Faerben_und_AusruestenGB dyeing for knits

8/7/2019 Faerben_und_AusruestenGB dyeing for knits

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Dyeing and

Finishing of

Woven and

Knitted Fabrics

Reg. NO 3083

Dorlastan Dyeing and Finishing of Woven and Knitted Fabrics

Asahi Kasei Spandex Europe GmbH

41519 Dormagen, Germany


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Contents Page

1. From Greige Goods to Finished Article 3

1.1 Relaxation 4

1.1.1 Relaxation on Steaming Tables 4

1.1.2 Relaxation by Steaming at the Tenter Feed End 5

1.1.3 Relaxation by Means of Hot Water 5

1.2 Hot-air Setting 5

1.3 Wet Treatment 5

1.3.1 Scouring 5

1.3.2 Dyeing Method 6

1.4 Aftertreatment 7

2. Article Characteristics and their Influences on the Procedure 7

2.1 Raschel Knits 7

2.2 Warp-knits 8

2.3 Knits 10

2.3.1 Flat Knits 10

2.3.2 Circular Knits 10

2.4 Wovens 12

3. Bleaching, Fluorescent Whitening and Dyeing 13

3.1 Dorlastan/Polyamide 13

3.1.1 Scouring 13

3.1.2 Fluorescent Whitening 13

3.1.3 Dyeing 14

3.2 Dorlastan/Polyester 15

3.2.1 Scouring 16

3.2.2 Fluorescent Whitening 16

3.2.3 Dyeing 17

3.3 Dorlastan/Wool 18

3.4 Dorlastan/Cotton 19

Appendix 24


2

Edition: 01: 07/94 02: 09/98 03: 01/04 04: 07/04 05: 04/05 06: 03/06

Published by and responsibility Approval

gez. ppa. Schmidt gez. Nahl

Marketing Dorlastan Geschftsfhrer


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1.From Greige Goods to Finished Article

The characteristic features of an elastic fabric are extensibility and elastic

recovery. They are achieved with the help of elastane threads which areincorporated in stretched condition during greige fabric production. In the course

of the subsequent storage and finishing, the greige fabric with the elastane

threads is relaxed and becomes compressed, and thus obtains its elasticity. The

amount of stretch of an elastic fabric depends on the fabric structure formed by

the non-elastic yarns, which in turn is strongly influenced by the processing

technique (circular knit, warp knit, etc.). The elastic recovery is determined by

the retractive force of the stretched elastane threads and by the resistance of the

compressed textile structure.

Greige fabric is not suited for making-up, so the appropriate conditions for

achieving the desired finished article properties must be created prior to this step.They include color, luster and touch for both, elastic as well as non-elastic fabrics.

Elastic fabrics must additionally provide reoverable stretch. To meet these

requirements, suitable finishing processes must be chosen that are able to

produce finished articles of nice appearance and hand with the desired technical

and elastic properties.

Greige fabric should always be delivered to the finisher on rolls because many

qualities show a strong tendency to shrink if plaited down, which may result in

irreversible crease and lay mark formation. Moreover, unrelaxed greige goods

should not be stored for a long time in rolled-up, and particularly tightly rolled-up,

condition because such storage may lead to moir formation.

If stored in warm and humid condition, elastic greige goods, especially elastic

knits, may start to become denser before finishing is even begun. As a

consequence, fabric width and m2-weight may change. To enable the finisher to

take such circumstances into account, the greige good supplier must provide him

with all the details of manufacture.

If such details are not available to the finisher, as it frequently happens, he should

find out about the shrinkage by preliminary tests, especially if he is not familiar

with the good and works with the fabric for the first time. A good method todetermine the maximum density of any fabric is to boil a piece of the greige

cloth and subsequently dry it tension-free, e.g. in a tumbler. Such treatment will

cause any fabric to shrink extremely as it would never do in normal processing

procedures. The degree of shrinkage tells the finisher which are the most suitable

finishing procedures for the respective fabric.

Regardless whether a greige fabric containing elastane displays a strong natural

tendency to shrink or whether the shrinkage must be enhanced, the customers

requirements must always have first priority. The maximum shrinkage must be

appropriate to reach the desired m2-weight, running length and width in the

finished product. If this is achieved after relaxation, and there is no other reason

to apply it, you may well do without heat setting (e.g. in case of raschel power

nets).


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If however, the dimensions of the relaxed fabric does not meet the customers

requirements for width and weigth, or if the edges show excess curl (e.g. with

warp knits) heat setting is inevitable.

Another important point in this context is dimensional stability (i.e. low shrinkage

values). If hot air fixation is applied to influence m2-weight and stretch, it must be

sufficient to create this stability.

Once a greige good has been relaxed and possibly stabilized, it must be ensured

that the resulting properties are not unnecessarily endangered or even lost during

further processing. This means:

Tensions in longitudinal direction should be kept as low as possible

Wet treatment temperatures should not exceed 100C (except for articles

containing polyester) Chemicals that impair the elastic properties of Dorlastan should not be

applied

The combined strain resulting from chemicals, time, temperature and tension

should be reduced to a minimum.

Like other fabrics, elastic fabrics must be subjected to all the standard

operations of finishing, such as scouring, setting, dyeing, dressing and possibly

raising, shearing or decatizing. In addition, however, further measures are

necessary to develop, stabilize, and maintain or reverse the stretch effect

You find a description of the various operations involved in the finishing of elastic

fabrics in the following sections.

1.1 Relaxation

The greige fabric can be relaxed by means of steam or hot water. For this

purpose, the fabric must be fed to the machine with low tension so that it can

shrink freely at least to the desired cloth density.

