Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06C—FINISHING, DRESSING, TENTERING OR STRETCHING TEXTILE FABRICS
  • D06C21/00—Shrinking by compressing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F—MECHANICAL WORKING OR DEFORMATION OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F1/00—Mechanical deformation without removing material, e.g. in combination with laminating
  • B31F1/12—Crêping

Definitions

• This invention relates to the longitudinal compressional treatment of flexible web materials such as knitted and woven textile fabrics, papers, plastic films, and so-called "non-wovens M , the latter being of natural or synthetic substance formed into webs, e.g., as by air laying or wet laying of fibers.
• the untreated web is driven longitudinally by using a low friction surface to press the web against a rotating drive roll and then, within a short distance of the i drive point, retarding forces are applied to the traveling web.
• the opposition between the driving and retarding forces, while the material remains confined face-wise, produces desirable physical change in the web material, for instance, increase in its bulk, thickness and elasticity.
• the web can be compacted longitudinally within its own plane, without folding of -the web upon itself or formation of crepe, but with crimping in. situ of the tiny individual fibers ("microcreping" of the fibers) that make up the threads or yarns of the fabric.
• the longitudinal compressive treatment can form barely perceptible undulations or crepes in the web as a whole Cmicrocreping" of the web), in which the overall appearance of the faces of the web is still one of smoothness, without superficial coarse crepe or folds being present. If, however, coarse crepe is desired, this can be achieved by suitable enlargement of the treatment * cavity.
• the treatment can increase the softness or drapability of a web, increase its covering effect and opacity, make the surface texture of the web more appealing, render the web shrinkproof, apply decorative effects to the web, or cause components of the web to be more intimately interengaged in a way that is useful.
• Paper webs can be made stretchy and have their burst resistance improved.
• This angled retarder/flexible retarder arrangement seeks to achieve a balance between conflicting requirements.
• the substantial angle of the angled retarder enables an effective longitudinal compressive force to be applied to the web.
• the flexible retarder as it maintains the . needed face-wise containment of the web while the web changes its angle of travel, also flexes to prevent choking of the travel of the treated web and to relieve excess pressure to prevent the web from snagging under the leading tip of the angled retarder blade.
• change in the web-gripping character of the drive roll for instance due to wear of the drive roll surface or presence of foreign substances
• variations in pressure of the web against the drive roll due to change in the untreated web thickness or in the forces that press the confining surface and web against the drive roll or due to wear or change in the geometry of the confining surfaces
• variation in the supply tension applied to the untreated web as it enters the treatment change in the stiffness or softness of the untreated web as may occur due to change in moisture content or temperature of the original untreated web
• change in the depth of the retarding passage through which the web passes change in other retarder qualities due, e.g., to dimensional or speed change
• change in susceptibility of the web to its being retarded e.g., due to change in the frictional qualities of the web to be treated
• the point of treatment of the material under the low friction primary surface tends to shift forward or backward, and to affect the quality of the treatment. This requires backward or forward adjustment of the primary surface.
• the softening of wadding of original thickness of the order of 0.001 inch (0.025mm) requires extremely high speeds of treatment to be practical, which may generate excessive heat that cannot be tolerated by the angled retarder/flexible retarder arrangement or the web being treated.
• One important object of the present invention is to provide new techniques for longitudinal compressional treatment of webs which have the advantages of a single roll, bladed configuration but which reduce or eliminate the various critical features of the treatment. Another object is to enable uniform, high quality treated web products to be obtained with a wide range of materials and thicknesses, and especially with very thin webs. Another object is to provide a technique that enables use of relatively heavy, long-wearing elements capable of extended operation even at high speed. Another object is to provide a machine of • improved simplicity of construction. Other objects of the invention are to achieve increase in production and energy e ficiencies, and novel specific treatments for web materials.
• One specific object of the invention is to provide an improved method of shrinkproofing webs, for instance heavy diagonal weave fabrics such as cotton denims.
• the invention features a bladed single roll machine (and methods using the machine) for' microcreping a running length of web by applying extrusion retarding forces in which (a) the machine is adapted to treat the web in response to retarding forces produced by tangential extrusion and (b) resilient self-adjustment of the extrusion orifice is achieved by employing, to define one of the web-contacting surfaces that forms the extrusion orifice, a plate-form blade member parallel to the roll which is resiliently urged toward the drive nip in the direction of extent of the plate member.
• the web-contacting surface defining the other side of the extrusion orifice is a cantilevered integral continuation of the primary pressing surface; this second web-contacting surface is preferably capable of restricted flexing under treatment conditions, to a curved shape in the direction opposite to that of the roll surface, to a curvature having a radius of the order of magnitude of the radius of the roll; the first web-contacting surface is movable while remaining parallel to its original plane to gradually vary the geometry of the treatment cavity, i.e.
