US 3564677 A
Description (OCR text may contain errors)
Feb. 23, 1971 F, KALWMTES 3,564,677-
METHOD AND APPARATUS OF TREATING MATERIAL TO CHANGE ITS CONFIGURATION Filed Nov. 6, 1967 5 Sheets-Sheet 1 INVENTOR F/PAA A A144 1/.4/ 7'55 ATTOR EY F. 23, 1971 F. KALWAITES 3,564,677
METHOD AND APPARATUS OF TREATING MATERIAL PO CHANGE ITS CONFIGURATION Filed Nov. 6, 1967 3 Sheets-Sheet 2 INVENTOR flbA/vx A741 IVA/Z1155 ATTORNEY Feb. 23, 1971 w ns 3,564,677
METHOD AND APPARATUS 0F TREATING MATERIAL To CHANGE ITS CONFIGURATION v 3 Sheets-Sheet 3 Filed NOV. 6, 1967 INVENTOR FfiA/VK h/A/ r55 BY W ATTORNEY United States Patent 3,564,677 METHOD AND APPARATUS 0F TREATING MA- TERIAL TO CHANGE ITS CONFIGURATION Frank Kalwaites, Somerville, N.J., assignor to Johnson & Johnson, a corporation of New Jersey Filed Nov. 6, 1967, Ser. No. 680,617 Int. Cl. D02g 3/00 US. Cl. 281 20 Claims ABSTRACT OF THE DISCLOSURE This is a method for treating various materials such as films, yarns, sheet materials, etc. to change the configuration of the material. The material to be treated is moved in a first direction and at a first speed. The direction the material is moving is changed to a second direction. At substantially the same time the direction of the movement is changed the speed at which the material is moving is also changed. The apparatus comprises a pair of rotatable rolls rotating in the same direction and positioned with respect to each other to form a nip of minimum clearance. A blade is placed into the nip in contact with the surface of both rolls. The material to be treated is passed between the blade and one roll around the edge of the blade and delivered from between the blade and the second roll in its new configuration.
This invention relates to method and apparatus for treating various types of materials to change the configuration of the material. The materials which may be treated in accordance with the present invention are sheet materials, such as films, paper, woven fabrics, nonwoven fabrics, fibrous webs, etc. or various other materials such as sliver, roving, yarns (both continuous filament and staple fiber type), etc. The method and apparatus of the present invention may be used to crepe or compact material or another embodiment of the present invention may be used to draft or elongate material. Other embodiments of the method and apparatus of the present invention may be used to split oriented film into individual fibers or to impart a curve or kink to yarns or filaments. Still further embodiments may be used to provide a softened or textured effect to sheet material and improve the hand of the material.
There are innumerable known methods for treating materials to crepe, compact, draft, or change the configuration of the material in various manners. There are also innumerable ways to impart a crimp to yarns or produce texturized yarns. There are also various types of machines presently available to treat materials for creping, compacting, curling, kinking, drafting, etc.
I have discovered a new apparatus which has a minimum of moving parts, is made up of members of very simple design, and is uncomplicated in overall construc tion and operation. The individual elements of my new apparatus are well known in the art, however, their unique combination to produce my new machine is not. This unique combination of old elements provides a machine which is simple and unexpectedly may be utilized to treat materials in many different manners, i.e., the machine may be used to compact, crepe, draft, curl, etc.
In accordance with the present invention, the material to be treated to have its configuration changed is continually moved in a first direction at a first speed. While the material is moving in the first direction it is momentarily gripped, preferably across the entire width of the material. Substantially immediately after gripping the material, the direction the material is moving is changed to a second direction and simultaneously the speed at which the material is moving is changed.
3,554,677 Patented Feb. 23, 1971 Apparatus for carrying the new method into practice comprises a pair of rotatable rolls With the rolls rotating in the same direction. The axis of the rolls are parallel and the rolls are positioned with respect to each other to form a nip with a minimum of clearance between the rolls at the nip. A blade is positioned adjacent the nip and extends parallel to the axis of the rolls and is in contact with the surfaces of both of the rolls. Material fed between the blade and the surface of one roll is moved about the edge of the blade and is delivered from between the surface of the other roll and the blade in a new and different configuration.
