Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
  • D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
  • D04H1/736—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged characterised by the apparatus for arranging fibres
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01G—PRELIMINARY TREATMENT OF FIBRES, e.g. FOR SPINNING
  • D01G15/00—Carding machines or accessories; Card clothing; Burr-crushing or removing arrangements associated with carding or other preliminary-treatment machines
  • D01G15/02—Carding machines
  • D01G15/04—Carding machines with worker and stripper or like rollers operating in association with a main cylinder
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01G—PRELIMINARY TREATMENT OF FIBRES, e.g. FOR SPINNING
  • D01G15/00—Carding machines or accessories; Card clothing; Burr-crushing or removing arrangements associated with carding or other preliminary-treatment machines
  • D01G15/02—Carding machines
  • D01G15/12—Details
  • D01G15/36—Driving or speed control arrangements
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01G—PRELIMINARY TREATMENT OF FIBRES, e.g. FOR SPINNING
  • D01G15/00—Carding machines or accessories; Card clothing; Burr-crushing or removing arrangements associated with carding or other preliminary-treatment machines
  • D01G15/02—Carding machines
  • D01G15/12—Details
  • D01G15/46—Doffing or like arrangements for removing fibres from carding elements; Web-dividing apparatus; Condensers
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres

Definitions

• the present invention relates to an installation and a process for the production of nonwovens by the dry process.
• Installations for the production of dry nonwovens generally include a section for forming a veil or a sheet, which comprises one or two cards, followed by a consolidation section by water jets, generally on several rotary cylinders and successive conveyors, then a water extraction section by high vacuum, most often, then, a drying section and finally a winding.
• an installation has been found which makes it possible to produce nonwovens by the dry route with an area weight even of between 40 and 80 g / m 2 by direct carding at high rates and with resistance ratios.
• machine direction / cross direction of less than 2.5 / 1, even less than 2/1, even less than 1.5 / 1 and very close to 1.0 well suited to qualitative markets, such as professional wipes or cosmetic masks, where nonwovens are desired to be as light as possible, provided that the rotational speeds of the elements of which the installation is made are suitably adjusted.
• Productivity is increased by 40 to 50% compared to an installation with spreader-lapper and stretcher of the same width in the production of light nonwovens.
• the invention requires only a carding machine and not other additional machines such as lapper and stretcher, requires much less investment, implements much less moving mechanical elements (rollers, belts, for example) and consumes less energy per kilo of product.
• the installation for producing dry nonwovens comprises a card drum driven in rotation in a first direction of rotation and at a first circumferential speed of rotation by first drive means, giving a veil fiber. It is characterized in that it comprises, immediately downstream of the drum in the direction of passage of the fibers of the installation, a transfer cylinder driven in rotation in a second direction of rotation, contrary to the first direction of rotation, and at a second circumferential speed of rotation by second rotational drive means, the second speed being greater than the first speed, the transfer cylinder having at the periphery a lining comprising a plurality of teeth inclined relative to the radius of the cylinder and oriented in the second direction of rotation, and immediately downstream of the transfer cylinder, a system comprising, from upstream to downstream in succession immediately, at least one doffer, at least one condenser, at least one detacher, a first endless conveyor belt , a suction drum and a second endless conveyor belt, the suction drum being adjacent to the upper strand of the first and second conveyor
• the ratio of the second speed to the first speed is greater than or equal to 1.6, and better still greater than or equal to 1.7.
• the invention also relates to a process for producing nonwovens, in which the installation according to the invention is operated according to the speed ratios according to the invention.
• a nonwoven product based on artificial and / or synthetic fibers such as viscose, lyocell, polyester or polypropylene, of mass per square meter of between 40 and 80 g / m 2 and whose fibers have a strength between 1.3 and 2.2 dtex and have a length between 30 and 50 mm, the ratio of the tensile strength machine direction / cross direction goes from 1.0 to 1.5 and the elongation in machine direction is between 35 and 70% and preferably between 40 and 60% and the elongation in the cross direction is between 70 and 130% and preferably between 90 and 125%.
• artificial and / or synthetic fibers such as viscose, lyocell, polyester or polypropylene
• the resistance measurements in the long direction (MD) and in the cross direction (CD), and of mass per m 2 are carried out according to the ERT standards of EDANA (European Disposables And Nonwovens Association), namely:
• a sample is conditioned for 24 hours and the test is carried out at 23 ° C and a relative humidity of 50%.
