JPH08144164A - Preparation of blanket with uniform thickness - Google Patents

Abstract

PURPOSE: To produce a synthetic fine fiber blanket having a uniform thickness from an non-uniform blanket having thin or feather-like side edge portions. CONSTITUTION: An non-uniform blanket is cut into plural small blanket pieces 52 having an uniform length in the lateral direction. The plural small blanket pieces 52 are arranged so that the thin side edge portions 22, 24 are superposed on each other to form the blanket having a desired width and a desired thickness. The fibers of the adjacent small blanket pieces are interlaced to form the integrated blanket having the desired width and the desired thickness. A scrim backing 58 may be taken to the blanket.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing synthetic microfiber blankets of uniform thickness and width from non-uniform synthetic microfiber blankets having winged or thin side edges.

[0002]

2. Description of the Prior Art In certain processes for producing synthetic fiber blankets for use as insulation, air, gas or liquid filtration media, etc., blankets collected directly from the fiber manufacturing process are spread across the width of the blanket. It does not have a uniform thickness. In one such method, the collected synthetic fiber blanket has a greater thickness along its central longitudinal axis than its lateral edges. The relatively thin, or winged, side edge of the blanket must usually be cut to form a blanket that has a more uniform thickness across its width. The cutting of the side edge is basically a non-productive process, but it is a necessary process in manufacturing, and scrap is generated from it.

[0003]

Therefore, there was a need to eliminate this side edge cutting step of manufacturing without adversely affecting the insulation or filtration media product.

[0004]

The method of the present invention solves the problems of the prior art and provides advantages not found in the prior art. In the method of the present invention, by continuously extruding the thermoplastic polymer through a large number of small holes of the rotary spinning device,
Form synthetic fibrils, such as thermoplastic polymer fibrils. The synthetic microfibers are collected directly from the fiber forming process to form a blanket where the portion along the central longitudinal axis is thicker than the portion along its side edges. The blanket thus collected is then laterally cut into a plurality of individual pieces of uniform length. The individual pieces of these blankets are arranged with the thin or vane-shaped side edges of the individual pieces overlapping, forming a blanket having an essentially uniform thickness over its entire width. The individual pieces of the blanket are then joined to form an integrated blanket by intertwining the fibers in the areas where the adjacent blanket pieces overlap.

Thus, the method of the present invention produces a synthetic microfiber blanket that is essentially uniform in thickness over its entire length and width. The method can produce a blanket having a uniform thickness, from 0.079 centimeters (1/32 inch) to over 2.54 centimeters (1 inch). The formed blanket contains only microfibers and no large diameter staples commonly used for joining, lofting, or to facilitate processing when processing such blankets. The formed blanket is a highly effective filter media that does not contain voids through the blanket that would render it unusable for air filtration and thermal insulation applications. When a binder is used in the blanket to bond the fibers of the filtration blanket together, the binder may seep into the filtrate for some applications. The blanket produced by the method of the present invention does not require a binder. Furthermore, this method allows the desired length of
It is possible to produce continuous blankets with a uniform width, which is much larger than that possible with the prior art methods.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a continuous, non-uniform synthetic process in which fibers for forming a blanket are extruded through a large number of holes in a rotary spinning machine, such as a rotary fiber manufacturing process, collected directly from the fiber manufacturing process. A portion of a microfiber blanket 20 is shown. Blanket 20 synthetic fibers typically have a diameter of about 2
Micron to about 10 microns and can be any of a variety of thermoplastic polymeric microfibers such as polybutylterfarate (polyester), polycarbonate, nylon, polypropylene, acrylic, or polyethylene fibers.

As shown in FIG. 1, blanket 20 has thin or vane-shaped side edges 22 and 24 with a thicker portion along the central longitudinal axis. In addition to the thin side edges 22 and 24, the blanket 20 formed from a collection of fibers is otherwise irregular and forms areas of different density within the blanket.

FIG. 3 illustrates a continuous, non-uniform synthetic microfiber blanket 20 being delivered to a puncture or stapling area 28 from a commercial fiber manufacturing area not shown. The puncture or stapling area 28 is used in the method of the present invention to optionally add more integrity to the blanket 20. If a puncture or needle punching area is used during the manufacturing process, the blanket 20 is regularly needled as it travels from the conveyor 40 through the puncture area 28 to the conveyor 42. During each stapling cycle, the barbed needles pass down the blanket 20 and are re-pulled through the blanket, further entwining the fibrils of the blanket and providing greater integrity to the blanket.

The puncture or stapling area 28 is 250 per minute.
It has a needle punch 30, such as a Fehrer needle punch, which has the ability to hit the needle up to 0 times. Needle punch 30
Is the lower, fixed, perforated floorboard 32, the upper,
Adjustable, perforated stripper plate 34 and needle board 36 with barbed needles 38 (preferably 36 gauge, star blade needles) mounted downward in a preselected pattern. Including. During operation, the blanket 20 slides over the lower fixed floorboard 32 from the conveyor 40 and the conveyor 4
Move to 2. The lower fixed floor plate 32 supports the blanket 20 during the puncture or needle striking process, and has holes having the same pattern as the needle pattern on the needle board 36. accept. An upper, adjustable, perforated stripper plate 34 is provided above the lower floor plate 32 to cover the blanket 20.
The blanket 20 is adjusted at a predetermined interval smaller than the thickness of the
To maintain a slight compression. The holes formed in the upper stripper plate 34 have the same pattern as the needle pattern of the needle board 36.
6, which is accurately aligned with the barbed needle that goes up and down through the stripper plate 34 when the blanket 20 is punctured.