1.1.1 Relaxation on steaming tables

This method is widely used. The shrinkage is largely determined by the article

itself, but can be controlled to a certain extent via the steam amount and the

feeding speed. The greige fabric is put onto the steaming table with overfeed,

taken off tensionless and then rolled up. If the fabric has a strong tendency to

curl at the edges (e.g. warp knits) or if a prescribed width must be achieved, it is

recommended to use steaming tables with lateral spiked chain guides.


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1.1.2 Relaxation by Steaming at the Tenter Feed End

Relaxation by steaming at the tenter feed end allows greater control of the cloth

shrinkage by means of overfeed and width adjustment of the tenter frame.A special advantage of this method is the constant fabric width over the entire

batch, so that the fabric can be rolled up evenly afterwards. This is an essential

prerequisite for a subsequent treatment in the dyeing beam.

When steamed in the tenter feed an elastic fabric does not shrink as much in

width as it would during preshrinking in other equipment because of the heavy

weight of the sagging fabric. The greige fabric should be fed to the tenter via

roller drive and not be drawn from the roll; if it is drawn from the roll, the

longitudinal shrinkage will increase from the beginning to the end of the batch

because of the decreasing roll weight and the diminishing take-off tension going

with it, i.e. the longitudinal shrinkage may vary over the entire batch length. Thenormal tenter temperature for shrinking ranges from 100140C. If shrinking and

hot air setting are combined, the processing temperate is approximately

185195C.

1.1.3 Relaxation by Means of Hot Water

Scouring and shrinking can be combined in low-tension open-width washers at

operating temperatures between 60 and 95C.

1.2 Hot air setting

Hot air setting must be applied if a fabrics shrinking tendency exceeds the

customers specifications with regard to m2-weight, running length and cloth

width. In addition, it has an area stabilization effect that can be used to eliminate

or to reduce undesired edge curling.

How much setting is required is highly dependent on the article, so no general

rules can be established. Since it is essential to maintain the elastic properties of

the fabric, the setting conditions should not be more severe than necessary, but

sufficient to meet the customers requirements and to achieve good shrinkage

values. Appropriate setting conditions can easily be determined by preliminarytests and will include exposure times ranging from 25 to 60 seconds. The setting

temperature is determined first of all by the type of Dorlastan that is used.

Polyether = 192196C, polyester = 185190C.

1.3 Wet Treatment

1.3.1 Scouring

Optimal preparatory treatment that guarantees good reproducibility of the entire

process includes the thorough removal of both the silicone lubricant required for

the processing of elastane and the lubricants of the non-elastic fiber components

in order to avoid mutual reactions of the two lubricant types. DiadevinDSP has

proven a suitable agent for this purpose.


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Whether scouring is performed in open-width or rope form depends primarily on

the article, but also on what equipment is available.

1.3.2 Dyeing Method

Selection of the dyeing method is determined by the articles tendency to crease.

Fabrics that are prone to creasing require open-width dyeing. This technique can

be performed on jig or beam dyeing machines.

Jig dyeing machines with sufficient controls to operate at very low tension, and

compensate as the fabric shrinks during dyeing are required. If an appropriate

low tension is guaranteed for the fabric feed, the jig is an economic solution for

dyeing stable fabrics that do not curl at the edges (e.g. wovens). High qualities

can be produced, if water pockets resulting from unnecessary standstills of thejig are avoided, and the exposure time and treatment temperature are limited to

the required levels. Water pockets disturb the smooth running of the fabric and

easily cause creasing. Once the pockets have formed, crease formation can only

be avoided by increasing the fabric tension, which leads inevitably to lower

qualities.

By the treatment on the jig the elastic material is stretched. If the resulting

elongation is only slight, it can well be reversed during the subsequent drying

by an appropriate overfeed. However, increased fabric tension and extended

exposure times at high temperatures as they are often required with dark colors

sometimes lead to greater elongations, which cannot always be compensated

for by the tenter overfeed during intermediate drying. The dyed fabric may be

slightly longer compared to the relaxed greige fabric and may have a lower

m2-weight combined with less stretch. To avoid these negative effects beam

dyeing is often preferred.

For beam dyeing, the elastic fabric must be subjected to optimal prior relaxation

and, if necessary, also to hot setting. These measures are necessary to prevent

the fabric shrinking in width in the autoclave resulting in the lateral perforations

of the dyeing beam being uncovered. At the tenter feed end, the fabric is evenly

wound on the dyeing beams at constant wounding tension. During the wholedyeing process, the liquid in the autoclave should circulate only from the inside

to the outside, the differential pressure should be maintained at 0.10.2 bar by

reducing the liquid flow rate, and the liquid temperature should be increased

and/or decreased only slowly.

In contrast to jig dyeing, dyeing on the beam always involves a risk of moir

formation, especially with dark colors. The above mentioned even wounding

tension, slow temperature change, and the use of dyeing beams of large

diameters adequately wrapped with non-dyeing leader cloth help to reduce

this risk to a minimum.

Goods that are not prone to creasing can be winch beck dyed, overflow dyed or

jet dyed in rope form.


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1.4 Aftertreatment

There are numerous possibilities for aftertreatment. Selection of the technique

depends on the composition of the article and the customers specifications.This will not be covered in detail in this general description.

2. Article Characteristics and their Influenceon the Procedure

2.1 Raschel Knits

Compared to other elastic knit fabrics most types of raschel fabrics are relatively

stable, they have no or little tendency to curl at the edges, their shrinking

tendency is sufficient and reproducible, and rarely exceeds the desired level.

Raschel fabrics shrink most during relaxation at the beginning of the finishingprocess, but often they compact even further in the course of the subsequent

finishing steps. Because of this the finished product has the precalculated and

required width, weight of the fabric and extensibility.

