Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06B—TREATING TEXTILE MATERIALS USING LIQUIDS, GASES OR VAPOURS
  • D06B5/00—Forcing liquids, gases or vapours through textile materials to effect treatment, e.g. washing, dyeing, bleaching, sizing impregnating
  • D06B5/02—Forcing liquids, gases or vapours through textile materials to effect treatment, e.g. washing, dyeing, bleaching, sizing impregnating through moving materials of indefinite length
  • D06B5/08—Forcing liquids, gases or vapours through textile materials to effect treatment, e.g. washing, dyeing, bleaching, sizing impregnating through moving materials of indefinite length through fabrics
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06B—TREATING TEXTILE MATERIALS USING LIQUIDS, GASES OR VAPOURS
  • D06B1/00—Applying liquids, gases or vapours onto textile materials to effect treatment, e.g. washing, dyeing, bleaching, sizing or impregnating
  • D06B1/04—Applying liquids, gases or vapours onto textile materials to effect treatment, e.g. washing, dyeing, bleaching, sizing or impregnating by pouring or allowing to flow on to the surface of the textile material
  • D06B1/06—Applying liquids, gases or vapours onto textile materials to effect treatment, e.g. washing, dyeing, bleaching, sizing or impregnating by pouring or allowing to flow on to the surface of the textile material flowing along an inclined surface

