JPH07144359A - Method and apparatus for producing laterally stretched web using rotary disk - Google Patents

Abstract

PURPOSE:To enhance the quality of a naturally stretched web by providing a web feed mechanism by supplying both selves ends of the web of pair of rotary discs to grasping parts at a speed different from that of the discs. CONSTITUTION:Pulleys 2a, 2b are provided outside a pair of stretching pulleys 1a, 1b and bellts 3a, 3b, 4a, 4b are trained over the respective pulleys. The pulleys 2a, 2b are driven by motors M1a, M1b through shafts 5a, 5b and the stretching pulleys 1a, 1b are independently rotated through bearings 6a,6b with respect to the shafts 5a, 5b. Both selvedge ends of a web 8 are grasped by the pulleys 1a, 1b and the belts 4a, 2b, 4b and and subsequently grasped by the pulleys 1a, 1b, and the belts 3a, 3b to be rapidly fed by the speed difference of the pulleys 1, 2. The web 8 is folded by overfeed to be provided with a large number of longitudinal wrinkles 9 to be grasped by the pulley 1. The web is laterally stretched by the fan-shaped track formed by the pulleys 1a, 1b. Therefore, the laterally stretched film becomes uniform and is enhanced in the quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for easily laterally stretching a web, and more specifically, it utilizes a rotary disc for stretching to improve the quality of the laterally stretched web and to provide special performance.
The present invention relates to a horizontal stretching method and device.

[0002]

2. Description of the Related Art As a method for stretching a web horizontally,
The tenter system is common. However, the tenter method is not only economical in equipment but also requires a large floor space for equipment installation, and is not economical except for mass production. Therefore,
Various simple horizontal stretching devices have been proposed, but they have many drawbacks and are rarely put into practical use. One of the simple horizontal stretching devices is a stretching device using a pulley (BP
849, 436). In this system, the stretching tension in the vertical direction acts on the central portion, and the intermediate portions of both pulleys hang down, whereby the stretching of the central portion is delayed and the central portion of the web becomes thick (bowing phenomenon). In order to avoid such a phenomenon, a method of installing turn rolls in multiple stages between both pulleys has been proposed (Japanese Patent Publication No. 57-30056).
Since the film is stretched horizontally on the turn roll, the film is rubbed and scratched, which deteriorates the quality of the film. In addition, with this turn roll alone, the bowing phenomenon is improved but not eliminated. The present invention is a horizontal stretching method that uses this simple rotary disk stretching device, has less bowing phenomenon, does not require a turn roll in the stretching process, or has a small number even if used, and reduces scratches entering the film. is there.

A method of folding the web with a folding device before entering the horizontal stretching device and then bringing it into the stretching device has also been studied (Japanese Patent Publication Nos. 45-29119 and 62-28).
226, hereinafter referred to as prior invention A). However, in such a system in which the folding device and the horizontal stretching device are separate devices, if the folding device is folded too tightly, the wrinkles deteriorate the quality of the web. If the wrinkles are weakly inserted, the wrinkles are unwound from the folding device to the stretching device, and when the wrinkles are grasped by the stretching device, the folding is not uniform. Another drawback is that the folding device is not simple.

[Problems to be solved by the present invention]

As a subject of the processing method, a simple means is desired. The horizontal stretcher by the tenter method, which is used as a normal horizontal stretcher, is a means for stretching a thin film in a heating room such as an auditorium. Not suitable for production.
Also, in the tenter method, it is not easy to modify the device to satisfy the above quality because it is a large device, and
With the tenter device, the ears of the web cannot be brought out of the device,
Unlike the improved method of the rotating disk method of the present invention, which will be described in detail below, it is not possible to adopt a method of changing the speed of the ear portion further outside the grasped web edge portion.

Webs required to be horizontally stretched include not only biaxially stretched films, but also non-woven fabrics and net-like materials, and as films, there are perforated films, horizontal tear films, and horizontal shrink films. In those fields, many products are produced in small quantities in many kinds, and there is a demand for a means for easily obtaining high-quality products.