• At least 3 samples are cut with an area of at least 50,000 mm 2 with a cutting device called a cutter.
• Each sample is weighed on a laboratory balance with an accuracy of 0.1% of the mass of the weighed samples.
• a sample is conditioned for 24 hours and the test is carried out at 23 ° C and a relative humidity of 50%.
• a dynamometer is used for the test, comprising a set of fixed jaws and a set of movable jaws moving at a constant speed. The jaws of the dynamometer have a useful width of 50 mm.
• the dynamometer is equipped with a recorder, which plots the curve of the tensile force as a function of the elongation. 5 samples are cut of 50 mm, more or less 0.5 mm in width and 250 mm in length, this in the long direction and in the cross direction of the nonwoven.
• the samples are tested one by one, at a constant tensile speed of 100 mm per minute and with an initial distance between jaws of 200 mm.
• the dynamometer records the curve of the tensile force in Newtons as a function of the elongation.
• the invention also relates to a process for producing the above nonwoven product, in which the installation according to the invention is operated by giving its various elements the rotational speeds making it possible to obtain the desired ratios.
• the diameter of the transfer cylinder is preferably less than that of the card drum.
• the ratio is, for example, between 0.40 and 0.50.
• the card drum has a diameter between 900 and 1500.
• the angle of inclination of the teeth with the radius can be between 70 ° and 80 °.
• the radial height of the teeth is advantageously between 0.7 and 1.5 mm.
• the teeth are distributed uniformly over the entire periphery of the transfer cylinder, the interval between two teeth neighbors being between 1.3 and 2.3 mm.
• the width of the teeth at their base is between 0.70 and 1.2 mm.
• the distance between the carding drum and the transfer cylinder is less than 1 mm, being preferably between 0.4 and 0.6 mm.
• the lateral flanks of the teeth can be straight or curved.
• the teeth are preferably pointed.
• the transfer cylinder and its lining may be made of metal.
• the card drum is made in the same way as the transfer cylinder by having teeth inclined at an angle identical to the inclination of the teeth of the transfer cylinder in the opposite direction.
• the teeth are inclined in the direction of rotation.
• the anisotropy of the nonwoven is further reduced by a suction cylinder adjacent to the upper strand of the second conveyor belt.
• the installation generally includes, at the end, a consolidation device on the suction cylinder and or downstream from it.
• the consolidation device may be by water jets or by hot air jets or by calender or by needling or be carried out in a hot air consolidation oven or the like.
• FIG. 1 is a diagram of an installation according to the invention.
• FIG. 1 is a view on a larger scale of the teeth of the lining of the transfer cylinder.
• the installation of FIG. 1 comprises at least one card drum 1 driven by its own motor, a transfer cylinder 2 driven in rotation by its own motor, which totally discharges the drum 1 of the fibers on its surface.
• one or two combers 3 and 4 driven by their own motor take the fibers from the surface of the transfer cylinder 2.
• the condensers 5 and 6 and the detachers 7 and 8 driven by their own motor, then a transfer to a conveyor belt 9.
• the installation then comprises a drum 10 aspirating condensation and transfer disposed between the conveyor 9 and a conveyor belt 11 entering an installation by consolidation by water jets.
• the consolidation installation by water jets conforms to that described in European patent 1554421. It comprises a first cylinder 12 for consolidation by water jets tangent to the mat 11 and comprising a pre-wetting injector 13, disposed substantially at the transfer point between the mat 11 and the cylinder 12 and injectors 14 and 15 for consolidation.
• This first consolidation cylinder 12 is optionally followed by other consolidation cylinders by water jets, to give better resistance to the nonwovens thus produced.
• the distance between the drum 11 and the mat 9 and between the mat 11 and the cylinder 12 is between 2 and 15 mm.
• the transfer cylinder 2 is equipped on its periphery with a metal gasket G.
• This lining G is composed of a plurality of teeth 16.
• the double arrow L represents the direction parallel to the longitudinal axis of the transfer cylinder 2, that is to say the direction orthogonal to the plane of Figure 1.
