Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02J—FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS, ROPES OR THE LIKE
  • D02J1/00—Modifying the structure or properties resulting from a particular structure; Modifying, retaining, or restoring the physical form or cross-sectional shape, e.g. by use of dies or squeeze rollers
  • D02J1/22—Stretching or tensioning, shrinking or relaxing, e.g. by use of overfeed and underfeed apparatus, or preventing stretch

Definitions

• the present invention relates to sailcloth and in particular to an improved woven sailcloth having the strength and stretch properties of a laminated cloth, which is suitable for use on large classically designed boats.
• Laminated cloths consist of at least two components, but generally are made of three components.
• each of a loose woven polyester backing cloth and a tightly woven polyester front cloth are pre-coated with alternate parts of a two part adhesive.
• High tenacity warp yarns are placed between the two cloths at regular intervals and the sandwich so produced is passed through a rotary press to activate the adhesive.
• a sheet of plastic film is placed between two high tenacity woven fabric cloths which have been pre-coated with alternate parts of a two part adhesive. Again the sandwich is passed through a rotary press to activate the adhesive.
• the method of producing laminates makes the product more suitable for the manufacture of one particular sail design type and this is not always acceptable to the end user.
• the high modulus fibres of the ara id, polyethylene and polyester-polyarylate types have a different rate of shrink under heat than normal tenacity yarns such as polyester, nylon or polypropylene.
• These high modulus yarns are sold under trade names such as KEVLAR, TWARON, TECHNORNA, DYNEEMA, SPECTRA and VECTRAN.
• the yarn is pre-shrunk under a tension sufficient to stretch the yarn about 1.5%.
• polyester yarn is heated to at least 200°C at a tension of at least 375 gms.
• Nylon is also suitably heated to at least 200°C at a tension of at least 375 gms.
• Another suitable yarn for use in the process is polypropylene.
• the invention also provides a pre-shrunk normal tenacity yarn which has been pre-shrunk at a temperature greater than the heat-setting temperature of the yarn and which has preferably been stretched about 1.5%.
• the invention further provides a process for the manufacture of woven sailcloth comprising weaving a high modulus yarn with a normal tenacity yarn wherein the normal tenacity yarn has been pre-shrunk at a temperature greater than the heat-setting temperature of the normal tenacity yarn.
• the yarn is also preferably stretched about 1.5%.
• the high modulus yarn is woven in the weft direction and the normal tenacity yarn is woven in the warp direction.
• the high modulus yarn is used in the warp direction and the normal tenacity yarn used in the weft direction, whereas in a sailcloth intended for use on a classic boat the high modulus yarn is used in the weft direction.
• the invention has made it possible to combine the two components in a single fabric which does not contain bubbles in the final cloth.
• the invention further provides a yarn setting machine for heat treatment of synthetic yarn comprising an oven, at least one roller over which the yarn is rolled through the oven and a winding head to draw the yarn through the oven and wind it onto a spool or the like.
• the machine may further comprise a cooling unit to cool the yarn emerging from the oven.
• the cooling unit preferably has at least one roller to roll the yarn through the unit.
• the machine is also provided with a means to adjust the tension of the yarn passing through the setting machine. This means may be a tension compensator which controls the speed of the drive of the winding head.
• Figure 1 is a schematic drawing of a yarn setting machine.
• a yarn setting machine for heat treatment of synthetic yarn consists of an oven (1), which can be heated using electricity in the range of ambient to 350°C under the control of a thermostat. Alternatively gas heating or hot air may be used.
• Rollers (2) and (3) are used to roll the yarn through the oven (1). These are driven by means of chain and sprockets or alternatively toothed belts and wheels, hydraulic motors, or individual electric motors may be used.
• a means to allow the speed of rollers (2) to be different to the speed of rollers (3) is provided, such as change gear wheels or variable speed drive. The difference in speed between rollers (3) and (2) determines the tension in the yarn during the treatment.
• a tension meter is used adjacent to rollers (3) from time to time to measure the tension.
• a cooling unit (4) is provided to cool the yarn emerging from the oven (1), the cooling being assisted by a fan and/or cooled air.
• the yarn is wound using a commercially available winding head (6).
• a tension compensator (5) is provided which moves to take up any slack and which has an output either mechanically or electronically to control the speed of the drive (7) of the winding head (6) to allow for the slack. All parts of the machine which are in contact with the yarn are smooth and should preferably be made from or coated with a ceramic material.
• the yarn (8) as supplied by a manufacturer is taken from the supply package (11) and passed around the rollers (2), the number of turns dependant on the thickness and type of yarn to be processed.
• the yarn (8) then passes through the oven (1), the yarn (8) being passed backwards and forwards in the oven (1) using a plurality of guides, to increase the total length of yarn in the oven depending on the thickness and type of yarn (8) to be processed.
• the yarn (8) exits onto guide (9), enters the cooling unit (4) and is returned by guide (10) onto rollers (3).
• the yarn (8) is passed around the guides within the compensator (5), the number of guides used depending on the thickness and type of yarn processed.
• the yarn (8) is then wound on the winding head (6) .
• the yarn must be processed at a higher temperature than the cloth will subsequently be subjected to in manufacture.
• the setting temperature is therefore dependant on the curing temperature of the resin system in the sailcloth manufacture and adjusted for any modifiers that may be added to the mixture.
• the heat setting temperature of the normal tenacity yarn must be exceeded.
• the tenacity value of a yarn is an indication of the strength of the yarn and is calculated as:-
• Modulus is an indication of the resistance to stretch and is calculated as:-
• yarns can be divided into four categories.
• Low tenacity yarns include natural fibres and some man-made fibres for apparel uses
• medium tenacity yarns include man-made fibres for general purpose non-critical end use
• high tenacity yarns include man-made fibres for industrial uses such as sails, tyres and the like.
• High modulus yarns are high strength yarns with the advantage of high resistance to stretch and include yarns such as Kevlar, Spectra and Vectran (all trade marks).
• the dividing line between the first three categories is not well defined, but for the purpose of the present application low tenacity yarns would have a tenacity value of less than 45 cN/Tex.
• High tenacity yarns would have a tenacity value of between 45 and 95 cN/Tex with a 2% modulus figure (i.e. modulus calculated using the load at 2% extension) of between 550 and 950 cN/Tex. Yarns with values exceeding this would be considered to be high modulus yarns.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Woven Fabrics (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Gloves (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Polarising Elements (AREA)
• Laminated Bodies (AREA)
• Reinforced Plastic Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=11040237