The invention will be more fully understood from the description which follows taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic side view of one form of apparatus for carrying out the process of the present invention,
FIG. 2 is a schematic side view of apparatus for carrying out another embodiment of the present invention,
FIG. 3 is an enlarged cross-sectional view of the double roll and blade portion of the apparatus of the present invention,
FIG. 3a is a modification of the apparatus shown in FIG. 3,
FIG. 4 is a schematic top view of apparatus for carrying out still another embodiment of the present invention,
FIG. 5 is a schematic side view of apparatus for carrying out yet another embodiment of the process of the present invention,
FIG. 6 is a schematic top view of the apparatus according to FIG. 5.
In FIG. 1 there is shown a standard let off roll 10 containing the supply of material 11 to be processed in accordance with the method and apparatus of the present invention. The material is a high molecular weight plastic film, highly oriented transverse to the longitudinal direction of the film. The material is let off from the roll and passes around a guide roll 12. The guide roll may be stationary or rotatable. The material is passed through a pair of rolls 13 and 14 and a nip blade 15 in accordance with the present invention. The axis of the rolls are parallel and the rolls form a nip at A with a minimum clearance between rolls. A stationary blade 15 is positioned at the nip so that one side of the blade touches the roll 13 and the opposite side of the blade touches the second roll 14. The first roll 13 is a metal roll having a slightly roughened surface, i.e., a sandblasted, knurled or similar type surface. The second roll 14 is resilient and may be covered with a relatively hard rubber. Rubber having a Durometer hardness of to has been found satisfactory.
One of the rolls is directly driven by a suitable motor and pulley mechanism not shown for purposes of clarity. The driven roll is geared to the other roll so that the other roll is also driven. The rolls rotate in the direction of their arrows as shown in the drawing. The second roll 14 is driven at a surface linear speed greater than that of the first roll 13. The ratio of surface linear speeds of second roll to first roll may be from about 2:1 to 5:1. These ratios have been found satisfactory when treating oriented plastic films. The treated film after leaving the pair of rolls and blade is passed to another guide roll 20, Which may be stationary or rotatable, and the film wound up on a standard windup mechanism 21. In operation the film as it passes through the two roll and blade system is momentarily gripped across its entire width at the point where the blade is in contact with the surface of the first roll (first nip). The film is again momentarily gripped across its entire width at the point where the blade is in contact with the second roll (second nip). The second roll rotates at a peripheral linear 3 speed faster than that of the first roll and the speed at which the material is moving is immediately increased as soon as the material passes through the first nip.
The action of the two rolls and blade system is applied to incremental portions of the length of the material treated. This action over an infinitesimal length of the film splits the film into a network of interconnected fibers to form a web of interconnected fibers having some free fiber ends. It is believed that as the film passes between the two nips the film is split in the incremental length of film between the nips. The split portion then passes out from the areas between the two nips and is replaced by a new portion of film between the nips which is then split, and so on. Hence, the distance between splits in the final film may be controlled to some extent by the thickness of the blade. The pattern of splits in the final film or web of interconnected fibers may also be controlled by separating or grooving the blade so that the splitting forces are placed across the width of the film in an intermittent manner. Yet another manner for patterning the split in the film is to reciprocate the blade, e.g., move the blade in and out between the two rolls so that the nips are formed intermittently as the film is being processed. This movement may be rather slow to provide large distances between splits or very rapidly, even ultrasonically, to produce very fine splits.
Though the process and apparatus of FIG. 1 have been described in conjunction with the treatment of an oriented plastic film other materials might also be passed through the apparatus in a similar manner such as staple fiber webs, woven fabrics, yarn or a series of yarns to treat the material with a similar action as described above over infinitesimal increments along the length of the material.
