FR2594448A1 - PROCESS FOR WIRING PURE OR MIXED LINEN - Google Patents

Abstract

1. Process for spinning pure or blended flax, designed for the textile industry to form a yarn by twisting flax fibres from bundles of long fibres swingled and agglomerated by pectins, implementing at least one spinning frame, characterized in that : - the length of the fibres is mechanically reduced by a suitable treatment, followed by another mechanical operation so as to obtain only short, extremely fine fibres, - the short fibres are carded to form a ribbon, - the ribbon is drawn to adjust its weight per unit length and the said short fibres are controlled while they are being drawn on the spinning frame, - the ribbon is twisted to form a roving, - the roving is wetted, - the wetted roving is drawn and is twisted to form the yarn.

Description

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  The invention relates to a process for spinning flax.

  It will find particular application in the textile industry for the realization of coils of pure linen yarn or mixed with

  other natural, artificial or synthetic fibers.

  Since ancient times, flax has been cultivated for its textile fibers and its seed which provides a drying oil. It claims deep, fertile and humus-rich soil, which has localized its culture in particular parts of the world,

  the USSR, China and Northern Europe.

  Harvesting flax is done during the summer. The stems are torn off and riddled

and scutching.

  In the stem, the elementary fibers of an average length of 2 to 3 cm and a mean diameter of 13 to 15 microns, are agglutinated to each other by a pecto-ligneous complex, to form the fibrous bundles. These are on the periphery of the stem, in the Liberian zone and, at maturity, are strongly

  adherents to the central woody trunk.

  Retting is a biological operation whose essential purpose is to dissociate the fibrous bundles from the woody trunk. There is retting on the ground and retting with "water." When retting on the ground, at the time of pulling, the stems are

  spread out on the floor and remain there for 3 to 6 weeks.

  Under the effect of humidity and temperature, saprophytic fungi present on the plant at the time of uprooting proliferate and secrete enzymes that partially dissolve

  pectic cement welding fibers to wood.

  The essential role of scutching is to separate the fibers from the wood. For this, the stems undergo the grinding operation that breaks the wood while leaving the fibers intact, then they are beaten to drop the shives or woody debris. The useful product is scutched linen or tow; but one of the by-products also has a textile value: it is the tows of scutching, fibers more or

  shorter, separated from the scutched flax at the time of threshing.

  The scutched flax whose apparent length is generally between 70 cm and 1 meter, consists of bundles adhering to each other longitudinally and transversely. In fact, the scutched flax delivered to the spinner, corresponds to the entire fibrous corona of the Liberian zone in which the cellulosic elementary fibers only represent 70% by weight, the rest being noncellulosic substances decomposing into hemicelluloses,

  pectic substances, lignins and mineral elements.

  It is this particular fibrous morphology that makes linen work very specific and at the least difficult and costly compared to other well-known fibers such as

  cotton, wool and synthetic fibers.

  Among the known spinning processes, the scutched linen undergoes the combing operation whose role is threefold: to clean the tow, by removing the last traces of shives; to separate the bundles bound together by the cortical bark and parenchyma and thereby to refine the technical fibers; eliminate short staple fibers and

  of head that are combing tows.

  This operation, which is already particularly onerous, has, moreover, the disadvantage of being carried out on a heavy, unproductive machine with a design almost 100 years old. This machine known as large combing machine is very expensive to buy since of imposing size and carrying out operations alternatives

repeated.

  The resulting combed linen is spread and the tablecloth thus obtained

  is stretched to provide a continuous ribbon.

  It is stretched and doubled successively on 5 machines called stretching benches whose rattle is triple: to improve as much as possible the regularity of mass of the ribbon; gradually reduce its linear density (or title); refine the technical fibers by cleaving the fibrous bundles. This third function, which is fundamental to allow a suitable spinnability, is obtained by stretching the ribbon in a field of increasingly fine needles by means of a

  drawing train (steel-wood) working in a thin layer.

  This operation in the known processes is carried out on a very specific material of a particularly high purchase price: The tape leaving the last pass is then stretched on a bench-pin, also very specific and very expensive. in order to obtain a slightly twisted wick to be worked

on a spinning machine.

  To make a thin wire, it is essential that the constituent fibrous elements themselves are very thin and close to the elementary fiber. However, the fibrous elements of the ecru strand, have an average length of between 15 and 20 cm and often have between 3 and 10 elementary fibers in section. It is therefore necessary to dissociate the elementary fibers during the spinning operation or before it. To do this, the wet ecru mop was long spun by passing it into a water tank heated to a temperature of approximately 70 ° C and stretching it in a rolled, high-pressure rolled-down rolling mill. spacing between 65 and 80 mm. But this way of proceeding leads to very difficult working conditions and does not make it possible to obtain

  yarns finer than Nm 21 (48 tex) validly marketable.

