.ws what competitors (both home and ab
,he progression of style or fashion. This incl
o new machinery. 4 Gives the public whatk
the best colour and design his studio can pm
led bracket.
u are virtually sure of a sale. Get the right %
.et. It is useless trying to sell fawn/brown a d
y require small all-over geometrics in soft beige
:s not produce styles that are in fashion, it
rhy research is one of the most valuable parts of
alk is about research.
has
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Goodstaff.
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Once
YOU
theknow,
designer
Mr M E Fielding
A new
method of
.
'
I
!
polyester
and blended polyester fabrics
,u
talent. Being a trend setter does not, however,
E FIELDING
in an attempt to influence public taste. Designers
It developments in style and colours are u
sY ~
THE dyeing of polyester and particularly polyester in blended fabric is a high-cost
tking, rather than overnight decisions.
:ntion workmanship. If the workmanship of hc operation, using expensive dyestuffs and expensive equipment. Now coming from a most
lly woven or printed, colours not on standard, unlikely source, the woollen industry, is a method based on a well-known but previously
plain to the top management. Bad workmanship unused principle which offers a new economically attractive approach.
gives a company a bad name, thus preventing The method is of the vapour phase type, as only dye vapour is used. It is a continuous
process, there is no water usage, no effluent problem, no solvents nor is there the cost and
jisposal
problem of transfer printing paper. The disperse dye is held in a rechargeable
ung designer. We must train our young designen
will come when carpet designers of this country reservoir from which it is partitioned only on to the receptive fibres, leaving cellulosic
.rse. We used to have an Empire, SO why not a $bres and wool clean. Subsequent washing and/or reduction clearing of blends is unnecessary so that the method has a remarkable potential for efficiency and economy
:ery country, particularly the development
;ompared
with established methods.
et buyers. I n fact, we can and should influence
The recognized methods of dyeing polyester can be summarized as:
ial, we have the experience.
a Exhaustion dyeing from an aqueous bath, ie, carrier dyeing, H T dyeing and foam
JS right now, and studios do not need consultants
dyeing.
disposal. These young people are one day going
b
Dyeing
from a solvent.
le of the company, so confidence building at a
endous talent in this country, and this should& c Pad Thermosol dyeing.
not need strings of qualifications or diploma. d Transfer dyeing, ie, using unicolour transfer printing paper.
There are many problems with these methods, particularly in blends of polyester with
en, with good training, he will succeed.
;ellulosic fibres or wool. In (a) which is a batch process, dye usage is heavy, shade
patching of constituent fibres difficult, and rubbing fastness of the product is often
.uspect. (b) The problems always surrounding solvent processes make solvent dyeing a
Micult operation and solvent loss is costly. Method (c) Thermosol dyeing, is widely
Jsed for large scale cotton/polyester processing, particularly in the United States. The
ape dispersion is first padded on to the fabric and while a good proportion of the dye is
:aken up by the polyester part of the blend, some dye and all the dispersing agent, thick:ner and padding assistant remain in the interstices of the fibres. Extensive washing and
anetimes reduction clearing is necessary and while a Thermosol range is very productive,
:s capital cost, running costs and output of polluted effluent are very formidable items
'0consider. In transfer dyeing, method (d) almost the total amount of colour on the paper
transferred to the fabric and while on 100 per cent polyester the fastness and cleanliness
acceptable, the cost of the inked paper is prohibitive. If the method is used on blends
polyester with cellulosic fibres, the disperse dye condenses on the non-receptive fibres
nd a 'dirty' result is obtained, unless receptive resins are applied.
What is this new method and how was it evolved? British Patent No 1432197 describes
:baldly as 'Improvements in or relating to dyeing of synthetic fibres' but it cannot spell
if
87
I f
I
A
Dyeing polyester and blended polyester fabrics by the Troyfill method.
out the reasons which brought about its discovery.
The low cost woollen industry uses recovered wool wastes and rags as its raw materials
and has for many years suffered from an increasing problem of light coloured synthetic
fibre ‘bits’ in deep shade piece dyed woollens. A United Kingdom Government report
‘Reclaiming the 70’s’ saw the problem as one likely to destroy the industry. Every way
was tried to lessen the problem-more efficient sorting of rags, better carding and even
solvents to swell and dissolve the offending synthetics-but with no success. New dyeing
techniques were the only hope but the low profit margins on these cloths gave little scope
for expensive methods. Temperatures above 100°C were not suitable for recovered wool
fabrics and eventually carrier dyeing, with carefully selected carriers and disperse colours,
was the only possibility. Even then, the usage of very expensive dyestuffs was appallingly
inefficient, while poor rubbing fastness caused endless problems on the heavy shades of
black, navy and maroon.