With regard to FIG. 2 the various mechanical components are similar to those depicted in FIG. 1. A standard let off roll 25 containing the material to be treated 26 such as woven, knitted or nonwoven fabric, paper, plastic film, etc., is shown. The material to be treated is let off from the roll and passed about a guide roll 27 which is either stationary or rotatable. The material passes from the guide roll to the nip formed by a pair of rolls 28 and 29 and a blade 30. In the apparatus shown in FIG. 2 the rolls rotate in the direction of the arrows shown and the surface of the rolls would be similar to that described in conjunction with FIG. 1. The blade is positioned similarly to that described in FIG. 1, however, the second roll rotates at a slower peripheral linear speed than the first roll so that the peripheral linear speed ratio of the second roll to the first roll is something less than 1:1 and may be as low as 02:1. The material after passing through the nip passes about a guide roll 31, which may be stationary or rotatable, and the material wound up on a standard wind-up mechanism 32. By changing the speeds of the rolls so that the second roll is rotating slower than the first roll, a compacting or condensing action is given to the material over infinitesimal increments of its length. Depending upon the types of surfaces used, the speed ratio of rolls and the material being treated, the final material may be creped or have a pattern of ripples produced on its surface, or it may be relatively smooth but softer than the original fabric.
FIG. 3 is an enlarged cross-sectional view of a pair of rolls and blade which form the combined nip through which material to be treated in accordance with the present invention passes. The rolls 35 and 36 rotate in the same direction, as shown by the arrows. The ratio of peripheral linear speeds of second roll 36 to first roll 35 may be from 0.2:1 to :1 or even higher depending upon the treatment desired. Both rolls should have frictional surfaces so that they have a positive gripping action on the material being treated. It is generally preferred that the first roll 35 be a metal roll and have a slightly roughened surface such as narrow fluted, sandblasted or similar type surface while the second roll 36 is resilient, e.g., rubber covered or covered with one of the various plastic materials Which has resiliency. There is a minimum clearance or light touching of the two rolls at point B. The rolls must be close enough together so that the material does not get between the rolls but they should not be so close as to cause undue wear on the rolls during the operation of the apparatus. The diameter of the rolls may vary over a Wide range. The longer the rolls the greater the diameter need be to prevent flexing of the rolls. Diameters from about 3 to 7 inches have been found most suitable.
A blade 38 mounted on a suitable frame 39 is positioned between the rolls so that the blade is in contact with the surface of both rolls. The blade forms a nip at points C and D. The thickness of the blade and diameter of the rolls will determine the distance between the two nips C and D. The blade may be made of various rigid or semirigid materials such as steel, preferably spring steel, or various plastic material. Blades having a thickness of about .020 inch have been found suitable for use in accordance with the present invention. The edge of the blade may be straight or it may be beveled to either or both sides. It is preferred that the contact between blade and rolls be a line contact and not contact over any substantial portion of the surface area of a roll. The beveled side should not pass against the rubber roll to such a degree as to form a fiat nip. This is especially true when splitting oriented films as such a flat nip may cause breakage of the film.
The arrangement of the rolls 35 and 36 and the blade 38 is such that material as it passes around the blade is bent back on itself. The angle at which the material is bent as its passes around the blade should be less than 120 and preferably less than In most instances the angle will be less than 60. As shown in FIG. 3a if the blade 40 has a flat edge the angle a is a projected angle and the projected angle should be less than In FIG. 4 there is shown another embodiment of the process of the present invention which may be used to draft roving or sliver. A package 50 of roving or sliver 51 to be drafted is placed on a standard let-off mechanism 52. The roving or sliver passes from the package about a guide roll 53 and through the nips formed by the blade 54 and a pair of rotatable rolls 55 and 56. The rolls rotate in the same direction and the speed of the second roll is greater than the speed of the first roll. The ratio of speed of second roll to first roll may be from about 1.1:1 to as high as 3 or 5:1. The sliver after being passed through this mechanism passes about a second guide roll 58 and is wound up on a suitable creel or spool 59. The sliver as its passes through this mechanism is drafted over infinitesimal portions of its length by means of a pair of nips formed by the touching of the blade against the surfaces of the two rolls as described in accordance with FIGS. 1 and 3. Such an apparatus gives excellent control due to the very short distance between the drafting nip, hence sliver made from even the shortest fibers may be drafted by such apparatus.