• Figure 3 is a sectional view of the lining of the transfer cylinder 2 along a plane transverse to its longitudinal axis.
• the teeth 16 of the lining G are aligned in the form of adjacent rows parallel to the longitudinal axis of the transfer cylinder 2. In Figure 2, only two adjacent rows of teeth 16 have been shown.
• Each tooth 16 of the lining G is inclined relative to the radius of the transfer cylinder 2 at an angle A and is oriented in the direction of rotation of the cylinder 2 (circumferential speed).
• the circumferential distance e between two points of neighboring teeth is equal to 1.80 mm.
• the axial length H of a tooth is equal to 1.20 mm.
• a tablecloth of about 60 g / m 2 composed of 50% polyester fibers of 1.7 dtex and 38 mm in length and 50% of viscose of 1.7 dtex and 40 mm in length is produced at a speed about 78 m / min at cylinder 12.
• the card is a conventional card, without drum 2, and adjusted according to the optimum production settings in the production of nonwovens.
• the speeds of each element are described in the table below.
• the binding cylinder 12 is covered with a microperforated sleeve as described in French patent 2734285.
• the sheet is first wetted by an injector 13 projecting jets of water 140 microns in diameter with a pressure of 10 bar, the jets being spaced from each other by 0.9 mm in two rows.
• the sheet thus wetted and slightly consolidated is then subjected to the action of two successive hydraulic injectors 14 and 15 projecting water jets of 120 microns in diameter at increasing pressures of 70 bar and 90 bar, the jets being spaced apart others 1.4 mm in two rows.
• the binding cylinder 12 is followed by another binding cylinder, not shown, and covered with the same microperforated sleeve as the cylinder 12 and equipped with an injector projecting, on the face opposite to the injectors 14 and 15, jets of water of 120 microns in diameter at a pressure of 100 bar.
• the nonwoven thus obtained is then transferred to a suction mat connected to a vacuum generator, then dried at a temperature of 140 ° C in a through air oven.
• a nonwoven weighing approximately 60 g / m 2 is obtained.
• the nonwoven has a uniform appearance.
• Example 1 The conditions of Example 1 are repeated with an installation according to the invention, which now comprises a cylinder 2, but by operating the installation at the speeds indicated in the table below.
• a nonwoven weighing approximately 60 g / m 2 is obtained.
• the nonwoven has a uniform appearance, but the MD / CD ratio is poor.
• Example 2 The conditions of Example 2 are repeated. For this test, the speeds of the various elements are modified according to the table below. A nonwoven weighing approximately 60 g / m 2 is obtained. The nonwoven has a uniform appearance and a satisfactory MD / CD ratio.
• Example 2 The conditions of Example 2 are repeated. For this test, the speeds of the various elements are modified according to the table below.
• a nonwoven weighing approximately 60 g / m 2 is obtained.
• the nonwoven has a uniform appearance and an even better MD / CD ratio than in Example 3.
• Example 2 The conditions of Example 2 are repeated. For this test, the speeds of the various elements are modified according to the table below.
• a nonwoven weighing approximately 60 g / m 2 is obtained.
• the nonwoven has a uniform appearance and an even better MD / CD ratio than in Example 4.
• Example 2 The conditions of Example 2 are repeated. For this test, the speeds of the various elements are modified according to the table below.
• a nonwoven weighing approximately 60 g / m 2 is obtained.
• the nonwoven has a uniform appearance of an MD / CD ratio of 1.2, quite remarkable and unexpected.
• Example 1 is repeated with a conventional card without transfer cylinder, applying the speed ratios of Example 5 from the combers to cylinder 12.
• the nonwoven produced has many folds in the transverse direction and is unusable or unsaleable.
• MD means machine direction
• CD means cross direction
• the unit m / min is the unit of circumferential speed of the various components of the installation.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Nonwoven Fabrics (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2019
  • 2019-12-31 CN CN201980088235.1A patent/CN113508198A/zh active Pending
  • 2019-12-31 EP EP19828809.4A patent/EP3908687B1/de active Active
  • 2019-12-31 US US17/421,049 patent/US11987916B2/en active Active
  • 2019-12-31 WO PCT/EP2019/087194 patent/WO2020144084A1/fr not_active Ceased
  • 2019-12-31 ES ES19828809T patent/ES2953571T3/es active Active

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