Patent Application
20070234861
The invention is related generally to the field of textile processing technology and more particularly to fray-free cutting of textiles or the like for various purposes.
Many textile materials of woven or non-woven nature tend to fray when cut into pieces or shapes and subsequently handled during various operations. It is highly desirable that the cutting of textiles be carried out in a manner preserving the cut edges from fraying or other similar degradation. Indeed, advantages of precision cutting tend to be lost due to fraying and other edge-related concerns.
The prior art includes a number of disclosures of applying liquid polymeric materials for purposes of avoiding textile fraying, or for piece-to-piece bonding purposes in which anti-fray capabilities of bonding agents are noted. Pertinent documents include U.S. Pat. Nos. 6,630,043 (Sloot), 5,601,132 (Goodman), 5,783,623 (Skoufis), 5,981,034 (Gray et al.), 5,718,966 (Gray et al.), 5,538,280 (Gray et al.), 5,085,917 (Hodnett) and 4,261,285 (Pearl), and U.S. Published Patent Applications 2005/0170151 (Dobson et al.) and 2002/0017362 (Covert et al.).
There remains a need for improved high-precision cutting apparatus and methods with textile-preserving anti-fray edge protection.
It is an object of the invention to provide fray-free cutting overcoming some of the problems and shortcomings of the prior art, including those referred to above.
Another object of the invention is to provide an anti-fray protection along and about the perimeter of a certain area to be cut out of a textile sheet.
Another object of the invention is to provide an anti-fray protection for the textile sheet by utilizing high-precision technology for anti-fray substance application.
Still another object of the invention is to provide anti-fray cutting apparatus and method which precisely places an anti-fray substance to achieve the desired protection.
How these and other objects are accomplished will become apparent from the following descriptions and the drawings.
The present invention provides an improved apparatus for fray-free cutting at the perimeter of an area of a textile sheet. The invention is also a method for fray-free cutting at the perimeter of an area of a textile sheet on a textile-receiving surface.
The apparatus includes a textile-receiving surface, a controller having programmed information regarding the perimeter of the area, a cutter movable with respect to the surface as directed by the controller to cut the sheet at the perimeter of the area, and an anti-fray substance applicator movable with respect to the surface as directed by the controller based on the programmed information to form an anti-fray path along the perimeter.
The textile-receiving surface is preferably substantially horizontal. The inventive apparatus may further include a vacuum structure adapted to retain the textile sheet in position on the textile-receiving surface. The inventive apparatus also preferably includes support structure secured with respect to the textile-receiving surface, with the anti-fray substance applicator being attached to the support structure for controlled movement along the textile-receiving surface.
In highly preferred embodiments the support structure includes a beam spanning the textile-receiving surface and reversibly movable therealong, and the applicator is reversibly movable along the beam. In some preferred embodiments the cutter is also attached to such beam and is reversibly movable therealong. The applicator and the cutter are preferably movable both with the beam (i.e., movement in the X-direction) and with respect to (along) the beam (i.e., movement in the Y-direction) in a manner providing independent concurrent movement thereof. In certain highly preferred embodiments of this type, for perimeter lines extending parallel to the direction of beam movement, the controller is further programmed for concurrent application by the applicator and cutting by the cutter with the applicator and the cutter in the same Y-position along the beam, thereby to increase productivity.
In a variant of embodiments involving concurrent application and cutting, the beam may include a main portion and an arm movably projecting from the main portion with the anti-fray substance applicator being disposed on the arm. In such variant the arm may have a telescopic configuration for moving the anti-fray substance applicator in a direction perpendicular to the beam.
In some embodiments involving a single beam, the applicator and the cutter may be interchangeably attached to the beam such that the applying and the cutting step require mounting of the appropriate device to the beam.
In some preferred embodiments a second beam spans the textile-receiving surface and is reversibly movable therealong independently of the other beam, the cutter being secured to and reversibly movable along the second beam, while the applicator is secured to and reversibly movable along the first beam. The anti-fray substance is preferably a liquid, with the applicator being a liquid-dispensing device. In certain embodiments the liquid-dispensing device is a liquid jet. In other embodiments the liquid-dispensing devices are airbrushes or rollers for contact with the textile sheet.
The anti-fray liquid it preferably applied prior to the cutting. However, in some situations applying and cutting can be carried out essentially at the same time, an example of which is mentioned below. In some situations the applying step can occur immediately after the cutting step, rather than before or at the same time. In certain embodiments in which the cutter is a rotary-blade, the applicator is positioned to apply a flow of anti-fray substance onto the rotary-blade such that the anti-fray substance is applied onto the sheet by the blade at the time of cutting.
The anti-fray substance preferably sets after penetration into the textile sheet. Most preferably, the liquid-dispensing device is adapted for dispensing the liquid to penetrate less than the full thickness of the textile sheet, whereby, after dispensing, the liquid does not reach the textile-receiving surface.
It is highly preferred that the liquid be a quick-setting liquid which, when set in the textile sheet, is also substantially transparent and non-glossy. The liquid is preferably a hotmelt composition selected to accommodate the nature of the textile material being cut and other specific requirements such as selected speeds, etc.
The liquid-dispensing device is preferably configured and arranged such that the path of applied liquid is no more than about 5 mm in width. In certain embodiments the position of the liquid-dispensing device is controlled such that the opposite edges of the path of applied liquid are preferably on opposite sides of the perimeter. The liquid-dispensing device position may be controlled such that the opposite edges of the path of applied substance are substantially parallel to and substantially equally spaced from the perimeter. In alternative embodiments the liquid-dispensing device position is controlled such that the path of applied liquid is inside the area and closely adjacent to the perimeter.