Given these facts, area stabilization by means of hot air setting is usually not

necessary, which is a great advantage with regard to maintaining the fabric

properties. Since raschel fabrics are prone to creasing they are preferably treated

open-width.

Relaxation of foundation garment fabrics is performed mostly on steaming tables

or in modified steaming systems, rarely in open-width washers or dry cleaning

machines. To ensure that the final products are free from creases, they should be

processed roll to roll rather than plaited.

Sometimes hot air setting is performed, e.g. to improve the elastane runback.

The fabric is set at 180-195C for a period of approximately 2040 seconds.

Exposure time and temperature should always be kept to a minimum.

Most types of raschel fabrics are dyed open-width on beam dyeing machines.

Some qualities, however, (e.g. jacquard nets) may be dyed in rope form on winch

becks or, to reduce the risk of creasing, on overflow or jet dyeing machines.

Intermediate drying can easily and economically be carried out in a jet ribbon

drier; here, the foundation garment fabric is treated completely tensionless and

can thus shrink freely, which is essential with regard to the stretch of the final

product. Drying is effected at temperatures ranging from 80 to 130C.

Nowadays, however, intermediate drying of foundation garment fabrics is

normally carried out in the tenter at temperatures between 120 and max. 160C.

The tentering width should be a few centimeters less than the required width of

the final product and unless the desired running length and m2-weights do not

allow for it the overfeed should be sufficient to enable optimal shrinking without

disturbing the smooth and trouble-free running of the fabric.


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Raschel power nets are nearly always provided with a chemical finish to achieve

the required hand and necessary dimensional stability. The finish is applied in

a padder with good, uniform squeezing effect. Then the fabric is dried, and

possibly cured, by feeding it continuously through the tenter.

Today, mainly finishes containing little or no formaldehyde are used. Additional

fillers or softening agents are only applied, if the customers specifications render

them necessary, because the excessive use of softening agents may cause the

Dorlastan threads to show an unfavorable tendency to creep back at the seams

in the ready-to-wear apparel.

Final drying of the finished foundation garment fabric is performed in the tenter

at temperatures between 130 and 160C. With non-crosslinking finishing agents

the actual temperature and contact time is determined exclusively by the drying

effect; in case of crosslinking dressing agents it is the curing conditions to beobserved that determine these variables. Make sure to adjust the correct

overfeed for these goods that tend to stretch lengthwise, so that the defined

weight of the fabric, running length and extensibility are achieved.

It is quite common practice to enhance the whiteness of white foundation

garment fabrics by adding suitable tints to the finish bath.

To improve the touch and the surface smoothness of the fabric, decatizing is

sometimes employed as aftertreatment.

In such cases it is recommendable to work at temperatures between 120 and

130C and to expose the fabric to the steam for another 2 minutes after it has

evaporated from the cloth before the articles are cooled down thoroughly by

means of suction (for about 5 minutes).

2.2 Warp-knits

Knitted fabrics produced on warp-knitting machines with intermeshed Dorlastan

filament yarns as looped threads are far less stable than raschel fabrics and are

more likely to curl at the edges.

Elastic warp-knits have a very pronounced shrinking tendency, which is much

larger than that of raschel power nets. So if warp-knits were allowed to shrink

freely, they would often shrink much more than is accepted by the customer;

width and length would be insufficient, extensibility too large and thus weight of

the fabric too big. Given the above mentioned additional strong curling tendency,

hot air setting is a must in the finishing process of such qualities in order to avoid

edge curling and to achieve the required final product data. So

the finishing of warp-knits differs considerably from that of raschel power nets.

On the other hand, warp-knits are less prone to creasing, so that they can safely

be rope-dyed, if the necessary precautions have been taken.


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The pronounced shrinking tendency of elastic warp-knits makes a controlled

shrinkage absolutely necessary. A very good relaxation effect is reached by

steaming the greige fabric on steaming tables. Given the strong tendency to curl

at the edges, warp-knits should be pinned down at the edges and be fed to themachine with a defined overfeed. This prevents curling and excessive shrinkage.

Tenter frames with steaming equipment at the tenter feed end provide a very

economic solution to combine shrinkage and hot air setting. This method is often

used, but it has the disadvantage that the lubricants of the unscoured fabric

evaporate and may then precipitate on the tenter or on the fabric.

Relaxation of the greige fabric can easily be combined with thorough cleaning of

the greige fabric in an open-width washer working at low tension. It has proven

useful to insert a scray as an intermediate cloth store between open-width

washer and subsequent tenter. This reduces fabric tension because the warptension is particularly low compared to the common method of immediately

feeding the fabric to the tenter by means of saddle rolls.

The insertion of a scray before the tenter permits continuous operation even

if large numbers of rolls are combined to form batches, and if the ends of the

individual pieces must be sewn together without interrupting the work flow. To

avoid lay marks and creases, elastic warp-knits must always be conveyed from

roll to roll from the time they arrive as greige goods up to hot air setting, and

must never be plaited down in between.

Warp-knits may be dyed in rope form on winch back, overflow or jet dyeing

machines or open-width on beam dyeing machines. Even though warp-knits

are not very susceptible to creasing, you should make sure that the liquor-fabric

ratio is not too small if you dye in rope form, that temperatures are changed

slowly and dyebath lubricants (e.g. 0.52.0 g/l PERSOFTALL or 0.10.5 g/l

PERSOFTALLU) are added to prevent creasing. It is not really necessary to sew

the dyed fabric into a tube, but it becomes increasingly recommended the more

pronounced the fabrics tendency to curl at the edges (especially lock-knits) and

the less intensive the prior heat setting was.

