US3548460A - Process for drafting staple fibers - Google Patents

Process for drafting staple fibers Download PDF

Info

Publication number
US3548460A
US3548460A US734150A US3548460DA US3548460A US 3548460 A US3548460 A US 3548460A US 734150 A US734150 A US 734150A US 3548460D A US3548460D A US 3548460DA US 3548460 A US3548460 A US 3548460A
Authority
US
United States
Prior art keywords
drafting
fibers
band
fiber
pair
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US734150A
Other languages
English (en)
Inventor
Werner Naegeli
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pavena AG
Original Assignee
Pavena AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Pavena AG filed Critical Pavena AG
Application granted granted Critical
Publication of US3548460A publication Critical patent/US3548460A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
    • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
    • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
    • D02G3/22—Yarns or threads characterised by constructional features, e.g. blending, filament/fibre
    • D02G3/40—Yarns in which fibres are united by adhesives; Impregnated yarns or threads

Definitions

  • the invention also pertains to a draftable web comprising staple fibers which prior to drafting have been adhesively bonded together and which during drafting have been subjected to a high tensile load.
  • spinning-band denotes a conventional, non-twisted sliver or band, as such for example is produced by a carding engine, drawing frame, etc.
  • a stable band denotes a non-twisted band or silver consisting of individual fibers mutually adhesively interconnected by a setting adhesive.
  • twisted rovings are delivered to a ring spinning-drafting arrangement which initially drafts the rovings in a preliminary drafting zone and thereafter in a primary or main drafting zone a total of 20- to 60-fold, then delivers such to the spinning spindle in order to impart twist.
  • the draft in the preliminary drafting zone lies in the range of approximately between 1.1- to 2-fold, whereby in the main drafting zone drafts of approximately 15- to 30-fold still result.
  • mechanical fiber guide means are provided, for example in the form of slip rollers, small belts, and so forth. Notwithstanding such fiber guide means it is, however, not possible to further considerably increase drafting in the interest of a sufficient yarn quality. Additionally, such drafting arrangements are complicated, cause a great number of malfunctions, so that they are no longer adequate for higher requirements.
  • a primary object of the present invention has reference to an improved process for drafting staple fibers with relatively high drafts, specifically in a range of approximately 30- to ISO-fold, without requiring the use of mechanical fiber guide means.
  • a further important object of this invention relates to the production of an improved web composed of staple fibers which during drafting are subjected to a high tensile load.
  • Another noteworthy object of the present invention concerns itself with an improved process for imparting high draft to staple fibers by means of two pairs of rollers devoid of mechanical fiber guide means therebetween.
  • Still a further considerable object of this invention is directed to an improved process for drafting staple fibers resulting in higher drafts, simplication of the drafting arrangements, increased productivity and improved yarn quality.
  • the inventive process for drafting staple fibers takes places between a pair of feed or draw-in rollers and a pair of delivery rollers by means of the following process steps:
  • drafting takes place freely between the respective pairs of feed rollers and delivery rollers, with drafts in excess of 30, that is, while dispensing with conventional mechanical fiber guide means.
  • the individual fibers are subjected to a high tensile load, partially brought up to a value corresponding to the strength of the substance of the fibers.
  • high tensile load by means of a specific numerical range or value since such varies from material to material, what is meant is that the tensile load to which the individual fibers are subjected approaches or lies very near the tensile strength of the fibers, in other words, the strength of the substance of the fibers.
  • the inventive process is further characterized by the feature that, the drafting force applied to the individual fibers quickly increases during a small fraction of the total drafting time, and during the much longer remaining drafting time (corresponding to the withdrawal time) the fibers are withdrawn practically without force.
  • the individual stable band or a doubled fiber arrangement or strand of such stable bands is preferably guided up to the nip line of the pair of feed rollers.