[0006] The laterally rupturable web is required to have good linearity so that it can be straightly cleaved in the lateral direction. Horizontal tear film
It is used in simple packaging such as snacks and instant ramen bags. If breathability is required,
A non-woven fabric or a horizontal stretched web of perforated film, which is used for packaging of flowers at retail.

In the so-called shrink wrapping in which an object is wrapped with a web and is shrunk by a means such as heating to improve the adhesion, there is a field in which uniform shrinkage in the horizontal direction is required.
For example, when shrink-wrapping a columnar object such as a bottle and a bottle, the shape predesigned by printing on the web is uniformly stretched horizontally in order to obtain the desired design after shrinking. is important. The shrink web includes films, nets, nonwovens, and the like. Shrink labels are in a similar area.

Furthermore, in recent years, a method for producing a horizontal web in a cross-woven nonwoven fabric by a horizontal stretching method has been attracting attention (Japanese Patent Publication No. 62-22826). There has been a demand for means for adjusting the mesh density of these horizontal webs.

[0009]

The present invention has been earnestly researched on a solution for satisfying the above-mentioned product quality and apparatus requirements, and as a result, an oversupply function (vertical stretching is also possible) integrated with a horizontal stretching apparatus. By having functions), we have reached the concrete means described below. A rotating disk system is adopted as the stretching means. Grip both ears of the web on a pair of rotating disks,
This is a means for stretching the web horizontally by the divergent orbit of a pair of rotating disks. This stretching means has many aspects effective as a simple device. The advantage of the rotating disk system is that the device is simple. Moreover, despite being simple,
There is a portion where the tracks are parallel to each other at the inlet and the outlet, and that portion can be used for preheating and heat treatment. Among the rotary disc systems, the pulley system is superior in that point to the gripper system of the tenter because it can continuously and evenly grip the ears. In addition, since the space is used three-dimensionally, it is a compact device compared to the travel distance of the web, and it is very advantageous in terms of operability, device cost, and floor area in combination with a simple mechanism. . What is more characteristic is that the ear outside the grasped ear portion can be brought out of the apparatus. By grasping the portion outside the rotary disc by another grasping means on the outside and feeding the portion quickly, the web can be grasped by the stretching rotary disc in a folded state.

A disadvantage of this rotating disk system is that under the condition that tension is applied to the vertical portion at the center of the web during the stretching process (in normal horizontal stretching, tension is always applied in the vertical direction, although there is a degree difference). It has already been described that the center of the web in the drawing process hangs down and the bowing phenomenon easily occurs. As a means for solving this drawback, when the web is folded and stretched in the horizontal direction by the method of the present invention, vertical tension is not applied, and as a result, the horizontal stretching can be made uniform and a high quality horizontal stretched film can be obtained. It turned out as a result of the experiment.
Therefore, by stretching this horizontal stretched film vertically,
The biaxially stretched film gives a uniformly stretched biaxially stretched film. Further, a web that is stretched horizontally in a folded state has excellent physical properties as a horizontal tear film, such as a horizontal tear web that does not get caught in the middle of tearing and tears linearly. Since it can be stretched uniformly in the horizontal direction, it can be used as a horizontal shrinkable web to shrink uniformly in the horizontal direction, and in shrink shrink wrapping and shrink label fields where the design after shrink is required to be accurately reproduced Become. Since these tear films, shrink wraps, shrink labels, etc. are often produced in small quantities in a large variety, a simple stretching device is particularly desired. The simple type is particularly suitable for stretching a colored web that frequently changes colors.

As the kind of the web of the present invention, not only a usual stretching film, but also a perforated film, a net (Japanese Patent Publication No. 3-72455) and a non-woven fabric (Japanese Patent Publication No. 3-36).
948), centrifugally spun web, etc. (Japanese Patent Publication No. 59-3953).
It is also applied to stretching No. 9). Further, it can be applied to the production of a horizontal stretched web of orthogonal nonwoven fabric (Japanese Patent Publication No. 60-32573). The raw material of the web used in the present invention is not particularly limited. Various resins such as polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride resins, polyvinylidene chloride resins, polyester resins, polyamide resins, polyvinyl alcohol resins, and fluorine resins can be used as the raw materials.