Overflow or jet dyeing offer all the advantages of rope dyeing such as fullvolume, pleasant touch, strong density with the corresponding high extensibility,

no risk of moir, and in addition to that a much lower risk of running creases

compared to winch beck dyeing.

For quality reasons, dyeing times and temperatures should be restricted as much

as possible, i.e. the maximum working temperature is 98100C (except for

polyester/Dorlastan blends that are dyed at 120130C).

The most appropriate softening agents for warp-knits are those creating a soft,

supple touch and a pleasant, smooth surface. Note that all softening agents with

a smoothing effect also reduce the inner frictional forces in a fabric and thusincrease extensibility at constant elongation force and improve elastic recovery.


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The commonly applied softening agents, such as PERSOFTALSWA01,

PERSOFTAL ASN 01, PERSOFTAL U or PERSOFTAL OE, are well suited to

meet the standard expectations with regard to fabric handle. They can be added

either by the exhaust method or in the padder. Silicone rubber or silicone water-repellent products are the right softening agents to meet particularly strict

requirements with regard to smoothness and suppleness of the final fabric.

Excessive smoothness, however, impairs safety in the manufacture of ready-to-

wear apparels.

For final drying, the tenter frame is used. The drying temperatures range from

120 to 160C. Overfeed and width of the frame must be adjusted accordingly to

achieve the required length and width that have already been defined for heat

setting.

Sometimes a fabric is extended to much during dyeing due to excessivelengthwise tension. Unfortunately it is nearly impossible to repair this undesirable

effect by a corresponding overfeed in final drying, because the fabric has

suffered re-fixation during the dyeing under tension at the boil.

If, however, a fabric has shrunken in width or length during dyeing at low tension

because the previous heat setting was insufficient, it is possible to compensate

for this effect and to reach the required final product dimensions in the final

drying process. But the finished product may still shrink later during storage,

transport or scouring. Such undesirable subsequent shrinkage can be avoided

by drying the fabric at 120160C as described above, and then subjecting it to

a second heat setting in the defined final state. However, slight changes of shade

may result from this procedure.

2.3 Knits

Knits are produced by two different methods, flat knitting and circular knitting.

The finishing properties of knits are similar to those of warp knits. However, knits react

even less sensitive to finishing processes and are less prone to creasing than warp

knits because of the predominant use of spun yarns.

2.3.1 Flat Knits

Flat knits containing Dorlastan are usually dyed in the yarn, so that no piece

dyeing is required. For waistbands and tops and fully fashioned knitwear, the

finishing is restricted to steaming; yard goods require additional setting.

2.3.2 Circular Knits

Circular knits must be delivered either in tubular form or open-width. The greige

goods must be divided into these two groups according to article characteristics

and the intended field of application.


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Fabrics that are processed and delivered in tubular form, e.g. elastic waistbands

for underwear, are treated on becks, in jets, or in continuous machines.

Relaxation takes place during the entire wet treatment. Subsequently, the

goods are hydroextracted, dried in jet ribbon driers without setting, and thencalandered. Since the product is not subjected to any setting, the required shrink

resistance must be reached by shrinking the product sufficiently (by maximum

overfeed in longitudinal direction, no stretching to the limit in vertical direction)

during other finishing procedures.

Recently, thermosetting of tubular knitted fabric on tube setting plants has been

introduced into finishing; the tube can either be treated by the vertical or by the

horizontal method.

By this setting technology the article properties like m2-weight, extensibility, tube

width and running length can be varied within certain limits like with open-widthtreatment.

However, it must be taken into consideration that excessive vertical stretching

may leave lateral marks (depending on the fiber).

Circular knits that must be delivered open-width and be subjected to heat setting

in order to create dimensional stability and to reduce the tendency to curl at the

edges can be dyed in rope form or open-width. Which technique is chosen

depends primarily on the fabric properties but also on the equipment availibility.

Articles that are not prone to creasing can be rope-dyed without any risk of crea-

se formation; additional advantages of this method are a large fabric volume and

a soft touch. Knits that are prone to creasing should be dyed open-width on the

beam to ensure a smooth finished product without creases.

Any open-width dyeing must be preceded by a reliable heat setting. Otherwise

the knitted fabric will shrink in width, which results in color irregularities because

part of the beam perforation becomes uncovered. In addition, moir effects will

occur. With beam dyeing, smooth, elegant, but also less voluminous final

qualities are achieved.

Knits should always be pre-scoured because they may contain lubricated fiberstaple yarns or be produced from raw cotton. Both types of fibers may contain

impurities, which should be removed prior to any heat setting. If the fabric is first

set and scoured afterwards, it will be much more difficult to wash out any

contaminations. Pre-scouring of non-set knitted fabrics must be performed very

carefully because of the large risk of crease formation (liquor ratio, temperature

control, moving the fabric during the process, possibly open-width treatment).


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2.4 Wovens

In contrast to knits, for which mainly bare Dorlastan is used, wovens are produced

exclusively with Dorlastan combination yarns. In combination yarns, the Dorlastanthread is normally well covered.

There are two types of fabrics, mono- and bi-elastic ones. In mono-elastic fabrics,

the Dorlastan is worked in either in warp or in weft direction. Bi-elastic fabrics

have incorporated Dorlastan threads in both directions.

Experience has shown that elastic fabrics with a large percentage of elastic yarns

(in most cases knits made of smooth textile filament yarns) shrink more than is

required to achieve the desired stress-strain properties. So the shrinkage must be

controlled and limited. Elastic wovens, however, often contain only a very low

percentage of Dorlastan, which is frequently combined with staple fiber yarns.This combination causes a high inner friction going along with a rather sluggish

shrinkage. If the standard finishing methods for elastic wovens fail to produce

sufficient compression to reach the defined stress-strain values, additional

measures must be applied. A very effective technique to achieve a clearly

improved shrinkage that normally meets standard requirements is a tension-free

treatment with hot air (e.g. in the tenter providing for the possibility of shrinking)

or dyeing at the boil (e.g. for piece dyeing in rope form).

