Stenter machine

1. Stenter Machine
Stenter is the mostexpensive and important fabric drying and finishing machine. Stenter is a
machine or apparatus for stretching or stentering fabrics. Itis also known as a ‘tenter’ in the
woollen industry. The purpose of the stenter machine is tobringing the lengthand widthto
pre-determine dimensions andalsofor heat setting andit is usedfor applying finishing
chemicals and alsoshade variationis adjusted. The main functionof the stenter is tostretch
the fabric widthwise andtorecover the uniformwidth.
Stenter machine consists of two endless auto-lubricated driven chains, typically 40 to 60 m in
length carrying pins or clips to hold the fabric edges while passing through a number of hot-air
chambers (3–5, each of about 3 m). Hot air is directed onto the fabric equally fromaboveand
below. A stenter has the provision for overfeeding the fabric to allow required shrinkage
during heat setting of fabric while the width is increased to the precisely specified value by
the chains. The use of clip stenter has declined becauseof the difficulty of applying overfeed.
The stenter speed ranges from 10 m/min for heavyweight furnishing fabrics to 100 m/minfor
lightweight dress-goods.
Functions:
 Drying,
 Heat setting,
 Weft straightening,
 Finishing, Curing after application of finishes
 Coating
The Stenter machine is used for the drying of woven and knitted fabrics. Itis a very versatile
and common machine in textile finishing. Almostevery open width textile fabric is treated on
Stenters during its textile processing. For maintaining universal use, the Stenter range is
usually standing separately, not in a continuous line with other machines. Four types of
processes aredone on Stenter which are drying, heat setting, finishing andcoating. The
Stenter machine usually consists of 8-10 chamber and eachchamber contains 2-blowers,
each blower providedinseparate casing and each casing contains 12 nozzles, i.e. total 24
nozzles are providedineachchamber (12 facing down and 12 facing up). In eachnozzle there
is 48 openings, each of whichare supplying the air to the fabric. In presentstudy, CFD
analysis of fan housewas carried out in three stages. In firststage, CFD analysis of Fan B with
casing was done; in second stageCFD analysis Fan A with casing was done; finally, in third
stage, CFD analysis of Fan B with nozzles wereperformed. Results were presented in terms of
pressureand velocity contours. TheCFD stimulation results were compared with experiments
and CFD results provided by M/s InspirOn engg. PvtLtd, Odhav, Ahmedabad, and found in
good agreement.

2. The controllers fittedinamodern stenter may monitor and control the following
parameters:
1. Chamber temperatures,
2. Moistureretention,
3. Stretch/shrinkage(over feed),
4. Fabric width,
5. Fabric weight,
6. Padder pressures,
7. Exhaust humidity.
Types of Stenter Machine:
A tenter or stenter is a transportdevice that carries fabric fromone point to another
continuously in open width with precisewidth control. The stenters are of twotypes, pin
stenters andclipstenters,depending on the means of holding the fabric onto the chains.
In clip stenters, the clips are in two sections, upper and lower; the upper being in either in an
open or closed position. At the entry point of the fabric, the upper jaw descends and grips the
edge of the fabric. At the delivery point, the jaw opens and releases the fabric. The clip stenter
requires a specific edge, preferably a selvedge, to grip and is usually confined to woven fabrics.
The more common pin stenters have pins about 5 mm long, mounted in two rows, about 3–4
pins/cm, along the baseplate. The pins are thicker near the baseto preventdirect contact of
the fabric with the hot baseplate. Clip stenters leave no pin marks in the selvedges, but
customers will accept pinholes in the selvedges associated with pin stenters.
Functions of Stenter Machine:
However, the stenter is the only drying machine that provides adjustmentand controlof fabric
width during drying. In addition to drying, the stenter performs severalother functions,
namely:
1. Imparting a particular mechanical finish affecting appearanceand feel, commonly
known as stenter finish.
2. Heat setting is doneby the stenter for lycra fabric, synthetic and blended fabric.
3. Widthof the fabric is controlled by the stenter.
4. Applying and fixationof several finishing agents by stenter machine.
5. Loop of the knit fabric is controlled.
6. Moisture of the fabric is controlled by the stenter.
7. Spirility controlled by thestenter.
8. GSM of the fabric is controlled by stenter.
9. Fabric is dried by the stentering process.
10.Shrinkage property of the fabric is controlled.
11.Curing treatment for resin, water repellent fabric is doneby the stenter.

3. Stenter Machine
Stenter Machine