Definitions

• the invention relates to a process for continuous impregnation of a fibrous web, such as a fabric, knitted fabric or a nonwoven, consisting of natural, synthetic, or artificial fibers, pure or mixed, unbound or bound, with an aqueous liquid, in particular of the type containing a treatment agent, latex, primer, dye, etc. and relates in particular to the impregnation of an unbleached cotton tablecloth with a view to a treatment, for example of scouring and / or bleaching.
• a fibrous web such as a fabric, knitted fabric or a nonwoven, consisting of natural, synthetic, or artificial fibers, pure or mixed, unbound or bound
• the chemical treatment of the fibers of unbleached cotton begins with the scouring which consists, after opening and mechanical cleaning, in removing the sheath of waxy and fatty materials which envelops them, so as to make them hydrophilic. After rinsing and expressing, the chemical treatment is generally completed by a bleaching operation. So that until recently, the treatment of cotton was carried out in batches, in a continuous manner, we now seek to carry out all the operations continuously, that is to say, to form a continuous sheet and to convey the cotton on a carpet through a succession of stations in which it is subjected, one after the other, to all the stages constituting its treatment.
• Another known means consists in impregnating the sheet in a tank containing the impregnation liquor, ensuring the wetting of the fibers and finally eliminating the excess liquid by passing through a scarf.
• This technique provides a satisfactory impregnation, however when the textile sheet has no cohesion, there is a tendency to deform it by the mechanical action exerted on the fibers, and to produce irregularities "of air occlusions. , which in the end do not allow its use as is.
• the object of the invention is to remedy these drawbacks and proposes a method of impregnating a textile sheet with an aqueous liquid, in particular of the type containing a treatment agent, characterized in that it consists in:
• the suction slot fulfills the function of expressing excess liquid from the web. This expression being, unlike the conventional scarf, carried out without pinching or contacting mechanical parts, does not cause any significant displacement of the fibers and does not disturb their organization. The risks of deformation of the sheet are low.
• the slot by its arrangement preferably in line with the liquid blade, exerts a suction force on it and helps to stabilize its flow. and to guarantee a distribution of the flow over the entire width of the sheet.
• the rate of expression is equal to the rate of residual liquid after spinning relative to the weight of the sheet. This objective is achieved by pouring a quantity of liquid onto the sheet such that the rate of the liquid spilled relative to the weight of the sheet (see its definition below, in the examples) is greater than a rate determined beyond which the rate of expression is a function of the depression created by the suction slot and independent of the quantity spilled.
• this threshold is determined experimentally. It corresponds to a spilled rate between 300% and 1500%. For the same liquid, it depends on the nature of the fibers, the weight of the tablecloth and its presentation: compressed or open, fabric, knitted or nonwoven. For example, for a carded tablecloth of unbleached cotton of 250 g / m 2 , impregnated with an aqueous scouring solution, it corresponds to a rate of the order of 600%.
• the take-up rate can then be varied between 150% and 400%. preferably between 250% and 300%.
• the method essentially aims at impregnating a textile sheet composed of unbound fibers, with a grammage of between 20 and 1000 g / m.
• the fibers can be of all kinds: natural, synthetic or artificial, alone or in a mixture.
• the sheet can be formed by any suitable means, mechanical or pneumatic.
• the ply may optionally be composite and obtained from two or more card webs associated or not with pneumatically formed webs.
• the process is also suitable for impregnating bonded textiles: fabrics, knits or others.
• Another object of the invention is to provide a liquid distribution device ensuring the formation of a continuous and as regular blade as possible. This is achieved with a liquid dispensing member provided with a weir with a portion of flow surface oriented towards the sheet, of width at least equal to that of the area to be impregnated.
• the weir consists of a sheet with a convex cylindrical profile, the downstream edge of which is serrated in order to facilitate detachment of the liquid blade.
• the laminar flow is improved by providing grooves in the region of the lateral edges.
• Another object of the invention is to improve the impregnation of a sheet made up of unbound fibers, deposited on a porous mat, by mechanical or pneumatic means. This is achieved by compressing the web, in particular by mechanical means, so as to reduce its thickness before it passes under the liquid slide.
• said compacting means is constituted by a pressure roller.
• the compaction of the sheet is further improved by having a vacuum slot immediately downstream of the compacting member so as to avoid relaxation of the sheet before it passes through the impregnation means.
• Another object of the invention is to design a continuous scouring and bleaching process of unbleached cotton fibers, making it possible to obtain a treated cotton sheet, having both mechanical strength and regularity of sufficient appearance. health so that the tablecloth can be used as it is, without any mechanical treatment other than cutting or other operation of transformation into finished product.
• the sheet can be manipulated, transferred, treated, rinsed, expressed without risk of rupture or deformation.
• the quality of its appearance it is it can be transformed directly into a finished product without having to card it again or rework it.
• FIG. 1 schematically shows a method of impe ⁇ gnation of a cotton web
• FIG. 2 is a perspective representation of a liquid dispensing device
• FIG. 3 shows schematically an installation for scalding and bleaching unbleached cotton fibers.
• FIG. 1 An impregnation installation is shown in accordance with the invention, applied to the treatment of a sheet of unbound fibers of unbleached cotton, for example.
• a forming system shown diagrammatically by the block (2) deposits the open and individualized fibers on an endless belt (4), driven in a plane translational movement according to the arrow.
• the carpet is porous; it may be a waterproof material which is suitably perforated or else a canvas.
• the carpet is stretched between horizontal rollers, one of which is powered.
• the sheet (6) from the former is relatively thick and uniform.
