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
  • D04H18/00—Needling machines
  • D04H18/04—Needling machines with water jets

Definitions

• the invention relates to an improved process for the manufacture of a light, non-woven textile sheet, by the technique known under the name of "water jets" under pressure; the invention also relates to an installation for implementing this method.
• this hydraulic interlacing technique consists first of all in making a base ply formed of elementary, natural, synthetic fibers, or formed of a mixture of these fibers, in particular with carding or lapping to obtain a highly aerated ply. several centimeters, even ten centimeters thick, and weighing only a few tens of grams per square meter, for example one hundred grams per 80 mm thick.
• the elementary fibers of this sheet are then entangled by means of a ramp of contiguous jets of water under high pressure (50 to 200 bars) to bring the aerated base sheet to a thickness of the order of one to several millimeters.
• the invention overcomes these drawbacks.
• this process is characterized in that, continuously:
• the base web is positively advanced on an endless porous support
• This base ply is brought to the moving porous support in the vicinity of a perforated rotary cylindrical drum, inside which a partial vacuum is applied;
• the base ply is mechanically compressed between the porous support and the rotary drum which both advance at substantially the same speed; - Then, when the base ply is compressed, a curtain of water is directed over it successively passing through the porous support, the compressed ply, the perforated drum, so as to suck up the excess water by partial vacuum;
• the elementary fibers are intermingled by directing the ramp of high pressure water jets on the wet compressed sheet obtained.
• the invention consists, continuously, first of all in positively advancing the base ply on an endless porous support, then in compressing the ply when it is in place on this porous support by a perforated drum advancing at the same speed as the porous support, and finally wetting the compressed sheet with a curtain of water under slight pressure acting through the assembly: porous support, compressed sheet, rotating drum, so that the sheet wet tablet obtained adheres to the periphery of the perforated rotary drum, before undergoing on this drum which rotates the intermingling action of at least one ramp of contiguous jets of water under high pressure.
• the dry sheet leaving the card or lapper is compressed between a porous support fabric and a perforated rotary cylindrical drum, then after having been previously wetted, is subjected to tangling by hydraulic means in the compressed state. wet, on the same drum.
• the vacuum inside the perforated rotary drum is between one hundred and one thousand millimeters of water column; indeed, it has been observed that if this partial vacuum is less than 100 mm of water, the sheet is too wet to be effectively tangled; Similarly, if it is a partial vacuum greater than 1000 mm of water, no proportional improvement is observed and energy is spent unnecessarily.
• the endless porous support in motion, supporting the aerated base ply is supported on a sector of the rotary drum to compress the ply just before wetting. It follows a slight entanglement of the elementary fibers, favorable for giving a handling cohesion to the compressed tablecloth wetted before the action of the jets of water under high pressure, which cause the main entanglement.
• the invention also relates to an installation for implementing this method. This installation is characterized in that it includes:
• an endless porous support conveyor intended to receive an aerated fibrous sheet of base formed of elementary fibers
• perforated rotary cylindrical drum comprising drive means, in synchronism with the speed of advance of the porous support, arranged tangentially by one of its generatrices to the porous support;
• At least a second ramp of high pressure water jets disposed in the vicinity of the rotary drum, opposite a second slot disposed on a generator of the fixed drum, for intermingling the elementary fibers;
• the endless porous support is a canvas made of synthetic monofilament, in particular polyester, having a porosity of between 30 and 60%, that is to say a ratio between the solid surfaces and the empty surfaces of between 30 and 60%, preferably close to 50%. It is therefore important that the support is strongly perforated to let the dampening water pass under slight pressure and allow the curtain of water not only to wet the compressed sheet, but to carry out a first light intermingling, favorable for the immediate continuation of the process.
• the first ramp of water jets intended to form the continuous curtain of water under slight pressure, is arranged opposite the porous support fabric at a distance of between 10 and 100 mm from said porous support.
• the pressure of the water from these jets is between 3 and 15 bars, preferably around 5 to 8 bars. Below 3 bars, the curtain disperses too quickly, and beyond 15 bars, the additional cost is no longer justified. It is important that the curtain of water coming from this first ramp perpendicularly hits the moving base sheet which advances and compresses, so as to wet it under optimal conditions.
• the perforated rotary drum intended to come into contact with the moving fabric is advantageously covered with a fabric made of steel or plastic monofilaments, having a porosity of between 10 and 20%, so as to allow the evacuation of the while remaining compatible with the tangle of hydraulic entanglement.
• the rotary drum has a diameter of between 300 and 1000 mm, so as not to unnecessarily increase the investment cost.
• the perforated rotary cylindrical drum surrounds a second hollow fixed coaxial cylindrical drum, connected to a source of partial vacuum to form a suction box.
• This fixed hollow drum has a vacuum of one hundred to a thousand millimeters of water column, so as to properly evacuate the water not retained by the sheet, coming either from the pre-wetting ramp or from the entangling injectors.
• the first slot arranged on the generator of the fixed internal drum facing the water ramp, has a width of between 10 and 20 mm, in order to recover all the excess water coming from the ramp and not retained by the water table. compressed.
