LOW PICK UP FINISHING Green Textile Operation: How Can We Make It Profitable?

07.11.2010

Public

BU Textile Chemicals

CHEMICALS

EMRAH ESDER

LOW PICK UP FINISHINGGreen Textile Operation: How Can We Make It Profitable?

Public

EMRAH ESDER

BU Textile Chemicals

CHEMICALS

07.11.2010

Slide 207.11.2010EMRAH ESDER, BU Textile Chemicals, CHEMICALS (Copyright Clariant. All rights reserved.)

Public: LOW PICK UP FINISHING

Carbon Footprint

� A carbon footprint is a measure of the impact our activities have on the

environment, and in particular climate change. It relates to the amount of greenhouse

gases produced in our day-to-day lives through burning fossil fuels for electricity,

heating and transportation etc.

� The carbon footprint is a measurement of all greenhouse gases we individually

produce and has units of tones (or kg) of carbon dioxide equivalent

� A carbon footprint is made up of the sum of two parts, the primary footprint (shown

by the green slices of the pie chart) and the secondary footprint (shown as the yellow

slices).



Carbon Footprint

� 1. The primary footprint is a measure of our direct emissions of CO2 from the

burning of fossil fuels including domestic energy consumption and transportation

(e.g. car and plane). We have direct control of these.

� 2. The secondary footprint is a measure of the indirect CO2 emissions from the

whole lifecycle of products we use - those associated with their manufacture and

eventual breakdown. To put it very simply – the more we buy the more emissions will

be caused on our behalf.



Carbon Footprint – Textile Impact

� The textile industry is one of the biggest GHG emitters on Earth, owing to its huge

size and scope. Many processes and products that go into the making of fibers,

textiles and apparel products consume significant quantities of fossil fuel. Apparel

and textiles account for approximately 10 percent of the total carbon impact. The

estimated consumption for an annual global production of 60 billion kilograms of

fabrics boggles the mind: 1 trillion kilowatt hours of electricity and up to 9 trillion liters

of water.

� The direct carbon footprint contribution of manufacturing plants from yarn to

customer including spinning, knitting, dyeing, finishing, cutting and sewing, plus

transportation to the distribution center could reach up to 12.5 kg of CO 2 per kg of

fabric.

� The carbon emissions of T-shirt manufacturing in CO 2 equivalents could be more

than 12 times the product weight. Considering that the carbon footprint of steel is

about 2 kg of CO 2 equivalents per kg of steel, the pressure coming down from the

supply chain to the full industry is understandable



Carbon Footprint: Ways of reduction in Textile

� Although there are many points where Textile has an impact on carbon footprint,

Energy saving and emission reduction on textile are the main key topics to be

considered in order to reduce the impact today.

� There are many ways of saving energy & reduce emission in textile industry by using;

– Environment friendly chemicals

– Chemicals which require low temperature curing.

– Applications which save energy especially on drying and fixing stage.

– Applications which require less water consumptions.

– Products / Applications which require less waste water treatment.

– Combination of all.

�We can start saving and reduce emission by lowering our pick-up !



Focus – Low Pick Up Finishing

� There are 6 million tones/a of Textile Chemical usage in the world.

� 40% of Textile Chemicals used for finishing segment.

Low Pick up Finishing



Introduction:Impact - Low pick Up Finishing

�During the past decade, much emphasis has been given to reduce energy required in

desizing, bleaching, dyeing and finishing of the fabrics.

�The most effective way to reduce the energy consumed in finishing would be to

reduce the amount of water which must be evaporated. This is only possible by

reducing the wet pick up.

�Reduction of wet pick up is highly desirable because:

–It saves energy in drying and fixing process

–It reduces migration in dyeing and finishing.

–It has positive contribution for environment by lowering carbon footprints.



Definition – Low pick-up finishing

� Typically, pad applications of chemical finishes yield wet pickups in the 70–100 %

range. These high pickups necessarily require the removal of large amounts of water

during drying.

� Low pick-up finishing describes wet pick-up levels between 5%-40%. These values

are very much depends on CAV (Critical Application Value) which is related to fiber

type, fabric construction and absorbency.