  • the resulting web can be exposed to further drafting directly after the pair of delivery rollers such as in preliminary stages, whereby between the pair of feed rollers and pair of delivery rollers there is undertaken a larger draft than with the subsequent further drafting mentioned above.
  • the web produced according to the inventive process contains staple fibers which have been subjected to a high tensile load or stress during drafting.
  • drafting is performed between the nip locations of pairs of feed rollers and delivery rollers at a spacing exceeding the length of the drafted staple fibers, that is, short and long staple fibers can be drafted under favorable conditions with uniform length of the drafting zone.
  • the new and improved inventive drafting theory places a series of previously unknown requirements upon the stable band to be drafted which can be attained by means of a special preparatory process.
  • This preparatory process is described in detail in my co-pending United States patent application, Ser. No. 430,255 filed Feb. 4, 1965, and entitled Process for the Preparation of a Fiber Arrangement or Strand Composed of Staple Fibers for Undergoing a Subsequent High Draft and 3. Stable Band Produced According to the Aforesaid Process. It will be understood the present inventive drafting process makes particular reference to this preparatory process.
  • FIG. 1 illustrates in cross-section a theoretical ideal model of a staple fiber band useful for explaining details of the inventive drafting process
  • FIG. 2 is a perspective view of the staple fiber band depicted in FIG. 1;
  • FIG. 3 is a force-displacement diagram for explaining the process of breaking-out of a straightened and parallely disposed individual fiber from a stable band;
  • FIG. 4 illustrates in cross-sectional view a theoretical ideal model of a spinning band useful for clearly pointing out the differences in drafting between a spinning band and the inventive stable band;
  • FIG. 5 is a force-displacement diagram serving to explain breaking-out or withdrawal of an individual fiber from a spinning band
  • FIGS. 6 and 7 are respective force-elongation diagrams
  • FIG. 8 schematically illustrates in cross-sectional view a single zone-drafting arrangement employed for drafting a stable band according to the teachings of the present invention.
  • FIG. 9 schematically illustrates a drafting arrangement of a preliminary stage wherein a further pair of drafting rollers are arranged after a single-zone drafting arrangement as such is employed for carrying out the inventive drafting technique upon, for instance, a doubled fiber arrangement in a preliminary stage.
  • a fiber x is surrounded by six further fibers a, b, c, d, e and f of the same length. They are uniformly adhesively bonded with one another at the line of contact of the fiber surface. The start of these fibers is not disposed in a single plane, rather are staggered in lengthwise direction, as best shown in FIG. 2, according to the law of random distribution.
  • the specifically considered fiber x is shown dotted in the spacial illustration.
  • the model forms a section of a stable band which is assumed to move to the right of the drawing with a velocity V It is further assumed that the individual fibers x, a, b, c, a, e and 7 upon passing through the nip or clamping plane E corresponding to drafting, are accelerated from the velocity V to the velocity V There is now posed the question as to how the fiber x behaves during the course of the described drafting operation.
  • the fiber c has just passed through the nip plane E thereby having been accelerated to the velocity V
  • the contacting fibers x, b, d still move with the velocity V Consequently, the fiber c is subjected to a quickly increasing draft force K, for such length of time until the adhesive bond with the fibers x, b and d ruptures; as a result it moves away with practically no force, since no further forces act upon it.
  • the fiber x still remains at the velocity V since .it is still adhesively bonded with the neighboring fibers a, b, d, e and ;f.
  • the more closely considered fiber x still remains connected or bonded with the fibers a and b and with the fibers k, l, m and n following the fibers c, d, e and f.
  • the floating fiber x can thusas explainednever be accidently accelerated by the (fibers c, d, e and g withdrawn one after the other with the velocity V rather it maintains its velocity V until it also passes through the nip plane E
  • a fiber is considered to be floating if it is neither clamped rearwardly at the feed rollers nor forwardly at the delivery rollers.
  • a prerequisite for the fiber x to be entrained in uncontrolled manner is that more "than half of the fibers a, b, c, d, e, f surrounding the fiber x pass through the nip or clamping plane E at exactly the same moment.
  • the probability that this phenomena occurs with a random arangement of the fibers in the lengthwise direction, that is, that the beginning of the fibers of four of the six fibers surrounding the fiber x are exactly disposed in one plane is, however, extremely small.
