Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H5/00—Drafting machines or arrangements ; Threading of roving into drafting machine
  • D01H5/18—Drafting machines or arrangements without fallers or like pinned bars
  • D01H5/28—Drafting machines or arrangements without fallers or like pinned bars in which fibres are controlled by inserting twist during drafting

Definitions

• a pile fabric such as carpet
• the difference in shrinkage between the tufts of high and low shrinkage will produce high and low pile or long and short tufts in order to form a visual pattern.
• the potential shrinkage of fibres for these purposes can be realised by a simple and inexpensive process, such as steaming.
• thermoplastic fibre while it is hot and relatively plastic, to cool it while it is still held in an extended state and thereby stabilise it. Since the fibre is not completely plastic but is visco-elastic during the hot-stretch process, some elastic strain energy is created within the molecular structure of the fibre, but
• the volume is increased to a greater degree, thus causing the
• the hot-stretching process used to create the high shrinkage potential is carried out
• substantially twist-free bundle of parallel filaments usually several thousand in number.
• the continuous filaments are then usually converted to discontinuous staple fibres for further textile processing into yarn.
• the difficulty of stretching and temporarily setting fibres such as wool, which do not occur in continuous filament form and are not thermoplastic, has until recently prevented the industry from applying the concept of stretch and temporarily setting to wool and animal fibres.
• Such fibres are discontinuous and a strand comprised of wool fibres will normally attenuate by "drafting" de, fibres will slip in relation to their neighbours at much
• Finer wool fibres are generally valued more highly. They can be spun to finer yarns than coarser fibres, which permits lighter weight fabrics to be made, and they feel
• an after-treatment consisting of repeated aqueous rinsing
• the invention provides for a method of creating a transient equivalent of
• thermoplasticity in wool or animal fibres such that they can be extended by substantial amounts without breaking and without requiring to be at high moisture
• sliver is passed in a substantially straight line path through a stretching zone from
• pulley unit is freely propagated along the sliver uninhibited by contact with pulleys or
• the fibre length may be any suitable material.
• the fibre length may be any suitable material.
• the lustre of the fibre may be increased.
• the invention provides for a process for stretching
• the processes further comprise the step of using a combined false twisting and traction providing haul pulley flyer downstream of the energy applicator and outside of the energy application zone such that the path of the sliver through the
• the process further comprises the application of microwave or radio frequency, but preferably microwave, energy, to heat the sliver throughout its thickness very rapidly.
• the present invention also provides for a process for stretching and temporary setting
• linear microwave or radio frequency heater located in a straight zone in which the sliver is plasticised, stretched and then progressively dried as it passes along the
• the microwave or radio frequency heating can be augmented by the passage of
• Figure 1 illustrates in graph form the glass transition temperature of wool as a
• Figure 2 illustrates an apparatus for creating false twist and at the same time providing hauling traction
• Figure 3 illustrates the rope making industry's Spinning Jenny which embodies a haul pulley device similar to that in Figure 2;
• Figure 3a is the condenser and nipper
• Prior art methods of heating include creating an atmosphere of steam around the sliver, as described in PCT WO 91 /0283. This requires much longer periods of time to heat the core of sliver which is in a twisted, tensioned and therefore dense
• transient thermoplasticity in wool in the given conditions can be described as follows: Wool like most polymeric solids is subject to a temperature and moisture dependent
• the glass transition temperature In wool, the glass transition temperature is highly moisture dependent, being relatively low when
• the wool fibre moisture regain is high and appreciably higher when the fibre regain is relatively low (see Figure 1 ) .
• the mobile plastic state is a preferred subject of the present invention.
• the invention permits the wool sliver to pass in a substantially straight path, without
• twist is redistributed such that the thinner stretched sliver receives more twist than the earlier unstretched section of the sliver.
• live steam ie, saturated steam at approximately atmospheric pressure
• This also serves to pre-heat the sliver.
• the sliver may be
• the sliver is supplied at a controlled rate by a pair of feed (nip) rolls which also serve as a twist block.
• Twist factor is defined as the twist in turns per metre multiplied by the square root of the sliver linear density in grams per 1 000 metres.
• a twist factor of 2000 to 3000 is likely to be adequate to prevent drafting, with the lower end of the range being appropriate for long fibres and the higher end of the range for shorter fibres. The process is not limited to this range of twist factors, which are
• apparatus for creating false twist consists of a framework E carrying capstans B and pulleys C.
• Pulleys C act only as guides to change the sliver direction
• the framework rotates (driven) about the centre line x-y. In use the sliver moving in the direction of the arrows shown has false twist at A and is substantially twist- free at D.
• the capstan rollers B are circumferentially grooved as are the guide
• the capstan rollers B also rotate about their own axes in order to provide traction. This is an adaptation of a well known apparatus in the
• haul pulley flyer unit is required, which reduces string-up time and this haul pulley
• flyer unit is located downstream of the stretching zone and drying zone, such
• microwave (or radio frequency) heater is substantially the microwave (or radio frequency) heater
• the stretched sliver may be collected as twisted (ie, having real
• FIG. 5 is shown a general arrangement of parts for an example of stretch apparatus.
• a sliver 7 is supplied from a creel 1 to a pre-steamer 2 to
• microwave dryer 4 to the haul pulley flyer 5.
• the sliver is then collected by any suitable collection means such as a can coiler 6.
• a further application of the process and apparatus disclosed is to supply the stretch- set apparatus with sliver which has been pre-plasticised by a chemical reductive
• a further increase in degree of set can be achieved by increasing the distance between the microwave or radio frequency heater and the haul pulley flyer and optionally surrounding the sliver with a steam atmosphere.
• Yet a further increase in degree of set or permanence of stretch may be achieved by an oxidising after- treatment, for example with hydrogen peroxide solution, known to the industry for
• a sliver of 28.6 micron wool was treated with 1 0% sodium metabisulphite solution at 85°C and then squeezed in nip rolls as it entered the stretch zone of the process
• the diameter and crimp curvature of the fibre after steam relaxation as measured by the OFDA method were as follows.
• the fibre length (Almeter method) and the yellowness (Y-Z) are also shown.
• Example 2 A sliver similar to that described in Example 1 was pre-treated with metabisulphite in the same conditions. It was squeezed and stretched in the same conditions as in Example 1 , with the important exception that less microwave power was supplied,
• the stretched fibre was finer (although the diameter reduction was only 1 3% as compared to 1 5% in Example 1 ) .
• the crimp curvature and fibre length were increased and the yellowness was decreased.
• stretching slivers of wool or animal fibres which may advantageously be used either for the production of temporarily set stretched fibre having high shrinkage potential or for the production of permanently set stretched fibre having reduced diameter, increased length and modified crimp curvature.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Preliminary Treatment Of Fibers (AREA)
• Treatment Of Fiber Materials (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Applications Claiming Priority (3)

Publications (3)

Family

ID=19927241

Family Applications (1)

Country Status (6)

Families Citing this family (6)

Family Cites Families (5)

• 2000
  • 2000-10-27 EP EP00975027A patent/EP1240368B1/de not_active Expired - Lifetime
  • 2000-10-27 WO PCT/NZ2000/000212 patent/WO2001031097A2/en not_active Ceased
  • 2000-10-27 AT AT00975027T patent/ATE329071T1/de not_active IP Right Cessation
  • 2000-10-27 CN CN00817923.9A patent/CN1236117C/zh not_active Expired - Fee Related
  • 2000-10-27 AU AU13135/01A patent/AU769950B2/en not_active Ceased
  • 2000-10-27 DE DE60028604T patent/DE60028604T2/de not_active Expired - Lifetime

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