Continuous filament yarns may also be processed by apparatus similar to that depicted in FIGS. 3, 3a, and 4. When continuous filament yarns are processed in accordance with the present invention they are elasticized and provided with kinks or curls. There are a number of known techniques for elasticizing continuous filament yarns by providing them with kinks or curls by passing the yarns about a sharp knife edge. This process places stresses within the continuous filament yarn which cause the yarn to curl. In order for these techniques to produce suitable results the temperature at which the yarn is treated and the tension the yarn is under during treatment are extremely important and should be controlled. Generally, the lower the temperature of the yarn during the treatment the greater the force required to produce the desired elastic properties in the yarn.
One possible theory as to why yarns curl after being passed about a sharp knife edge is that ditferential forces are placed across the cross-sectional area of the yarn, i.e., the portion of the yarn closest to the knife edge is stressed less than the portion furthest from the knife edge.
The process and apparatus of the present invention, it is believed, place even greater differential stresses across the cross section of the yarn, which in turn reduces the temperature requirements at which the yarn must be treated and also allows for treatment of a very wide variety of continuous filament yarns. In accordance with my process as the yarn passes from C to D in FIG. 3 about the sharp knife edge the faster peripheral speed of roll 36 places a differential acceleration across the cross-sectional area of the yarn. The outer surface of the yarn is accelerated more than the inner surface pro ducing very pronounced and permanent curls and kinks in the yarn.
In the prior art process the amount of stress placed on the yarn as it passed about a knife edge is limited by the difference in the radius of curvatures of the inner and outer surface of the yarn. However, in accordance with the present invention there is no such limitation as the stress placed on the yarn not only depends on the difference in the radius of curvature but also on rate of acceleration of the yarn as it passes over the knife edge between the two nips.
The yarns which may be processed in accordance with the present invention are any of the continuous filament yarns such as polyester yarns, polyamide yarns, polyacrylic yarns, etc. It is generally preferred that the yarns have a circular cross section though other cross sections may also be processed. It is also generally preferred that the yarns have some original elasticity and not be excessively brittle as is the case with some high tenacity rayon yarns. The yarns may be either multifilament or monofilament yarns as desired.
Tht temperature at which the yarn is processed may vary from room temperature or below to 430 F. or so. The temperature should not be so high as to cause excessive degradation of the yarn. This high temperature will of course vary depending on the yarn used and is about 450 F. for polyester yarns and 400 F. for regular yarns.
The yarn may be raised to the desired temperature by various types of band heaters well known in the art or by heating the rolls and/or blade of the apparatus of this invention.
The amount and degree of curl placed in the yarn will also vary depending upon the pressure applied by the blade 38 and the rolls 35 and 36. Generally the greater the pressure applied the more pronounced the curl or kink produced in the yarn.
In accordance with the process de icted in FIGS. and 6 multifilament, zero twist yarns 60 are fed from packages 61 about a yarn guide 62 and spacer comb 63 to place the multifilament yarns in the same horizontal plane and approximately the same distance apart. Usually there is about a sixteenth of an inch to a half inch spacing between the yarns though even greater distances may be used to produce very lightweight webs. The yarns are fed through a pair of rolls 64 and 65 and nip blade 66 as described in accordance with FIG. 3. A feed roll 67 is placed in contact with the first roll 64 to place the yarns.
