Patent Application
20080092979
The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
It is understood that the first fabric side portion 14 and the second fabric side portion 16 are interchangeable, and reference to one may be interchanged with the other. Additionally, the plan view of
The central portion 12 can be any woven fabric known in the art. The material used for the central portion 12 is preferably fabricated using polyester monofilament of one layer or more than one layer, preferably 1-10 layers, and more preferably 1-3 layers.
The first fabric side portion 14 is a reinforced edge of the fabric 10. That is, the central fabric portion of the fabric running in the machine direction has side panels 14, 16. Side panels 14, 16 are reinforced with PPS or PEEK. The box board 18 generally covers the central fabric portion 12, and overlays, or extends to cover a portion of the side portions 14, 16 at first and second paper web overlays 20, 22.
In the fabric 10, the first side portion 14 is part of the central fabric portion 12 along a first demarcation line 24. The second fabric side portion 16 is part of the central fabric portion 12 along a second demarcation line 26. The second demarcation line 26 is opposite the first demarcation line 24. The first and second fabric side portions 14, 16 can be part of the central fabric portion 12, or woven to the central fabric portion 12. Weaving of the first and second fabric side portions 14, 16 to the central fabric body 12 is preferably performed on the same loom on which the central fabric body was woven.
There is no requirement that the first fabric side portion 14 have the same weave pattern as the central fabric portion 12 or the second fabric side portion 16. In the preferred embodiment, the first and second fabric portions 14, 16 have the same weave pattern, and at least one of the materials making up the central fabric portion 12 is part of the weave of the first and second fabric side portions 14, 16. Additionally, it is preferable that the first and second fabric portions 14, 16 have the same weave pattern as the central fabric portion 12.
Still further, the first and second fabric side portions 14, 16 can be subjected to the same processing as the central fabric portion 12. For example, heat setting, stretching, coating, and the like.
The material used for the central fabric portion 12 of the composite fabric 10 is preferably polyester, but may be PPS or PEEK.
The material used for the first fabric side portion 14 and/or the second fabric side portion 16 is preferably at least one of polyphenylenesulfide (PPS) and polyetheretherketone (PEEK), high temperature and hydrolysis resistant polymers, blends using PPS, blends using PEEK, alloys of PPS, alloys of PEEK, nylon, carbon impregnated nylon, or other conductive materials.
In the preferred embodiment, the side edges 14, 16 of the belt are woven with the same yarns as the base fabric of the central fabric portion 12, and the side edges are reinforced with polyphenylenesulfide (PPS) or polyetheretherketone (PEEK) to give added strength and excellent heat and hydrolysis resistance. PPS offers the broadest resistance to chemicals of any advanced engineering plastic. PPS has no known solvents below 392° F. (200° C.) and is inert to steam, strong bases, fuels and acids. Minimal moisture absorption and a very low coefficient of linear thermal expansion, combined with stress-relieving manufacturing, make PPS ideally suited for corrugator belt applications. In the preferred embodiment, substantially pure PPS or PPS with additional alloys, such as nylon, is used.
Additionally, the diameter of first fabric side portion fibers 28 used for the first fabric side portion 14, and the diameter of second fabric side portion fibers 30 used for the second fabric side portion 16 can be substantially the same as the diameter of the central fabric portion fibers 32 used for the central fabric portion 12.
When the first side portion is woven to the fabric body, it is preferably woven in the same plane.
The PPS or PEEK can be woven into the side edges 14, 16 so it lies preferably below the surface of the polyester. The surface of the polyester in the preferred embodiment is typically approximately 0.2 mm diameter to approximately 2.0 mm diameter, more preferably approximately 0.60 mm diameter and the PPS or PEEK is approximately 0.6-0.7 mm, preferably approximately 0.67 mm wide by approximately 0.2-0.5 mm, preferably approximately 0.36 mm high rectangular shaped so it is protected from wear. The PPS or PEEK can also be woven on the surface of the polyester fabric to form a knuckle nest to a polyester knuckle. Alternatively, the PPS or the PEEK is approximately the same diameter as the polyester and lies in the same plane.
When a spiral-pin seam 34 shown in
Both the spiral seam 34 and the loop seam 36 are preferably in-line with the plane of the fabric 10.
Permeability of the belt 10 is preferably in the range of approximately 50-2,000 cfm, more preferably in the range of 100-1500 cfm. The belt is therefore stable, yet flexible. It has a knuckled, woven surface for the necessary coefficient of friction to drive the board through the machine. The belt is also sufficiently permeable to allow the vapor to pass through the fabric to allow faster machine speeds and improved drying rates.
The edge portions of the fabric, when not in contact or otherwise covered by the web, is exposed to the harsher environment of the paper machine running conditions. Along with the seam, these are the weakest portions of the fabric. It is preferable that additional edge material is added to the main portion of the fabric. That is, a main central portion of the fabric running in the machine direction has additional or different materials added to the side panel area. The box board generally covers the main middle portion, and overlays, or extends to cover a portion of the side portions.
The fabric 10 as constructed is stable yet flexible, and has a knuckled or floated, woven surface for the necessary coefficient of friction to drive the board through the machine. The fabric is sufficiently permeable to allow the vapor to pass through the fabric to allow faster machine speeds and improved drying rates.
Alternatively, the fabric 10 can be manufactured without PPS or PEEK. In the present invention, a different edge material is added to the main portion of the fabric. That is, a main central portion of the fabric running in the machine direction has additional or replacement yarns in the side panel area. The box board generally covers the main middle portion, and overlays, or extends to cover a portion of the side portions.
Additionally, it is preferred that there is a smooth transition between the main portion of the fabric and the side portions.
The size of the first and second side portions is dependent upon the swidth of the box board. The width of the side portions may be 1 inch to all the way across the fabric or belt when measured in the weft direction. Preferably the width of the side portions is approximately 10 inches to approximately 30 inches, and more preferably approximately 24 inches when measured in the weft direction.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