With wovens, it would be possible to create a greige fabric with optimal

shrinkage, exactly the expected fabric weight and the desired degree of

recoverable stretch and being a non-shrinking fabric also with good shrinking

values, without applying any setting. The actual situation, however, is different.

The conditions in greige good production as well as in finishing always vary from

one batch to the next. Moreover, the buyer of the finished product may order

qualities of different m2-weights or stretch values. Such variations can only be

reached during finishing, which makes hot air setting necessary in nearly all

cases, because it is hardly possible to obtain all required characteristics in the

finished fabric by any other method.

After hot air setting further finishing processes may be required to obtain the

defined quality level. Such finishing may lead to an elongation of the elasticfabric, even if it is treated at low tension. If such an effect occurs, it must be

reversed later by shrinking, so that the fabric properties obtained by the setting

are regained. Possible methods are, for example, tension-free steaming or

sanforizing.


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3. Bleaching, Fluorescent Whitening and Dyeing

These important processes should be performed very carefully, because they do

not only give the fabric its final color, but also have a decisive influence on thequality of elastic fabrics.

For piece dyeing which does not require staining of the Dorlastan fiber, dyestuffs

exclusively determined for the non-elastic fibers are used.

Below you find some information about the various blends that are available.

3.1 Dorlastan/Polyamide

From the point of dyeing, polyamide filament yarns or fibers are ideal partners for

Dorlastan, because both fiber types can be dyed with the same categories ofdyestuffs, and the quality of the elastane is not impaired under the normal dyeing

conditions.

3.1.1 Scouring

As already explained in item 1.3.1, pre-scouring is recommended to achieve

optimal final colors.

Continuous scouring Discontinuous scouring

Impregnation in the 1st compartmentof the washing machine 3 ml/l Diadevin DSP

3 ml/l Diadevin DSP pH 89

pH 89 Exposure time: 30 min.

Temperature: 80C Temperature: 80C

Rinsing in the 2nd and 3rd compartment Rinse twice: 15 min. at 70C

at 7080C (counterflow), Rinse twice: cold with overflow

4th compartment cold (counterflow)

3.1.2 Fluorescent Whitening

Today, scouring, fluorescent whitening and reduction bleaching are preferably

combined, whereby a fluorescent whitening agent shows mostly affinity to the

polyamide. Optimal color light fastness is best achieved with BLANKOPHOR

CLE products.

The one-bath method and the following recipe is applied:

0.51.0 ml/l Diadevin NSE or Diadevin UN (APEO-free)

2.03.0 g/l Blankit CP

2.02.5 BLANKOPHOR

CLE as liquid (or CLE liquid B) pH 5 (acetic)


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3.1.3 Dyeing

The following classes of dyestuffs can be used for pure polyamide as well as for

polyamide/Dorlastan blends.

Acid dyestuffs for light and medium shades

Metallic complex dyestuffs for medium and dark shades or afterchroming

dyestuffs for very dark shades, particularly black

In special cases disperse dyestuffs may be used for very light shades.

Although polyamides and elastanes can be dyed with the same types of

dyestuffs, they react differently to the various classes. This must be taken into

consideration when selecting the dyestuff.

Whereas disperse dyestuffs are absorbed by polyamides and elastanes withmore or less the same intensity, so that no larger differences in shade occur,

acid dyestuffs create darker shades with polyamides than with elastanes. The

difference in shade varies, however, from dyestuff to dyestuff.

In addition to that, the dyeing properties within the group of polyamides differ

considerably from fiber to fiber, and in particular between polyamide 6 and

polyamide 6.6. In extreme cases, the combined effect of the above mentioned

differences in dyeing behavior may result in hardly stained elastanes that grin

through, if certain acid dyestuffs (with better affinity to polyamides) or metallic

complex dyestuffs are used.

The grin-through effect does not occur with clear Dorlastan (types V 500, V 800),

because the clear Dorlastan thread is transparent. Nevertheless, the percentage

of Dorlastan and the geometric appearance of Dorlastan in the article must still

be taken into consideration when choosing the dyestuff.

When using acid dyestuffs, it must be taken into account that dull and clear

Dorlastan appear differently in Dorlastan/polyamide blends. The right choice

of dyestuff and auxiliary agent is important, especially in case of high elastane

content (more than 30%).

Articles made of polyamide and dull Dorlastan can be dyed with acid or metallic

complex dyestuffs that are exclusively tailored to the polyamide component with

regard to affinity and fastness, if the elastane share does not exceed 20%. In

case of darker shades, however, the aftertreatment must include the stained

Dorlastan and be appropriate to stabilize its shade.

To avoid grin-through in articles made of polyamide and matted Dorlastan,

special measures are required. They must either be dyed with selected dyestuffs

that produce satisfactory tone-on-tone dyeing with standard leveling agents, or,

in special cases, with the help of suitable auxiliary agents like ASTRAGAL PAN,

which enhance the solid dyeing. The use of such agents, however, will entail aslight unavoidable deterioration of the wet and crock fastness. With unfavorable

dyeing conditions (unfavorable liquor circulation, little liquor exchange) it is


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essential to choose the best possible combination of dyestuffs and to use no

cationic auxiliary dyeing agents.

