EP0478171A2 - Impact resistant impression fabric - Google Patents

Abstract

An impression printing tape of woven fabric having 70 denier nylon 6,6 warp (12) and fill (14) yarns which is inked and cut after being woven and finished to form a tape.

Description

• This invention relates to a woven fabric, referred to as an impression fabric, which is used as a printing ribbon and has good print quality, long print life and resistance to damage from printing.
• Traditionally, an impression printing ribbon has been a one by one plain weave of dense construction. Almost all impression fabric is made from nylon 6,6 yarns with a small amount made from nylon 6, cotton or silk. The standard impression fabric construction for spools and cartridges has been a 4 mil thickness fabric made from 40 denier yarns in the warp and filling with about 170 warp yarns per inch and 115 fill yarns per inch.
• There has been interest in developing a more durable impression fabric because of ribbon failure. Some new printers have high impact energies which cause significant ribbon damage and ribbon induced cartridge failure. Many new ribbon products, both spools and cartridges, reink the ribbon to extend the useful print life. The additional printing on the ribbon causes significant ribbon damage. Frequently, the ribbon and consequently, the cartridge will fail before all the available ink has been depleted.
• Ribbon durability has been addressed in the market in a number of ways. The number of warp yarns was increased from 170 to 212 ends/inch and the number of fill yarns was increased from 115 to 120 picks/inch. This construction improves impact resistance but not to the degree that the market requires. The additional yarns make this construction more expensive to produce.
• A 5 mil thickness fabric with a 40 denier warp and 70 denier fill has been used for improved durability. This construction is well known for use on wide ribbon printers and improves impact resistance but not to the degree that the market requires. Significant filament damage occurs even to the larger 70 denier fill yarns.
• U.S. patent 4,874,263 addresses the problem by construction of a twill weave. At low constructions (170 warp yarns and 115 fill yarns per inch), the weave is unsuitable for an impression fabric because the warp yarns are snagged by matrix print wires. At higher constructions (thread count about 400 yarns per square inch), ribbon durability is improved at significantly increased cost.
• Therefore, it is an object of the invention to provide a woven impression fabric with increased impact resistance which has print life and quality at least as good as current commercial products.
• Other objects and advantages of the invention will become readily apparent as the specification proceeds to describe the invention with reference to the accompanying drawings in which:
• Figure 1 shows the typical woven fabric used to form the impression ribbon of the invention, and
• Figure 2 shows a printer cartridge having a ribbon made of the fabric of the invention.
• Looking now to Figure 1 a typical plain weave fabric 10 for use as a typewriter, printer, etc. ribbon is represented. Fabric 10, as is well known in the trade, consists of warp yarns 12 and weft or fill yarns 14 and is preferably woven on an air jet loom having a reed spread of 67.26 inches.
• The warp and fill yarns are 70 denier, 34 filament nylon 6,6 with the fabric being woven with 106 warp yarns per inch and 106 fill yarns per inch. It is within the scope of the invention to vary the number of warp and/or fill yarns per inch ±20. In the preferred form of the invention the warp yarn is twisted and the fill yarn is textured.
• After the above preferred fabric is woven, it is scoured at pH 9.0 and at a temperature of 180°F with sodium carbonate and nonionic detergent and left mildly acidic by running it through a bath of dilute citric acid. The fabric 10 is then dried on a tenter frame. The resultant fabric had a weight of 2.2 ounces per square yard and a thickness of 5.0 mils. The finished fabric had 120 ends/inch, 108 picks/inch and an ink capacity of 13.6 grams per square yard. The fabric 10 is cut into ribbons of required size by a hot knife or other desired slitter.
• Alternately, the finished fabric may be slit to an appropriate width, inked, then cut to length and incorporated into printer ribbon cartridges, or typewriter ribbon spools or the like, such as the cartridge 16 shown in Fig. 2. In forming printer cartridges, the ribbon is joined to itself in an endless loop by an ultrasonic weld. Fig 2 illustrates the ribbon 18 which is formed in an endless loop and packed into the cartridge 16 in conventional fashion. An ultrasonic weld is shown in exaggerated form at 20 and is also conventional.
• The herein disclosed impression fabric has increased wear characteristics and reduced physical damage during printing compared to commercially available inked impression fabrics. At the same time the new fabric has maintained the print life and quality generally found in commercial products.
• Although the preferred embodiment of the invention has been described, it is contemplated that changes may be made without departing from the scope or spirit of the invention and it is desired that the invention be limited only by the scope of the claims.

Claims (6)

1. An impression printing ribbon of woven fabric comprising a plurality of interlaced yarns of nylon 6,6 70 denier yarn, and being inked and cut to appropriate width.
2. The ribbon of Claim 1 wherein the number of warp yarns and fill yarns per inch is substantially the same.
3. The ribbon of Claim 2 wherein the number of yarns is 106 ±20.
4. The ribbon of Claim 1 wherein the warp yarns are twisted.
5. The ribbon of Claim 1 wherein the fill yarns are textured.
6. The ribbon of Claim 1 wherein the warp yarn are twisted and the fill yarns are textured.

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