  • the spinning band After passing the preliminary drafting zone, not further to be considered, the spinning band arrives at the main drafting zone equipped with small belts or the like. Here, other boundary conditions prevail.
  • the fibers are not bonded with one another and, furthermore, transmitted external forces K act upon a model as depicted in FIG. 4. These forces are generated because of tensioning the spinning band due to the form of the belt cradle or bridge and due to the belts themselves.
  • the withdrawal of an individual or single fiber from such a band in principle results in a forcedisplacement diagram as illustrated in FIG. 5. Initially, the force P increases under the influence of the external forces K until overcoming the static friction, then again gradually falls-01f in accordance with the sliding friction and the displacement path L.
  • the trace of the curve also confirms the continuous change of the static and sliding friction of the withdrawn individual fiber depending upon the contact relationship with the surroundings.
  • the drafting work undertaken during withdrawal of the fiber is expressed by the surface or area designated by reference character F
  • F the surface or area designated by reference character F
  • a stable band prepared by a setting bond exhibits a characteristic force-elongation relationship as such is shown in FIG. 6 by the curve a", for example depicted for a cotton material.
  • the curve a A readily apparent proportionality exists between the force P and the elongation s from the time of application of load till rupture of the b and, that is, the stable band approximately ideally follows Hooks Law.
  • the slope of the ascent of the curve a since such slope represents a measure for the required lengthwise stabilization of the stable band. The greater the slope of the ascent the better the lengthwise stabilization, in other words, that much less does the stable band elongate by virtue of the average drafting force and that much smaller is the danger of there appearing drafting waves.
  • a stable band can be considered to possess lengthwise or longi tudinal stability if there appears minimum elongation of such band upon being subjected to a drafting force.
  • Comparison measurements performed by means of a tensile tester manufactured by Instron Ltd., of High Wycombe, Bucks, England showed that the drafting work necessary during the indicated conditions on the average is smaller for bonded fibers (area F than for non-bonded fibers (area F Consequently, the average drafting force during free drafting of a stable band remains relatively small. This together with the high value of tangent a explains why a stable band permits drafting without drafting waves even with considerably increased length of the drafting zone.
  • the transverse stability is a further requirement which is placed upon the stable band prepared by a setting bond. If the stable band is stressed by pulling-out or withdrawing individual fibers, then the local appearing tensile forces must not be propagated directly backwards, rather these forces must be taken over as qiuckly as possible by the entire band and influence such as a unit. Furthermore, the cross-sectional configuration of the stable band forwardly of the drafting arrangement must also be maintained in the high draft zone in order to ensure for homogeneous drafting conditions. These effects are achieved by a pronounced transverse bonding of the individual fibers and by the therewith associated cross-sectional stabilization of the stable band prepared for drafting.
  • the stable band is considered to possess transverse stability if the band is stressed and the local appearing tensile forces are taken up as quickly as possible by the entire band and influence such as a unit.
  • cross-sectional stability it is to be understood that the stable band retains its cross-sectional configuration up to the time it enters the drafting arrangement.
  • an infeed or feed condenser 3 which extends almost up to the nip line of the pair of rollers 1, 1' of the two pairs of drafting rollers 1, 1 and 2, 2 required for carrying out the inventive drafting process.
  • This infeed condenser 3 which is provided with a bore 3a accommodated to the surface of the stable band 4 prevents the latter from being pressed flat by the squeezing effects of the pair of rollers 1, 1 and which would thus otherwise prematurely destroy its previously explained transverse stability, that is, prior to reaching the actual drafting zone.
  • a so-called limiting device 5 can be arranged in the high draft zone in order to further mitigate the influence of this squeezing effect, to compensate for electrostatic charges, and so forth.
  • the bore 5a of this limiting device 5 advantageously essentially corresponds to the cross-section of the stable band 4.
