NZ Denim Ltd.
Stenter
Document No : NZDL_Stenter_SOP_2019/01
Author Tanvir Mahmud
Document Owner NZ Denim Ltd
Approvals :
Standard Operating Procedure (SOP)
1.0 Process Definition
Stenter is such a finishing process where through different
chemical treatments fabrics’ different qualities such as hand feel,
weight, width, brightness etc. are met.
2.0 Process Requirements
2.1 Key Accessories
The following accessories are used:
pH papers
Buckets
Sewing machine
Measuring balance
Measuring tape
Scissors
Trolley/Batcher
2.2 Materials / Chemicals Used
Types of Fabric Finish Type Materials/Chemicals Used
1. Softener
100 % Cotton Fabric Soft
2. Additive
3. Acetic acid to adjust the pH
1. Hydrophobic agent/Flowro
100% Cotton Fabrics Water Repellent Finish
Chemicals
2. Softener
3. Additive
4. Acetic acid to adjust the pH.
3.0 Safety
Shall not wear loose clothing.
Shall wear rubber shoes.
Shall not touch rolling roller when machine is on.
Shall be careful when setting pin.
Shall wear appropriate PPEs when handling chemicals.
Shall not touch padders when machine is on.
Shall be careful when handling fabric trolley and batcher.
4.0 Operation Procedure
4.1 Operation Staff
Manager
Production Officer
Supervisor
Operator
Assistant Operator
Mixer man
Helper
4.2 Machine Set-up
Machine Parameters Set-up Value
Padder Pressure 1.5 to 4 bar (depends on the pickup
requirement of the fabric.)
Temperature setting (80-210)0C (according to the shade,
quality and process of fabric.)
Blower fan setting Low or high (according to the quality of
fabric.)
Exhaust fan setting Manual
Width of machine chain setting 80 cm up to 180 cm (according to the
required width of fabric.)
Overfeed 0%-20% (as per the required weight of
fabric.)
Thermo temperature (80-210)0C
Machine speed 10 up to 80 m/m (according to the
quality of the fabric.)
4.3 Checklist before Production
During finishing, re-finishing, heat set and stretch the below
checklist must be followed:
Need to set parameters according to program.
Need adequate number of people on machine feeding and
delivery side.
Need to get chemical solutions ready according to process.
On the feed side of the machine fabric trolley or batcher
shall be ready.
Fabric shall be guided properly and carefully through guider
and padder roller to the operating station.
Empty trolley or batcher shall be set up in front of the
machine.
Need to make sure machine panel board shows green light.
4.4 Operation Procedure for 100% Cotton Fabric
4.4.1 Calculation of Solution Amount
Chemical solution equation
Production officer or shift incharge will set chemical recipe according to
process need. When preparing the recipe every lot of fabrics quality
must be considered.
Volume X Chemical GPL
Solution Amount =
1000
For instance, say 5000 meters fabrics need to be finished and GPL=20,
then the solution will be:
500 X 20
Solution =
1000
= 10 Ltr.
4.4.2 Operation Procedure
At first chemical has to be weighed by electric balance and kept in
different buckets. According to chemical manufacturer TDS chemical has
to be diluted either with cold or hot water. In the mixing tank 50% has to
be filled with filtrated water solution in comparison with the total
solution. Then rest of the water solution has to be taken to the tank. 5-
10 minutes the mixture has to be stirred by electric mixer. Then the
solution has to be transferred to the chemical boxes. After running the
machine, operator will run 1 meter fabric first and check parameters,
softness, hardness, shade match quality etc. A swatch sample has to be
tested according to customer’s need. If the sample passes all the
requirements, then the process will continue for bulk
4.5 Product Quality Check
4.5.1 Shade Check
During processing a fabric bulk lot operator shall check shade. If any
discrepancy found operator shall inform the duty officer and shift officer
will take steps to solve that problem. If shift officer fails to solve the
problem, he must inform department head and department head must
give the final decision.
4.5.2 Fault Check
During the finishing process operator will check different types of faults
such as color spot, holes, shade variation, fabrics weave, chemical spot
etc. If any fault is found, first must check the feed side fabric which
means previous process. If in the previous process no fault is found, then
the machine shall be shut and chemical tanks, parameter and chemical
composition must be re-checked. If operator realizes where the problem
is, he may solve the problem himself. If he does not find out, he shall
inform shift officer and shift officer through proper investigation shall
solve the problem.
4.5.3 Width Check
Shall check the width of the fabric when transferring to inspection.
4.5.4 Fabric Bow and Skew Check
Shall check fabric bow and skew control according to standard.
4.5.5 Pin/Clip Setting Check
While finishing process is continuing shall be careful about the pin so
that it does not come on the body of the fabrics. Pin shall be in between
0.5 inch or alongside the selvedge.
4.6 Q.C. Sample Tests
During finishing process from every batch after every 1000 meters 1
meter sample fabric has to be cut for quality check and sent to QC.
Different quality parameters shall be checked such as dimensional
stability, washing fastness, water fastness, light fastness, pilling test,
crocking (dry & wet) etc. All the results must be recorded in QC register.
Process
5.0 Response to Equipment Faults
Machine Faults Response
Pinning shoe problem Mechanical Engineer should be called
Pinning brush problem Mechanical Engineer should be called
Electrical sensor selvedge
Electrical Engineer should be called
problem
Chain stops Electrical Engineer should be called
J-box compensator problem Electrical Engineer should be called
Mechanical/Electrical Engineer should be
Chain width disturbance
called
Mechanical/Electrical Engineer should be
Burner, blower, motor problem
called
Mechanical/Electrical Engineer should be
Padder, plaiter problem
called
6.0 Machine /Area Cleaning
After processing every batch of fabrics machine roller and padder
shall be cleaned.
After finishing every shift machine surrounding areas shall be
cleaned.
Filter shall be cleaned in every shift.
Every week at least once air duct has to be cleaned.
Every day at least once machine net shall be cleaned.
Every week at least once chemical mixing tank shall be cleaned.
After every recipe preparation, all the containers such as bucket
and mug shall be cleaned.
7.0 Forms and Document
The necessary forms & documents for finishing process are listed
below:
Process Batch Card
Daily Finishing Production Report
Machine Downtime Report
Recipe Sheet
Identification Sticker
Program Register of Stenter Machine
Production Register of Stenter Machine
