GB2152855A - Continuously applying a liquor to elongate material - Google Patents

Abstract

A method of continuously applying a liquor to elongate material, which comprises forming a linear assembly comprising a plurality of yarns 1, filaments, tow, threads or twines, and passing the assembly through an elongate treatment zone 5 having at least one constrictive throat 15 located in said zone. The throat has a cross-sectional area smaller than that of the linear assembly immediately prior to its passage through the throat such that said linear assembly is compacted on passage therethrough. After passage through the throat, the combination of liquor and linear assembly passes through a region in which it is maintained in a uniform, composite state. <IMAGE>

Description

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GB2 152 855 A

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SPECIFICATION

Method and apparatus for continuously applying a liquor to an elongate material

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The present invention relates to a method and apparatus for continuously applying a liquor, e.g. a treating liquor, to an elongate material. More particularly, the present invention relates to a method and

10 apparatusforcontinuouslyapplyingatreating liquor, e.g. a dye, toalinearassemblyof a plurality of yarns, filaments, tows, threads ortwines to thereby uniformly impregnate the linear assembly with the treating liquor.

15 Atpresentyarn is normally dyed by a batch process which involves the steps of:—

(a) forming a plurality of hanks;

(b) suspending the hanks from the lid of a vat, i.e. thetankofthedyeing apparatus;

20 (c) supplying to the vat about 20 litres of water per kilogram of yarn, i.e. a liquor ratio of about 20:1, and adding various auxiliary chemicals to form a liquor;

(d) lowering the hanks into the liquor;

(e) heating the liquorto a temperature of 50°C

25 whilst circulating the liquor through the hanks for a period of about 10 minutes;

(f) raising the hanks out of the liquor;

(g) adding dyestuffto the liquor, whilst circulating the liquor in the vat, to form a dyeing liquor;

30 (h) lowering the hanks into the dyeing liquor;

(i) increasing the temperature of the liquorto 95°C overa period of about 1 hour whilst circulating the dyeing liquor at about 10 litres per minute per kilogram of yarn;

35 (j) holding the temperature of the dyeing liquor at 95°Cforabout1 hour whilst circulating the dyeing liquor;

(k) optionally, lowering thetemperature of the dyeing liquorto 80°Cwith circulation of the dyeing

40 liquor overa period of about 15 minutes (omission of this step may result in more dye being present in the effluent liquor in step 1 below);

(1) discharging the exhausted dyeing liquor as effluent;

45 (m) optionally, adding clean warm watertothevat at a ratio of about 20:1 (i.e. about 20 litres of water per kilogram of yarn) and circulating the warm water;

(n) if step (m) is present, discharging the water as effluent and draining the hanks;

50 (o) off-loadingthehankstoacentrifugeand removing water;

(p) loading the hanks onto a conveyor and passing them through an oven to further dry them; and

(q) packagingtheyarns.

55 Although satisfactory dyeing of yarn can be achieved utilizing the above batch dyeing process, the process does have the disadvantage that a number of separate steps are involved which necessitate considerable handling of the yarn.

60 Afurther disadvantage of the above-described yarn batch dyeing process is that the dyebath must be of a size sufficient to accommodate all of theyarn to be dyed in a single batch. Therefore, if at any time it is desired to dye a smaller amount of yarn, then either

65 the dyebath has to be used at lessthan its optimum capacity, i.e. the dyebath is being used to dye an amount of yarn smaller than the maximum amount it is capable of accommodating, or it is necessary to have a further, smaller dyebath of a size suitable for 70 dyeing that smaller amount of yarn and thereby avoid the inefficient situation of having to use a large amount of dyeing liquorto dye only a small amount of yarn.

A still further disadvantage of the above-described 75 yarn batch dyeing process isthatthe packing of the yarns in the vat affects liquorcirculation which, in turn, affects the shade and levelness of dyeing. Hence fora particular shade and degree of levelness of dyeing, there are limitations on the variation of batch size. 80 From the above it can, therefore, be seen thatthe batch system of dyeing under utilizes capital investment in apparatus except in the special case of production runs where the yarn can be divided into integ ra I batch sizes equa I to the capacity of the 85 apparatus.

Further disadvantages of the batch dyeing of yarn are thatthe process utilizes large quantities of water and energy, and thatthe process imposes a heavy demand on the effluent system.

90 The main advantage of the above-described batch processforthe dyeing of yarn is that satisfactory uniformity of the dyeing of theyarn, known as level dyeing, can be achieved but only at a cost. Considerable care has to be exercised in liquor circulation, in 95 temperature change, in the use of auxiliary chemicals to adjust the rate of strike, and the equilibrium partition between liquorand theyarn.The yarn has to be presented to the liquorso that all parts have,

ideally, equal liquor circulation and so equal chance of 100 receiving dye. Foreconomic reasons there has to be arbitration between factors such as liquor ratio, rate of change of temperatures, time at high temperature and the extent of dye exhaustion. 5% and even 10% of the dye may be left in the dye liquor.

105 In view of the above, it would clearly be advantageous if a continuous process could be developed which avoids the disadvantages of the batch yarn dyeing process but still achieves satisfactory uniformity of distribution of the dye on the yarn. 110 Continuous processes are known forthe dyeing of tow in which the tow is continuously passed through a dye liquor trough and the amount of liquor applied to the tow is controlled by passing the tow, after it emerges from the trough, between two nip or 115 pressure rollers which squeeze the excess liquor from the tow. The tow is then passed to a further treatment stage where it is heated and the dye is fixed thereon. Such continuous processes are known as "pad-mangle" processes.

120 Although continuous processes for dyeing tow have the advantage, overthe batch dyeing technique, that they can readily accommodate differing quantities of tow being passed through the process, the existing methods of continuous dyeing have one or more of 125 the following disadvantages:—

(i) lack of uniformity of dyeing along and across the feedstock (by feedstock is meantthe material being dyed);

(ii) lack of uniformity of dyeing, surface to interior, 130 of the feedstock;

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(iii) control problems associated with the use of dye liquortroughs;

(iv) wastageofdyestuffasa result ofthe use of dye liquortroughs, particularly wastage occurring at

5 changes ofthe dyeing programme;

(v) the dyeing apparatus holds a considerable amount of feedstock and is not self threading so that changes in programme or involuntary stoppages are extremely wasteful offeedstock;

10 (vi) the dyeing apparatus marks and changes the feedstock;

(vii) dye liquor in the trough may become contaminated by materials, e.g. grease or water, leaching from the feedstock into the troug h; and 15 (viii) dye liquor in the trough may become deficient in dyestuffand acid because these transfer relatively quickly to the feedstock and also because the liquor that is recycled in such a continuous process is of a weaker dyestuff/acid strength than the initially intro-20 ducedfresh dye liquor.

Because ofthe above disadvantages associated with the existing continuous dyeing processes, continual monitoring and control ofthe process is therefore necessary, particularly to maintain a con-25 stant dye concentration and a constant pH and to ensure that the level of contaminants in the trough does not reach an unacceptable level.

A pad-mangle dyeing apparatus, in which the feedstock passes vertically through nip rollers and 30 which uses the nip rollers to form the trough, to some extent reduces the problem of weakening the dye liquor as a result of recirculation ofthe dye liquor. However, the use of a pad-mangle dyeing apparatus renders it difficult to maintain the conditions neces-35 saryforuniform addition ofthe dye liquorto the feedstock, particularly when the dye liquor addition exceeds 100% of the weight ofthe feedstock.