  • the high density or weight per unit volume of the stable band is of importance for drafting insofar as it permits delivering to the drafting arrangement as large as possible fiber mass with the smallest cross-section. As a result, greater drafts are possible without preventing the marginal fibers from becoming twisted.
  • the density is 0.3 gram/cm. for a cross-sectional area of 1.9 times 2.0 millimeters.
  • the stable band is of smooth, faultless appearance, also possesses a considerable transverse strength and transverse stability.
  • the stable band is delivered to the pair of feed rollers of a single zone-drafting arrangement via an infeed condenser possessing a bore of 18 millimeters. Then it is freely drafted to an extremely high draft of 1l5-fold by the pair of delivery rollers without using any kind of mechanical fiber guide means. After imparting twist to the drafted web there appears a yarn of 9.9 tex.
  • the length of the drafting zone between the pair of inlet or infeed rollers and the pair of delivery rollers amounted to 45 millimeters.
  • the length of the drafting zone of 45 millimeters exceeds the length of the longest fibers by 7 millimeters. Such length also exceeds the 2% staple diagram length of the fiber number diagram by 12 millimeters and the mean staple diagram length of the fiber number diagram by 27 millimeters.
  • a doubled, compact and uniform fiber arrangement or strand is formed from a number of stable bands and delivered to a drafting arrangement.
  • the degree of doubling and diafting is dependent upon the planned spinning operation.
  • both of the pairs of drafting rollers 6 and 6 and 7 and 7' which are required for carrying out the inventive process in the preparatory stage, have an infeed condenser 8 arranged in front of and extending up to the nip line of the pair of feed rollers 6 and 6', analogous to the arrangement of FIG. 8.
  • This infeed condenser 8 should be accommodated to the doubled stable fiber arrangement 9 which is to be drawn in.
  • this infeed condenser 8 prevents the doubled stable fiber arrangement from being spread wide by the squeezing effect of the pair of infeed rollers 6 and 6', which otherwise might especially result in the destruction of the transverse stability of the individual stable bands before reaching the actual drafting zone.
  • this roller 6' In order to reduce the squeezing effect of the pair of feed rollers 6 and 6', it is again advantageous to provide this roller 6' with a thick and relatively soft rubber coating 6", in the manner depicted in FIG. 9.
  • the pair of rollers 7 and 7' have a further pair of rollers 10 and 10 arranged thereafter, as shown, whereby the relatively small total draft of the preparatory stage in the present case is again divided.
  • Process as defined in claim 2 including the step of guiding said plurality of stable bands substantially up to the nip line of said pair of feed rollers.
  • step of increasing the drafting forces applied to said staple fibers acting upon the individual fibers includes bringing the drafting forces up to a value substantially corresponding to the strength of the substance of the fibers.
  • Process for drafting staple fibers of a stable band between a pair of feed rollers and a pair of delivery rollers comprising subjecting the individual fibers to a high tensile load in the drafting zone sufficient to cause a permanent lengthwise orientation of the micelles of the fibers.
  • Process for drafting staple fibers of a stable band between a pair of feed rollers and a pair of delivery rollers comprising subjecting the individual fibers to a high tensile load in the drafting zone sufiicient to cause a permanent lengthwise orientation of the molecular chains of the fibers.
  • a process for drafting staple fibers comprising the steps of: drawing in through a pair of feed rollers of nontwisted stable band, the individual fibers of which are mutually adhesively bonded by a setting adhesive agent, gripping in turn one or more of the individual staple fibers by a pair of delivery rollers to apply to each such fiber in turn a load which gradually increases up to failure of the bond between each gripped fiber and the fibers bonded thereto and which is distributed to all the remaining fibers of the band, subjecting the band to a negligibly small elongation so that no drafting waves are produced.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Spinning Or Twisting Of Yarns (AREA)
  • Nonwoven Fabrics (AREA)
  • Preliminary Treatment Of Fibers (AREA)
US734150A 1964-02-15 1968-06-03 Process for drafting staple fibers Expired - Lifetime US3548460A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH188164A CH526649A (de) 1964-02-15 1964-02-15 Verfahren zum Verziehen eines Stapelfaserbandes und nach diesem Verfahren hergestelltes Vlies
BE659699A BE659699A (de) 1964-02-15 1965-02-12