� A finish application below the CAV may result in a non-uniform speckled treatment,

while an application above the CAV could lead to finish migration. Cellulosic fibers,

because of their inherent hydrophilicity, have CAVs in the range of 35–40 % wet

pickup. Hydrophobic fibers like polyester can have CAVs of less than 5 %, allowing

much lower wet pickups than hydrophilic fibers.

� In order to minimize finish migration during drying and reduce the energy costs

associated with drying large amounts of water, various techniques have been

developed to reduce the amount of water used in finish applications.



Definition – Lower limits of pick ups & CAV values

CAV

CAV values of the fibersPick Up limits of the conventional process



Definition – Low pick-up finishing

� An additional benefit is that some applications will allow precise placement of

chemicals, leading to the possibility of fabrics with different finishes on their face and

back.

� Another advantage is the recovery and reuse of the finish liquor removed by some of

these techniques. To reduce the danger of uneven finish distribution on the fabric,

caused by low wet pickup, a thorough preparation is necessary by any method that

provides a very good and uniform absorbency.

� There are two main types of low wet pickup applicators. The first is the saturation–

removal (Expression) type where the fabric is completely saturated with the finis

liquid and then the excess liquid is removed mechanically or with a vacuum before

drying.

� With the Topical type, a precise amount of finish liquid is uniformly applied to the

fabric using transfer roll, spray or foam techniques.



Methods – Low Pick Up Finishing

�There are two main possibilities to reduce the pick up;

–Expression Methods: To remove/reduce surplus liquor by squeezing or other means.

–Increase nip pressure

–Increase hardness of the rollers

–Decreased diameter of the pad roller.

–Use special composition of rollers

–Use Vacuum extractors.

–Topical Methods: To apply limited amount of liquid during the applications.

–Foam Applicators

–Kiss roll applicators

–Spray applications

–Other transfer methods.



Topical Methods – Kiss-Roll

�The kiss roll, picks up the chemical finish and transfers it by direct contact to the

fabric.

�The amount of finish picked up is dependent upon how well the finish wets the roll,

the absorbency of the fabric and to a lesser extent, the surface speed of the roll relative

to the fabric speed.



Topical Methods – Transfer Rolls

� Another version of finish application with transfer rolls is the loop transfer system. A

loop of fabric is immersed in finish liquid and then squeezed with the fabric to be

treated between squeeze rollers.

� The finish is transferred to the fabric at a much lower wet pickup than possible by

direct immersion. These roll transfer techniques are especially useful for the

backside application of finishes, for example hand builders and flame retardants, to

pile fabrics (without crushing the pile).



General Findings- Kiss-Roll & Transfer-Roll applicators (Transfer Padding)

� Although simple I concept, It needs strict control in order to achieve homogeneous

add on.

– Loop must be seamless and dimensionally stable on transfer padding.

– Build up risk of the running chemicals on the rollers especially if there is no

uniform absorbency properties on the fabric.

� More suitable for

– Pre-coated fabrics with high absorption properties.

– Lightweight fabrics.

� It is possible to run around 25-40% add on.

� Functional finishes are possible.



Topical Methods – Triatex MA

�One interesting modification of the kiss roll applicator is the Triatex MA machine

which uses on-line monitoring to control wet pickup. Figure below, shows a schematic

of the system.



General Findings– Triatex MA applicators

� Average pick up level : 25 %

� Drying speeds can be increased as much as 50 % more compare to conventional

methods.

� Surface migration of the chemicals has been virtually eliminated so possible

chemicals saving can up to 20%.

� Different variety of finishing possible

– Resin Finishing

– Water & Oil repellents

– Antibacterial applications.

– Flame retardant applications.



Topical Methods – Spray Application

� Chemical finishes can also be applied by spraying. By controlling the flow rate

through the spray bars, the amount of applied finish can be set to the desired add-on.

Care must be taken to avoid overlapping spray patterns that could lead to an

unacceptable uneven finish distribution. Special care is needed with aerosols from

fluorocarbon sprays (inhalation, followed by repellency of the inside of the lungs is a

deadly danger).



General Findings – Spray application

� Very low add –on possible: 5%- 30%

� Fabrics with different structure can be treated;

– Velour

– Flat Woven

– Corduroy

– Terry fabrics.

� Different functional finishes possible

– Softeners

– Fluorocarbons

– Resins

– Anti-pilling treatments

– Fire retardants



Topical Methods – Foam Application

�One important application method for chemical finishes is the use of foam to apply the

finish to the fabric. By replacing part of the water in the chemical formulation with air,

the amount of water added to the fabric can be significantly reduced.

