JPH06507211A - Edge forming device for flash spun web - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] FIELD OF THE INVENTION Field of the Invention The present invention provides nonwoven fibers with a larger usable width than disclosed in the prior art. This invention relates to a combination of devices for forming sheets. In particular, the present invention provides (1) a swath ( swath) to contribute to the production of usable sorts. changing the spinning position pattern of the outer edge of the swath , and (2) the presence of a moving collection surface used to collect the web within the sheet structure. Forming the edges of flash-spun webs by reducing the effect width Regarding equipment combinations: In the preparation of fibrous nonwoven sheets, fibers are spread out from bundles. by reciprocating means at various locations across the width of the moving collection surface. Various methods and devices have been developed for directing the strands in a planned manner. ing. For example, U.S. Patent No. 2,736,676 (Flickart) uses a wobble plate. of a cylindrical body rotated around its centerline by a function or at a quantity angle from its longitudinal axis of symmetry The bending from the surroundings causes the solvent gas to be directed towards the glass fibers and the curved reciprocating bag. Flash spinning in a solvent gas stream by utilizing the combined action of a full An apparatus for unfolding and directing strands of polymer is disclosed.

The curved baffle acts to spread the strands into a wide web. By the baffle The reciprocating motion imparted by to point towards the target. This results in a nonwoven sheet of randomly oriented fibers.

The flash spun strands used in Stuber's seats are Polymer solutions in solvents at temperatures well above the atmospheric boiling point of potash solvents under pressure Made from strands flash spun from. solution spinning When the assembly passes into the ambient atmosphere, the solvent evaporates almost instantly and forms a filter. Mu--forms a strand containing a three-dimensional network of fibrillar elements. This strand is They are called reticular fibers and are described in detail in U.S. Pat. No. 3,081,519 (Braids et al.). be done.

Spinning assembly, rotatable baffle, electrostatic distribution for proper sheet distribution , and an apparatus for producing a nonwoven fiber sheet with a collecting surface is disclosed in U.S. Pat. No. 3,497,918. (Polock) and No. 4,666,395 (Shah). Commercially available non-woven poly Marcito (e.g., E.I. Dupot under the trade name Tyvek) (available from N. Dou Nemours & Co.) are typically Consists of a number of swaths with a trapezoidal basis weight distribution shape that overlap across the width. child Sheets of the form are disclosed and given priority by Borotsuk and Jer. . However, the edge of the sheet with small overlap (i.e., the throat at the edge of the sheet) This is the result of a method of accumulating a trapezoidal weight distribution shape at the edge of . This allows the edge Seats with the largest available sheet width such that there is significant waste due to trimming This often results in damage. For obvious reasons, this edge trimming waste It is desirable to reduce losses.

Clearly, what is desired is the use of trimmed edges to reduce the amount of waste. This device maximizes the possible sheet width. Therefore, it has the disadvantages inherent in the conventional technology. It is an object of the present invention to provide a combination of devices that are Other objects of the invention The advantages and advantages will become apparent to the skilled artisan upon reference to the following brief description of the drawings of the invention. There will be.

Overview of Eiy The present invention provides a device for forming a nonwoven fibrous sheet from overlapping swaths of fibrous material. related to the installation or combination of devices. The obtained sheet is of a given spinning back It has a larger usable range compared to the number.

This combination includes multiple center spinning bags and multiple edge spinning bags. racks, each with a baffle for placing the fibrous material onto a moving collection surface. I get kicked. A baffle is attached to the spinning back at the edge, which creates a triangular shape. Lay down a relatively narrow swath of fibrous material having a volume distribution shape. Spiny on the edge The backing works in conjunction with the product information to lay down the textile material. outermost swath A piece of fibrous material hits the product guide and slides down it onto a moving collection surface. . A baffle is attached to the spinning bag placed inside, and this is the basis weight of the trapezoid. Lay down a relatively wide swath of fibrous material with a cloth shape (.