  For two decades, industrial milling of wet flax has been carried out using wicks that have undergone chemical leaching or bleaching treatment. The elementary fibers thus chemically treated are partially separated and it is then possible to spin with cold water and to make thinner threads, more regular and stronger. However, apart from its advantages, such a treatment has a certain number of drawbacks: it is expensive, causes a loss in the order of 10 X and does not always make it possible to obtain a constant shade. Moreover, the production of mixed yarn is rather the fact of dry spinning, which does not easily allow the production of fine yarn mainly linen in short fibers. In short, all the current methods of spinning flax used industrially, have serious handicaps: either they are very limited in spinnability and do not allow the production of fine threads, or the obtention.quires fine quality n ' is possible that by implementing transformation processes

expensive with reduced productivity.

  The main object of the present invention is to provide a very economical method of spinning flax. The substantial gains that can be made are at the level of the workforce

  reduced and also in terms of investment in equipment.

  In fact, according to the invention, a large number of handling operations can be suppressed thanks to the use of highly productive machines which are encountered in other applications.

  textile sectors, such as the short fiber sector.

  Savings in material can also be achieved since the invention eliminates the need for machines specific to flax (combing and preparation). Another object of the present invention is to present a process for spinning flax which makes it possible to obtain a pure or mixed linen yarn of a cleanliness hitherto unequaled industrially, while

  retaining the appearance of traditional flax.

  The raw material used is very shortened technical fiber flax of variable length and very mechanically refined for example by using an opener (without any chemical or physicochemical treatment) whose length and fineness are quite close to the characteristics of the fiber

elementary.

  The prior foreshortening is carried out on lengths of the order of 5 to 6 cm and then the material is refined, that is to say that the beam which initially comprised ten to forty elementary fibers in section is reamed: much more fibrous element

  end and comprising only a few elementary fibers.

  In the case of production of blended yarns, another natural fiber or artificial or synthetic fiber is also used, the intimate mixture being at the very beginning of preparation. The preparation, that is to say the different physical operations before spinning, is derived from that used for other short fibers such as cotton or other artificial fibers of the same size: carding, two stretching passages and bench-i-pin. The spinning according to the invention, which is carried out after the physical preparation, is derived from the conventional spinning of wet flax: dipping the wick continuously in water which can

  to be cold; rolling comprising a stretch control system.

  Flax fiber has not undergone any chemical or physicochemical treatment, it is unbleached and therefore has retained a good part of its non-cellulosic constituents: hemi-celluloses and

pectic substances.

  It has several advantages: -5- - it has not suffered a significant loss of non-recoverable material and consequently, its cost is limited, - it is very accessible to water because of its great finesse and its low length and does not require chemical treatment prior to spinning, - it provides the pectic cements which, after softening and drying, contribute to give more cohesion

between the fibers in the yarn.

  The yarn thus obtained has a real "linen appearance" even when it is made in mixture with artificial or synthetic fibers, this being due to the fact that the flax fiber has remained

  ecru and was spun in the wet state.

  This gives the yarn a high technological and commercial added value compared with the same yarn made in the dry state, because the appearance of the yarn obtained by the process of the invention resembles

  a lot to traditional linen threads.

  Wet spinning and subsequent drying avoid hot-spray fixing, which often needs to be done

  when a mixing yarn is made in the dry state.

  Among the advantages of the method include: the appearance of the yarn and its regularity are very close to the same characteristics of the classic linen yarn; in cleanliness, the yarn of the invention is even higher because it has no major defects, - the price of yarn is between that of conventional linen yarn and that of cotton yarn, but however closer to

that of the cotton thread.

  Other objects and advantages of the present invention

  will appear in the following description which is not

  however, given as an indication only and not intended to limit it. According to the present invention, the process for spinning pure or blended linen, intended for the textile industry for forming a yarn by twisting flax fibers from long fiber bundles scuffed and agglomerated with pectins, is characterized in that: - the length of the fibers followed by another mechanical operation is mechanically reduced by a suitable treatment so as to obtain only short and excessively fine fibers, - the short fibers are cut to form a ribbon stretching in order to regulate its linear density, - stretch and twist the ribbon to form a wick, - wick the wick, - stretch the wet wick and give it a twist

to form the wire.

  The invention will be better understood on reading the

  following description accompanied by a drawing in annex which schematizes

  the draw string of the spinning machine of the present invention.

  The present invention relates to a process for spinning pure flax

or in mixture.

  It will find particular application in the textile industry for the formation of a yarn made by twisting fibers of

entangled linen.

  The present invention comprises a large number of advantages among which we can mention: The cost of transformation is greatly reduced compared to that of the traditional process, to the point of approaching that of the

spinning type short fibers.

  Combing equipment and preparation specific to flax, excessively expensive to purchase, consuming a lot of energy, requiring a lot of maintenance and requiring a large workforce, is excluded from the circuit of the invention. It is replaced by a lighter material, manufactured in large series and

  requiring reduced manpower and maintenance.