Standard combinations of auxiliary dyeing agents

0.51.0% AVOLAN IS

0.21.0% LEVEGAL FTS K 01 or 0.42.0% LEVEGAL LPA

ph 84

Recipe for better staining of Dorlastan

2% AVOLAN IW heat up from 40C to 98C

ph 7.55.5 within 45 minutes, keep

x% TELON, SUPRANOL, ISOLAN dyestuff at 98C for 30 minutes

0.52.0% ASTRAGAL

PAN (and keep at 98C for 30 minutes)

(With some dyestuffs, this combination of auxiliary dyeing agents should not be

used; see dyestuff table in the appendix.)

The Dystar product range of acid and metallic complex dyestuffs has been

tested with the two aforementioned combinations of auxiliary agents and has

been optimized to produce proper tone-on-tone dyeing of blends containing

polyamide and Dorlastan. The attached dyestuff table will help the dyer to select

the best dyestuff.

3.2 Dorlastan/Polyester

A Dorlastan/polyester combination is a difficult blend for the finisher, because

polyester types with normal dyeing properties must be dyed at higher

temperatures than polyamide (HT conditions: 120130C) or require the use of

carriers. This may lead to a deterioration of the elastic properties of the final

article, although Dorlastan still surpasses all competitive elastanes.

Since the disperse dyestuffs used for this blend also stain the elastane

component considerably, an alkaline reductive aftertreatment is required to

obtain good wet fastness.

If the polyester type in the blend allows the use of cationic dyestuffs, the

Dorlastan is hardly stained, provided the correct dyestuff is chosen.


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3.2.1 Scouring

The following scouring procedure has proven to be a good choice:

2.04.0 ml/l Diadevin DSP

possibly 1.0 ml/l RESPUMIT NF

possibly 1.52.0 ml/l PERSOFTAL L or 0.20.5 ml/l PERSOFTAL LU

pH 89

Exposure time: 2030 minutes

Temperature: 7080C

Liquor ratio: 1:10

Rinsing: 2 x at 80C

1 x cold with overflow

3.2.2 Fluorescent Whitening

In addition to the exhaust method with carriers, there are some other methods

that are particularly recommended for fluorescent whitening because of their cost

efficiency:

Thermosol method

In this method, the brightening agent is padded in the foulard. Subsequently, the

fabric is thermosoled in the tenter without intermediate drying. This step may be

combined with hot air setting. The following recipe is suggested for greige good

treatment:

1.05.0 g/l BLANKOPHOR ER liquid 330% 01

For shading:

Dianix brilliant violet B

Dianix brilliant violet R

Liquor absorption: 6080%

Drying at: 140CThermosoling: 2030 s at 190195C

AF method (adsorption/fixation method)

Here, the brightening agent is applied as an additive on the surface of the fabric

by the exhaust method (a fabric pretreated that way acquires a yellow cast). After

rinsing, the fabric is dried and heatset in the tenter. During this stage, the

fluorescent whitener is thermosoled into the fabric to produce the desired level of

whiteness.


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When applying the AF method, no anionic auxiliary agents must be used,

i.e. previous anionic scouring is not allowed, because this would impair an

undisturbed absorption of the whitener by the fabric.

Adsorption phase

0.10.3% BLANKOPHOR ER liquid 330% 01

12% Glauber salt

Acetic acid ph 4.5

The treatment is always started cold. The degree to which the fluorescent

whitener is adsorbed is highly dependent on the dyeing conditions. With rope or

jig dyeing, no adsorption will usually occur when the liquor is cold. For dye-bath

exhaustion, a temperature of about 4050C is required. The temperature is

raised slowly, i.e. by about 1C per minute. The adsorption phase is completedwith a cold rinse.

Fixation phase

After drying at 140C, the fabric is finally set at 190195C for 20 to 30 seconds.

If no fiber setting is required, the whiteness may also be developed by drying at

170180C.

3.2.3 Dyeing

To keep the damage to the elastic properties of a fabric made of a polyester/

Dorlastan blend within acceptable limits, the dyeing temperature must be

increased carefully and suitable carriers must be selected in the appropriate

amounts.

Two methods are available:

Dyeing with carriers:

Temperature increase and carrier (type, amount) must be adjusted to each

other to reach an acceptable compromise.

The following procedure is applied:

12% LEVEGAL DLP

x% carrier, e.g. LEVEGAL PTN 01

y% disperse dyestuff

pH 4.5

maximum dyeing temperature 108115C


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Dyeing without carriers

If carriers cannot be used for ecological reasons, dyeing can be performed

under HT conditions. The following procedure is applied.

12% LEVEGAL DLP

y% disperse dyestuff

pH 4.5

maximum dyeing temperature 125130C

maximum exposure time 3045 minutes

The range of disperse dyestuffs offered by DyStar with the respective application

information is enclosed in the appendix.

Starting temperature, heat-up rate and carrier amount used in the dyeing process

depend on the dyeing rate of the polyester and on the type and the quantity ofthe applied disperse dyestuff. For further information, please refer to the

recommendations of the dyestuff manufacturers. After dyeing, the fabric needs

alkaline reductive aftertreatment in order to improve colorfastness. The following

recipe is used:

24 ml/l caustic soda 50%

24 g/l hydrosulphite

2030 minutes at 80C

(For lighter shades, 70C and 3g/l soda ash instead of caustic soda suffice.)

3.3 Dorlastan/Wool

A Dorlastan/wool blend is not problematic with regard to dyeing, because the

standard conditions of wool piece dyeing (acid dyestuffs and temperatures below

100C) do not have a negative effect on the elastic properties of Dorlastan. Acid

dyestuffs usually produce solid dyeing of both the wool and the Dorlastan

threads; no special dyestuffs or auxiliary agents are necessary. Moreover, the

elastane share of such blends is usually rather small and hardly visible in the

finished fabric.