A spinning assembly for spinning fiber strands, which receives the strands and The strand is bent downward in the orthogonal plane and unfolded at the same time as the strand is expanded. a rotatable baffle for reciprocating the hand in a generally horizontal plane; It has means for rotating.

When the baffle is viewed with its central axis of rotation in the horizontal position, the baffle is It has an integral body with a circular boss part, and the fillet part goes around this boss part. The minutes are increasing. The middle spinning bag has a baffle with a fillet part. This fillet portion intersects with the disc portion to generally form a mid-low surface. , and the moving collecting surface with the unfolding strand placed below the mid-placed spinning bag. designed to form a swath with a trapezoidal basis weight distribution shape when placed on top. It will be done. The spinning back at the edge has a baffle with a fillet part. The fillet portion intersects the disk portion to form a generally convex surface and expands The strands were placed on a moving collecting surface placed below the spinning back at the edge. Sometimes it is made to form a swath with a triangular basis weight distribution shape. Ba The center axis of rotation of the fuffle is located at the circular edge at the top of both the boss part and the disc part. perpendicular to and coincident with the center.

Additionally, this combination includes product guides parallel to each edge of the moving collection surface. made The product information is a unfolded strand bent by the baffle of the spinning back at the edge. By placing the part of the unfolded strand on a moving collecting surface that is in contact with the part of the Made to minimize the width of the unfolded strand.

The tabby baffle is a sheet that is compacted by reducing edge loss due to a decrease in basis weight. To eliminate separate edges and further facilitate trimming the edges.

It is understood that tabby baffles may be used alone or in combination with product information. There will be. However, the best results are obtained when both are used together.

Brief description of the drawing Figure 1 shows an apparatus for depositing reticulated fibrous material onto a moving collection surface to form a nonwoven fabric. FIG. This device consists of a spinning assembly, a rotatable baffle, Means for rotating the baffle and collection means located below the baffle are provided.

Figures 2.3 and 4 respectively show the preferred use of an intermediate spinning bag. FIG. 1 is a front view, a vertical cross-sectional view, and a top view of a trilobal baffle.

Figures 5a-5d illustrate baffles of the type shown in Figures 2-4, which The pinning assembly is shown in the operating position. These four drawings are buff The effect of this or the direction of movement of the unfolding strand is shown when the lever is rotated 90°.

Figure 5e shows the shape of the trapezoidal basis weight distribution created by the baffle shown in Figure 4. .

Figures 6.7 and 8 respectively show the modified FIG. 3 is a front view, a vertical cross-sectional view, and a plan view of a trilobal baffle.

Figures 9a-9d illustrate modified baffles of the type shown in Figures 6-8. Indicates the direction of land movement.

Figure 9e shows the shape of the triangular basis weight distribution created by the edge baffles shown in Figure 8. Indicates the condition.

FIG. 10 is a diagrammatic representation of the edge product guide and moving collection means used in the present invention. FIG.

FIG. 11 is an end view of the edge product guide and moving collection means used in the present invention. be.

FIG. 12 shows a method of establishing a sheet edge using the baffle shown in FIG.

Figures 13.14 and 15 show how to minimize sheet edge waste and the method shown in Figure 8. baffles and/or the product guide shown in Figures 10 and 11. Indicates an increase in available sheet width.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS With the present invention, the available range is greater than with similar devices used in the past. A combination of equipment is used to make a nonwoven sheet having a .

A modified baffle replaces the previously used standard, which is housed inside an interspersed spinning bag. Used in edge spinning packs in place of baffles in semi-packs. this strange The modified baffle has a triangular basis weight distribution shape instead of a trapezoidal basis weight distribution shape. The protrusion and fillet sections are different to provide a narrower swath with 2-4 and as shown in U.S. Pat. No. 3,497 except that it is made into the shape shown in FIG. Standard parts described in No. 918 (Polotsk) and No. 4666395 (Shah) baffle 1 through a body 11, a rotatable baffle 12, and a shaft 14, similar to the link baffle. 2 and a collecting surface 15. illustrated As such, the collecting surface 15 preferably runs around the rolls 16 and 17. It is an assembled endless belt. Coming out of the spinning assembly 11 Strands 18 are spread out by baffles 12 and collected on a belt (collection surface) 15. strands and combined with a number of other strands to form nonwoven sheet 20.