The use ofthe above-described continuous dyeing processes have proved unsatisfactory when applied 40 to yarns as the uniformity of distribution ofthe dye on the yarn is poor. Aso-called "frosting" effect occurs which is when the outermost fine fibres or filaments of the yarn are not dyed to the same extent as the main bulk ofthe yarn. Frosting is particularly emphasized by 45 the use of a pad-mangle dyeing apparatus since such an apparatus raises fibres by adherence to the nip rollers atthe exit from the nip. Further, the means by which theyarnsare heated forthe purpose of dye strike and dye fixation can affect the uniformity of the 50 distribution ofthe dye on the yarn. Forexample,ifthe yarns are heated by passing them through an electrically heated zone whilsttheyarns are loosely held, the outerfibres are usually depleted of liquor which leads to more dyeing liquor, and hence more 55 dye, migrating to these fibres, thereby resulting in these fibres being more highly dyed than the remaining fibres. If, however, the yarns are heated insteam whilst being loosely held, condensate tends to leach dye from the surface ofthe yarns as it wicks to the 60 interiorof the yarns, thereby enhancing the frosting effect. Increasingthe amount of dyeing liquor aggravates drainage along the fibres.

There are dyeing systems which envelope the fibres during fixation of thedye butthese systems areonly 65 used on fibres which are subsequently blended as staple and are unsuitable for use on yarns.

It has now been found that, by using a new method of continuously applying a liquorto an elongate material in accordance with the present invention, the 70 above-stated disadvantages ofthe known batch and continuousdyeing processes may be overcome and that a dyed product may be obtained having a uniformity of dyeing which compares favourably with that ofthe batch dyeing techniques.

75 According to the present invention there is provided a method of continaously applying a liquorto an elongate material, which comprises forming a linear assembly of a plurality of yarns, filaments, tow, threads ortwines, hereinafter referred to as "linear 80 assembly", continuously feeding liquor, e.g. a dyeing liquor, to said linear assembly whereby to impregnate said linear assembly with said liquor, characterized in that said linearassembly/liquorcombination is continuously passed through an elongate treatmentzone 85 andthrough at least one constrictive throat located in said elongate treatment zone, theoreach of said constrictive throats having a cross-sectional area smallerthanthat ofthe linear assembly immediately priorto its passagethrough said constrictivethroat(s) 90 suchthatsaid linear assembly is compacted on passagethroughsaidconstrictivethroat(s),and wherein, after passage through the constrictive throat(s),said liquor/linear assembly combination passes through a region in which it is maintained in a 95 uniform, composite state.

As used herein in connection with the present invention, the terms "compacted" and "compaction" are intended to indicate thatthe overall cross-sectional area ofthe linearassembly of yarns, 100 filaments, tows, threads or twines is reduced.

In the method ofthe invention the liquor and linear assembly are held in a uniform composite state after they emergefromthe constrictivethroat(s) such that all oftheyarns, filaments, tows, threads ortwines of 105 the linear assembly have uniform amounts ofthe liquor in their surroundings. The liquor and linear assembly are held in this uniform composite state until substantial completion ofthe desired interaction between the linearassembly and the liquor, e.g. in the 110 case where the liquor is being used to treatthe linear assembly the active constituent of the treating liquor, such as a dye, has transferred from the treating liquor to the linear assembly. Thereafter, the linear assembly may befurthertreated,for exampfe„the active 115 constituent, such as a dye, may be diffused into the material ofthe linear assembly and be fixed inthe molecular structure ofthe material ofthe linear assembly, i.e. heldby packingforcesand/or hydrogen bonding and/or covalent chemical bonding and/or 120 ionic bonding.

In the methodof the present invention it is important thatthe liquor/Hnear assembly fills the space availabtein the treatment zone immediately priorto, i.e. upstream from,theconstrictivethroat(s) 125 so as to form a reservoir(s) of liquor extending upstreamfrom the restrictive throat(s). Preferably,the linear assembly has a cross-sectional area such that, on its passageth rough the elongate treatment zone, it is slightly compacted by the inner surface ofthe 130 treatmentzone upstream from the constrictive

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throat(s).

In a particularly preferred embodiment ofthe method ofthe present invention, the passage ofthe liquor/linearassembly through the elongate treat-5 mentzone is such that:

(a) the linear assembly is appreciably compacted by the constrictive throat(s) on its passage therethrough;

(b) the liquor/linear assembly fills the space avail-10 able in the elongate treatmentzone immediately upstream from the constrictive throat(s) and the linear assembly is slightly compacted by the inner surface of the elongate treatment zone; and

(c) in the region ofthe elongate treatmentzone

15 downstream from the constrictive throat(s), the liquor partially fills the space available in the elongate treatment zone and the linear assembly is slightly compacted by the inner wall ofthe elongate treatment zone.

20 The amount of liquor in this (these) "reservoir(s)" should preferably remain constant, thereby maintaining an invariant liquor flow rate.

Some or all ofthe liquor may, for example, be fed to the linearassembly before the "reservoir", in which 25 case there will be part ofthe elongate treatment zone only partially filled with the liquor/linear assembly combination.

Preferably the greater proportion ofthe liquor is fed at such a rate to the linear assembly at a point within 30 the "reservoir", so that a substantially stationary 'plug' of liquor isformed upstream of that point.

In these circumstances the rate of counterflow of liquid relative to the yarn is higher upstream ofthe liquor entry pointto that downstream ofthe liquor 35 entry point and the effective balancing pressure created per unit length of reservoir is greater upstream ofthe liquor entry pointthan downstream of the liquor entry point. This has the effect of reducing the magnitude of fluctuation in the length ofthe 40 reservoir, due, for example, to variations in the linear volume ofthe material ofthe linear element (i.e. excluding voids and liquor space). Furthermore, if the cross sectional area ofthetreatmentzone upstream of the liquor entry point is less than that downstream of 45 the liquor entry point then since less liquor space is available, less liquor is involved in a linear variation of the reservoir and therefore the fluctuation in volume ofthe reservoir will also be less. The cross-sectional area ofthetreatmentzone upstream ofthe said liquor 50 entry point is therefore preferably less than that downstream of the said liquor entry point. Oneway of achieving this is to provide an extra constrictive th roat upstream ofthe said liquor entry point, in which case any liquor entering beforesuch extra restrictive throat 55 must not be such as to create a reservoir upstream of said extra constrictive throat.

Preferably the elongate treatment zone is of circu lar cross-section and preferably the or each constrictive throat is in the form of a constrictive orifice of circular 60 cross-section.

The whole ofthe liquor may, for example, be fed to the linear assembly by introducing it into the elongate treatmentzone upstream from the constrictive throat(s) intended to produce reservoirs. However, it 65 is also possible to feed a part ofthe liquorto the linear assembly before the linear assembly enters the elongate treatment zone or downstream ofthe constrictive throats.

At, or in the region of, the point at which the liquor is fed to the linear assembly, the linear assembly may, forexample, be passed through a guide boxto separate the yarns, filaments, tows, threads or twines forming the linear assembly and thereby facilitate the even distribution ofthe liquorthroughoutthe linear assembly.

The liquor may, for example, be heated before it is fed to the linear assembly and such heating may, for example, be achieved by passing the liquorthrough a beat exchanger. Such heating would help to solubil-ize, in the solvent medium, e.g. water, ofthe liquor, other components, e.g. dye, ofthe liquor.

In one embodiment of the method ofthe present invention the linear assembly is conditioned before the liquor, e.g. a dyeing liquor, isfed thereto, the purpose ofthe conditioning being to aid the even distribution ofthe liquorthroughoutthe plurality of ya rns,filaments, tows, threads ortwinesforming the linearassembly. Such conditioning may, forexample, comprise one or more ofthe steps of:

(i) washing the linearassembly, e.g. with water, preferably containing a scouring agent and removing excess washing fluid from the resulting wet linear assembly, for example, by passing the wet linear assembly between nip or pressure rollers, this treatment removing or reducing the amount of contaminants, e.g. grease, on the yarns, filaments, tow, threads ortwinesformingthe linearassembly;

(ii) heating the linear assembly, for example by passing the linear assembly through a heat exchanger, to raise the temperature ofthe linear assembly to an appropriate temperature fortreatment with the liquor;

(iii) directly contacting the linear assembly with steam; and

(iv) adjusting the pH ofthe linearassembly.