  The raw material used is short fiber, mechanically refined preferably (without chemical or physico-chemical treatment) whose length and fineness are quite close to the characteristics of the elementary fiber. It is ecru and therefore has not suffered a significant loss and has retained much of its noncellulosic constituents. Consequently, its cost is limited; it is very accessible to water because of its great fineness and its short length and does not require chemical treatment prior to spinning; it brings the pectic cements which, after softening and drying, contribute to give more

  cohesion between the fibers in the yarn.

  The type of preparation used makes it possible to make any mixture of flax and other fibers without any difficulty and the

  fibrous mixture is very homogeneous.

  The spinning process of linen, thanks to the stretching system, makes it possible to spin not only pure linen, but also any type of linen mix and other fibers. The yarn thus obtained has a real linen appearance, as does the canvas or knit made of this yarn, because the flax fiber has remained natural and has been spun in the wet state. gives the yarn a high technological and commercial added value compared to the same yarn made in the dry state.In addition, the yarn obtained has no major defects by

  opposition to traditional linen thread.

  Wet spinning and subsequent drying avoid hot-spray fixing, which is often done when a wire is

  mixing is carried out in the dry state.

  According to the flax spinning method of the present invention, a raw material composed of scutched fiber bundles is started. This is flax grown under traditional conditions, which has been retted and then scutched. The

  Long fiber bundles are then agglomerated with pectins.

  The first operation to undergo these fibers is a reduction in their length associated with refining. It is indeed necessary to reduce by appropriate treatments the length of the fibers which initially is of the order of 70 cm to 1 m, to a length of fibers

  short, that is to say substantially of the order of 2 to 5 cm.

  This reduction in length is done mechanically by a cut or a cracking followed by a working which performs the refining. It is necessary to obtain short and very fine fibers. This first operation does not generally require a chemical or physico-chemical intervention. It is indeed necessary that the fiber retains its natural qualities so that the resulting yarn has the

  linen character "from the point of view of its appearance and touch.

  The preliminary shortening is carried out on lengths of the order of 5 to 6 cm and then the material is refined, that is to say that the beam which initially comprised ten to forty elementary fibers in section is brought back to a fibrous element much more

  end and comprising only a few elementary fibers.

  It is then necessary to perfect the cleaning of the -8-

  fibers, to parallelize them and to produce a veil then a ribbon.

  According to the process of the present invention, this is done on a high productivity card derived from those used in short fibers. The feeding and the discharge of the machine are automatic which minimizes labor costs, thus contrasting with the high cost of combing practiced in traditional spinning. The carded ribbon obtained is then combined with other ribbons and the whole is stretched to form a new ribbon whose regularity is improved. In addition, one or more passes may be made to obtain a substantially constant linear density ribbon. The ribbon is then stretched and then slightly twisted to form a wick. This phase of the process can be carried out on benches

pin.

  One of the characteristics of the invention is to spin in the wet state this lock of short fibers. To do this, the wick first goes into a tray of water that can be cold, integrated into the spinning machine, then it is stretched + in a rolling train

  designed to work at best this type of material.

  As previously described, the work of spinning short fiber flax requires some precautions. In particular, the control of short fibers is necessary during

  their passage in the drawing train of the spinning machine.

  Figure 1 shows schematically a draw string spinning machine. A spool bench spool 1 serves to feed the drawing train 2 which delivers a wire 3 which wraps around a spool.

spindle 4.

  According to the invention, the control of the short fibers is achieved by using a stretching train 2 with a sleeve 5. The sleeve stretching machine makes it possible to ensure the guiding of the

short fibers.

  The wick undergoes pre-stretching between the feed rollers 6 and the sleeves 5 and then a drawing proper

  between the sleeves 5 and the delivery cylinders 7.

  To improve fiber control, the path of the fibers in the drawing train 2 is carried out in a circular arc. Of course, other implementations of the present invention within the reach of those skilled in the art. could also have

  be considered without departing from its scope.

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Claims (6)

  1. A process for spinning pure or mixed flax, intended for the textile industry for the formation of a yarn by twisting flax fibers, from long fiber bundles scuffed and agglomerated with pectins is characterized in that - the fiber length is mechanically reduced by a suitable treatment followed by another mechanical operation so as to obtain only short and excessively fine fibers, - the short fibers are cut to form a ribbon which is stretched in order to to regulate the linear density, - stretch and twist the ribbon to form a wick, wick the wick, - stretches the wet wick and gives it a twist to form the wire.   2. Process for spinning flax according to claim 1,   characterized in that the flax wick is wetted with cold water.   3. A method of spinning flax according to claim 1, characterized in that one controls the yarn fibers during their stretching to form a wire.   4. A method of spinning flax according to claim 1, characterized in that the unbleached fibers are brought to characteristics of length and fineness close to the elementary fiber. 5. A method of spinning flax according to claim 1, characterized in that the length of the fibers is between 2 and 5 cm.   6. A method of spinning according to claim 1, characterized in that the wick describes an arc of a circle during its passage in the drawing gear (2).