The sheet 20 is compressed by pressure applied by rolls 21 before exiting the belt 15. The compressed sheet 22 is then removed for storage or further processing. spread out An electrostatic band is used to charge the web as it leaves the baffle 12. Electrical means 23 are provided.

A standard three-lobed rotating baffle used in an intermediate spinning bag is shown in Figure 2-4. shown. The baffle 12 includes a boss portion 30, a disk portion 31, and a fillet portion. It consists of 32 minutes. In this embodiment, the boss portion 30 is a flat disc. It is a right cylinder standing on part 31.

As shown in FIGS. 2 and 3, the baffle is placed in a position with its central axis of rotation 33 in a vertical position. When observed in the It is perpendicular to the circular edge 35 at the top of the disk portion 31 and coincides with the center of both edges. do.

The fillet portion 32 extends around the boss portion 30, as shown in FIG. sloped generally from the side surface 36 of the disk portion 30 to the top plane 37 of the disk portion 31; Forms a low contour surface. The fillet portion 32 actually has 1 to 12 pieces. It has been found that evenly spaced protrusions 38 can be used successfully.

The upper surface 39 of the projection 38 is slightly wedge-shaped, i.e. this surface The area closer to the boss portion 30 is made narrower than the area closer to the boss part 30. This is the most You can see it clearly. The edge of the wedge is indicated by line 40. However, in the actual structure It is understood that all the curvature of the surface of the fillet portion 32 is gradual. Should. The reason for this will become clear from the following explanation of how to use the baffle. It will be.

The intersection of the fillet portion 32 and the side surface 36 of the boss portion 30 is located at the top of the boss portion 30. Below 34, each protrusion forms a series of lines, hereinafter referred to as boss intersection lines. It is called (B, 1. L, ). B.1. L is indicated by number 41 in Figure 2 . As shown, B, 1. L is generally S-shaped for each fillet portion 32 The curve is

The intersection of the fillet portion 32 and the top surface 37 of the disk portion 31 A series of lines, one for each fillet section 32, inside the circular edge of the top of 1. , which is hereinafter referred to as the disk intersection line (D, IL, ). D, L L is indicated by the number 42 in FIG. As shown, D, 1. L, 42 is generally CD slightly concave between each protrusion 38; 1. L, 42 is the protrusion 38 It is also possible to form an equilateral triangle with rounded corners.

B.1. L, 41, 1. Although L and 42 are shown as clear lines in the drawing, In the actual structure, there is no fillet portion on the side of the boss portion 30.

Now, referring to Figure 5a, we can see that the spinning bag in this particular orientation is When fully used, the strand 18 is attached to the filament at a point midway between the two protrusions 38. It will be observed that the let part is tapped. Strands are spread out and vertically bent downwards. That is, when the strand leaves the edge of the disk section, The centerline of the unfolded strand is vertical.

As the baffle rotates (clockwise in this case), the unfolding strand bends to the left. It starts to get worse. For this particular example, when the strands leave the disk The center line of the unfolded strand is the disk intersection line CD.

1, L, ) 42. Therefore, the baffle was shown in Figure 53. When rotated 1° from the position to the position shown in Figure 5b, the centerline is approximately 1° from vertical. Can be bent. In general, baffles are designed with a given minimum swath width and Stretch at a sufficiently large angle so that the basis weight distribution shape meets the product mixing requirements. we have to bend the curve. With a rotation of approximately 40°, the strand 18 will move as shown in Figure 5b. Tap the maximum slope point of the left slope of the protrusion 38 so that the This rotation angle In this case, the centerline of the unfolded strand is bent approximately 35° from the vertical direction, and this is the point of maximum leftward bending for this particular example.