�In addition, surfactants are included in the formulation to be foamed.

�Even if they are carefully selected, they may cause effect reduction of repellent

finishes.

�The chemical formulation is mixed with air in a foam generator producing high

volumes of foam that can be applied to fabrics in a number of ways. The ratio of liquid

to air in a foam is referred to as the ‘blow ratio’, conveniently determined



Topical Methods – Foam Application

� The stability of the foam is influenced by the components of the chemical system, the

viscosity of the foam and the method of foam preparation.

� The half-life of a foam is the time in which 50 % of the liquid in a given foam volume

has been drained from the foam.

� Foams for textile applications can have half-lives from a few seconds to several

hours.

� Foam applicators can be used either for one side or for two sides

Single side Applicators



Topical Methods – Foam Applications

Double side Applicators



Topical Methods – Foam Applications

� To make foam applications useful in Textile Applications, foams must be sufficiently

stable to insure uniform application of the chemical to the fabric.

� Stability of the foam depends on many factors;

– Surface tension of the liquid

– Viscosity and elasticity of the film separating the bubbles

– Presence of electrolyte in the system.

– The size and uniformity of the bubbles in the foam.

– Foam temperature.



General Findings – Foam Finishing

� In conventional finishing fabric passes in to a bath containing chemicals with typical

solids content ranging from 2-10 %. In this method, fiber content largely dictates the

wet pick up of the fabric.

� General wet pick up at conventional systems;

– 100% Cotton: 70-100 %

– Blends of Polyester/Cotton: 60-80 %

– 100% Polyester: 40-50%

� In conventional process, over 90% of applied finish is water which must be removed

in drying operation.

� In a typical foam application process 5 to 25% solid content finish can be delivered to

the fabric.

� With foam systems, up to 75% of the water in the finishing formulation is replaced by

air, thereby eliminating 75% of energy needed to remove water in the final

evaporation process.



General Findings– Foam Finishing

� Ideal results on effects and uniformity can be achieved 30-35% add on cotton.

� Especially on resin finishing made with foam at 26-28% add on can achieve same

properties compare to standard pad finishing with 65% wet-pick up.

Great Saving is possible

Finishing of 50/50 Polyester/Cotton




Resin Finishing on 50/50 Polyester/Cotton




� Even with such highly absorbent fabric as cotton flannel by combination of increased

line speed and reduced temperatures energy saving can be achieved more than

70%.

Softener application on 100% cotton flannel



General Findings - Disadvantages

� Main disadvantages:

– The finisher does not have the same flexibility in adjusting the finish formulation to

get required properties as he does in conventional finishing

– Set-up time is longer.

– Fabric dries out before it can be framed out to width.

Conclusion



Conclusion

� For low pick-up systems, ideal add-on for the fabrics is 15%-35%

� Most of the functional finishing such as resin, fluorocarbon, antibacterial on Cotton

and it’s blends:

– By experiment, the most comparable results with foam finishing(100% co &

Co/polyester blends) against to conventional padding process were taken around

28 %-30% add-on.

– With that add-on values, dusting issue has also been minimized.

– Below 25% it is difficult to maintain consistency but also problem of product

distribution on the fabric because of limited solubility.

� Below 25% add-on values, there may be 5% fluctuation. In order to reduce that

value, we need to around 30 % or slightly above especially for functional finishes.



Conclusion

� Despite the established many advantages of low pick up finishes and especially

foam finishing represents less than 20 % of all finishing.

� Main Advantages:

– Get low pick up even down to 5% for various applications, quicker water drying

with energy saving of more than 50%.

– Chemicals can be saved in many circumstances in textile finishing treatments.

Stenter speed can be increased for drying or stenter, predrying can be eliminated.

– Shorten the length of equipment, plant and reduce the investment.

– Reduce environmental pollution and water waste.

– Can be carried on single or double-side of fabric (can be imposed on both sides

with different agents).

– Apply to different kinds of fabric, whatever its structure and composition

– Over all, it will help us to reduce carbon footprint !



Check out Clariant 4E’s Concept !

Technology

LOW PICK UP FINISHING Green Textile Operation: How Can We Make It Profitable?