• tangential extrusion as described below imparts a squeezing force to the web in a manner that avoids problems inherent in the geometry of the diversionary treatment processes.
• the geometry and forces of the tangential extrusion allow variation in position in its plane of the lower web-contacting member which, in effect, permits automatic adjustment of the treatment cavity geometry to reduce the risk of snagging or improper treatment forces or takes away from the criticality of the adjustment of this member.
• the exact limit in the variation of the extrusion passage from true tangency depends upon the entire set of variables that apply and the result desired.
• An angle of 20 may be permitted in certain instances while still obtaining desirable results of the invention. In the case of using a 0.010 inch (0.25mm) blue steel primary or stiffer member, it is generally desired that the angle not exceed 20 .
• Fig. 1 is a diagrammatic, highly magnified side sectional view of the treatment cavity of a machine constructed according to the invention.
• Figs, la and lb are views similar to Fig. 1 of other embodiments of the treatment cavity according to the invention.
• - 10 - Fig. 2 is a side view of the machine of Fig. 1 partially in section.
• Fig. 2a is a sectional view taken along 2a-2a of Fig. 3.
• Fig. 3 is a top plan view of the machine of Fig. 1 along 3-3 of Fig. 2.
• Fig. 4 is a top plan view of a second embodiment of the invention.
• Fig. 5 is a view similar to Fig. 4, at a 0 reduced scale. Structure
• roll 10 is rotatab.ly mounted and is driven in the direction of arrow A by a standard drive mechanism such as a chain or belt 5 drive from a motor.
• a pressing member 20 mounted by a vertically moveable shoe 16 to cantilever outwardly from the shoe.
• Vertical movement of the presser mounting assembly is controlled by a pressure cylinder (not shown).
• Pressing member 20 is oriented in shoe 16 at an angle with respect to the horizontal, so that edge 18 of the cantilevered portion of member 20 is pressed toward the surface of roll 10.
• Primary member 14 comprises a sheet of 25 spring steel which is cantilevered forward from its attachment bracket 22. Primary member 14 extends over roll 10, and is urged toward the roll by edge 18 of pressing member 20, to form a nip region (the narrowest region between primary member 14 and roll 30 10). Primary member 14 extends downstream from the nip region to slightly overlie the upstream edge of blade 24 (which is resiliently urged in its plane toward the nip by air cylinders as described below). Primary member 14 has only limited capability of 35 bending, it being thicker and relatively stiff in comparison to flexible retarders used in angled retarder machines such as those described in the Background above. Preferably, the primary member is of at least 0.010 inch (0.25 mm) thickness blue steel 5 and has a smooth surface in the nip region. In the embodiment shown, roll 10 has a diameter of 12 inches (30.5 cm).
• An extrusion orifice lying downstream from the nip region, is defined on the upper surface of 10 the web by an extension of lower surface 28 of primary member 14 and on the lower surface of the web 12 by surface 16 of web-contacting blade member 24.
• the pressure of presser 20 on primary member 14 and the 15 reaction of the downstream portion of the primary member to the compacted web which fills the cavity therebeneath and exerts upward pressure can cause the downstream portion of primary member 14 to curve slightly, and thus to diverge from the surface of 20 roll 10.
• this portion of primary member 14 may take a curve in the region immediately downstream of the nip having a radius of the order of magnitude of the radius of roll 10.
• member 24 is 25 a planar blade-like member supported at either side respectively by vertical plates 34 which include a front adjustment slot 36 and a rear adjustment slot 38 to receive lock bolts 41 therethrough.
• a bracket 32 which is connected to the piston 42 of an air cylinder 30.
• blade 24 in its holder is resiliently urged to the left in Fig. 2, relative to its support 34.
• This application of 35. resilient pressure in the direction of the plane of the blade is diagrammatically represented in Fig. 1 by the arrow and spring S.
• the orientation of the extrusion orifice is affected by the angle of the leading portion of the upper surface 26 of blade ' member 24 (measured relative to a tangent to the roll at point P, the point of final positive drive by the nip between roll 10 and primary member 14).
• restricted angle b is generally between 0 and about 15°, 20° being the upper limit that can be employed for best results in a wide variety of instances.
• the configuration of the treatment cavity which lies between the nip and the extrusion orifice can be further controlled by air cylinders 30 which urge the blade resiliently toward the nip region.
• a configuration is shown which enables extremely effective shrinking of cotton denim cloth in the dry state at temperatures in. the range of 300 to 350°F (150 to 175 ⁇ C).