As the baffle continues to rotate, the strands 18 begin to strike the top surface of the protrusion 38; The centerline of the unfolded strand begins to return to the vertical direction. The baffle will rotate an additional 20°. (60'' from FIG. 5a), the strand 18 will move as the protruding baffle rotates further. The unfolding strand begins to strike on the right slope of the protrusion 38, and the center of the unfolding strand The line is curved to the right. When the baffle is rotated an additional 20” (80° from Figure 5a), The centerline of the unfolded strand is bent approximately 35° from the vertical as shown in Figure 5d. , which is the point of maximum rightward flexion for this particular example.

If the baffle continues to rotate another 40° from the position shown in Figure 5d (Fig. 5a to 1 20°), the centerline of the unfolded strand, which again occupies the position shown in Figure 5a. Gradually return to the vertical direction until

From the above explanation, the 360° rotation of this trilobal baffle results in 3 rotations of the unfolded strand. It will be obvious to create a complete round trip cycle. As mentioned above, Figure 5a- When dropped onto a moving collection surface, the baffle rotation shown in 5d A swath with a trapezoidal basis weight distribution shape (as shown at 44 in Fig. 5e) is obtained. . The width of the swath and the shape of the swath are important; both potions are collected from the baffle. It is important to note that it is affected by the distance to the focal plane. Trapezoidal basis weight distribution shape It is understood that the profile of the baffle can be changed significantly as long as it is possible to create a swath of There will be. Using radically different fillet portion 32 shapes and contours Can be done. Therefore, the shape and contour of the fillet portion 32 shown in Figure 2-4 is limited. It is understood that these are not specified and are for illustrative purposes only. Good morning.

Now, referring to Figure 6-8, we can see that the modified rotating baffle is When driven at the same distance as in the case, the basis weight distribution shape is triangular instead of trapezoidal. Spinning inset, except that certain contour changes were made to create a distribution shape. Similar in many ways to Puck's pamphlet.

The main difference is that the intersection of the fillet portion 32 and the top surface of the disk portion 31 (i.e. D.1. L, 42") is generally convex between the individual protrusions 38. In other words, D, 1. L, 42' is between each protrusion 38 of the trilobal baffle. Drooping down. This is clearly seen in FIG. This is convex glue, T, L, 42' This creates a narrow swath with a triangular basis weight distribution shape.

Furthermore, as mentioned above, B.1. L, 41, 1. What is L, 42'? Figure 6- Although it is shown as a clear line in Figure 8, in the actual structure, the fillet part is the boss part. 30 and the top surface 37 of the disk portion 31. Should. That is, there is no sharp bend in B, T, L, or IL. .

Now, referring to Figure 9a, we can see that the spinning of the edge in this particular direction condition is When using a baffle, the strand 18 is It will be observed that the fillet area is patted. Strands are spread out and vertical The direction is bent downward. i.e. when the strand leaves the edge of the disk section The center line of the unfolded strand is vertical. The rotation sequence illustrated in Figures 5a-56 9a-96. Created by spinning baffles on the edges. The unfolded strands are rotated to the left and right at a smaller angle than the center spinning baffle. Can be bent. This results in a narrow triangular basis weight distribution 45 as shown in Figure 9e. Used in conjunction with product information. Referring to FIG. 10, the deployed strand collection means Generally designated 70, this includes the machine frame 71, 72, product guides 73 and 74, and and a belt guide 75 surface. Now, referring to FIG. 11, the belt guide 75 is It supports the moving belt 76, on which the deployment strands are placed. Product information 73 and 74 are shown positioned at an angle of approximately 30 degrees from vertical. Product information 7 3 and 74 are attached to movable supports 77 and 78.