under slight tension as they are fed to the mechanism. The first roll 64 is metal and has a slightly roughened surface such as a sandblasted surface, and the second roll 65 is a rubber covered roll. The rolls rotate in the same direction as shown by the arrows and the speed ratio of second roll to first roll is from about 1.01:1 to 2:1. The multifilament yarns on being passed through the nips formed by the blade and the pair of rolls are curled or kinked. The curl being much like that in a coil spring. The curled yarns 68 are passed through a first set of nip rolls 70 and 71 which maintain yarns under slight tension. This tension is not enough to remove the curl or the kink in the yarns but is sufficient to prevent sagging of the yarns out of their horizontal plane. The yarns are passed from this first set of nip rolls and 71 to a second set of nip rolls 72 and 73. Between the two sets of nip rolls there is a beater mechanism 74. The beater mechanism is a roll 75 having bars 76 fastened to the roll and parallel to its axis which intermittently contact the plane of the yarns passing between the sets of nip rolls as the roll 75 rotates. This action places the yarns under tension straightening the yarns as the beater bar contacts the yarns. When the beater bar 76 is not in contact with the yarns, the yarns relax and take their curl again but the curl of individual filaments is not in registry with the other filaments and hence the individual filaments of the multifilament yarns are separated and merge into a helter-skelter pattern with individual filaments of adjacent multifilament yarns. Though only one beating step is shown, a plurality of such steps may be used. The more the yarns are tensed and straightened, and allowed to relax and curl, the more the individual filaments tend to separate from each other and merge into a helter-skelter pattern or web of filaments.
The individual filaments pass from the second set of nip rolls to another set of nip rolls 80 and 81 comprising a metal roll 80 and a roll 81 which is fluted. The fluted roll intermittently tenses individual filaments when the high points contact the filaments and relaxes the filaments when the land area 82 of the roll is not in contact with the metal roll 80. The intermittent tension or relaxation applied to the multifilament yarns by the fluted roll nip further separates the yarns into individual filaments and causes these filaments to merge and entangle with adjacent filaments both in their own yarn and in adjacent yarns to form a weblike structure 85 of continuous filaments arranged in a helter-skelter pattern. The web is passed about a suitable guide roll 86 and wound up on a standard wind up mechanism 87.
In the double roll and blade unit the first roll should have a frictional surface that is sand-blasted or knurled as this aids in controlling the input of the material to the rolls and blade. The rolls should be positioned with respect to each other so that there is a running clearance between them of about .002 to .003 inch. The blade contacts the surface of both rolls.
In curling multifilament yarns a ratio of second roll speed to first roll speed of 1.2:1 has been found most satisfactory. If the ratio is raised too high the multi-filament yarns will be stressed and there will be breakage whereas lower ratios will not produce sufiicient curl in the yarns. In treating oriented films to split them into fibrous webs ratios of second roll speed to first roll speed should be about 4:1 as lower ratios do not split the films sufficiently into split fibers and higher ratios will tend to break films and cause tears and rips.
If the blade has a beveled edge it is preferred that it is used against the input or first roll as generally when used against the output or second roll it will tend to cause further scuffing of the material being treated.
In the process described in accordance with FIGS. 5 and 6 the curled yarns may be relaxed and tensed by various beater motions, i.e., a reciprocating motion, and up and down motion, air motion, etc. In some instances the beater motion may be replaced by a soft bristle brush to produce intermittent tension and relaxation.
The materials which may be treated in accordance with the present invention are any of the plastic films which may be oriented such as polyethylene, polypropylene, and various other synthetic polymer films. The yarns which may be treated may be continuous filament yarns, staple fiber yarns, roving, sliver, etc. and may comprise any of the natural, man made or synthetic fibers. Other materials may also be treated in accordance with the present invention such as needled fabrics, nonwoven fabrics, woven fabrics, knitted fabrics, etc.
In treating multifilament yarns to produce filament webs many of the various synthetic filaments may be used such as rayon, the polyamides, the polyesters, the polyolefins,
etc. The denier of the filaments may vary from about one denier up to 20 denier or higher and the yarns may contain anywhere from 10 to 100 filaments or more.
Although all of the various holders, pulleys, belts, beaters or like mechanical means including suitable framing have not been illustrated completely in the drawings or described in the specification for driving or supporting the various rotating cylinders, rolls, or beaters at their desired or required speeds or with the rotation or movement indicated by their direct arrows, it is to be appreciated that such elements have been omitted to keep the drawings and descriptions distinct and to avoid the introduction of matters which are well known expedients in the art. The mechanical driving means and various frames which are used are conventional and merely involve the application of well known mechanical principles.
