JPS5838541B2 - Fabric foil manufacturing method from plastic film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing cloth foil from plastic film, particularly embossed to form alternating relatively thick longitudinal ribs and relatively thin webs. Preparing a plastic sheet with longitudinal edges, tearing the selected web to separate the sheet into a number of tapes or ribbons of desired width, and feeding the tape into a loom or knitting machine. This invention relates to the production of cloth foil by producing woven or knitted fabrics.

Conventionally, in the production of cloth foil from monofilament of plastic tape, tape or ribbon (1)
7' Withdrawing the Shirasuk0 tentacles, quenching and orienting them, and then extruding the plastic through a die having a series of separate slits sized such that the tape has the desired width; or (2) extruding the plastic through a die that cuts or scores the film, thereby separating it into tapes, as described, for example, in U.S. Pat. No. 3,598,220; and 3503106, by extruding the plastic through a wide slit to form a flat sheet and dividing the sheet before or after orientation to create a tape of the desired width. It was done.

One of the disadvantages of the first and second methods is that they require complex dies with multiple apertures, ridges or contours.

Additionally, different dies are required to create tapes of different widths.

A disadvantage of the third method is that even if a very sharp knife or cutter is used to split the film, the film follows the lines of orientation induced during melt withdrawal or orientation after quenching. Because of this tendency, the width of the tape is not uniform.

These lines of orientation vary somewhat from the straight or machine direction over long distances of the sheet.

The monofilaments of the tape are therefore non-uniform in strength or size.

Tape breaks often occur during manufacturing and use due to lack of uniformity in strength.

In addition, another drawback is that a very sharp knife must always be used to split the film without tearing it, which requires frequent replacement and sharpening of the splitting knife, and production line It is necessary to take a break.

In addition, the knife creates an uneven cut on both edges of the split tape, and the tear then begins to propagate across the tape, resulting in the tape cutting.

Furthermore, the slitter must first be assembled with great care and precision in order to accurately cut the film into a uniform tape.

This is time consuming and therefore costly.

Typically, when a flat film is divided or otherwise separated into a number of tapes, the tapes are wound onto spools for use as warp threads or wound into suitable individual pieces for later use. It is packaged in

In a subsequent weaving or knitting process, the tape is unwound from the individual wrappers or spools and fed to a suitable machine to produce a woven or knitted fabric.

Wrapping or spooling and unwinding is time consuming and relatively costly.

Additionally, handling individual packages is relatively inefficient compared to handling a single wide film or sheet.

To overcome the aforementioned winding and handling problems,
For example, segmentation and organization techniques have been developed as disclosed in US Pat. No. 3,214,943.

In that method, flat sheets of film are directly divided in an in-line operation and tapes of a predetermined width are fed to a knitting machine.

Similarly, split-weaving techniques are known in which woven fabrics are made from oriented flat films that are split in an in-line operation.

However, the continuity of operation and the uniformity of the knitted or woven fabric are adversely affected by the factors mentioned above, among others:
Frequent replacement of splitting knives, production line stoppages due to tape cuts caused by imperfections in the film, or tears caused by uneven cuts on the edges of the tape, and non-uniformity of the split tape. resulting in imperfections in the silk or knitted fabric.

The present invention relates to a cloth foil made from monofilaments of tape and to a method of manufacturing the same, in which a wide sheet of plastic film is first extruded through a die of simple construction and then passed through an embossing roll to form the film on one or both sides. A continuous longitudinal sushi pattern is then embossed to create alternating relatively thick longitudinal ribs and relatively thin longitudinal webs.

The film is then typically oriented in the longitudinal direction.

After orientation, the film can be easily and uniformly divided by selectively tearing the web to create monofilaments of tape of desired width.

The film that holds the sushi is made of a sushi rod, a guide rod, and a comb guide, which are equipped with relatively blunt blades to separate the web without cutting.
Desired portions of the web can be separated by passing the web over a device such as a 3000 ml or the like.

The desired width of tape can be obtained by simply selecting which webs to tear or split.

The tearing method of the present method does not require the use of sharp knives or rotary cutters that need to be frequently replaced or sharpened.

However, it is possible to use a knife or cutter in accordance with the principles of the present invention without sharpening the knife or cutter blade, i.e., by blunting the blade so that the dull blade tears the web rather than cutting it. I can do it.

The method of the present invention provides a uniform woven or knitted fabric and allows for the use of low maintenance, flexible and simple equipment for separating or dividing the film into tapes of the desired width.

The longitudinally striated film is preferably torn into tapes during the on-line process with a knitting or weaving machine.

Other advantages of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the following detailed drawings.

The drawings should not be considered as limiting the scope of the invention, as the drawings illustrate only typical embodiments of the invention and, therefore, the invention may include other equally valid embodiments. It should be noted that

Referring now to FIG. 1, there is shown an embossed longitudinal strip, generally designated 10, having a number of parallel continuous vertical ribs 11 interconnected by thin webs 12. The film is shown with a .