• a pressure roller (7) rotatably mounted about a horizontal axis, transverse to the direction of movement, cooperating with a counter-roller (8) placed on the canvas, has the function of partially expelling the air from the tablecloth by reducing its thickness. It is important to expel this air, because it forms pockets opposing the subsequent penetration of the liquid.
• a depression under the sheet by means of a first suction slot (9), to prevent it from naturally swelling under the effect of elastic restoring forces exerted by the fibers themselves.
• the depression presses the fibers against the fabric and promotes the action of the liquid afterwards.
• the slot (9) is in communication with a vacuum source, not shown.
• the sheet resulting from this compacting means has undergone no other deformation than a reduction in height. Its homogeneity is not broken.
• a tablecloth of unbleached cotton having, initially according to the grammage and the method of forming, a thickness of between 40 and 150 mm, is thus compacted up to a height between 10 and 30 mm.
• the effect of a vacuum created under the sheet can also be used.
• This (10) is composed of two elements: a distributor (11) of the liquid and a suction member (13).
• the distributor member (10) is designed to deliver the liquid in the form of a curtain, or blade, transverse to the direction of displacement of the sheet, the liquid being set in motion by the action of simple gravity.
• a suction member (13) is provided, consisting of a suction slot of determined width, the vacuum height of which is chosen so as to be able to control the rate for expressing the liquid in the tablecloth.
• the dispenser (11) comprises a liquid accumulation zone, separated into two compartments (113. 114) by a transverse partition (112) pierced with orifices connecting the 2 compartments (113,114).
• the first compartment is supplied with liquid by a pipe and supplies the compartment (114).
• This arrangement makes it possible to reduce turbulence inside this latter compartment.
• On its outer wall there is provided a weir (115) of convex cylindrical shape, whose generatrices are horizontal and oriented perpendicular to the direction of travel of the web.
• the free edge of the weir is serrated, that is to say it is provided with pointed projections (115 ') in the extension of its surface, in order to facilitate the detachment of the liquid from the surface of the weir.
• the curvature of the weir is chosen so that the liquid flowing from the overflow from the compartment (114) forms a laminar flow with streams of current as parallel as possible.
• the tangent of the weir at its free edge is preferably substantially vertical.
• the surface condition is also a factor to take into consideration; it is chosen smooth to reduce disturbances. The flow from the weir thus forms a curtain, or blade, a continuous liquid in its transverse direction and substantially planar.
• the size of the opening of the slit is determined so as to exert a suction of sufficient duration when the sheet passes at its level. It therefore extends downstream of the weir over a distance determined as a function of the nature of movement of the sheet.
• the depression generated by the slot is chosen so as to be sufficient to wring out the sheet. Furthermore, it has been found that it is possible to control the rate of expression of the sheet by adjusting only the level of vacuum, when the liquid flow rate exceeds a threshold.
• Lightly colored water was poured out with the device described.
• the suction slot was 30 mm wide and the vacuum was 90 mb (relative vacuum).
• the flow rate (D) of the discharged water was gradually varied. It can be seen that from a spilled rate threshold (Td) corresponding to around 600, the rate of expressing (E), or of carriage, varies very little.
• Td f (E) becomes asymptotic.
• the spilled rate (Td) is the ratio expressed as a percentage between the mass of liquid spilled and the mass of fibers traveling under the mass of said liquid.
• a needled nonwoven of viscose fibers was treated in the same way as in Example 1.
• a cotton jersey was treated in the same way as in Example 1
• the bleaching process consists in opening, cleaning, effec ⁇ killing, if necessary, the cotton blend of different origins and qualities, and in forming (21) a sheet of between 50 and 1000 g / m 2 , preferably between 100 and 600 g / m 2 by any suitable means, mechanical (carding) and / or pneumatic.
• This sheet is supported and driven by a belt through the various treatment stations.
• the tablecloth is introduced into a vaporizer (23) heated to a temperature close to 100 ° C. in which it remains, while remaining continuous thanks to an appropriate storage means, for a determined period depending on the liquor and the take-up rate. .
• the hydrophilic scoured sheet is impregnated with a bleaching solution (hydrogen peroxide with sodium hydroxide essentially) by means of a third device with a liquid blade and a vacuum slit (25).
• a bleaching solution hydrogen peroxide with sodium hydroxide essentially
• the sheet is again introduced into a vaporizer (26) heated to a temperature close to 100 ° C. in which it stays thanks to an appropriate storage means, for a time long enough for the bleaching to be effective.
• the maximum amount of water contained in the sheet is extracted in (28), and it is dried in an oven (29) which is preferably through air.
• the tablecloth can be used directly for the manufacture of packaged hydrophilic cotton or else be transformed into fibers after shredding for the production of nonwoven products.
• the invention is not limited to the embodiments shown. It includes all equivalents and all appli ⁇ cations within the reach of those skilled in the art.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Treatment Of Fiber Materials (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Paper (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

Country Status (9)

Families Citing this family (13)

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• 1990
  • 1990-04-11 FR FR909004647A patent/FR2660942B1/fr not_active Expired - Lifetime
• 1991
  • 1991-04-10 EP EP91908815A patent/EP0524268B1/de not_active Expired - Lifetime
  • 1991-04-10 DE DE69102763T patent/DE69102763T2/de not_active Expired - Lifetime
  • 1991-04-10 ES ES91908815T patent/ES2057890T3/es not_active Expired - Lifetime
  • 1991-04-10 AT AT91908815T patent/ATE108229T1/de not_active IP Right Cessation
  • 1991-04-10 CA CA002080487A patent/CA2080487C/fr not_active Expired - Fee Related
  • 1991-04-10 US US07/934,513 patent/US5509161A/en not_active Expired - Fee Related
  • 1991-04-10 AU AU77525/91A patent/AU7752591A/en not_active Abandoned
  • 1991-04-10 WO PCT/FR1991/000290 patent/WO1991015622A1/fr active IP Right Grant

Non-Patent Citations (1)

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