any method to form a net-like body stretched both vertically and horizontally. By the method of the present invention, heating temperature and stretching ratio can be adjusted to a network of polypropylene, polyethylene, polyamide, polyester, polyvinyl chloride, polyvinylidene chloride, fluororesin, polyvinyl alcohol, polystyrene, polyether, polyimide, and modified products thereof. It can be adapted by changing.

[Detailed explanation with drawings]

The configuration and implementation examples of the present invention will be explained in detail with reference to the drawings.

FIGS. 1 and 2 show an example of an apparatus for stretching and heat treating a net-like body, and FIG. 1 is a schematic plan view thereof, and FIG. 2 is a schematic side view thereof. In FIGS. 1 and 2, 1 is an unstretched net-like body in which vertical and horizontal filaments made of thermoplastic resin are bonded together to form an orthogonal shape. Ru. 3 is a rubber roll to be nipped and determines the introduction speed of the net-like body 1. The preheated mesh body 1 is rolled into a small diameter roll 4°5.
After passing through 6.7, it is guided to a heat treatment roll 8.

The preheating roll 2 and the small-diameter roll 4.5 are driven at the same low speed, and the small-diameter roll 6.7 and the heat treatment roll 8 have a surface speed higher than the preceding roll group by the desired vertical stretch ratio. By rapidly drawing the film in a narrow range between the small diameter rolls 5 and 6, the mesh is drawn uniformly.

Net-like body 1 passed through nip roll 9 and turned roll 10
1 is guided to a horizontal stretching device, passes through a turn roll 12,
Two discs 13, 13' are arranged in a V-shape and are guided to the narrowest part. A large number of needles (pins) 14, 14' are planted around the circumference of the disk 13, 13' at a pitch of several millimeters to several tens of millimeters, and the turn rolls 12 are arranged in accordance with the width of the vertically stretched net 11. The disk 13.13' is gradually stretched horizontally by changing its position and hooked onto the pin 14.14', following the curved trajectory of the disc 13.13'.

Although heating is not shown, the entire horizontal stretching device is housed in a hot air chamber, and hot air is blown out from between the two disks 13 and 13' to the outside of the circumference of the disk. The hot air that comes out is collected and circulated for use. The temperature of the hot air is below the melting point of the thermoplastic resin constituting the network and is determined by the stretchability of the network. Since the hot air penetrates through the mesh, the thermal efficiency is good, and the effect of uniform heating is also great. A net-like body stretched horizontally with a trajectory that widens toward the end is generally heat-treated at the point where the trajectory of the widest part becomes parallel, passes through a turn roll 15, and is taken out as a net-like body 16 that has been stretched vertically and horizontally and is heat-treated. be done. Products that require shrinkage heat treatment are taken out from the turn roll at position 15' in FIG. 2, and products that do not require heat treatment are taken out from the turn roll at position 15'' in FIG.

It is a 13.13゛ disk orbit arranged in the shape of a square in Figures 1 and 2, and the narrowest part at the beginning becomes the preheating area, and conversely, the widest part also runs approximately one foot width. There is an area,
This area is suitable for foot width heat treatment. The horizontal stretching ratio is generally 3 to 8 times, and is indicated by the ratio of the width between the discs at the narrowest point where the net-like body is introduced and the position from which the final product is taken out.

The stretching ratio is determined by the stretchability of the raw material network, the performance required by the network shape and application, and the product width.

When finely adjusting the stretching ratio, it is also possible to change the position of the introduction turn roll 12 and the position of the take-out turn roll 15 in FIGS. It can also be adjusted depending on the angle.

In FIG. 3, a folded tubular unstretched mesh body 1
7 is supplied through nip rolls 18 and 18', and vertically below it there are pulleys 19 and 19' on each side of the same shape and size that rotate in opposite directions in the same plane and are driven at the same circumferential speed. and guide pulleys 20.20'' and 21.21' located between the pulleys 19.19' and guide pulleys 22, 22', 23.23' on both sides, and two belts 24, 25 each. .24', 25'
are arranged in a circular manner almost symmetrically. These devices are located in a chamber 26 shown in broken lines and in a chamber 27 shown in solid lines.
The chamber 2G is heated with steam, and the chamber 27 is heated with hot water.

