heat setting of fabrics

1. HEAT-SETTING
SUBMITTED TO:
MISS PREETI GAUTAM
SUBMITTED BY:
SIMRAN
BT-30952
TEXTILE 5TH SEM
JNGEC, Sunder Nagar

2.  Heat setting is a heat treatment by which shape retention,
crease resistance, resilience and elasticity are imparted to the
fibers.
 Change in strength, stretch ability, softness , dye ability and
sometimes in color.
 Changes occur due to structural and chemical modification of
fibers.
Introduction

3.  They consist of long chain molecules randomly held
immediately after spinning.
 Fibers are stretched several times their length to impart
desirable properties.
 As chains come more closer, there is increased H-bonding
and van der wall forces.
 This makes the structure more stable.
Thermal behavior of synthetic fibers

5. 1. Heating phrase
2. Penetration phrase
3. Transition and stretch phrase
4. Cooling phase
Process of thermosetting (four
distinct phrases)

6. Heat setting can be carried out at three different
stages:
 In grey condition
 After scouring
 After dyeing
Stages of heat setting

7.  If heat setting is carried out in loom state, mineral oils and non-ionic
emulsifiers can modify the fiber.
 Structure and rubbing and perspiration fastness may be reduced due to
the solubility of disperse dye in the coning oil.
 However, grey heat setting is useful in warp knitting industry as in that
material carry less amount of lubricants.
 Yellow color due to heat setting can be removed by bleaching.
 Fabric is less sensitive to crease formation in next processes.
Heat setting at grey stage

8. Heat setting is done after scouring if it is suspected
that:
 goods will shrink .
 Cloth has developed stretch or other properties after
scouring.
Heat setting after scouring

9. These fabric shows considerable resistance to stripping
compared with dyeing on unset fabric.
Disadvantage of this are:
 Yellow color developed can not b removed.
 Handle of cloth may get altered.
 Risk of color to get fade.
Heat setting after dyeing

10.  Contact method
 Steam setting method
 Hydro setting method
 Heat setting using tenter frame
 Selective infra red emitter method
Methods of heat setting

11.  Fabric is run in contact with heated metal surface.
 Mainly used for polyester/cotton blended fabrics.
 Width of the fabrics can not be controlled while
fabrics run flat against the roller surface.
 Variation on degree of setting can be caused due to
variation in tension.
Contact method

12.  Short staple polyester yarn including polyester/cotton
blends are normally set by relaxation in saturated steam.
 Steaming is carried out in an autoclave fitted with vacuum
pump.
 Woven or knitted fabrics are batched in open width on to a
perforated roller and saturated steam is then injected.
Steam setting method

13.  Hydro setting or aq. Heat setting is done with hot water in a high
temperature liquid circulating machine.
 Fabric in flat form is batched onto a perforated metal cylinder and
immersed in hot or boiling water for a shorter period of time.
 Water promotes swelling and may cause hydrolysis leading to
depolymerisation.
 Hydro setting at boil is equivalent to dry setting at 185
Hydro setting method

14.  Stenters are widely used for stretching, drying, heat setting and finishing of fabrics.
 Fabric is held by pins mounted on base plate or by chips in which fiber edge is clamped.
 Stanter rails are divided into three sections:
1. Feeding in, with padding mangle.
2. Selvedge uncurler (for knitted goods)
3. Shrinkage apparatus
 The choice of heating system used can be direct gas, indirect steam or oil heating or electrical
heating.
Heat setting under tenter frame

16.  Textiles are exposed under selected areas of magnetic spectrum of infra red
rays.
 Wavelength of radiation source must be chosen w.r.t the absorption band
of fiber.
 Energy is given to the internal fiber structure.
 Absorbed energy is redistributed within the structure of fiber, H-bonds and
van der wall forces binding the molecules together.
 They arrange themselves into position of lowest energy.(least stress)
Selective infra red emitter method

17.  Structural changes
 Dimensional stability
 Stiffness
 Crease recovery
 dyeability
Effect of heat setting on various
properties of synthetic fibers

18. THANK YOU 