Embossed sheet 10 can be manufactured in a number of different ways.

A preferred method involves passing a molten plastic sheet coming from an extrusion die (not shown) into two counter-rotating rolls, one with a raised pattern and the other with a smooth or smooth surface. This feeds into the inlet of two rolls which also have a raised pattern on them.

The vertical ribs may be formed on one or both sides of the sheet, or alternatively, as disclosed in U.S. Patent Application No. 3 by Kim, Liu and McDuff, associates of the assignee.
No. 24,028 (U.S. Patent No. 3,922,329) and U.S. Patent Application No. 324,030 (Kim and Liu, supra).
It is also possible to form vertical main ribs on one side and horizontal connecting ribs on the other side, as described in U.S. Pat. No. 3,914,365.

It is important that the vertical ribs 11 be formed parallel to the vertical axis of the sheet 10 so that tapes of uniform width can be produced in unlimited quantities in subsequent steps.

The spacing between the ribs 11 of the embossed sheet can be as low as 2 ribs per inch (91 ribs per 1,27 CIIL) or as low as 200 ribs per inch (78 ribs per 1 CIIL).
, 7) can also be made into ribs.

The thickness of the web 12 is about 5% to 25% of the thickness of the rib 11.
The range is up to

The cross-sectional shape of the web 12 in the sheet can vary, for example in the shape of °U +t or °v11, or other shapes are also possible.

Similarly, the shape of the cross-section of the rib 11 can also be completely varied, including circular, triangular, truncated or rectangular cross-sections, without any limitations.

While embossing the ribs, the polymer is exposed to temperatures well below the melting point of the crystalline material, in the case of partially crystalline polymers such as polypropylene, or at temperatures significantly below the melting point of the crystalline polymer, such as polyvinyl chloride. In some cases, the temperature must be below the softening point.

For example, in the case of polypropylene, embossing roll temperatures between 15°C and 130°C are sufficient, while for unplasticized polyvinyl chloride temperatures from room temperature to 50°C can be used.

Orientation by pulling the embossed sheet in a straight line
Compared to traditional methods for flat plastic sheets,
This can be carried out under conditions applicable to the polymer used.

A typical method is to pass the embossed sheet over a series of heated rolls rotating at progressively faster speeds.

The spacing between the pull rolls is preferably kept small to minimize lateral shrinkage or drawdown of the sheet.

The degree of orientation will depend on the properties of the polymer used and the desired strength and elongation properties.

Typically the orientation can vary from 2X (where X is times) to 1OX.

After the orientation step, a slow cooling or heat treatment step can be included.

Although the conditions of this heat treatment step depend on the polymer used, this step reduces the amount that the tape or fabric foil made therefrom will shrink when exposed to high temperatures during use.

After orientation and slow cooling, the oriented longitudinally sushi sheet is wound onto supply rolls and split or torn in a separate operation, or split in the process line.

Referring to FIG. 2, oriented and streaked sheet 1
To form the tape from scratch, use the anti-abrasive rods 16 and 17.
and 18 or dull blade comb guide (com
Easy tearing and excellent uniformity can be achieved using a tearing device, such as (not shown) or the like.

Sheet 10 is nip rolls 1
9 passes through a skim rod which tears and divides the sheet 10 into tapes of the desired width consisting of two or more ribs 11.

The sheet 10 is first cut or torn at its leading edge at the desired portion of the web, and adjacent tapes are passed separately through the thread removal rods 16, 17 and 18, so that the thread removal rods become adjacent as the sheet progresses. By orienting the tape in a vertically diverging direction and tearing the sheet into tapes, tapes of desired widths can be easily divided.

For example, three ribs 11 connected by a web 12
The tape 10a consisting of the tape 10a is inserted from below the anti-abrasive rod 16, onto the rod 17 for removing anti-miscellaneous substances and under the rod 18 for removing anti-miscellaneous substances, while the adjacent strip 10b, which also has three ribs 11, is inserted as a tape. 16 rod for catching apricots
It is inserted from above under the rod 17 for removing dirt and onto the rod 18 for removing dirt.

As bands 10a and 10b progress, bands 10a and 1
The web between 0b is torn, thereby forming a uniform tape of the desired width.

Since the sheets tear only at the relatively thin web 12 between the sheets 11, there is no need for careful alignment of the tearing device as in gang 5litters.

Additionally, because the skidding rods or comb guides do not have sharp edges, they do not have the tendency to cut through the ribs 11 as would occur if a sharp knife or rotary cutter were used.

The aforementioned tearing or splitting operation is preferably carried out in a line process with a loom or knitting machine, in which the oriented sushi sheet is pulled from a wound roll and cut into the desired width by a selected guide. Alternatively, it is passed through a thread-removing rod and fed to the loom at a speed synchronized with the weaving operation.

The advantage of this method is that the tape remains flat without twisting or folding, thus ensuring maximum and even coverage of the fabric.