In the attempts to find some other solution, transfer printing from a unicolour paper
was tried on a melton fabric made from wool/polyester rags which had a totally unacceptable appearance. The white ‘bits’ were perfectly covered but in the subsequent
evaluation there were two serious drawbacks. There was severe deposition of loose
disperse colour on the wool which gave a hopeless dry rub fastness. Scouring cured this
satisfactorily, but this process, together with a second drying and finishing process would
be uneconomic. The very high cost of the paper was also uneconomic. On the other hand,
the beautiful finish imparted to the wool melton by the blanket callender was noted and
it was realized that if the problem of deposition on the wool was solved, here was a ‘bit
dyeing’ method already integrated into a dry finishing routine.
It was then realized firstly, that if a heavily dyed polyester fabric was used in the transfer printing machine in place of the printing paper, the dye in it would partition on to
the white polyester bits. Where there were no polyester bits, the colour would simply
remain in the polyester cloth, and there would be no deposition on the wool. Wool
88
has no affinityfor disperse dye vapour. Secondly, it was immediately apparent that when
[be polyester cloth had given up most of its store of colour, it could simply be re-dyed
Jfldbegin a fresh cycle.
For these twin reasons, the heavily-dyed polyester cloth was christened the ‘reservoir
cloth’ since it stored the colour, released it slowly as and when required, and was replenished when empty. The phenomenon of partitioning from a polyester cloth is not
,nknown as, of course, sublimation testing uses this principle; but British Patent No
1132197 recognizes the novelty of a rechargeable reservoir cloth as a means of selectively
dyeing polyester and other synthetics.
Once the principle was established, work proceeded rapidly. A piece of polyester fabric
,!as jet dyed to a heavy navy shade and run through a Hunt & Moscrop Transfaprint
with a badly contaminated navy melton at ten yards per minute. The result
’ ,&,as quite dramatic in that the melton now looked Derfea and its wet and drv rub fastness
;,.as unaffected. Further tests showed that the same‘piece of polyester reservdir cloth could
be used over a hundred times without noticeable deterioration of result and the necessity
:o recharge with colour.
Work then commenced on a production plant and the line drawing taken from the
Datentshows the principle of running the reservoir cloth in a continuous loop. It is first
iharged with colour on the pad mangle at (3), is dried over cans at (5) and then gives up
Lolourin the blanket callender at (7). In practice, only one recharging of the reservoir
;loth per shift is necessary, unless some fabric containing an excessive amount of syn[hetic contamination is being processed. The reservoir cloth does deteriorate eventually
after successive re-dyeings but only after many hundreds of cycles through the circuit.
y the Troyfill method.
Calculations show that dyestuff is being released from the reservoir cloth at the rate of
i
.tss than 0.2 per cent on weight of fabric per cycle. As the woollen cloth is approxi,very.
mately four times the weight of the reservoir it follows that the white surface polyester
red wool wastes and rags as its raw matxeasing problem of light coloured synthetic ibre bits visible to the consumer are being dyed a dark navy shade with only 0.5 per cent
of dyestuff on the weight of woollen fabric. All colours are possible and a throughput to
.IS. A United Kingdom Government r e m
date of some two million metres without problem is testimony enough. The process
le likely to destroy the industry. Every
has
the enormous advantage of being a remedial one; only if ‘bits’ show after normal piece
ent sorting of rags, better carding and
dyeing
need it be used.