Family Applications (1)

Country Status (11)

Cited By (1)

Families Citing this family (3)

Family Cites Families (4)

• 1994
  • 1994-01-05 IE IE940003A patent/IES940003A2/xx not_active IP Right Cessation
• 1995
  • 1995-01-04 DE DE0738339T patent/DE738339T1/de active Pending
  • 1995-01-04 DE DE69509358T patent/DE69509358T2/de not_active Expired - Fee Related
  • 1995-01-04 DK DK95905749T patent/DK0738339T3/da active
  • 1995-01-04 ES ES95905749T patent/ES2133725T3/es not_active Expired - Lifetime
  • 1995-01-04 WO PCT/IE1995/000001 patent/WO1995018881A1/fr active IP Right Grant
  • 1995-01-04 AU AU14241/95A patent/AU1424195A/en not_active Abandoned
  • 1995-01-04 EP EP95905749A patent/EP0738339B1/fr not_active Expired - Lifetime
  • 1995-01-04 AT AT95905749T patent/ATE179467T1/de not_active IP Right Cessation
  • 1995-01-04 JP JP7518405A patent/JPH09512865A/ja active Pending
  • 1995-01-05 ZA ZA9553A patent/ZA9553B/xx unknown
• 1999
  • 1999-04-29 GR GR990401087T patent/GR3030077T3/el unknown

Non-Patent Citations (1)

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