Large sheet widths for various basis weights of the nonwoven sheets whose production method is the object of the present invention In addition to the shape of the baffle on the spinning back at the edge, , by changing the speed and direction of rotation of the baffle and the strength of the electrostatic charge on the unfolded strand. can be done. All baffles in an intermediate spinning pack operate at the same speed (power) The baffle of the Tsufuchi spinning pack is can be operated at the same speed as the engine, but they can operate at different speeds or rotations. It will be understood that it is possible to drive in the opposite direction. This results in a narrow swath width and Due to the high packing density, the electrostatic charge applied to the strands from the spinning pack at the edge is The level of charge applied to the strands from the spinning puck generally lower than the current level (i.e. 60% to 100%, preferably 70% to 80% lower).

Generally, one to four edge strips are applied to apply the strands along each edge of the sheet. There is a pining puncture. The spacing between the edge spinning backs is determined by the final seam created. can be changed to manage the size and shape of the objects. I can give you an example. deer However, this is largely governed by the number of bags used and the desired sheet format. Ru.

When the sheet is placed on a moving belt, the outward bends of the unfolding strands Use the product guide to direct the material along both edges to the mounting belt. It is preferable. The surface of the product guide allows the charged strands to easily slide apart. It must have a surface with low friction and high electrostatic strength so that the Available now Preferred for forming product guides while using commercially available flash spinning solvents. A new material was found to be polycarbonate. Product information surface installation is preferably within a range of 45° from the vertical direction. but, The preferred range is less effective, but the product guide should be larger than 45° from the vertical. Be careful not to place it at an angle. Preferably, the product information is used 1 to 4 strands of spinning backs fold over it. be long enough to be able to slide down and onto a moving belt. Ru. The product information is that the fibrous material is cut from the edges and used as a tearless tape. Controlled straightness of strands laid to sufficient thickness to get air transported Used to form edges. This results in strands with separate edges. minimize problems associated with handling. The distance from the edge of the product guide is the distance across the machine. It is adjusted over a distance of about 30 cm in the direction of

Figures 12.13.14 and 15 show benefits from the use of edge baffles and/or product guides. Improvement of usable sheet width and (edge trimming) and spinning of discarded equipment How to pile up the individual basis weight distribution shapes from the pack 44 at the edge of the sheet? Indicates whether it is possible. Figure 12 has a "usable width" that is considerably smaller than the total sheet width. This figure shows a configuration representation of the basis weight distribution shape at the edge of a six-layer sheet. Figure 13 (Edge baffle (not available, but product information available) is to move the material 47 inward to create a contour 48. Therefore, the product guide narrows the total sheet width and trims the edges and disposes 53 as shown in Figure 12. A method to make it smaller than 52 will be shown. The usable sheet width 56 in FIG. It is almost the same as that of 12. Figure 14 (There is a baffle on the edge, but there is no product information) ) increases the available sheet width (57>56) and the sheet edge contour 49. Impact of edge baffles on reducing trim waste 54 with major changes and improvements shows. Figure 15 (with edge bar and product guide) shows the product edge guide and The improvement in edge profile obtained when using both edge baffles is shown. use The possible width 57 is approximately the same as in FIG. 14, but the trimmed edges 55 are Note that it is further reduced relative to 54 in FIG. 14 and 53 in FIG. debt In use, the combination of the edge baffle and product guide of the present invention reduces edge loss by approximately 5. 0% and increases the usable sheet width by approximately 20cm.

Although specific embodiments of the invention have been described in detail above, the spirit or essence of the invention without departing from the basic attributes (many changes, substitutions and rearrangements are possible). It will be understood by practicing engineers. When indicating the scope of the invention, reference is made to the above description. This should be done for patent matters rather than patent matters.