Conditioning ofthe linearassembly priorto it being contacted with the liquor may, for example, be advisable if the individual yarns, filaments, tows, threads ortwinesforming the linearassembly do not all have the same characteristics with regard to their affinity for the liquor.

The effect of passing the liquor/linear assembly through at least one constrictive th roat is such that the compaction ofthe linearassembly as it passes through the constrictive throat(s) results in the liquor being forced, or "squirted", through the constrictive throat(s) in the same direction as the passage ofthe linear assembly but at a faster speed than the linear assembly is passing therethrough, and also results in the liquor being decelerated upstream from the constrictive throat(s) and relative the main direction of passage ofthe liquor/linear assembly. This is believed to give rise to the situation wherein the liquor and the linearassembly may both be passing atthesame speed through the region ofthe elongate treatment zone upstream from, and remote from, the constrictive throat(s) (see aforesaid discussion ofthe formation of a "reservoir" of liquor and the effect of applying the liquorto the linearassembly in the region of, or before, this "reservoir"), the linear assembly is

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passing through the region ofthe elongate treatment zone immediately upstream ofthe constrictive throat(s) at a faster speed than the liquor is passing through the same region, and the liquor is passing 5 through the constrictive throat(s) at a faster speed than the linear assembly is passing through such constrictive throat(s).

The overall result ofthe presence ofthe constrictive throat(s) is thatthe liquor is 'orced to move relative to 10 the linear assembly and thereby achieves a better, and more uniform, distribution ofthe liquorthroughout the plurality of yarns, filaments, tow, threads ortwines forming the linearassembly.

The presence of at least one constrictive throat 15 downstream from the point at which the liquor is fed to the linearassembly results in a pressure gradient in the liquor, the maximum pressure being in the region ofthe entrance to constrictive throat(s) and the pressure gradually decreasing on both the upstream 20 and downstream sides ofthe region of maximum pressure. Further, the pressure upstream from the constrictive throat(s) balances the pressuredown-stream from the constrictive throat(s).

As stated above the linearassembly and the liquor, 25 after passing th roug h the constrictive th roat(s), pass through a region wherein they are maintained in a uniform composite state such thatthe yarns, filaments, threads, tows ortwines ofthe linearassembly have uniform amounts ofthe liquor in their surround-30 ings. The linearassembly and liquor are maintained in such a uniform composite state until the uniform distribution ofthe liquorin the surroundings is no longer critical, for example, in the case of yarn dyeing, until the dye has transferred from the liquorto the 35 yarns. The liquor/linear assembly composite may, for example, be heated in orderto activate or accelerate the treatment process. The method of heating the liquor/linear assembly composite may, for example, be by an electric heater or a fluid heating jacket located 40 aroundthe containing outerwall ofthe elongate treatment zone downstream from the constrictive throat(s). Preferably, the heating is spread over the cross-section ofthe liquor/linearassemblycomposite, forexample, by utilizing, as the heating source, 45 microwave or high frequency electromagnetic radiant energy, or when convenient by passing an electric current directlythrough the liquor.

In a particularly preferred embodiment of the method ofthe present invention the liquor is heated 50 before it is fed to the linear assembly and, after the liquor/linearassembly has passed through the constrictive throat(s), the liquor/linearassembly is passed through a hotzoneinwhichthetemperatureis maintained in the downstream direction.

55 If the liquor is a dyeing liquor, then in the hot zone the dye transfers from the liquor onto theyarns, filaments, tows, threads ortwines forming the linear assembly. However, in this case, the hot zone may not achieve sufficiently complete transfer of the dye onto 60 the yarns, filaments, tows, threads ortwines of the linear assembly and in this case a further hotzone is preferably provided. This further hot zone may, for example, comprise a continuous belt passing around a drum with the liquor/linear assembly composite 65 passing between the belt and the drum and passing one or more times around the drum. In such an arrangement for the further hot zone, the temperature ofthe liquor/linear assembly composite is maintained, the composite isflattened by its passage between the belt and the drum, the intimacy ofthe linear assembly and liquor is maintained, and the desired interaction between the liquorandthe linear assembly is permitted to be completed, e.g. the transfer of dye to the linearassembly. In the case of dyeing yarn, a still further hotzone may be provided, e.g. in the form of a J-box, but in this still further hot zone it is not necessary to maintain the linear assembly and liquor as a uniform composite since the desired interaction therebetween has already been allowed to take place.

The impregnated yarns,filaments, tows, threads or twines ofthe linear assembly may, for example, have further liquor or a different liquor applied thereto downstream ofthe constrictive throat(s), e.g. to alter the pH, and/or may come into contact with steam condensate as a result of heating the yarns directly with steam, in which cases a further constrictive throat may be used to improve the uniformity of distribution ofthe liquorthroughout each ofthe yarns, filaments, threads, tows or twines forming the linear assembly, thisfurtherconstrictive throat being located downstream ofthe point of introduction of thefurtherfluid and/or steam. The linear assembly may be further treated by passing it through a wash bath and/or through a mangle, e.g. to remove any excess fluid, and/orthrough a drying oven and/orthrough an oil applicator.

After treatment, the yarns, f i lam ents, tows, th reads ortwines may, for example, be packaged on rollers, creels or bobbins suitable forfurthertextile processing for storage or transportation, or be cut into desired lengths, or separated by guide pins into a warp sheet, and then preserved in this manner until collected.

If, in the method ofthe present invention, the liquor isfedtothe linearassembly by introducing itintothe elongate treatment zone and the linear assembly is directly contacted with steam which is introduced into the elongate treatment zone upstream from the point of introduction of the liquor, then the steam will have, in addition to its intended function of conditioning the linear assembly, the added effect of restricting the flow ofthe liquor and so further stabilizing the volume ofthe reservoir of liquor upstream ofthe constrictive throat(s), this restriction inflow being the result, as indicated above, ofthe presence ofthe constrictive th roat(s). Restriction in the flow of the liquor is preferably achieved bythe presence of a constrictive throat upstream from the point at which the liquor is fed to the linear assembly, this constrictive th roat being additional to the constrictive throat(s) positioned downstream ofthe point at which the liquor is fed to the linear assembly.

More preferably the constrictive throat upstream of the liquorentry point has a cross-sectional area similarto that of thefirst constrictive throat downstream of said entry point. This will further stabilize the "reservoir" volume by stabilizing the time variation ofthe amount of liquor passing out ofthe "reservoir" by the constrictive throat downstream of

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the liquor entry point; said stabilization occurring due to the forces per unit length generated by liquor penetrating the constrictive throat upstream ofthe liquor entry point exceeding those forces per unit 5 length required to pump the equivalent amount through the constrictive throat downstream ofthe liquorentry point.

If such a constrictive throat is present, upstream of the liquorentry point, the linearassembly is prefer-10 ably dampened with water orsteam before entering sa i d co n stricti ve th roat, to red u ce p u 11 -th ro u g h ten -sion on the linear assembly.

According to the present invention there is also provided an apparatusfor applying a liquorto an 15 elongate material, which comprises meansforcon-tinuously feeding a liquorto a linearassembly of a plurality of yarns, filaments, tows, threads or twines whereby to impregnate said linearassembly with said liquor, characterized in that said apparatus also 20 comprises an elongate treatmentzone for passage of said linear assembly therethrough, at least one constrictive throat for passage of said linearassembly therethrough and to compact said linearassembly, said at least one constrictive throat being located in 25 said elongate treatmentzone and downstream ofthe means forcontinuously feeding said liquorto said linear assembly, and means located downstream of said constrictive throat(s) for maintaining said linear assembly and liquor in a uniform composite state. 30 Preferably the elongate treatment zone is of circular cross-section and preferably the or each constrictive throat is in the form of a constrictive orifice of circular cross-section.