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3.4 Dorlastan/Cotton

The standard medium for cotton dyeing and finishing is an alkaline medium.

Blends containing Dorlastan, however, must not be exposed to the alkalineagents without control. The agents effect combines with those of heat and time

and might have a negative impact on the properties of the elastane.

The following dyeing and finishing procedures are recommended:

Substantive dyeing

Can be applied without hesitation even with a fastness improving aftertreatment,

if required.

Reactive dyeing

With dyestuffs that are suited for a dyeing temperature of 50C according to the

manufacturers data.

Indanthren dyeing

By the IK, IW, and IN method up to max. 60C.

Sulfur dyeing

By procedures with a reduced amount of alkali additives (e.g. sulfhydrate) at

approx. 70C.

Boiling off

Should be performed with the lowest possible amount of alkali additives

(2g/l soda)

Bleaching

Caustic treatment and mercerizing

Can be applied without negative effects despite of the high amount of alkaliadditives because processing temperatures are low.


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Add the usual stabilizers. In practice, the following recipe is applied successfully:

Winch back, liquor-fiber ratio1:30 soft water

0.2 g/l magnesium sulfate

2.04.0 m/l DIADAVIN DSP 01 (APEO free)

0.30.5 ml/l BAYSTABIL LF

0.51.0 g/l BAYSOLEX EXT-N

6.010.0 ml/l hydrogen peroxide 35%

Caustic soda pH 10.511.0

0.20.8% BLANKOPHOR BA liquid

for 3060 minutes at 9095C

Rinse thoroughly and apply the following aftertreatment to improve the white

effect:

2.0 g/l BLANKIT IN

3.0 g/l sodium sulfate

for 30 minutes at 70C

Special surface finishes, e.g. by enzyme treatment (Biofinish) are possible,

since they are not detrimental to the Dorlastan.

Note

If you have any questions on dyeing or finishing matters, please do not hesitate

to contact our Marketing Dorlastan department:

Dormagen, Germany Phone +49 21 33 / 51-50 85

Bushy Park, USA Phone +1 84 38 20-65 10


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Dyeing Procedure

(%) 1/1 V 500 V 850 V 900

S.D.

Telon Yellow FG 0,5 2 1 2

Telon Yellow RLN micro 0,65 1 1r 1

Telon Yellow FRL micro 1,0 2 1 2

Telon Yellow 4R micro 0,65 2 1 2

Telon Brown 3G 3,4 2 1 1r

Telon Red FRL micro 1,2 3 2 3

Telon Red 2BL micro 0,7 3 2 3rTelon Red 2B 0,8 3 2 3

Telon Red BRL micro 0,7 2 1 3

Telon Blue RR 0,7 3 2y 3

Telon Blue BRL micro 1,2 1 2 1

Telon Blue GGL 1,7 2 1 2y

Telon Yellow A3GL 0,7 3 2 3

Telon Yellow ARB 1,0 3 1 3

Telon Yellow A2R 0,9 2 1 3

Telon Yellow A3R 0,85 2 1 3Telon Orange AGT 0,5 2 1 3

Telon Red A2FR 1,3 2 1 2

Telon Red AFG 0,65 3 2 3

Telon Rubine A5B 0,35 2 1 2

Telon Blue AR 2,6 2 1 2

Telon Blue AGLF 1,8 3 2 3

Telon Blue AFN 3,0 3 2 3

Telon Blue A3GL 2,5 3b 2 3

Telon Navy AMF 1,6 2 1 2r

Telon Black AMF 1,75 1br 1y 1r

Telon Flavine M-7G 0,75 2 1r 2

Telon Yellow M-5GL 1,7 1r 2 2

Telon Yellow M-4GL 1,0 2 2r 2

Telon Orange M-GSN 1,3 1 2 2

Telon Red M-R 0,6 1 1 1

Telon Red M-GWN 1,1 2 1 2

Telon Red M-BL 0,85 2 1 2

Telon Red M-3B 0,5 1 1 1r

Telon Rhodamine M-BN 0,3 3bl 2bl 3bl

Telon Violet M-RWN 1,4 1 2 3

Telon Blue M-BLW 2,7 2 3 3r

Dyeing of Polyamide / Elastan Blends:

Staining on Dorlastan Type V 500, V 850

and V 900


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Dyeing Procedure

(%) 1/1 V 500 V 850 V 900

S.D.

