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
  • D06C7/00—Heating or cooling textile fabrics
  • D06C7/02—Setting
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/70—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment combined with mechanical treatment
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/0027—Screen-cloths

Definitions

• a fabric having an initial width of, say, 114 inches should not be subjected to a machine direction tension above 350 pounds, unless the yarns and the weave employed permit a somewhat higher tension without preventing a substantial reduction in the residual shrinkage of the fabric.
• Another way of expressing the amount of tension is that it should not exceed about 0.04 gram per denier for the yarns used in weaving the fabric. This applies to both the warp direction and the filling or weft direction. If the tension tends to increase above the preselected value, as shown by a dynamometer, the attendant in charge of the treating procedure should immediately take steps to reduce the tension to the desired point. This, it will be appreciated, can readily be done by pressing a button on 3,192,599 Patented July 6, 1965 the machine which will cause the tension roll to move inwardly to the required extent.
• a more general way of expressing the amount of tension preferably imparted to the fabric in both the machine direction and the cross machine direction in the course of the finishing treatment, is that it should be kept below 0.04 gram per denier. This has been definitely established in relation to fabrics formed of conventional nylon, and no substantial departure from the indicated value is expected for other fabrics, regardless of their construction and the materials of which they are formed. In all cases the tension on the fabric, in both directions, should be such that the fabric being treated is permitted to shrink in both the Warp and filling directions from the dimensions of the original fabric as woven on the loom.
• HT-l nylon A special nylon sold under the designation HT-l nylon has no tendency to melt upon heating but chars when heated to too high a temperature. It is capable of withstanding temperatures for short periods of time up to 600 F.
• ordinary nylon of the Type 6 variety has a melting point around 425 F., while another nylon designated Type 66 melts at about 482 F.
• These ordinary nylons have been found to shrink to the extent of 7 percent to 11 percent when subjected to the heat encountered in the drying stage of a paper-making machine.
• HT-l nylon which may be characterized as high temperature nylon sold by E. I. du Pont de Nemours and Company under that designation, shrinks only about 1 percent. Such nylon maybe used advantageously in accordance with the present invention.
• the loop or section of fabric employed to form the dryer belt may be subjected to transverse or cross machine direction tension normally applied in the production of such belts, but here again it has been found desirable to reduce this tension to a substantial extent, or to eliminate it altogether.
• the residual shrinkage in the cross machine direction may thus be reduced to a desirable minimum or eliminated .altogther.
• 'Finishing fabric at the tensions described has a is been found to result in some bagginessin the edge portions of the belt that is objectionable, but this can be rectified by trimming off the edge portions of'the fabric. In general it has been found that this bagginess has a tendency to extend inwardly from the free edges of the belt only to the extent of 2 to 18 inches.
• the original woven fabric to be treated in accordance with the present invention should be formed of such length and width that it will have the desired dimensions after its lengthwise and transverse shrinkage and after the proper trimming of the edge portions.
• apparatus of the type disclosed in the pending US. application of Christie et al., erial No. 22,973, filed April 18, 1960, may be used, if the fabric is finished in endless belt form.
• somewhat different apparatus is required if the fabric is treated while in fiat, continuous form. Provision must then be made for passing fiat fabric from a supply roll through the various treating zones and then winding it up in finished form on a storage roll. Sufiicient lengths of the finished fabric may then be taken from the storage roll to form the desired dryer fabric belt.
• the apparatus disclosed in the Christie et al. application is directed primarily to the treatment of Fourdrinier fabrics, it may also be used for the treatment of other fabrics such as the dryer fabric with which the present invention is concerned. It will be understood that in that form of the invention which involves the application of no tension to the fabric in the cross machine direction, the tenter frame structures disclosed in the Christie et al. applications may be omitted.
• the treatment described in the Christie et al. application involves the passage of an cndles fabric, in belt form, for a number of cycles through the treating zone of the apparatus. The application of a desired tension to the fabric in the machine direction, as it is continuously advanced through its various cycles, is accomplished by the movement of one of the end rolls about which the belt is passed.
• the warps will extend crosswise of the belt and the wefts length- 5 wise. If the fabric is woven flat, in continuous form, the warps will extend lengthwise and the wefts or filling yarns crosswise of the belt, and the desired length then will be formed into a belt by fastening the free ends together by suitable clips, or the like.