The means for continuously feeding the liquor to 35 the linearassembly may, for example, be positioned to introduce the liquorto the linear assembly upstream from the elongate treatment zone. However, it is preferable to position the means for introducing the liquor into the elongate treatment zone upstream from 40 the constrictive throat(s).

At, or in the region of, the meansfor continuously feeding the liquorto the linear assembly, there may be provided a guide boxforseparating the yarns, filaments, tows, threads ortwines forming the linear 45 assemblyandtherebyfacilitatetheevendistribution ofthe liquorthroughoutthe linear assembly.

The apparatus according to the present invention may,forexample, comprise means, e.g. a heat exchanger, for heating the liquor before it is fed to the 50 linearassembly.

Conditioning means may,for example, be provided in the apparatus according to the present invention to condition the linear assembly before the liquor is fed thereto. Such conditioning means may, for example, 55 comprise oneor more of thefollowing:—

(1) washing means to wash the linearassembly and means, e.g. nip or pressure rollers, to remove excess washing fluid, e.g. water, preferably containing a scouringagent, from the resulting wet linear

60 assembly;

(2) heating means, e.g. a heat exchanger, to raise thetemperature of the linearassembly;

(3) steam inlet means adapted to allow steam to directly contactthe linear assembly; and

65 (4) means for adjusting the pH ofthe linear assembly.

The apparatus according to the present invention preferably comprises means for activating or accelerating the treatment process, e.g. an energizing or hotzone, after the liquor has been fed to the linear assembly and after it has passed through the constrictive throat(s). The energizing or hot zone may, for example, comprise oneor more of the following:—

(a) steam injection meansfordirectlycontacting the steam with the liquor/linear assembly composite and thereby raise the temperature ofthe composite, in which case steam condensate will increase the total liquor volume and a further constrictive throat may, for example, be utilized downstream ofthe point of introduction ofthe steam to aid in the uniform distribution of this increased total liquor volume;

(b) meansfor introducing furthertreating liquoror another fluid, e.g. for adjusting the pH, or containing a catalyst, reactive chemical or a metal complexing agent;

(c) a heater, e.g. an electric ohmic heater or a jacket for passing hot fluid therethrough, the heater being adapted to surround the fluid/linear assembly composite and heatthe composite;

(d) heating means in theform of a microwave heater or a high frequency electromagnetic wave generator, such heating means avoiding thetemperature gradient occurring between the heater wall and the centre of liquor/linear assembly composite when an electric ohmic heater or a fluid heated jacket is used; or

(e) a battery of cells made up of an alternating series of annular electrical insulators and conductors through which the liquor/linear assembly composite passes such that an electric current can be made to flow through the liquor.

If the apparatus according to the present invention is to be used to treat the linear assembly with a dyeing liquor and thereby dye theyarns, filaments, tows, threads or twines forming the linear assembly, then it may be desirableto include, in addition to an energizing or hotzone, a further hotzone located downstream of said energizing or hot zone and in which the linear assembly and dyeing liquor are maintained in intimate uniform contact. For example, thefurther hotzone may comprise a continuous hot belt passing around a hot drum such thatthe dyeing liquor/linear assembly composite may be passed between the belt and the drum and one or more times around the drum. A still further hotzone may, for example, be provided downstream of said energizing or hotzone and said further hotzone, e.g. in theform of a J-box, to complete the desired interaction between the linear assembly and the dyeing liquor. For example, if the linear assembly comprises a plurality of yarns, the diffusion ofthe dye onto the yarns and the molecular fixation ofthe dye within the fibres ofthe yarns is completed in the hot zone(s).

The apparatus may, for example, also comprise meansforwashingthetreated linearassembly, a mangle for removing excess fluid from the linear assembly, and meansfor drying the linearassembly after passage through the washing means and the mangle. The apparatus according to the present invention may, for example, also comprise an addi70

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tional constrictive throatorthroatsfor improving the uniformity of distribution of the treating liquor throughout each of the yarns, filaments, tows, threads ortwines forming the linear assembly and/or a wash 5 bath and/ora mangle, e.g. to remove any excess fluid, and/or an oil applicator, these being located such that the linear assembly passes therethrough after its passage through the constrictive throat(s) in the elongate treatment zone and, if present, the energiz-10 ing/hotzoneand/orfixingzone.

Packaging means, e.g. rollers, bobbins orcreels,for the treated yarns, filaments, tows, threads ortwines, or means for cutting the treated yarns, filaments,

tows, threads ortwines into desired lengths, or guide 15 pins forseparating said treated yarns,filaments, tows, threads ortwines into a warp sheet, may, for example, be provided in the apparatus ofthe present invention.

In addition to the constrictive throat(s) located downstream ofthe means for continuously feeding 20 the liquorto the linear assembly, an additional constrictive throat is preferably provided upstream of the meansfor continuously feeding the liquorto the linearassembly.

If this further constrictive th roat is present then, 25 preferably, meansforwetting orsteaming the linear assembly priorto its entering said further constrictive throat is also provided.

The presentinvention will now be further described with reference to the accompanying drawings, in 30 which:—

Fig. 1 is a schematic representation of one embodiment of an apparatusfor carrying out the method of the presentinvention;

Fig. 2 is a schematic representation of a further 35 embodiment of an apparatusfor carrying outthe present invention;

Fig. 3 is a schematic representation of a still further embodiment of an apparatusforcarrying outthe method ofthe present invention;

40 Fig. 4 is a cross-sectional viewtaken along line l-l of Fig. 3,

Fig. 5 is a side view ofthe device illustrated in Fig. 4,

Fig. 6a is a schematic view of a still further embodiment of an apparatusforcarrying outthe 45 method ofthe present invention.

Fig. 6b is a plan view of a part ofthe apparatus of Fig. 6a, and

Fig. 7 is a modified version ofthetreatmentzone of Fig. 6b.

50 Forconveniencethefollowing description iscon-fined to the use of a dyeing liquor as the liquor, but it is to be understood that other liquors could also be used in place ofthe dyeing liquor.

Referring to Fig. 1 ofthe drawings, a plurality of 55 yarns 1 are drawn from creel 3 (only two yarn packages illustrated) through an elongate treatment zone 5. As the yarns 1 pass through the elongate treatmentzone 5 they are contacted with a dyeing liquorfedinto the elongate treatment zone through a 60 tube 7 and inlet 9. The dyeing liquor is fed to the elongate treatmentzone 5from a dyeing liquor reservoir 11 by means of a pump 13, e.g. a peristaltic pump.The pressure ofthe dyeing fluidfed to the elongate treatmentzone 5 is continually monitored by 65 a pressure gauge 14 positioned between the pump 13

andtheinlet9.

After being contacted with the dyeing liquor, the yarns 1 are drawn through a constrictive throat 15 having a cross-sectional area smallerthan that ofthe elongate treatmentzone immediately upstream and downstream fromthe constrictive throat 15. As the yarns pass th rou g ft th e constrictive th roat 15, they a re compacted and accelerate thedyeingliquorthrough the constrictive throat 15 at a faster speed than the yarns themselves pass through the constrictive throat 15, and also decelerate the dyeing liquor upsteam against the flow of the yarn. The effect of this is to achieve a satisfactorily uniform impregnation of yarns.