Telon Blue M-RLW 2,7 2 3 3r

Telon Blue M-GLW 2,8 2 3 3

Telon Blue M-2R 1,8 1 2 2

Telon Turquoise M-GGL 2,1 2 3y 3

Telon Turquoise M-5G 2,3 1 3y 3

Telon Green M-BW 1,6 1 2 2bl

Telon Green M-6GW 2,0 1 1 2bl

Isolan Yellow K-GLN 250 % 1,0 2 2 2

Isolan Yellow GRL 0,9 2 1 1

Isolan Yellow K-PRL 200 % 1,3 1br 1r 1r

Isolan Orange K-RLS 150 % 2,0 2 2bl 2bl

Isolan Scarlet K-GLS 150 % 1,9 3 3 3

Isolan Bordeaux R 220 % 0,95 1 1bl 1bl

Isolan Brown K-3GLS 150% 2,1 1y 1r 1r

Isolan Blue 3GL 1,3 2 1 1

Isolan Grey K-PBL 200 % 1,3 2 1 1Isolan Black 3RL 2,7 2 3 3

Isolan Yellow SP-2RL 1,8 2 2br 2

Isolan Red SP-G 1,2 2 1r 2r

Isolan Blue SP-R 1,1 2 1 2

Isolan Grey SP-G 1,1 2r 1 2

Isolan Orange S-RL 1,2 1br 1 2r

Isolan Red S-RL 1,0 1 1 2

Isolan Brown S-GLN 1,0 1 2 2

Isolan Brown S-RL 1,0 1 1r 2

Isolan Navy Blue S-RL 2,0 1r 2r 2

Isolan Olive S-G 1,0 1 2 2

Isolan Grey S-GL 1,8 1 3 3

Isolan Black 2-BGL 2,9 2r 3 3

Isolan Yellow 2S-GLN 0,92 2 1r 2

Isolan Yellow 2S-RL 0,85 2 2r 2

Isolan Scarlet 2S-L 1,3 1y 1 1

Isolan Red 2S-BR 1,2 2 2r 2

Isolan Bordeaux 2S-B 0,95 1y 1 2

Isolan Brown 2S-BL 0,85 1y 1r 1



and V 900


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Blends: PA / Dorlastan 80/20

PA: PA 6.6

Elastan: Dorlastan V 500, V 850, V 900

Evaluation:

1 = slight dyeing of Dorlastan fibre y = yellowish

2 = medium dyeing of Dorlastan fibre r = reddish

3 = ton-in-ton-dyeing br = brownish

bl = bluish

dyeing procedure:

0,5 % Levegal FTSK 01

0,5 % Avolan IS only M.C. dyes

pH depending on the dye range

98C / 45 min.



and V 900

Dyeing Procedure

(%) 1/1 V 500 V 850 V 900

S.D.

Isolan Dark Blue 2S-GL 2,4 1br 2 2

Isolan Olive 2S-BGL 1,0 1y 1r 1r

Isolan Black 2S-LD 2,5 2r 3 3r

Isolan Black 2S-LGN Liq. 6,25 1y 2 2y


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Appendix

1. Dyestuff recommendations for dyeing PES/Dorlastan blends

The even exhaustion and diffusion properties of composite dyestuffs are key

factors for a successful dyeing of PES/Dorlastan blends. Due to these

properties the exposure time is shorter and reproducibility is optimized Right-

First-Time . The optimized reproducibility helps to avoid a subsequent addition

of dyestuffs with its negative effect on the characteristics of Dorlastan.

1.1 Dyeing at 125130C

Right-First-Time dyeing of PES/Dorlastan blends with good reproducibility and

optimal wet fastness can be achieved with the selection of dyestuffs listed

below.

1.1.1 DianixAC-E dyestuffs for light shades


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-70 -50 -30 -10 10 30 50 700

0

-50

-30

-10

10

30

50

70

90

b

a

Yellow AC-E new

Red AC-E 01

Blue AC-E

110


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Three-color combinations:

Medium shades: Dianix yellowish brown CC/ruby CC/blue CC.

Dark shades: Dianix yellowish brown CC/ruby CC/navy CC.

In bluish red shades (cherry red, wine red), washfastness can be increased

by the use of Dianix red K-2B.

-70 -50 -30 -10 10 30 50 700

0

-50

-30

-10

10

30

50

70

90

110b

a

yellow SE-G

brilliant blue R

yellowish brown CC

red K-2B

violet CC

turquoise S-BG

green CC

black CC-G

navy CC

blue CC

red CC

red C-4G 150%

ruby CC

1.1.2 Selected medium energy range Dianix dyestuffs for medium to

dark shades


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Three-color combinations: Dianix yellowish brown XF/ruby XFN/navy XF

Dianix flavin XF/scarlet SF/bleu XF for ultimate washfastness.

1.1.4 Advantages

Tone-on-tone staining creates optimal reproducibility and minimizes shade

corrections.

Good general fastnesses with Dianix AC-E dyestuffs and selected medium

energy range Dianix dyestuffs.

Three-color combinations including tone-on-tone staining of the elastane

fiber after reduction cleaning minimize grin through and shade changes

during post-setting.

Very good washfastness with selected Dianix XF/SF dyestuffs.

-70 -50 -30 -10 10 30 50 700

0

-50

-30

-10

10

30

50

70

90

110b

a

flavin XF

yellowish brown XF

blue XF

navy XF

black XFruby XFN

carmine SF

scarlet XF

1.1.3 Selected DianixXF/SF dyestuffs for dark shades of ultimate

washfastness


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1.2 Dyeing at 115C

1.2.1 DianixAC-E dyestuffs for light shades

1.2.1.1 Advantages


corrections.

Good general fastnesses.

Largest possible dyestuff standardization creates optimal reproducibility.

Good level dyeing properties and covering of differences in material.

Extraordinary light fastnesses.

-70 -50 -30 -10 10 30 50 700

0

-50

-30

-10

10

30

50

70

90

110

b

a

yellow AC-E new

red AC-E 01

blue AC-E


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1.2.2 Selected medium energy range Dianix dyestuffs for medium to

dark shades


Three-color combinations: Medium shades: Dianix yellowish brown CC/ruby CC/blue CC.

Dark shades: Dianix yellowish brown CC/ruby CC/navy CC.

In bluish red shades (cherry red, wine red), washfastness can be increased by

the use of Dianix red K-2B.

1.2.2.1 Advantages


corrections.

Good general fastnesses.

Three-color combinations including tone-on-tone staining of the elastane

fiber after reduction cleaning minimize grin through and shade changes

-70 -50 -30 -10 10 30 50 700

0

-50

-30

-10

10

30

50

70

90

110b

yellow SE-G

brilliant blue R

yellowish brown CC

red K-2B

violet CC

turquoise S-BG

green CC

black CC-G

navy CC

blue CC

red CC

red C-4G 150%

ruby CC

Faerben_und_AusruestenGB dyeing for knits

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