The invention will be further illustrated in greater detail by the following specific examples.
EXAMPLE I A polypropylene film 1.2 mils in thickness, and about inches wide and highly oriented in the cross direction, i.e., width, is fed to the apparatus depicted in FIG. 3. The input roll 35 is a metal roll with a knurled surface, knurled in a diamond pattern. The output or second roll 36 is a roll covered with rubber having a Durometer hardness of 65. The rolls rotate in the same direction as shown by their arrows and the rubber roll rotates at 4 times the speed of the metal roll. The rolls have a clearance between them of .002 inch. A spring steel blade 38 having a thickness of .020 inch and beveled on one side of the thin edge is placed in contact with the surfaces of both rolls, the beveled edge contacting the metal roll and the other edge of the blade contacting the rubber roll. The film is passe-d through the blade and pair of rolls at a speed of 9 feet per minute and the oriented film is split into a split fiber web of interconnected fibrous elements having free fibrous ends. The splitting is uniform throughout the entire area of the film.
EXAMPLE II A nonwoven fabric weighing 260 grains per square yard comprising a 220-grain per square yard film web of 1 /2 inches, 1% denier rayon fibers bonded with 40 grains per square yard of a polyacrylic binder printed on the web in a pattern of four horizontal Wavy lines per inch is passed through a pair of rolls and blade. The first roll, or input roll, is a metal roll having a sandblasted surface and the second roll is a rubber covered roll. The blade is spring steel, .010 inch thick, and fits into the nip formed by the two rolls. The blade contacts the surfaces of both rolls. The second roll rotates at a speed slightly less than that of the first ro'll so that the speed ratio of second roll to first roll is about 6:1. The nonwoven fabric is passed onto the first roll about the edge of the blade and out on the second roll. The fabric is compacted and softened. The softness of the original fabric is 70.5 while the softness of the final fabric is 83 as measured by Thwing Albert, Handl-O-Meter, Softness Tester.
EXAMPLE III Twenty-four multifilament, zero twist, polyester yarns are placed in a parallel horizontal plane with the yarns approximately inch apart. The yarns used are 670 total denier per yarn, 13 denier per filament. The parallel plane of 24 yarns is passed through the apparatus depicted in FIGS. 5 and 6. The yarns are taken from suitable webs and drawn under a guide bar and through a spacer comb to form the plane of yarns which is fed to the double roll and blade unit. A uniform tension is placed on the yarns as they are fed to the blade unit. This uniform tension is provided by the feed roll 67 in contact with the input roll 64. The input roll is a steel roll having a sandblasted surface. The second roll 65 has a rubber covered surface with the rubber having a Durometer hardness of approximately 50. The blade 66 is spring steel and has a thickness of .020 inch. and a beveled edge. The bevel edge contacts the surface of the steel roll and the other edge contacts the rubber roll. The ratio of the speed of the rubber roll to the speed of the steel roll is 1.2:1. The parallel multifilament yarns after passing through the blade and pair of rolls is substantially uniformly curled and are passed to a pair of nip rolls under a minimum of tension. The minimal tension is sufficient to prevent sagging of the curled yarns. The nip rolls rotate at approximately the same speed or slightly faster than the steel roll 64. The yarns are passed from the first pair of nip rolls to a second pair of nip rolls which are running faster than the first pair and at a ratio sufiicient to draw the yarns out to their full length and apply firm tension (approximately 1.24:1).
The yarns move from side to side or shift as they pass between the two pairs of nip rolls which tends to separate or individualize the filaments. Between the first and second pair of nip rolls there is a beater roll 74 as shown in the drawings FIGS. 5 and 6. As the beater roll rotates the filaments are alternately stretched and relaxed. This action separates and individualizes the filaments. From the second pair of nip rolls the yarns pass to their third pair of nip rolls consisting of a rubber roll and a steel roll. The rubber roll has flutes on its surface. The third pair of nip rolls rotate at a faster speed than the second pair so that the filaments are intermittently tensed and relaxed which separates filaments and merges them into a uniform web. A uniform web weighing approximately 150 grains per square yard and comprising individual continuous filaments merged into a helter-skelter pattern is formed.