The impregnated yarns 1, after passage through the constrictive throat 15, are drawn through a heating zone 17 in which the dye is transferred fromthe liquor to theyarn. In the embodiment illustrated in Fig. 1 the heating is effected by means of an electric heater, e.g. an electric heating coil surrounding a tube through which the yarns 1 are drawn.

Theyarns 1 are drawn through the apparatus illustrated in Fig. 1 by means of a hot roller 19, which may be grooved to maintain the composite liquor-linear assembly so that all fibres remain in intimate contact with the liquor and wrapping belt 21, and may, forexample, then be washed, dried and packaged, or be cut into desired lengths (packaging and cutting means not shown).

Fig. 2 illustrates an alternative embodiment of an apparatusforcarrying outthe method ofthe present invention, in which apparatus a plurality of yarns 23 are drawn from creel 25 (only two yarn packages shown) and through an elongate treatment zone 27 whereinthe yarns 23are contacted with a dyeing liquor being fed into the elongate treatment zone 27 through inlet 29. The dyeing liquor is fed into the elongate treatment zone 27 from a dyeing liquor reservoir 31 by means of a pump 33, e.g. a peristaltic pump. Located between the pump 33 and the dyeing liquor inlet 29 is a heat exchanger 35, the purpose of which is to heatthe dyeing liquorto an appropriate temperature to aid in its dyeing of theyarns 23.

After being contacted with the dyeing liquor, the yarns 23 are drawn through a constrictive throat 37, the construction and function of which isthe same as thatoftheconstrictivethroat15depictedin Fig. 1.

In ordertotransferthedyefromthe liquorontothe yarns 23, the yarns, after passage th rough the constricting throat 37, are drawn through a zone 39 in which they are heated by direct contact with the steam introduced through inlet 41.

The yarns 23 are then drawn through the apparatus by a mangle 43 to remove dye exhausted liquor from the yarns 23.

As intheembodiment illustrated in Fig. 1, the yarns 23 are passed between a roller45, and wrapping belt 47 and may, for example, then be washed, dried and packaged, on rollers, or cut into desired lengths (packaging rollers and cutting means, not shown).

Referring nowto Fig. 3 there is illustrated a further embodiment of an apparatusforcarrying outthe method ofthe present invention, in which a plurality of yarns 49 are drawn from yarn packages on a creel 51 (only three yarns on a creel are indicated) through an

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elongate treatmentzone 53. In the elongate treatment zone 53, the ya rns 49 are firstly contacted directly with steam introduced through inlet 56, the purpose of this steam treatment being to condition the yarns such 5 thatthey may be subsequently impregnated and dyed satisfactorily. Theyarns are then drawn through a guide box 57 which separates the yarns 49, thereby facilitating access to the yarns 49 by dyeing liquor which is introduced into the guide box 57 through inlet 10 59. The guide box is shown in greater detail in Figs. 4 and 5 of the drawings.

After being contacted with the dyeing liquor, the yarns49 aredrawn through two constrictive throats 61 and 63, the construction and function of which is 15 the same asthat ofthe constrictive throat 15 depicted in Fig. 1.

In orderto increase and/or maintain the temperature ofthe yarns 49 and the liquor pumped through inlet59,theyarns49,togetherwith the liquor, are 20 drawnthroughahotzone65,theheatinthiszone being provided bypassing an electric current through the liquor utilizing a battery of cells 55 made up of an alternating series of annularelectrical insulators and conductors through which the yarns and dyeing liquor 25 pass. Alternatively, the heat in zone 65 may be provided by means of microwave or high frequency radiation.

When the yarns 49 exit from zone 65 an appreciable proportion of dye will have transferred from the 30 dyeing liquorto the yarns, with some dye having diffused into thefibres and some dye having been fixed in the fibres of theyarns.

Tofurthertransfer dye from the liquorto the yarns 49,theyarn/dyeing liquor combination emitting from 35 hot zone 65 is directly contacted with steam introduced through inlet 67. Theyarn/dyeing liquor combination isthen passed through afurther constrictive throat 69 to improve the uniformity of distribution of the dyeing liquorthroughouttheyarns49. 40 In ordertocompletethetransferof dyetotheyarns 49, the yarns are passed through a hot vessel 71 containing a hot,flexible belt 73 and a hot drum 75, the drum 75 being rotated by means of a belt 77 driven by an electric motor (not shown). The vessel 71 also 45 contains an inclined region 79 and an exit 81. The yarns 49 are taken between the drum 75 and belt 73 and the linearassembly of yarns 49 are flattened thereby to form a tape which is passed one or more times around the drum 75 and is held in intimate 50 contact with the dyeing liquorto substantially complete the transfer of dye to the yarns 49.

The yarns 49 and the dyeing liquor are then dispensed from belt 73 into the inclined region 79 where theyarns 49 are accumulated and stored 55 without compaction or tension until fixation is substantially completed. Yarns 49 are then withdrawn from vessel 71 through exit 81 for rinsing, drying and repackaging (these latterthree steps are not illustrated).

60 Figs. 6a and 6b together illustrate a further embodiment of the invention, in which a scouring apparatus is included beforetheelongatetreatmentzoneandin which yarn separation means are also provided. The scouring apparatus is illustrated schematically in Fig. 65 6a but is not shown in Fig. 6b. The yarn separating means are shown in Fig. 6b but for convenience are omitted from Fig. 6a.

Referring to Fig. 6a yarns are fed from creels 100 via a yarn feeder roll 101 into a scouring tube 103 provided with an inlet 104 for scouring solution and a tank 102 into which scouring solution drains from scouring tube 103. A constriction 105 is formed at the exit to scouring tube 103. The yarns leaving the scouring tube 103 pass over a further guide roll 106 and through a mangle 108 and thence into the elongated treatmentzone 110. As shown in Fig. 6b two rows 107 and 109 of pins are provided, one before and one after mangle 108 for separation ofthe yarns.

The elongated treatment zone 110 is provided with an inlet 111 (e.g. for steam) and a guide box 112 (simiiarto that illustrated in Figs. 4 and 5) having an inlet 113 for liquor. Constrictive throats 114and115 are provided between inlet 111 and guide box 112 and downstream of guide box 112 respectively.

Afurther row 116 of pins is provided for separating the yarns leaving the elongated treatment zone 110 before they pass over roll system 117 and guide roll 118 (not shown in Fig. 6b). In Fig. 6b constrictive throats 114and 115 are the same dimensions and the guide box 1 is disc shaped and has two pins instead of three, and is also provided with a transparent lid for inspection purposes.

Fig. 7 illustrates schematically a modified elongated treatmentzone 119 having inlets 120 and 121 (for steam and liquor) and two restrictive throats 122 and 123 positioned respectively between inlets 120 and 121. Restrictive throat 123 is simiiarto that shown in Fig. 6b at 115 but restrictive throat 122 extends the whole distance between inlets 120 and 121, and is of greater internal diameterthan restrictive throat 123.

The present invention will now be further illustrated by way ofthe following Examples.

EXAMPLE 1

The apparatus used in this Example comprised a glass tube having a diameter of 14 mm and a length of 10 cm, this tube having a liquor inlet at the upstream end thereof. Liquorfrom a reservoir was introduced into the glass tube through the liquor inlet by means of a pump located between the reservoir and the inlet. Downstream ofthe glass tube was located a stainless steel tube having a diameter of 4.75 mm and a length of 15 cm, and downstream ofthe stainless steel tube was located a winding roller.

Two yarns each of 2.2 Ktex were drawn through the glass and stainless steel tubes by means ofthe winding roller and waterwasused asthetreating liquor introduced through the liquor inlet and thereby applied to the yarns.