Publications (1)

Publication Number Publication Date
US3548460A true US3548460A (en) 1970-12-22

Family

ID=25656139

Family Applications (1)

Application Number Title Priority Date Filing Date
US734150A Expired - Lifetime US3548460A (en) 1964-02-15 1968-06-03 Process for drafting staple fibers

Country Status (6)

Country Link
US (1) US3548460A (de)
BE (1) BE659699A (de)
CH (1) CH526649A (de)
DE (1) DE1510378B2 (de)
GB (1) GB1102362A (de)
NL (1) NL6500999A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116203108A (zh) * 2023-05-04 2023-06-02 苏州市纤维检验院 一种纺织品静电衰减测试设备及其测试方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1905268A (en) * 1930-11-05 1933-04-25 Textile Patent & Process Co In Method of drafting textile fibers
FR1007089A (fr) * 1948-02-24 1952-04-30 Blin & Blin Ets Procédé d'étirage des textiles et dispositif permettant la mise en oeuvre du procédé
GB757583A (en) * 1953-11-28 1956-09-19 Spinnfaser Ag Improved method for improving the uniformity of drafting frame slivers of synthetic fibres
US2771639A (en) * 1950-07-03 1956-11-27 Aymerich Jose Maria Bosch System for drafting fibrous materials
US3020697A (en) * 1958-11-07 1962-02-13 Callaway Mills Co Method and apparatus for producing multi-colored single yarn in simulation of ply yarn
US3191375A (en) * 1962-08-16 1965-06-29 Pavena Ag Process for the manufacture of a twisted yarn
US3381343A (en) * 1966-01-06 1968-05-07 Agriculture Usa Apparatus for drafting textile fibers
US3392425A (en) * 1967-05-08 1968-07-16 Johnson & Johnson Apparatus for drafting sliver

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1905268A (en) * 1930-11-05 1933-04-25 Textile Patent & Process Co In Method of drafting textile fibers
FR1007089A (fr) * 1948-02-24 1952-04-30 Blin & Blin Ets Procédé d'étirage des textiles et dispositif permettant la mise en oeuvre du procédé
US2771639A (en) * 1950-07-03 1956-11-27 Aymerich Jose Maria Bosch System for drafting fibrous materials
GB757583A (en) * 1953-11-28 1956-09-19 Spinnfaser Ag Improved method for improving the uniformity of drafting frame slivers of synthetic fibres
US3020697A (en) * 1958-11-07 1962-02-13 Callaway Mills Co Method and apparatus for producing multi-colored single yarn in simulation of ply yarn
US3191375A (en) * 1962-08-16 1965-06-29 Pavena Ag Process for the manufacture of a twisted yarn
US3381343A (en) * 1966-01-06 1968-05-07 Agriculture Usa Apparatus for drafting textile fibers
US3392425A (en) * 1967-05-08 1968-07-16 Johnson & Johnson Apparatus for drafting sliver

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116203108A (zh) * 2023-05-04 2023-06-02 苏州市纤维检验院 一种纺织品静电衰减测试设备及其测试方法
CN116203108B (zh) * 2023-05-04 2023-08-08 苏州市纤维检验院 一种纺织品静电衰减测试设备及其测试方法

Also Published As

Publication number Publication date
DE1510378B2 (de) 1976-08-12
GB1102362A (en) 1968-02-07
CH526649A (de) 1972-08-15
BE659699A (de) 1965-08-12
DE1510378A1 (de) 1970-08-06
NL6500999A (de) 1965-08-16

Similar Documents

Publication Publication Date Title
EP0217345A3 (en) Method and apparatus for spinning staple fibre yarns
DE1510324A1 (de) Verfahren zur Herstellung eines ein loesliches Fixiermittel enthaltenden gesponnenen Garnes
US2673546A (en) Apparatus for treating impregnated yarn
US3548460A (en) Process for drafting staple fibers
US3512232A (en) Process for preparing twistless yarns
US3548462A (en) Process for the preparation of a fiber arrangement or strand composed of staple fibers for undergoing a subsequent high draft
EP0062643B1 (de) Verfahren zur herstellung von spinnfasergarnen
US2845771A (en) Direct spun shantung yarn and method of making same
US2089021A (en) Asbestos yarn
US2323882A (en) Drafting mechanism for roving frames
US1905268A (en) Method of drafting textile fibers
US2640229A (en) Sliver compressor
US3153316A (en) Bulky yarn and method of producing the yarn
US2304885A (en) Yarn drafting process
ES2000127A6 (es) Procedimiento de hilado de lino puro o en mezcla
US2154675A (en) Drafting apparatus and method
EP0129724A2 (de) Verfahren zur Herstellung von feinen Jute- und juteartigen Garnen
JP2610489B2 (ja) 空気仮撚法によるアクリル繊維と天然繊維との混紡糸
US3331104A (en) High speed drafting apparatus
US1804968A (en) Manufacture of yarn
US4103396A (en) Dual zone wet drafting device for twistless yarns
AT260738B (de) Verfahren zum Verziehen von Stapelfasern
US1766864A (en) Double-draft arrangement for spinning flax, jute, and similar fiber
CN219861751U (zh) 并条机牵伸装置
JPH0160088B2 (de)