As a result of earnest research by the present inventors, when grasping the edge portion of the web by utilizing the ear-holding force of the rotating rotary disk for stretching, the web is fast-forwarded and folded in an excessive supply state, and the state is maintained. Has reached the method of gripping the web. Specifically, it is a method in which a web feed mechanism that can make the speed different from that of the rotating disk is provided in the vicinity of the both ends of the web being gripped on the rotating disk. As a concrete mechanism for this feeding, a method using a nip roll, a method in which multiple rotating disks are used, a method in which the ears are slit and then the slit ears are quickly pulled out can be solved. In these methods, both ears of the web positively act by a feeding device integrated with the device.
On the other hand, in the above-mentioned prior invention A, the method is completely different because the disturbing ears are cut and then folded by the separately provided folding means.

When the web is slowed down by the mechanism for changing the speed of the web, at least the selvages of the web are stretched and gripped by the rotary disc for stretching. This method is suitable for biaxial stretching of a reticulated web and adjustment of the mesh of a horizontal web of orthogonal nonwoven fabric.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of the embodiment will be described in detail below with reference to the drawings.
FIG. 1 is a plan view showing an example of a pulley type stretching device as an example of the stretching rotary disk of the present invention. 2 shows the pulley of FIG. 1 as viewed from the side. The pair of pulleys 1a and 1b are arranged in a divergent manner. This pulley extension is in principle a conventional pulley extension (BP894,4
36). In the present invention, pulleys 2a and 2b are provided outside the pair of stretching pulleys 1a and 1b to form a double pulley, and a belt 3 fitted to each pulley.
a, 3b and 4a, 4b are hung. Pulley 1a,
The belts 3a and 3b hung on 1b are hung almost on the half circumference of the pulley, and the belts 4a and 4b of the pulleys 2a and 2b are hung on only an initial part of the pulley. Pulleys 2a, 2b
Is the motor M1a, M1b through the shafts 5a, 5b.
Drive with. The stretching pulleys 1a and 1b are the shaft 5a,
5b can be independently rotated through bearings 6a and 6b (the inside of the pulley 1 is shown by dividing a part of the drawing). By driving the drive pulley 7a of FIG. 2 through the motor M2, the power is transmitted to the belt 3a, and the pulley 1a
To drive. The drive of the pulley 1b is also the same. The drive methods for these pulleys are merely examples, and the drive methods are not limited to these methods. For example, there is a system in which the shaft 5 is a double pipe and the pulleys 1 and 2 are driven.

Both ends of the original web 8 are provided with pulleys 2a.
And the belts 4a, 2b and 4b. Pulley 2
The a and 2b rotate at high speed with respect to the pulleys 1a and 1b. The web 8 gripped by the pulleys 2a and 2b is then gripped at both ends by the pulleys 1a and 1b and the belts 3a and 3b. At that time, the web fast-forwarded by the speed difference between the pulleys 1 and 2 is over-fed and folded, and a large number of horizontal wrinkles 9 enter and are gripped by the pulley 1. Web 8 is pulley 1
After being securely gripped, it is not necessary to grip the webs 8 at both ends by the pulley 2 and the belt 4, so that the webs 8 are removed through the turn pulleys 10a and 10b.

Web 8 held by pulley 1 and belt 3
Is stretched in the horizontal direction by the diverging orbit formed by the pulleys 1a and 1b, like ordinary pulley stretching, and the stretched web 1
It becomes 2. If necessary, turn rolls 11a, 11b ... Are provided at the end of the stretching process or in the heat treatment zone.
In the state without the horizontal wrinkles 9 in FIG. 1, a large number of these turn rolls 11 are required over the entire surface substantially along the pulley from the initial stage of horizontal stretching. Is not necessary, or even if it is necessary, a small number can be used. The stretched web 12 is heat-treated in a cylinder 13 if necessary, cooled in a cylinder 14 and then taken up.