In this Example, it was found that, when the glass and stainless steel tubes were inclined upwardly from the point of entry ofthe yarns into the glass tube and the water was pumped into the glass tube through the liquor inlet at a rate of 12g per minute, water dripped from the entry point ofthe yarns into the glass tube. However, it was also found that, if water containing 4g of a xanthate gum per litre of water was used as the treating liquorandthisliquorwas pumped into the glass tube at a rate of 12g per minute, all ofthe liquor was taken up by theyarns in approimately equal amounts in each yarn and no dripping from the entry

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point of the yarns into the glass tube occurred.

EXAMPLE 2

Example 1 was repeated utilizing water containing 4g of a xa nthate g u m per I itre of water as the treating 5 liquor. However, in this Example, one ofthe two yarns was pretreated, before passing itthrough the glass tub, by immersing itinwaterandthen passing it through a mangle such that it contained about 40% of free water. The results of this Example indicate that all 10 ofthetreating liquor was taken up by the yarns with thetreating liquor being partitioned between the pretreated yarn and the un-pretreated yarn in a ratio of approximately 2:1.

EXAMPLE 3

15 Example 1 was repeated exceptthatthetreating liquor comprised 10g Acid Red 37 dye, 20g formic acid, 1 g of wetting agent, (i.e. dodecyl benzyl sulphon-ate), 20g of Coacervate (i.e. Irgapadol manufactured by Ciba-Geigy) and 2g of a xanthate gum per litre of 20 water, and a steam box was placed downstream ofthe stainless steel tube and before the winding roller, the steam box being open to the atmosphere, having a yarn passage length of 4 metres and having no means for maintaining the yarns and treating liquor in a 25 uniform composite state. The yarns were drawn through the apparatus at a rate of 2 metres per minute.

By using the procedure of this Example it was observed thatthe dye was poorly distributed along the yarns and that projecting fibres appeared to have 30 relatively little dye on them giving the appearance known as "frosting" to the yarns.

EXAMPLE 4

Example 3 was repeated except thatthe steam box was replaced by an electrically heated tube having a 35 diameter of 4.75 mm and a length of 83.8 cms, this electrically heated tube being attached to the downstream end ofthe stainless steel tube. With 200 watts inputtothe electrically heated tube there was a noticeable issue of steam along theyarns leaving the 40 heated tube.

Aftertreatment in accordance with this Example, the yarns did not appear "frosted" and little dye rubbed off theyarns leaving the heated tube, thereby indicating that most ofthe dye had transferred from 45 thetreating liquorto the yarns within the heated tube. The yarns were, however, unevenly coloured by the dye.

EXAMPLE 5

Example4was repeated except that a constrictive 50 throat having a diameterof 3.18 mm was positioned at the downstream end of the stainless steel tube and before the electrically heated tube. The winding roller was positioned close to the downstream end ofthe electrically heated tube.

55 Several samples of yarn were drawn through the apparatus. Sample 1 was a portion of yarns drawn directly from the storing package, sample 2 was a portion ofyarns which had been heated in steamfor8 minutes after passage through the electrically heated 60 tube, and sample 3 was a portion ofthe sample 1 yarns after passage through the apparatus and extraction and return ofthe dye by a levelling process.

On rinsing the treated samples, virtually no dye rinsed off sample 2 and only about 5% ofthe added 65 dye rinsed off sample 1. Sample 2 was slightly deeper in colourthan sample 1 and both appeared to be dyed more deeply at the surface than in the interior ofthe yarns. Sample 3 was lighter in colourthan samples 1 and 2 and was uniform inside to outside of theyarn.

EXAMPLE 6

Sample 5 was repeated with yarn samples 1 and 2 as in Example 5 except thatthe treating liquorwas preheated to about 80°C and with only 50 watts supplied to the electrically heated tube. Less steam was observed to be issued from the yarns as compared to Example 5.

The colour of the surface and interior of the yams were similar to each other and simiiarto a "levelled sample".

The colour of the yarn surface and the colour of the cutyarn cross-section were simiiarto that of yarn which had been batch dyed to a level shade throughout.

EXAMPLES 7-12

Example 6 was repeated in each of Examples 7-12 exceptthat in Example 7 the Acid Red 37 dye in the treating liquorwas replaced by CI Acid Blue 80, in Example 8 the Acid Red 37 dye was replaced by CI Acid Brown 44, in Example 9 the Acid Red 37 dye was replaced by CI Acid Yellow 17, in Example 10 the Acid Red 37 dye was replaced by CI Acid Orange 10, in Example 11 the Acid Red 37 dye was replaced by a mixture of 2% CI Acid Red 114,1.1 % CI Acid Red 129 and 0.19% CI Acid Red 119 (the percentages being based on the total yarn treated and representing the amount of dyestuff containing the stated dye as the active dye component), and in Example 12 the two 2.2 Ktexyarns were replaced by7 ends of 720 tex wool yarns.

Similar resultsto that of Example 6 were obtained in each of Examples 7-12.

EXAMPLE 13

Twenty-two ends of 2.2 Ktex yarn were drawn at about 1.5 m/minute through an apparatus according to Fig. 2 ofthe accompanying drawings wherein the internal diameter of the tubes through which the yarns passis 14mm and the constrictive orifice has a diameterof 11 mm.The winding rollers were positioned about 70 cms downstream from the end ofthe tubfng through which the yarns pass.

Thetreating liquor had the composition: 2g a xanthate gum, 20g Coacervate, (i.e. Irgapadol manufactured by Ciba-Geigy), and 1g wetting agent, (i.e. dodecyl benzyl sulphonate), per litre of water.

Thetreating liquorwaspumpedat ambient temperature at a rate of about 15Q% of the weight ofthe passing yarn.

No steam or heat was applied to the apparatus. A 60 cm cut length of the wet bundle of yarn taken after passing through the tubing ofthe apparatusand before thewinding rollers was separated into individual yarns and the amount of liquor on each yarn was determined by weighing the wet yarrtand weighing theyarn again after drying. The results obtained are given below in Table 1.

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TABLE 1

No. Of yac

% Average Liquor on yarn, based on cut of yarn. 93-87 88-92 93-97 98-102 103-107 108-112 113-117.118-122

2

■is]

3

4

4

2

3

2

2

EXAMPLE 14 Example 13 was repeated except that 18 yarn ends were drawn through the apparatus of Fig. 3 ofthe accompanying drawings, and only two constrictive 5 throats (61,63) were present (i.e. constrictive throat 69 was omitted) and the hot vessel 71 was omitted. The results obtained in this Example are given below in Table 2.

TflBLE 2

i h

Ho. of yar verage Liquor on yarn, based on cut of yarn,

83-87 88-92 93-97 98-102 103-107 108-112 113-117 118-122

ns f

-

5 1 8

5 .

-

-

EXAMPLE 15 Example 14 was repeated exceptthat 10g of Acid 10 Red37and20g of formic acid were additionally present in each litre of water and steam was supplied to the wet yarn bundle downstream ofthe constrictive throats 61 and 63, the steam being supplied from a small pressure boilerthrough a 1 mm orifice at a 15 rate of about 25g/minute.

The bundle of yarns, aftertreatment, appeared slightly lighter in colour on the outside compared with the interior of the bundle.

EXAMPLE 16

20 Example 15 was repeated exceptthat a constrictive throat (i.e. throat 69 of Fig. 3) was positioned about 15.24 cm downstream ofthe steam entry point. The colour difference from the outside to inside ofthe yarn bundle, aftertreatment, appeared less than for 25 Example 15.

Very little dye rubbed off onto absorbent paper at the winding rollers but heating forafurther8 minutes in steam slightly increased the colour depth and reduced the amount of dye rinsed offfrom less than 30 5% to almost nil.

The colour of individual yarn ends was measured using a Macbeth 2000 spectrophotometer and the results obtained are given below in Table 3.