• This mooring ramp is formed of contiguous conventional injectors arranged at predetermined distances to ensure the formation of a continuous and thin curtain.
• the aerated base sheet is held positively and that the dampening water curtain exerts its action orthogonally on a compressed sheet and through a porous support, and that the pre-wetting water completely crosses the sheet not only to cause a first slight tangling, but above all to be eliminated entirely by the partial vacuum of the suction box, it follows that not only are surface defects due to the action of the first low pressure jets eliminated, but also it facilitates the transfer of the web from the porous supply support to the periphery of the perforated rotary drum, before the action of the jets of intermingling water under high pressure.
• the compression carried out between two porous surfaces minimises the elimination of air from the aerated base sheet without disturbing the organization of the elementary fibers. Furthermore, the slight partial vacuum of the fixed drum forming a suction box ensures good retention of the wet sheet against the periphery of the rotary drum and thereby ensures the transfer to the jets of water under high entanglement pressure.
• the compressed wet sheet which advances on the rotary drum is then tangled in a conventional manner by one or more parallel ramps of jets of water under high pressure, alternated or not, according to the desired results.
• Each ramp arranged in the vicinity of the rotary drum is parallel to the pre-wetting ramp and is also arranged opposite a slot provided for this purpose on a generator of the fixed drum forming a suction box.
• the single attached figure is a schematic representation of an installation according to the invention.
• the installation according to the invention comprises an endless porous conveyor (1), formed by a canvas of polyester monofilaments having a porosity close to 50%, that is to say having a ratio between the solid surfaces and the empty surfaces close to half.
• This endless fabric (1) is driven in movement by a driving roller (2), actuated for example by an asynchro motor, and passes over guide rollers (3,4,5) for return.
• the tensioning of the fabric (1) is carried out by a tension cylinder not shown.
• a base ply referenced (10) from a card or a conventional tabler not shown is deposited.
• This tablecloth (10) which advances in the direction indicated by the arrow (FI), for example made of polyester fibers 60 mm in length, has at this stage an average thickness of eight centimeters, for an average weight of one hundred grams at square meter.
• the installation comprises a perforated rotary cylindrical drum (20) disposed in the immediate vicinity and in contact with the fabric (1) on the descending portion, disposed between the driving roller (2) and the guide roller (3).
• This perforated rotary drum (20) is rotated by an asynchronous motor not shown, at the same linear peripheral speed as the speed of movement of the fabric (1).
• This rotary drum (20) is covered with a steel monofilament fabric which has a porosity of 15%.
• the perforated rotary drum (20) is in contact with the fabric (1) which runs over a portion of an arc of a circle.
• this rotary perforated cylindrical drum (20) has inside a second fixed hollow coaxial cylindrical drum (25) connected to a vacuum source not shown, so as to form a suction box.
• the installation comprises a first ramp (30) of water jets, arranged to the left of the fabric (1) relative to the area (A), so as to form a curtain d 'water
• the fixed hollow drum (25) forming a suction box present in alignment with the water curtain
• a window (32) fifteen millimeters in width disposed over the entire generator of the cylinder (25), so as to suck the excess water from the water curtain (31).
• the sheet (10) which advances on the porous support (1) is progressively compressed by pinching between the porous support (1) and the rotary perforated drum (20), which both advance at the same linear speed, then is wetted by the curtain of water (31) and the excess water not retained by the compressed base ply, is sucked into the central box (25).
• the obtained wet compressed web (40) is held on the periphery of the perforated rotary roller (20) due to the vacuum in (25).
• This ply (40) which advances in the direction of arrow F2 is then subjected to the action of three injector ramps, respectively (41,42,43), directing on this ply (40) a plurality of jets of contiguous water at a pressure of 100 bars.
• the hollow fixed central cylinder (25) has slots (45,46,47) similar to (32) and also arranged on generators, for suctioning and remove the intermingling water.
• the tangled spunlace sheet obtained (50) is detached from the rotary cylinder (20) by passing over a detour roller (51), then from there is conveyed at (52) to the rest of the usual interlacing installation.
• a spunlace sheet (50) of polyester fibers having a density of 0.14 g / cm 3 is thus obtained.
• the method and the installation according to the invention make it possible to successfully treat hydrophobic fibers or mixtures of these fibers with other hydrophilic fibers or even sheets entirely of natural fibers.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Treatment Of Fiber Materials (AREA)
• Nonwoven Fabrics (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9475965

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (32)

Family Cites Families (11)

• 1995
  • 1995-02-03 FR FR9501473A patent/FR2730246B1/fr not_active Expired - Lifetime
  • 1995-12-27 DE DE69500811T patent/DE69500811T2/de not_active Expired - Lifetime
  • 1995-12-27 US US08/718,376 patent/US5718022A/en not_active Expired - Lifetime
  • 1995-12-27 WO PCT/FR1995/001741 patent/WO1996023921A1/fr active IP Right Grant
  • 1995-12-27 ES ES95943283T patent/ES2109106T3/es not_active Expired - Lifetime
  • 1995-12-27 AT AT95943283T patent/ATE158826T1/de not_active IP Right Cessation
  • 1995-12-27 DE DE29521570U patent/DE29521570U1/de not_active Expired - Lifetime
  • 1995-12-27 JP JP8523296A patent/JPH09511288A/ja not_active Ceased
  • 1995-12-27 EP EP95943283A patent/EP0754255B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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