Although heating in the drawing process of FIGS. 1 and 2 is omitted, ordinary hot air, hot water, infrared heaters, steam or the like can be used. In FIGS. 1 and 2, the pulley 1 is the pulley 2.
If the pulley 1 is made slower, but on the contrary, the web is stretched in the vertical direction, and a biaxial stretching effect can be obtained. This method is suitable for biaxial stretching of the net, horizontal stretching while adjusting the mesh of the horizontal web in FIG.

A plurality of rotary discs for stretching used in the stretching apparatus of the present invention are pin type,
There are gripper types, etc., and different types can be used in combination. For example, the outer rotating disk is a pulley type and the inner rotating disk is a pin type. The outer rotating disk and the inner rotating disk do not have to have the same circumference. The gripper type of another example of the stretching rotary disc is the system shown in Japanese Patent Publication No. 63-44049. This type is used as the outermost rotary disk when used in the multiple rotary disk of the present invention, because the ear does not go out of the device. Further, in FIG. 1, an example of a double rotating disk is shown, but there are also cases where multiple wrinkles such as triple and quadruple are used to form wrinkles in multiple stages or to extend vertically in multiple stages. In addition, by making it multiple, there is also an effect that the grip is surely performed.

FIGS. 3A and 3B show another example of a spinning disk for drawing which is a pin disk. FIG. A is a plan view and FIG. B is a side view. The pair of disks 21a and 21b are motors M3.
Drive with a and M3b. A large number of needles (pins) 22 are projected in the circumferential direction of the disk 21, and the turn roll 23
Both ends of the original web 8 are pierced by the needles 22 and held by the needles a and 23b. The turn roll 23 is a roll having a cushioning property such as a brush roll that does not hinder the crossing of the pins and a non-woven fabric roll. Immediately after the ears of the web 8 are pierced, there are nip rolls 24a and 24b whose speed can be changed by the motor M4. The nip rolls 24a and 24b that hold the ears of the web are grasped to control the speed of the ears. Rotate faster than the speed of the grip of the rotating disk to feed the web with the needle 2
Hold with 2. After that, the divergent orbit is stretched horizontally as in FIG.

FIG. 4 is similar to FIG. 3, but immediately after both edges of the web 8 are gripped, the ears are slit by the slitter 25 and the ears 26a, 26b slit by the nip rolls 24a, 24b. Take it out of the system. Slitter 25
A rotary blade such as a knife, a razor blade, a hot-blade laser, or a score cutter is used. The mechanism for changing the speed of the nip roll 24 with respect to the rotary disk 21 is the same as that in FIG. 3 (the drive system is omitted in the figure).

In FIG. 5, the nip rolls 27a and 27b are inside the rotating disk and are driven to rotate (a drive device is omitted). The surface speed of the nip roll 27 is set to the rotary disk 21.
By making the speed higher than the speed of the gripping part, the original web 8 is gripped by the nip roll 23 with the needle 22 piercing the ear part in the state of being over-supplied. Others are the same as in FIG. When the speed of the nip roll 27 is slowed and the web is stretched vertically, the position of the nip roll 27 can be moved to the inlet side so that the web 8 can be gripped when it is not gripped by the rotating disk 21 yet. desirable. Therefore, the position of the nip roll 27 is set so that the web 8 is rotated by the rotating disk 2.
It is possible to move before and after the position where it is nipped by 1.

FIGS. 3, 4 and 5 show an example of a pin disk as a rotating disk, but a pulley type and a gripper type (only in FIG. 5).
You can also use the disc.

FIG. 6 shows the shape of the turn roll 11 shown in FIG. 2, in which at least a part of the plurality of turn rolls is
In some cases, it may be effective to use the medium-high drum roll 28.
Since the middle-high portion extends beyond the outer circumference of the pulley, the track of the web in the central portion becomes long, which is effective in eliminating the bowing phenomenon.