EXAMPLE 17

35 Example 16was repeated exceptthatthedye liquor was supplied hot and steam heating was replaced by electric heating. No difference in colour could be observed between the outside and the interior of the yarn bundle. The colour of individual yarns was 40 measured as in Example 16 and the results obtained are given below in Table 3.

rams 3

Macbeth standard

Light

Devia-•

ness tion

% of the

L value for the 18 yarns *

(L)

of "L"

95

96

97

98

99

100

101

102

103

104

105

Example

16

31

0.9

1

1

4

2

1

"

2

3

1

2

1

Example

17

31

0.6

-

-

1

2

5

3

4

-

2

1

-

* 100 represents 100% ofthe Lvalue, i.e. 100% of 31 = 31 and the remaining percentages represent percentages ofthe Lvalues, e.g. 95 represents 95% of

45 Lvalue of 31 =29.45. The values in the columns underthe percentages ofthe Lvalue are the number of yarn ends having that percentage of the Lvalue.

The colour ofthe yarns treated in Example 17, i.e. the outside colour and the colour oftheyarn 50 cross-section, both correspond with the colour of the same yarns treated conventionally by batch dyeing.

EXAMPLE 18 Example 17 was repeated except that the treating liquor additionally contained Acid Blue 80 dye and 55 20g of potassium dihydrogen phosphate per litre of water in place of the Acid Red 37 dye and formic acid. Additionally the yarns were steamed at its point of entry into the apparatus of Fig. 3 and were drawn through the apparatus using a steam heated drum of 60 2 metres circumference enclosed in a steam box, the drum having a continuous impervious belt passing thereover. The yarns passed twice around the drum before collection (sample 1). One metre of yarn was furthertreatedto level the dye between theyarn 65 (sample 2). Another sample (sample 3) of about 50g of yarn was conventionally batch dyed.

Samples ofthe treated yarns were wound on cards such that individual yarns formed adjacent pads. Also,bundles of yarn pulled through papertubesto 70 form a tightly packed parallel yarn assembly and werecutto expose the yarn cross-sections.

Colour was measured on a Macbeth 2000 spectrophotometer and the results obtained are given belowinTable4.

TABLE t

Macbeth

Standard

-

Light

Devia

ness tion

% of the

L value for side appearance

of the 18 yarns

**

(L)

Of "L"

96l

97

98

99

100

101

102

103

Sample

--

1

28 *

0.4

1

-

1

5

5

3

3

Sample

2

30

0.3

-

-

6

6

5

1

-

Sample'

3 .

28

0.4

-

1

1

6

2

6

1

1

75 ** 100 represents 100% ofthe "L" value, the remaining percentages represent the respective percentages ofthe "L" value (e.g. for sample 1,96 represents 96% of 28 which is equal to 26.88), and the figures in the columns below the percentage values 80 representthe number of yarns having a lightness equivalent to that percentage ofthe "L" value.

The colour depth ofthe cross-section and side of samples 1 and 2 were simiiarto that ofthe batch dyed sample(sample3). 85 EXAMPLE 19

10 as formed wool ya rns of about 460 tex each were treated using an apparatus shown schematically in Fig. 6a excluding the scouring tube and mangle and using the modified elongated treatment zone 119 90 shown schematically in Fig. 7. The yarns were drawn from creels 100 at 3.6 metres per minute directly into the elongated treatmentzone 119 in which the constrictive throat 122 was 100 mm long and 5 mm in internal diameter, constrictive throat 123 was 20 mm 95 long and 3.3 mm in internal diameter and the remainder ofthe elongated treatment zone 119 was 6 mm internal diameter. Hot dye liquor ofthe composition used in Example 3 was pumped into inlet 121 using the pumping system shown in Fig. 2 at a rate

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equal to 125% ofthe weight of yarn passing through the elongated treatment zone 119. The separation pins 116 were not utilized in this Example. Theyarn was given several minutes extra heating to complete 5 diffusion ofthe dye into the yarns and then rinsed in water, dried and mounted on cards for inspection. The procedure was then repeated on a second sample ofthe same yarns except thatthe dye feed rate was increased to 150% if the weight of yarn. 10 At a feed rate of dye liquor of 150% the reservoir which extended upstream of constrictive throat 123 extended into constrictive throat 122 and varied in length by 111 to 118mm. With a dye liquor input rate of 125% oftheweightofyarnsthereservoirwasmore 15 variableand remained wholly withinthe region between inlet121and constrictive throat 123.

On inspection ofthe resulting dyed yarns a colour variation was visible between the yarns and the hue was affected by extraneous matter. This result is to be 20 compared with thatinthefollowing Example20.

EXAMPLE 20

9 as formed yarns further soiled by arial settlement during storage were treated in the apparatus schematically shown in Fig. 6a but with the elongated

25 treatmentzone 110 as shown in Fig. 6b and utilizing the separation pins 107,109 and 116 of that Figure.

The scouring section was operated by injecting 250% ofthe weight ofthe yarn passing through scouring tube 103 via inlet 104 of hot water containing 30 5g per litre of a non-ionic detergent. The constriction 105 (3.3mm internal diameter) effectively stripped 100 ofthe 250% detergent solution from the yams which flowed countercurrentto the yam and was collected intank102.The detergent solution intank 35 102 was found to include a considerable amount of grease and also 0.5% of solids based on the weight of yarn passed through the scouring tube 103. Afurther 100ofthe250% detergent solution was removed by mangle 108.

40 The constrictive throats 114and115 were both 20 mm long and 3.3 mm in internal diameter. The guide box 112 was33 mm in diameterand 10 mm in height and had two pins dividing the yarns into three tracks. A transparent face was provided for inspection 45 purposes.

Dye liquorwas pumped into inlet 113 as in Example 19 and steam was pumped into inlet 111. The rate of input of dye liquorwas 150% ofthe weight of yarn passing through the elongated treatment zone 110. 50 In contrast to the result in Example 19, the dyed yarns showed equal dyeing and the hue was unaffected.

EXAMPLE 21

10 scoured wool yarns (—460 tex each) were drawn 55 from creels directly into elongated treatment zone

110 illustrated schematically in Fig. 6b.The construction and dimensions of zone 110 were those given in Example 20. No steam was injected into inlet 111 but the application of dye liquor was the same as 60 Example 20.5 kg tension was required to pull the yarns through the zone 110.

EXAMPLE 22

The procedure of Example 21 was repeated except that steam was injected into inlet 111. It was found 65 that only 0.6 kg was required to pull the yarns through to zone 110. The change in length ofthe yarn finally collected was less than 3% of that leaving the creels 100 before treatment. Furthermore, the yarn texture was unaffected. 70 Itwasfoundthatatadyeliquorinputof 130% of yarn passing through zone 110 the reservoir of dye liquorformed was stable and occupied the whole space between constrictive throats 114and115 and a pump pressure of 5 pounds per square inch de-75 veloped. Air bubbles escaped upstream of constrictive throat 114.

The resulting dyed yarns were inspected in the form of kn itted panels and wound on ca rds and were found to have a consistency of dyeing simiiarto that 80 obtained by batch dyeing.

This Example was repeated several times and showed consistent results.

EXAMPLE 23

8 nylon/wool blend yarns and an all nylon staple 85 ya rn of si mil a r weig ht 460 tex fo r each ya rn were treated as in Example 19 but with dyestuff was a mixture of 1 g per litre of nylomine blue (acid blue C.I. 62) and 5g per litre of nylomine yellow (acid yellow 119). No nylon dye retardant was present.The nylon 90 was found to dye to the same hue as the wool.