Although several specific examples of the inventive concept have been described for purposes of illustration the invention should not be construed as limited thereby nor to the specific features mentioned therein except as the same may be included in the claims appended hereto. It is understood that changes, modifications, and variations may be made in the method and apparatus herein described without departing from the spirit and scope of the claimed invention.
What is claimed is:
1. A method of continually treating material to change its configuration comprising continually moving the material to be treated in a first direction and at a first speed, momentarily gripping the material immediately after gripping said material changing the direction the material is continually moving to a second direction at an acute angle to said first direction, immediately after changing the direction the material is moving momentarily gripping the material a second time and substantially simultaneously changing the speed at which the material is moving to a second speed.
2. Method according to claim 1 wherein the second speed is faster than the first speed.
3. A method according to claim 1 wherein the second speed is slower than the first speed.
4. A method according to claim 1 wherein the angle the second direction makes with the first direction is less than 60 degrees.
5. A method of continually treating oriented plastic film comprising continually moving the film in a first direction and at a first speed, momentarily gripping the film, immediately after gripping said film changing the direction at which the film is moving to a second direction having an angle of less than degrees with the first direction immediately after changing the direction the film is moving momentarily gripping the film a second time and substantially simultaneously increasing the speed that the film is moving whereby the film is split into an interconnected web of fibers.
6. A method according to claim 5 wherein the film is oriented in the direction of its width and the film is removed longitudinally.
7. A method according to claim 5 wherein the film is momentarily gripped across its entire width.
8. A method according to claim 5 wherein the film is intermittently gripped across its width.
9. A method according to claim 5 wherein the film is a polyolefin film.
10. A method according to claim 5 wherein the speed of the film is increased from about 2 to 5 times its original speed.
11. A method of continually treating a polyolefi film oriented in the direction of its width comprising continually longitudinally moving the film in a first direction, momentarily gripping the film across its entire width, immediately after gripping the film changing the direction at which the film is moving to a second direction having an angle of less than 90 degrees with the first direction immediately after changing the direction the film is moving momentarily gripping the film a second time and substantially simultaneously increasing the speed that the film is moving to about 2 to 5 times its original speed whereby the film is split into an interconnected web of fibers.
12. A method according to claim 11 wherein the angle between the first and second direction is less than 60 degrees.
13. Apparatus for treating material to change its configuration comprising a pair of rotatable rolls, the axis of said rolls being parallel and the rolls positioned with respect to each other to form a nip between the rolls having a minimum clearance between the rolls at said nip, means for rotating said rolls in the same direction and at difierent surface linear speeds and a blade adjacent said nip and extending parallel to the axis of said rolls, said blade being in contact with the surface of said rolls whereby material having a configuration passed between the blade and one roll is delivered from the blade and the other roll in a different configuration.
14. Apparatus according to claim 13 wherein said blade is in line contact with the surfaces of both of said rolls.
15. Apparatus according to claim 13 wherein said blade has a beveled edge in con-tact with the surface of one of said rolls.
16. Apparatus according to claim 13 including means for heating said blade.
17. Apparatus according to claim 16 including means for heating said rotatable rolls.
18. Apparatus according to claim 13 wherein one of said rolls is a metal roll having a slightly roughened surface and the other roll has a resilient surface.
19. Apparatus according to claim 13 wherein the clearance between the rolls is less than .003 inch.
20. Apparatus according to claim 13 wherein one roll is a metal roll having a slightly roughened surface and the other roll is a rubber roll, the minimum clearance between the rolls is less than .003 inch and the blade is in 'line contact with the surfaces of said rolls.
References Cited UNITED STATES PATENTS 2,115,313 4/1938 Matthew et a1 28--72(Ai) 3,028,653 4/1962 Evans 281 (K) 3,137,912 6/1964 Preston et a1. 281(.5) 3,412,443 11/1968 Backer 2872(.l3)
LOUIS K. RIMRODT, Primary Examiner U.S. Cl. X.R.