ynthetics-but with no success. New dyeips
rofit margins on these cloths gave little s q
Demand from woollen trade
* 100°C were not suitable for recovered wool
Troyfill (Finishers) Ltd (a member of the Illingworth, Morris Group) was then set up
refully selected carriers and disperse colours,
e of very expensive dyestuffs was appallingly :O deal with the demand from the woollen trade generally; any company using re,ed endless problems on the heavy shades of qanufactured raw materials and piece dyeing could expect trouble at some time. Even
.ompanies using pure wool experienced polypropylene contamination from tares, and
m, transfer printing from a unicolour p
a
p
e
r nany such pieces have been successfully rectified. More recently, the rectification of
.vool/polyester rags which had a tot&y,un- piece dyed all wool worsted which contain a single wrong wool/polyester warp thread is
.re perfectly covered but in the subsqumt becoming a major part of the work of Troyfill. It is quite astonishing to see a disastrous
cks. There was severe deposition of loose me-inch pin stripe made perfect at up to twenty yards a minute without affecting shade
3peless dry rub fastness. Scouring cured this Jr fastness !
a second drying and finishing process would The process has thus achieved what it set out to do-but in doing so has opened the
iper was also uneconomic. On the other hand, loor to a completely new conception. If the method can dye synthetic fibres that shouldn’t
elton by the blanket callender was noted and l e there, why not use it as a basic method for dyeing synthetic fabrics and synthetic/
ition on the wool was solved, here was a ‘bit iatural blends? Wool/polyester fabrics have already been experimentally dyed by firstly
gad dyeing the wool and then using Troyfill to dye the polyester and set and finish
ry finishing routine.
iy dyed polyester fabric was used in the trans- he fabric in a 20-second operation.
ig paper, the dye in it would partition on to The possibilities for dyeing cellulosic‘polyester fabrics have enormous potential
:no polyester bits, the colour would simply .dvantages. a Dye usage for single side treatment as low as 25 per cent of a Thermos01
.vould be no deposition on the wool. wool iyeing. b No water usage. c No effluent or water disposal, d Low capital cost.
89
e No limitation on speed of line if setting cans are used. f Low operating S b
g Low space requirement.
It is obviously more difficult to dye a fabric level using this method than it is to ‘fill ip
the bits’ and yet the reservoir cloth shows amazing resilience in its levelling action. Tht
large quantity of dye acts as a buffer supply and small variations do not result in shade
differences on the dyed fabric. The same principle on modified equipment has potential
for non-woven fabric and development work on polypropylene non-wovens has reached
a most interesting stage. Patents have been filed 011 the process in the major textile
countries and several Grants of Patent have been made. Joint development projects arc
being discussed with companies in various parts of the world and in widely differing
sections of the textile industry as the potential of this new conception becomes mor,.
fully understood.
‘Troyfill’ is a registered trade mark.
Troyfill (Finishers) Limited is a member of the Illingworth, Morris Group of Companies.
T h e role of the designer
GILLIAN CRAVEN
I SHOULD like this afternoon to discuss the importance to the designer to broaden his
horizons by visiting European textile and fashion exhibitions or by visiting and discussing
ideas with other members of the fashion trade from spinners to garment makers. A
designer today, as I am sure you are all aware, is no longer a person, and no longer
invariably a mule person, who spends all his day hunched up over a piece glass in a remote
corner of the mill. Today the designer’s function has extended to include a much wider
field, including public relations, marketing and sales.
Even so, there are still some members of the trade who find it difficult to understand
the designer’s need for research and contact outside his working environment. Contaa
with other members of the textile and garment trade is absolutely essential. It is after dl
one trade-the end product is the garment bought by the ultimate consumer. It is extremely important that the two sides of the industry-textiles and garment making-should
work closely together and see each other as an integrated unit.
Textile designers must never fall into the trap of making cloth for cloth’s sake-they
must design with a clear end product in mind. Textile design courses at Leeds University
include pattern cutting and drafting and most of the students have had some previous
garment designing experience-not before time, I might add. On the other hand garment
designers must see their design and the fabric as one unit, one made exactly for the other,
not a garment design that seems superimposed upon a fabric.
I think that one of the most important functions of the textile designer is to meet his
customer and discuss ideas with him. This benefits both parties. The textile designer
then gets a feeling for what the fashion designer wants and an appreciation of his
individuality-they are all different and it is up to the designer to cater as commercially ac
possible, for all these individual tastes. I have always found garment designers to be only
too pleased to discuss ideas-they are just as keen to find out what the textile trade is
thinking-after all we have to work so much further ahead. It is equally important for
spinners, particularly fancy-yarn spinners, to have similar discussions with designers.
Fashion prediction is always a precarious business but because the textile designer has
90
,
’