If individual packages of warp threads are used to feed the loom, it is very difficult to avoid twisting, thus having an adverse effect on the coverage and uniformity of the woven fabric.

Similarly, multiple feed (feeding a large number of yarns,
The yarn to be charged into the knitting machine (multiple feed) is selected by winding a sheet of oriented sushi from a roll in a line process combined with the knitting machine, and using an appropriate guide or a thread-removing rondo. It can be manufactured by tearing the web to form a tape of the desired width and feeding the tape to a knitting machine.

If it is desired to produce a coarse woven or knitted fabric with greater porosity than that obtained by knitting or weaving flat tapes, the first step as shown in FIG. The embossed and oriented film can be opened into a network structure generally marked 20, whereby the individual primary filaments 2 are interconnected by fibrils or connecting ribs 22.
Separate into 1.

The fibrils or connecting ribs 22 are the main filaments 21
are held evenly so that they are parallel to each other and spaced evenly apart.

The desired porosity for the knitted or woven fabric determines the degree to which the network should be opened.

After opening the sheet into a mesh structure, the desired tape width is selected and the fibrils located between adjacent tapes are divided or torn with a skim rod or other device as described above.

The network structure may be formed by mechanical fibrillation, for example, as described in U.S. Pat. No. 3,495,752, or by U.S. Pat.
No. 329) and the naturally occurring fibrillation of double-sided embossed sheets as described in U.S. Patent Application No. 324,030 to Kim and Liu, supra (U.S. Pat. can.

The double-sided embossing method described in the above-mentioned patent application is particularly desirable for use in the production of rough tapes for fabric stripping because the interlocking filaments on the back side of the sheet provide dimensional stability as well as strength. .

In the double-sided embossing method, the sheet is formed on one side with a large number of parallel main ribs in the vertical direction, and on the opposite side with a large number of parallel connecting ribs in a direction perpendicular to the direction of the main ribs. It will be embossed like this.

Preferably, the ratio of the cross-sectional area of the main rib to the connecting rib is at least 1.
．． 5:1, and the ratio of the height of the main ribs to the thickness of the web between the main ribs is at least 3:1.

Alternatively, the connecting rib may be made in a discontinuous manner so that no substantial major portion thereof intersects over the opposite major rib.

The direction of the connecting ribs on the back side of the sheet must intersect with, but need not be perpendicular to, the direction of the main ribs.

Typically, any angle between 45° and 900° from the longitudinal direction of the main rib is sufficient.

If double-sided embossing is used, the resulting tape will be sturdier, i.e. more resistant to creasing or bending, because there are connecting filaments connecting the main filaments, as illustrated in Figure 3. There is sex.

Bonded or bicomponent plastic sheets formed by extruding two or more different polymers together to form a sheet of separate polymer layers can also be used.

One layer of the sheet typically has a component made of a relatively high melting point polymer, while the remaining portion is made of a relatively low melting point polymer.

Fabric foils made from such tapes can be easily adhered at their intersection points by thermal calendering or at intermittent points by embossed hot pressure rolls placed at selected locations.

Such adhesion can eliminate fraying and improve the dimensional stability of the fabric foil.

The method is generally applicable to fiber-forming thermoplastic polymers.

It contains low-density polyethylene, high-density polyethylene, polypropylene homopolymers, propylene random copolymers, propylene random copolymers containing up to 10% of other olefins, and containing up to 25% of other olefins. polyolefins such as block copolymers of propylene, polyamides such as nylon 6, nylon 66, polyesters such as polyethylene terephthalate and other high molecular weight thermoplastic polyesters, and polyvinyl chloride.

Bonded plastic sheets as described above are also applicable.

Additionally, two-component plastic sheets can be used, with the higher melting point component forming the majority of the main ribs.

Additionally, polymer alloys and mixtures of polymers can also be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating a portion of a lengthwise sushi sheet that may be made into a tape in accordance with the principles of the present invention. FIG. 2 illustrates, in accordance with the principles of the present invention, a roll of longitudinally stretched sheet material and an apparatus for tearing the sheet into tapes of the desired width and feeding them to a loom or knitting machine. This is a diagram. FIG. 3 is a diagram illustrating an open network having continuous longitudinal filaments and an apparatus for tearing a tape of a desired width from the network in accordance with the principles of the present invention.

Claims (1)

[Claims] 1. A cloth made from a longitudinally oriented plastic film having embossed longitudinal ribs and alternating relatively thick longitudinal ribs and relatively thin longitudinal web sections. A method of manufacturing foils, wherein the film is advanced from a supply roll and the leading edge of the film is first cut into two or more strips each having a desired width by a crack in at least one selected web section from the web sections. separating the tapes and bifurcating each tape in a direction perpendicular to the direction of adjacent tapes by a relatively blunt blade disposed in the path of the selected web portion while maintaining uniform longitudinal tension across the film; The splitting at the crevices continues along the web portion by proceeding in the same direction as shown in FIG. The method comprising: producing a product.