• member 50 of spring steel, is supported between the primary member and an above-lying member 15. It has an extended portion 50 which overlies the emerging fabric and presents a plasma coated abrasive surface of tungsten carbide of roughness in the range of 300 to 350 rms. This member has a desirable effect on the surface of the fabric to provide a soft, "buttery" feel, and, as well, aids in ensuring smooth movement of the fabric through the machine despite the high level of compressive forces being applied. Referring to Fig.
• the presser member 14 extends a distance L of 0.2 inch (5.1 mm) from the line of pressure of the presser corner 18, the angle b of surface 26 of blade 24 is set between about 12° and 15°, and the distance of penetration U of the tip of the blade under the primary member during running conditions is of the order of 0.05 inch (1.27 mm).
• the axis X of the tangential extrusion orifice TEO remains substantially parallel to the tangent to the drive roll.
• Fig. 1 is highly magnified so that the segment of primary member 14 shown in Fig. 1 is very short and the force of presser 20 is effective to press the cantilevered portion of member 14 downward toward the leading portion of blade 24. Since blade 24 is rigid in the direction perpendicular to its plane, it is possible to achieve the desired magnitude of force R (as regulated by the level of air pressure applied to air cylinders 30). Because of the resistance thus encountered by the web, the web extrudes at a rate considerably lower than its rate of travel at the nip region.
• a column of retarded material thus fills the extrusion passage and resists forward movement of material being driven forward by the roll nip. Because the web in this region is confined at its faces (by roll 10 and primary member 14) it undergoes longitudinal compressive treatment immediately following point P while the "in-line" resilience of the blade member ensures uniformity of the treatment.
• the plane of blade 24 lies substantially parallel to the drive direction, there are numerous advantages as to simplicity of construction and adjustment. Because there is a very small component of force on blade 24 in the direction perpendicular to the plane of the blade, the blade is relatively free to move in its plane in two types of movement. I-n one type of movement, the transverse leading edge of surface 26 of blade 24 can remain generally perpendicular to the direction of web travel as the blade moves closer or farther from the nip region, substantially in its own plane. Movement closer shortens the length of the treatment cavity, while narrowing the extrusion passage at a gradual and controllable rate. The thinner the web and the finer the crepe desired, the shorter the treatment cavity should be, and usually the higher the resilient pressure to be applied.
• the air pressure in both cylinders 30 is adjusted.
• a small amount of movement of this type can occur automatically during operation, by virtue of the resilience of the mounting of the blade member, in response to variations in the character of the fresh web or in response to change in speed of the drive roll.
• a second type of movement by blade 24, again in the plane of the blade, involves slight pivoting or self-aligning of the leading edge transverse to the direction of web travel. Such movement avoids the need for critical adjustments and also may be desired to account for variations in web thickness across the width of the web.
• Figs. 4-5 illustrate a second embodiment of the invention in which the bottom of the extrusion passage is defined by member 124 which has an upstream edge formed by fingers 98 (only 3 shown).
• the fingers are sized to fit within grooves 99 on roll 10* to create a smooth transition from the surface of the roll to the lower extrusion orifice-defining surface 126.
• Fingers 98 are narrower than grooves 99 to allow pivoting of member 124 as described above and to avoid contact between the sides of the grooves and fingers 98.
• Grooves 99 are " deep enough to provide clearance between the lands 97 of the grooves and fingers 98.
• the fingers have no wearing engagement with the drive roll, and the smooth sides of the fingers will remain smooth, thus avoiding snagging of the web.
• the operation and structure of the machine " of Figs. 4-5 is the same as that of Figs. 1-3, and corresponding reference numerals are used in both sets of figures.
• the surfaces defining the extrusion orifice are polished, useful, e.g., where speeds of operation are high or where the level of retarding forces required are low.
• one or both of the surfaces may be specially treated to provide desired effects.
• the metal surface may be plasma coated with tiny particles of tungsten carbide to provide relative high friction, long wear surfaces.
• special shaping of the trailing edges or the surface of the machine elements including provision of slots, pinked edges and the like, can be employed to produce plisse stripes and- other desired aesthetic and functional effects.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Treatment Of Fiber Materials (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)

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• 1985
  • 1985-03-29 JP JP60501642A patent/JPS61501764A/ja active Pending
  • 1985-03-29 WO PCT/US1985/000541 patent/WO1985004369A1/en not_active Application Discontinuation
  • 1985-03-29 EP EP19850901856 patent/EP0176566A4/de not_active Withdrawn
  • 1985-11-21 FI FI854598A patent/FI73625C/fi not_active IP Right Cessation
  • 1985-11-28 NO NO854771A patent/NO854771L/no unknown

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