From the above Examples it can be seen that dripping of treating liquor from the entry point ofthe elongate material being treated into the treating apparatus may be avoided by utilizing a treating 95 liquorof sufficient viscosity, e.g. by including a gum in the liquor (see Examples land 2). Examples 3 and 4 illustrate that poor dyeing of yarns is achieved if the dyeing liquor is simply applied to the yarn and the yarn is then either passed through a steam box or an 100 electrically heated tube. Examples 5 onwards illustrate that improved dyeing of yarn is achieved by the inclusion, in the dyeing apparatus, ofatleastone constrictive throat, the constrictive throat(s) being located downstream ofthe entry point ofthe dyeing 105 liquor.

Also from the above Examples it can be seen that thetreating liquor may, for example, contain auxiliaries, e.g. wetting agents such as dodecyl benzyl sulphonate and/or coacervates such as Irgapadol 110 manufactured by Ciba-Geigy.

In summary, it can be seen from the above Examples that satisfactory continuous dyeing of yarn can be achieved by utilizing an apparatus and method in accordance with the presentinvention. 115 Although the present invention has been described with reference to the presence of one elongate treatment zone, it is to be understood that, if desired, two or more such elongate treatment zones may be utilized, these zones being located in series with one 120 another.

Furthermore, whilst the method ofthe invention has been particularly described with reference to the treatment of a linearassembly with a liquor, i.e. a dye liquor, the invention contemplates and equally ap-125 plies to situations where the linearassembly is used to effecttreatmentof a liquor e.g. as a carrier for a treating agent forthe liquor or catalyst for reaction effected in the liquor. In such an application the elongated assembly could be recycled through a 130 treating agent pick-up or catalyst-regeneration zone.

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Claims (21)

1. A method of continuously applying a liquorto an elongate material, which comprises forming a linearassembly comprising a plurality of yarns,

5 filaments, tow, threads ortwines, hereinafter referred to as "linear assembly", continuously feeding liquor to said linear assembly whereby to impregnate said linearassembly with said liquor, characterised inthat said liquor/linearassembly combination is con-10 tinuously passed through an elongate treatment zone and through at least one constrictive throat located in said elongate treatment zone, the at least one said constrictive throat having a cross-sectional area smallerthan that ofthe linear assembly immediately 15 priorto its passage through said at least one constrictive th roat such that said linea r assembly is compacted on passage through said at least one constrictive throat, and wherein, afterpassage through said at least one constrictive throat, said 20 liquor/linearassembly combination passesthrough a region in which it is maintained in a uniform, composite state.

2. A method as claimed in claim 1, characterised in thatthe linear assembly is appreciably compacted

25 bythe at least one constrictive throat on its passage therethrough.

3. A method as claimed in claim 1 or 2, characterised inthatthe liquor/linearassembly combination fills the space available in the elongate treatment

30 zone immediately upstream from the at least one constrictive th roat and the linear assembly is slightly compacted bythe inner surface ofthe elongate treatmentzone.

4. A method as claimed in any of claims 1 to 3, 35 characterised in that in the region ofthe elongate treatmentzone downstream from the at least one constrictive throat, the liquor partially fillsthe space available in the elongate treatment zone and the linearassembly is slightly compacted bythe inner 40 wall of the elongate treatment zone.

5. A method as claimed in any ofthe preceding claims, characterised in that the passage ofthe liquor th rough the elongate treatment zone is such that a reservoiroftreating liquor is formed upstream ofthe

45 at least one constrictive throat.

6. A method as claimed in claim 5, characterised in thatthe amount of liquor in the said reservoir remains essentially constant, thereby maintaining an essentially invariant liquorflow rate.

5®

7. A method as claimed in claim 5 or 6, characterised in thatthe liquor is fed to the linear assembly in the region ofthe reservoir.

8. A method as claimed in any of claims 5,6 or 7, characterised inthatthe linearassembly passes 55 successively through a first and a second constrictive throat disposed in spaced relationship in said elongated treatmentzone and in which said liquor is fed to said linear assembly at a point between said first and second constrictive throats.

60

9. A method as claimed in claim 8, characterised in thatthe rate of feed of liquorto the linearassembly and the rate of passage ofthe linear assembly through the elongated treatment zone are such that the reservoir fills the free space available between the 65 said consecutive constrictive throats.

10. A method as claimed in claim 9, characterised inthatthe reservoir extends partially along the length ofthe first of said consecutive constrictive throats.

11. Amethodasclaimed in any of claims 1 to 10, 70 in which the liquor is a dyeing liquor.

12. Apparatus for applying a liquorto an elongate material, which comprises means for continuously feeding a liquorto a linear assembly comprising a plurality of yarns, filaments, tows, threads or twines

75 whereby to impregnate said linear assembly with said liquor, characterised in that said apparatus also comprises an elongate treatment zonefor passage of said linear assembly therethrough, at least one constrictivethroatforpassageof said linearassem-80 blytherethrough and to compact said linearassembly, said at least one constrictive throat being located in said elongate treatment zone and downstream of the meansfor continuously feeding said liquorto said linearassembly, and means located downstream of 85 said constrictive throat(s) for maintaining said linear assembly and treating liquor in a uniform composite state.

13. Apparatus asclaimed in claim ^.characterised in that said elongate treatment zone is of

90 circular cross-section and said at least one constrictive throat is in theform of a constrictive orifice of circular cross-section.

14. Apparatusasclaimed in claim 11 or 12, characterised in that said meansfor continuously

95 feeding the liquorto the linear assembly is positioned to introduce the liquor into the elongate treatment zone upstream from said at least one constrictive throat.

15. Apparatus as claimed in any of claims 12 to 14, 100 characterised in that at or in the region ofthe means for continuously feeding the liquorto the linear assembly,there is provided a guide boxforseparat-ing the yarns, filaments, tows, threads or twines forming the linear assembly and thereby facilitate the 105 even distribution of thetreating liquorthroughoutthe linearassembly.

16. Apparatus as claimed in any of claims 12 to 15, characterised by also comprising a heat exchanger, for heating the liquor before it is fed to the linear

110 assembly.

17. Apparatus as claimed in any of claims 12 to 16, characterised by including conditioning means to condition the linear assembly before the liquor is fed thereto, said conditioning means comprising at least

115 one ofthe following:—

(1) washing means to wash the linear assembly and means to remove excess washing fluid from the resulting wet linear assembly;

(2) heating means to raise the temperature ofthe 120 linearassembly;

(3) steam inlet means adapted to allow steam to directly contactthe linearassembly; and

(4) means for adjusting the pH ofthe linear assembly.

125

18. Apparatusasclaimedinanyofclaims12to17, characterised by including activating or accelerating meansfor activating or accelerating the treatment process after the liquor has been fed to the linear assembly and after it has passed through the at least 130 one constrictive throat.

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19. Apparatus as claimed in claim ^characterised in that said activating means comprises one or more ofthe following:—

(a) steam injection meansfordirectlycontacting the steam with the linear assembly/liquor composite

5 and thereby raise the temperature ofthe composite,

(b) means for introducing further liquor or another fluid containing a catalyst, reactive chemical ora metal complexing agent;

(c) a heateradapted to surround the linear assem-10 bly/fluid composite and heatthe composite;

(d) heating means in theform of a microwave heater or a high frequency electromagnetic wave generator, or

(e) a battery of cells made up of an alternating

15 series of annular electrical insulators and conductors through which the linear assembly/liquor composite passes such that an electric current can be made to flowthrough the liquor.

20. A method as claimed in claim 1, substantially 20 as hereinbefore described in any one ofthe Examples.

21. Apparatus as claimed in claim ^substantially as hereinbefore described with reference to and as illustrated in Figs. 1 to 7 ofthe accompanying

25 drawings.

Printed in the United Kingdom for Her Majesty's Stationery Office, 8818935, 8/85, 18996. Published at the Patent Office, 25 Southampton Buildings, London WC2A1AY, from which copies may be obtained.