In certain embodiments of the invention the applicator is a preformed-strip dispenser, and the anti-fray substance is a preformed strip of textile-adherent material. The preformed-strip dispenser includes a carrier web from which the preformed strip is released when it adheres to the textile sheet.
One important aspect of this invention is that the programmed information includes information regarding specific graphic characteristics of the textile sheet and information regarding the perimeter of the area relative thereto. In such situations the apparatus further includes a sensor positioned to sense the specific (graphic or other) characteristics of the textile sheet, and the controller is configured to utilize sensed information and the programmed information to compensate for deviations of the sensed from the programmed information of the specific graphic characteristics. Most preferably, the specific graphic characteristics and the controller programming are such that the controller compensates for non-uniform distortions of the textile sheet.
In the present invention, the specific graphic characteristics may include registration marks at and/or around the perimeters of printed graphics on and to be cut from the textile material, the registration marks having been applied during the printing of graphics thereon. In some cases, however, the textiles will not include graphics or even registration marks thereon, and the information to be sensed may be sheet edges and/or other characteristics.
In certain alternative embodiments of this invention, an anti-fray instrument is utilized instead of the anti-fray substance applicator. Such anti-fray instrument may be a laser device configured and arranged to induce an anti-fray state in the textile by application of laser energy as directed by the controller based on the programmed information to form an anti-fray path along the perimeter of the area. Such laser device is preferably adapted for application of laser-energy having a focal point set to induce the anti-fray state of less than the full thickness of the textile sheet, whereby the anti-fray-induced portion of the textile does not touch the textile-receiving surface.
The laser device may be configured and arranged to apply laser energy onto the textile along the perimeter to thereafter be cut by a blade. In different embodiments the laser device is configured and arranged to apply laser energy onto a blade-cut edge immediately upon or after cutting. The laser device may be carried with the cutter.
The inventive method includes: applying an anti-fray substance onto the sheet along a path at the perimeter by an anti-fray substance applicator movable along the surface as directed by a controller based on programmed information regarding the perimeter; and cutting the sheet at the perimeter by a cutter movable along the surface as directed by the controller based on the programmed information.
In preferred embodiments of the method of this invention, the applying step is prior to the cutting step. In certain preferred examples of the method of this invention the cutting of the sheet commences while the applying step is still in progress on the sheet.
The preferred examples of the method include steps of automatically sensing the specific graphic characteristics, and utilization by the controller of sensed information and the programmed information to compensate for deviations of the sensed from the programmed information of the specific graphic characteristics. In some of such examples the specific graphic characteristics and the controller programming are such that the controller compensates for non-uniform distortions of the textile sheet.
The term “textile” as used herein means any kind of woven and non-woven cloth-like material, i.e., materials made by weaving, knitting or felting, etc. Such materials may be of natural, synthetic fibers or combination of both. This includes woven KEVLAR® fibers, fiberglass and variety of other materials.
The term “sheet” as used herein refers to materials that are in a roll, folded or in another form used for storage or transportation.
The phrase “penetrate less than the full thickness of the textile sheet” as used herein means that the anti-fray liquid composition enters the textile sheet to a depth of less than about 90% of the textile thickness. The controller may be programmed to regulate the amount of the dispensed liquid based on the textile surface characteristics, and the viscosity and setting time of the liquid. The liquid is preferably dispensed through a flow-rate-controlling mechanism chosen according to the characteristics of the textile and the liquid. The liquid is dispensed in an amount sufficient to form the anti-fray protection of the textile while avoiding adherence of the textile to the textile-receiving surface.
The term “closely adjacent” as used herein with reference to the path of applied anti-fray substance means very close to but not abutting the perimeter of the area; e.g., there may be about 1-3 mm between the path of applied liquid and the perimeter of the area.
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In certain highly preferred embodiments, the anti-fray substance is a liquid.
Precision cutting technology as set forth in various United States and other patents of Mikkelsen Graphic Engineering (MGE) of Lake Geneva, Wis. is applicable to the apparatus and method of this invention. The disclosures of MGE's U.S. Pat. Nos. 6,772,661 (Mikkelsen et al.), 6,619,167 (Mikkelsen et al.), 6,619,168 (Alsten et al.) and 6,672,187 (Alsten et al.), and U.S. Published Patent Application No. 2004/0083862 (Mikkelsen et al.) are incorporated herein by reference.
In preferred embodiments, the liquid anti-fray composition is a hotmelt composition selected to accommodate the nature of the textile material being cut. A wide variety of hotmelt compositions are available having different physical characteristics and qualities. Suitable hotmelts preferably are applied at a temperature of 150-200° C., have a softening point (Mettler) of 70-130° C. and a medium-fast set rate. They are preferably water-resistant, flexible when set, and stable under variable climate conditions. Preferably, the composition chosen will remain effective even after machine washing of the textiles. Suitable hotmelt materials would be apparent to those skilled in the art who are made familiar with this invention;
Hotmelt compositions typically include a base polymer and a polyolefin. Base polymers may be ethylene vinyl acetate copolymers, polyamides, polyesters, polyurethanes, etc. One highly preferred hotmelt for use in this invention is hotmelt 85000 available from Forbo Adhesives. Such material includes an ethylene vinyl acetate monomer, tackifying resin and paraffin wax. Suitable alternatives for use in various situations would be apparent to those skilled in the art.
While the cutter shown in the drawings is of the rotary-blade type, other types of cutters are also usable, such as regular tangential drag-blade cutters and oscillating tangential cutters. The preferred rotary-blade cutter is a motor-driven device with a spinning multi-edged round blade. The nature of the cutter is not an essential element of the invention.
While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.