The needle board 36 is driven by an ordinary reciprocating drive mechanism and reciprocates in a vertical direction as shown by an arrow in FIG. As a portion of the blanket 20 moves through the puncture or stapling area 28, the needle board 36 is lowered to move the barbed needle 38 into the holes in the stripper plate 34, the holes in the blanket 20 and the floor plate 32. Pass through. The needle board 36 is then pulled back to its original position, pulling the barbed needle 38 through the blanket 20 and the perforated stripper plate 34. This stapling operation further entangles or interlocks the microfibers of the blanket, providing greater integrity to the blanket.

As shown in FIG. 3, the blanket 20 moves from the puncture or stapling area 28 to the cutting or cutting area 46. The cutting or cutting area 46 includes conventional cutting or cutting devices such as a reciprocating cutting device 48 and a back plate 50.
As the blanket 20 passes through the cutting zone 46 and the back plate 50, the blanket 20 is reciprocally moved in the vertical direction as indicated by the arrows in FIG. It is cut into individual pieces of sasa. The individual blanket pieces 52 are then transferred to the conveyor 5
4 from the cutting area 46. The length of blanket strip 52 is limited only by the width of subsequent puncturing operations in which the blanket strips are joined to form an integrated blanket of uniform width and thickness.

The individual blanket strips 52 are removed from the conveyor 54, turned 90 degrees, and conveyed to the conveyor 56.
They are arranged on top of each other. As shown in FIG. 2, the individual blanket strips 52 are arranged on the conveyor 56 with the side edges 22 and 24 of the individual blanket strips 52 stacked together to form a blanket having a uniform thickness and width. Form. As shown in FIGS. 2 and 4, the blanket strip 52 becomes an integral part of the final product and can be placed on a continuous scrim backing sheet or mat 58 that adds strength and dimensional stability to the product. . Roll 6 for scrim lining sheet or mat 58
0 to the upper surface of conveyor 56.

FIG. 4 shows the second puncture area 6 of the manufacturing method of the present invention.
A superposed blanket strip 52 is shown passing through 2. The blanket pieces 52 that are superposed are on the conveyor 5
The needle 6 is periodically punched as it moves from 6 to the conveyor 64 through the puncture area 62. During each stapling cycle, the barbed needle pierces downwardly through the overlapping blanket strips 52 and is then re-pulled through the blanket strips 52 to entangle the fibers of adjacent blanket strips, thereby causing the individual blanket strips to become entangled. 5
The two are joined and processed into a continuous, integrated blanket 66 of uniform thickness and width. When the scrim backing sheet or mat 58 is used as a backing material for a particular product being manufactured, the needle also penetrates the scrim or mat to entangle the fibers of the scrim or mat with the microfibers of the blanket, or Engage and join the scrim or mat to the blanket 66.

The puncture area 62 has a needle punch 68, such as the Fehrer needle punch, capable of up to 2500 needle strike cycles per minute. Needle punch 68 includes a lower, fixed, perforated plate 70, an upper, adjustable, perforated stripper plate 72, and a barbed needle 76 (preferably 36 gauge, star blade needle). ) Downwardly mounted in a preselected pattern. During operation, the blanket pieces 52 are transferred from the conveyor 56 to the lower fixed floorboard 7
Slide over 0 and move to conveyor 64. The lower fixed floor plate 70 supports the blanket pieces 52 during the puncturing process and is perforated with the same pattern of needles on the needle board 74 to accept needles that project through the blanket during needle strike. The upper, adjustable, stripper plate 72 is adjusted on the lower floor plate 70 by a predetermined distance that is less than the thickness of the integrated uniform blanket 66, fixed in place, and fixed by the needle. Blanket piece 52 that enters the needle punch 68 during the striking operation
And maintaining the integrated uniform blanket 66 leaving the needle punch in a slightly compressed state. The holes formed in the upper stripper plate 72 have the same pattern as the needle pattern of the needle board 74, and the blanket pieces 52 of the needle board are pierced to join the pieces together to form a continuous, integrated piece. , Uniform blanket 66
It is precisely aligned with the barbed needles that go up and down through the upper stripper plate 72 when forming the.

The needle board 74 is driven by an ordinary reciprocating drive mechanism and reciprocates in the vertical direction as shown by the arrow in FIG. As a portion of blanket strip 52 moves through puncture area 62, needle board 74
Is lowered and the barbed needle 76 is moved to the stripper plate 72.
Thread through holes in blanket strip 52, scrim backing sheet 58 (if present) and floorboard 70.
The needle board 74 is then pulled back to its original position, pulling the barbed needle 76 through the scrim (if present), the blanket strip 52 and the perforated stripper plate 72. By this needle striking operation, the fine fibers of the adjacent and overlapping blanket pieces are entangled or meshed with each other, and the blanket pieces are joined together to form a continuous, uniform uniform blanket 6
6 are formed. Scrim backing sheet or mat 5
When incorporating 8 into the final product, the fibers of the scrim sheet entangle or mesh with the microfibers of the blanket piece 52, and the scrim backing sheet blankets 66.
Fixed on the underside of.