In the case where the horizontal stretched web is a horizontal stretched web of orthogonal non-woven fabric, when the reticulated web having slits in the horizontal direction is horizontally stretched by the rotating disc, the speeds of the outer disc and the inner disc are changed to change the mesh vertical length. To expand the direction,
It can also be used to make the mesh dense, and can serve as both the horizontal stretching device and the mesh adjusting device. FIG. 7A shows the original web 8 having a large number of slits 31 in the horizontal direction, and the ears 32 have no slits. B of the figure shows a horizontal stretched web 33 which is stretched horizontally in the usual manner. FIG. C is an example in which the mesh is widened by slowing the web feed mechanism in the system of the present invention. On the contrary, FIG. D is an example in which the web feeding mechanism is made faster to make the mesh tighter. When the mesh size is reduced, it is necessary to laminate with the vertical web in the contracted state, or adhesively fix the wrinkles of the ear part so that the ear part holds the contracted state when the web is separated from the pulley. If there is an adhesive layer on the surface of the horizontal web, it is bonded by the heat of the pulley or by positive heating. As another means, it is effective to supply another adhesive to the ears.

[0025]

According to the method of the present invention, as a merit of the apparatus, the apparatus cost, the apparatus space, the energy used, etc. are reduced by an order of magnitude with a simple apparatus, and the product cost is reduced. Also, since it is a simple device, it is easy to operate, and is most suitable for high-mix low-volume production. As a physical property advantage, it can be uniformly stretched, and as a horizontal tear web,
It is a web that does not get caught and can be split horizontally in a straight line. As a horizontal shrinkable web, uniform shrinkage characteristics are good. Therefore, as an advantage in use, it can be manufactured at low cost and high quality for the uses exemplified below. Use of horizontal tear film in simple packaging of snacks and other non-woven fabrics for retailing flowers. Field of biaxially stretched net. Packing applications using horizontal shrinkable nonwoven fabric such as shrink labels for PET bottles and 1 bottle. Use of the horizontal stretched web while adjusting the texture of the horizontal nonwoven web.

[Brief description of drawings]

FIG. 1 is a plan view of a horizontal stretching device (pulley system) of the present invention.

2 is a side view of the device of FIG.

FIG. 3 is a pin disk type horizontal stretching device. A: Plan view, B: Side view.

FIG. 4 is an edge web slitting method (plan view) in the horizontal stretching apparatus of the present invention.

FIG. 5 is an example of a horizontal stretching device in which the web feed mechanism is an internal nip roll (plan view).

FIG. 6 is an example of a turn roll in the web stretching process used in the present invention.

FIG. 7 is a state of mesh of a cross-woven nonwoven web stretched web.

[Explanation of symbols]

1a, 1b, 2a, 2b: pulley type rotating disk, 3a, 3
b, 4a, 4b: stretching belts, 5a, 5b: rotating disk supporting main shaft, 6a, 6b: bearings, M
1a, M1b, M2, M3a, M3b, M4a, M4
b: motor, 7: drive pulley, 8: original web,
9: Horizontal wrinkles entering the web, 10: Turn pulleys for belts, 11a, 11b ...: Turn rolls, 1
2: Horizontal stretched web, 13: Heating cylinder, 14:
Cooling cylinders, 21a, 21b: Pin type rotating disk, 2
2: Many pins 23a, 23b: Turn roll, 24a, 24b: Nip roll 25: Slitter, 26a, 26b: Nip roll, 2
7a, 27b: Each roll of the nip roll in the horizontal stretching device, 28: Middle-high part of the drum type turn roll, 31: Many horizontal slits put in the original web, 32a, 32
b: edge of the web, 33: horizontally stretched web.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area B29L 7:00 28:00

Claims (2)

[Claims] 1. In a method of holding both edges of a web on a pair of rotary discs for stretching and laterally stretching the web by means of a diverging orbit formed by the pair of rotary discs, the speed of the web can be different from that of the rotary disc. A method for laterally stretching a web by folding or stretching at least an ear portion of the web by a feeding mechanism and supplying the web to a grip portion of a rotating disk. 2. A horizontal stretching device for a web, wherein a pair of rotary discs for stretching has means for gripping both end portions of the web, and a horizontal stretching device for web that horizontally stretches in a diverging orbit formed by the pair of rotary discs. A horizontal web stretching device having a web feed mechanism capable of feeding the web to both ends of the web at a gripping portion at a speed different from that of the rotating disk.