• the dryer fabrics of the present invention will be subjected to treatments with one or more resinous materials as successive portions of the belt pass through a particular region, and the fabric will also be subjected to different temperature conditions.
• the resinous materials which may be applied to the dryer fabrics in accordance with the present invention, may be of the same general character as those disclosed in the Beaumont et al. Patent No. 3,032,441, granted May 1, 1962, or they may be of any of a variety of other types adapted to adhere to the warp and weft yarns and to bond these together at their crossing points.
• Typical of such other resinous materials are Rhoplex having 50 percent solids and having one part of this material diluted with one part of water.
• the curing of this resin is preferably carried out at 400 F.
• Another suitable treating liquid is a 30 percent solution of Bendix phenolic resin V-108. This, after being dried, may also be cured at 400 F.
• Another suitable treating solution is a 30 percent solution of Hycar 2600 X 91.
• the treating solution is formed by adding 60 parts of Hycar to 40 parts Water. After such solution is applied to the fabric and dried, it is cured at 3 00 F.
• Yet another suitable treating solution is Bendix C900 resin emulsion. This should be diluted to 25% solids and there should be added hexamethylenetetramine, based on the resin solids, as a curing agent, or of the V-108 resin may be used for this purpose.
• the curing temperature for the C-900 resin is 400 F. In general it may be said that resins of the expoxy family and polyurethanes may be used. In the foregoing treatment of the fabric, temperatures ranging from 190 F. to 480 F.
• the lower temperatures are used in the earlier stages, while the fabric is wet. During the total treatment the temperature is increased to at least 400 F.
• the maximum temperature should, of course, be below the melting point of the fibers used in the fabric and should not be so high as to bring about'excessive degradation of the fibers.
• the yarns used in the weaving of the dryer fabrics of the present invention may be any of those suggested for use in the production of Fourdrinier cloth in the patent to Holden et al. No. 2,903,021, granted September 8, 1959.
• the warps and wefts may be of the same construction or of different construction, and they may be in the form of multifilament yarns or monofilament yarns.
• CD (CD) (MD) 2131 14010300/3-ply,25Zx 50 440400 1 3- l 5 12%8 nylon.
• the first portion of the combined number such as 140 in the number 140-10300, means that the single raw yarns used have a denier size or weight of 140, expressed in grams per 9,000 meters of the yarn.
• the second portion such as in the number mentioned, means that there are 10 filaments in each raw yarn bundle.
• the third portion of the combined number, such as 300 in the number specified above refers simply to a bright, high tenacity yarn to which that number is applied by its producer.
• 25Z x 12 /28 identified with piece No. 2131
• the numbers 51 and 52 identify types of Dacron. Type 52 is a bright, high tenacity yarn whereas 51 is another well-known type of Dacron yarn.
• Fabric No. 2221 was woven 1%. feet longer than usual, to allow for lengthwise shrinkage during finishing, this fabric was subjected to lengthwise tension below 350 pounds at all times, over the 114 inch width, i.e., warp direction, of the fabric. Thus not more than 3 pounds per inch tension was applied to the fabric in the machine direction throughout the finishing operation. This contrasts sharply with the conventional treating method, in which a minimum tension of 5 pounds per inch is applied in the lengthwise or machine direction of the fabric. In the treatment of piece No. 2221 it was applied to the tenter pins of the finishing machine during treatment with the two solutions, thus maintaining it at a 114 Width during such treatments. The length and width of the fabric was recorded during all of the cycles involved in the finishing treatment, with the following results being noted:
• the dryer can temperature usually does not exceed 325 F. Therefore the invention is concerned primarily with difficulties arising from changes in temperature of the dryer fabric up to that limit and from alternate changes in condition of the fabric from Wet to dry and dry to wet.
• the temperature of the fabric will be raised from room temperature to a relatively high temperature determined by that of the dryer cans. So also when the paper web tears or breaks, and especially if the machine must be temporarily shut down to correct the difficulty, a quite high temperature difference occurs.
• the temperature of the dryer fabric does not vary over as wide a range. However it must be recognized that the temperature does vary to the extent of between 70 and 325 F. at rather frequent intervals.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Woven Fabrics (AREA)
• Paper (AREA)
• Treatment Of Fiber Materials (AREA)

Priority Applications (7)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22906507

Family Applications (1)

Country Status (4)

Cited By (1)

Citations (15)

• 1962
  • 1962-11-27 US US240435A patent/US3192599A/en not_active Expired - Lifetime
• 1963
  • 1963-11-05 GB GB43614/63A patent/GB1044587A/en not_active Expired
  • 1963-11-20 BE BE640184A patent/BE640184A/xx unknown
  • 1963-11-20 SE SE12818/63A patent/SE318474B/xx unknown

Patent Citations (15)

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