Determine whether stapling the blanket pieces 52 to form an integrated, uniform blanket 66 leaves pinholes in the blanket 66, making the blanket unsuitable as an air filter. For this purpose, a blanket formed according to the invention was tested. The test equipment used for this test is Climet CL-6300
Laser Particle Counter. As the test results shown in the table below show, this blanket performs well and this blanket allows the air to flow unfiltered, thus making it a pinhole which makes the blanket unsuitable as a filter medium. It turns out that does not include. The blanket tested consists of polycarbonate fibers with an average fiber diameter of about 3 microns. This blanket is lined with REM (N) filter lining. The test conditions were an air flow rate of 100 cfm, a pressure drop of 1.000 Hg, a temperature of 25.1 ° C. (77.2 ^° F.), a relative humidity of 42.8%, and a counter air flow of 0.100 cfm. Particle size Particle count Particle count efficiency Micron Upstream Downstream% 0.19 ~ 0.3 99,534 8,571 91 0.3 ~ 0.5 36,148 1,914 94 0.5 ~ 1 20,705 286 98 1 ~ 3 659 2 99 3 ~ 5 27 1 96> 5 7 0 100 Total 157,080 10,774 93

The overall efficiency of this blanket was 93%. Thus, the method of the present invention produces a unitary, uniform thickness blanket that is free of pinholes that make the blanket unsuitable as an air filter media.

The number of stapling cycles per minute in each puncture zone and the density of the pattern of needles used on the needle board depends on the speed of the blanket passing through the puncture zone and the physical properties required for the product.

[Brief description of drawings]

FIG. 1 shows a portion of a non-uniform blanket assembled directly from a fiber manufacturing process, showing a cross section of a blanket having thin or winged side edges.

FIG. 2 Multiple individual pieces of a blanket arranged in a stack before puncturing individual pieces of the blanket and joining each piece into an integrated blanket of uniform width and thickness. FIG.

FIG. 3 is an elevational view schematically showing the steps of puncturing the non-uniform blanket of FIG. 1 and cutting the blanket into individual pieces of uniform length.

FIG. 4 is an elevational view schematically showing the steps of puncturing individual pieces of superimposed, non-uniform blankets to form an integrated blanket of uniform thickness and width.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location D01G 25/00 E 7339-3B

Claims (10)

[Claims] 1. A method of manufacturing a synthetic microfiber blanket having a uniform thickness, comprising: a thin side edge portion, wherein a portion of the central portion along the vertical axis is more than a portion along the side edge portion. Providing a thick, continuous synthetic fibril blanket, and cutting the synthetic fibril blanket into individual pieces of a plurality of blankets of uniform length transverse to the longitudinal axis of the blanket. And arranging the individual pieces of the plurality of blankets so that the thin side edges overlap to form a second blanket having a desired width and thickness; And a step of joining the blanket to the blanket. 2. The method of claim 1, wherein the individual pieces of the blanket are joined together by puncturing, wherein the fibrils of adjacent individual pieces of the blanket are entangled. 3. The method of claim 1, wherein the individual pieces of the blanket are joined by intertwining the fibrils of adjacent pieces of the blanket. 4. The method of claim 1, wherein the synthetic fibril blanket is a thermoplastic polymeric fibril having an average fiber diameter of about 2 to about 10 microns. 5. The synthetic microfiber blanket is punctured before cutting, and the microfibers of the blanket are entangled,
The method of claim 1, wherein more integrity is provided to the blanket. 6. The method of claim 1 including the step of securing a scrim backing to the second blanket. 7. The method of claim 6, wherein the scrim liner is secured to the second blanket by intertwining the fibers of the scrim liner with the fibrils of the second blanket. 8. A method of manufacturing a synthetic microfiber blanket having a uniform thickness, comprising: a thin side edge portion, wherein a portion of the central portion along the longitudinal axis is more than a portion along the side edge. Providing a continuous synthetic microfiber blanket of thick thermoplastic polymer microfibers; puncturing the blanket to entangle the microfibers to provide more integrity to the blanket; Cutting the blanket into a plurality of individual blanket pieces of uniform length in a direction substantially perpendicular to the central longitudinal axis of the blanket; and separating the individual blanket pieces of the plurality of blankets from the thin side. Arranging the edges to overlap so as to form a second blanket having a desired width and thickness; piercing individual pieces of the plurality of blankets to form adjacent blankets. By intertwining the fine fibers of the pieces, wherein the comprising the step of joining separate pieces of the plurality of blankets. 9. The method of claim 8 including the step of securing a scrim liner to the second blanket. 10. The method of claim 9, wherein the scrim liner is secured to the second blanket by intertwining the fibers of the scrim liner with the fibrils of the second blanket.