F Engineering G, 1 FIG, 5a FIG, 5b FIG, 5c FIG, 5d FIG, 9a FIG, 9b FIG, 9e FIG, 9d FIG. 10 ===22yo7 173 FIG. 11

Claims (9)

[Claims] 1. For a given number of spinning packs, the gap with the larger available width A device for forming woven fiber sheets, consisting of multiple intermediate spinning packs and multiple rim spinning packs, each of which spins the fibers in a generally horizontal path. a spinning assembly for spinning a strand, the apparatus further receiving a strand; This is generally done by bending the strands downward in a vertical plane while widening the strands. A rotatable bar that reciprocates simultaneously deployed strands in a generally vertical plane. a baffle and means for rotating the baffle, the baffle having a center of rotation thereof; The fillet part that extends around the boss part when viewed from the axis in the horizontal direction. It is a one-piece body consisting of a circular boss part on a disc part with an inner spacer. The baffle of the pinning pack has a fillet part, and this fillet part is The developed strand intersects with the spinneret to form a generally concave surface and the unfolded strand Trapezoidal basis weight when placed on a moving collection surface placed below the packaging pack. It is designed to form a swath having a cloth shape, and the spinning pack at the edge is The baffle has a fillet portion that intersects with the disk portion. generally forms a convex surface and the unfolded strands are at the bottom of the spinning pack at the edge. A strip having a triangular basis weight distribution shape when placed on a moving collecting surface The central axis of rotation of the baffle is formed by the boss part and the disk. A device perpendicular to and coinciding with the center of the circular edges of both tops of a part. 2. Both the middle spinning pack and the edge spinning pack have expanded strands. The charging strength of the spinning pack at the edge is moderate. The device according to claim 1, wherein the charging strength is 60 to 100% of the charging strength of the spinning pack. . 3. 1 to 4 pieces placed along each edge of multiple spinning packs The combination according to claim 1, wherein there is a spinning pack at the edge. 4. For a given number of spinning packs, the gap with the larger available width A combination of devices that form woven fiber sheets, and multiple intermediate spinning packs. and a plurality of rimmed spinning packs, each of which is generally oriented in a horizontal path. a spinning assembly for spinning fiber strands; Receiving this generally involves bending the strands downward in a vertical plane while widening them. Rotatable to move the unfolded strands back and forth generally in a vertical plane a baffle capable of rotating the baffle and means for rotating the baffle; A fillet that extends around the boss when viewed from the center axis of rotation in the horizontal direction. It is a one-piece body consisting of a circular boss part on a disc part with a width The baffle of the mushroom spinning pack has a fillet part, and this fillet part is intersects the disc portion to form a generally concave surface and the deployment strand is intersected trapezoidal shape when placed on a moving collection surface placed below the spinning puck. The spinning pattern at the edge is designed to form a swath with a basis weight distribution shape. The baffle of the disc has a fillet portion that intersects with the disc portion. A spinning pack with a generally convex surface and an expanded strand at the edge. Has a triangular basis weight distribution shape when placed on a moving collection surface placed below. The central axis of rotation of the baffle is formed by forming a swath that perpendicular to and coincident with the center of the circular edges on both tops of the disk portion; Furthermore, this device combination is parallel to each edge of the moving collecting surface and contact with the part of the unfolding strand bent by the baffle of the packing pack. Maximize the width of the unfolded strand by placing the unfolded strand portion on a moving collection surface. A combination with multiple product guides made to be small. 5. Both the middle spinning pack and the edge spinning pack have deployment struts. The charging strength of the spinning pack at the edge is Claim 4: The charging strength is 60 to 100% of the charging strength of the spinning pack placed inside. A combination of 6. 1 to 4 pieces placed along each edge of multiple spinning packs The combination according to claim 4, wherein there is a spinning pack at the edge. 7. 5. The combination of claim 4, wherein the product guide is formed of an insulating material. 8. 5. The combination of claim 4, wherein the product guide is formed of polycarbonate. 9. The product guide is slanted inward towards the spinning pack at the edge and perpendicular to the vertical direction. 5. The combination of claim 4 located between 45° from the direction.