The tubular mesh body 17 fed through the nip rolls 18, 18' is preheated in the steam chamber 26, and its ends are connected to pulleys 19, 19' and belts 24, 25, 24', 25.
”, and is stretched in the horizontal direction at the same time on the front and back sides along the widening arc trajectory of the pulleys 19° and 19°. At this time, heating is done by hot water filled in the hot water heating chamber 27. The pulley 19 The net-like body 17 that has been stretched to just below the belt 24125.24'25' is reversed, and the solid webs of the pulleys 19 and 19' support the stretching tension, and it rises while being stretched horizontally upward, and the belt 24125.24'25' The pulley 19.19 is in the middle of the two belts at the position just before it leaves the pulley.
The blade 28.28' inserted into the groove provided at the center of the outer circumference of the piece makes an incision at the center of both left and right ear ends to form two pieces, front and back, which pass through turn rolls 29 and 29' to form a net-like body 30 and 30'. . This horizontally stretched net-like body 30, 30' is vertically stretched for as long as necessary, and then the ends of both ears are slit to form a product.

〔Effect of the invention〕

Stretched net-like bodies are useful in industry, but the product unit price is often low, and since they are used in a variety of fields, they are often used in a wide variety of small quantities. Conventional tenter-type equipment is
Although it is high quality and suitable for mass production, the equipment cost is very high, the equipment requires a large floor space, and it is a large equipment, so it is not suitable for high-mix, low-volume production. In addition, with one-sided tenter-type machines, the mesh may become uneven due to stretching of the chain, and the product may become stained with oil from the chain.

The present invention has a simple mechanism, is an inexpensive device, and takes up little floor space.
Moreover, since it is a simple device, it is suitable for high-mix, low-volume production. Regardless of the simple device, preheating and heat treatment are possible, and it is also possible to easily switch to no heat treatment, foot width heat treatment, contraction heat treatment, etc. In addition, it is easy to adapt to changes in product width and the width of the raw material unstretched network. As shown in FIG. 3, it is also possible to take two sheets, and simple heating with hot water is also possible.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic diagrams of a vertical stretching device and a horizontal stretching device using two identical pins, with FIG. 1 being a plan view and FIG. 2 being a side view thereof. FIG. 3 is a schematic diagram of a horizontal stretching device using a belt and a boob.

Claims (3)

[Claims] (1) In a horizontal stretching and heat treatment method for a net-like body in which thermoplastic resin filaments are integrally bonded almost perpendicularly in the vertical and horizontal directions, a pair of left and right disks having the same circumferential speed are separated from each other by the center line and are symmetrical. A net-like body is introduced between the left and right disks of the device, which are arranged so that the outer circumferences are in the same plane or have a trajectory that widens toward the end at a certain angle, and the ends of both ears are grasped by the outer circumferences of the left and right disks. , in a heated atmosphere, advance the divergent trajectory of the left and right disks to stretch in the horizontal direction, or grasp the ends of both ears of the net-like body past the divergent trajectory of the left and right disks until the parallel part or the part where the trajectory becomes slightly narrower. A horizontal stretching heat treatment method for a net-like body in which a width or shrinkage heat treatment is performed. (2) In the method for grasping both ends of the net-like body on the outer periphery of a disk according to claim (1), a belt groove is cut on the outer periphery of the disk, and the belt under tension is fitted into the groove. By circulating the belt and gripping both ends of the net between the grooves of the disc (pulley), the net can be stretched horizontally.
Heat treatment method. (3) In the method for grasping the ends of both ears of the net-like body on the outer periphery of the disk according to claim (1), a large number of pins are planted on the outer periphery of the disk, and these pins hook the ends of both ears of the net-like body. A method of horizontal stretching and heat treatment of a net-like body by gripping.