Stenter Machine

Stenter machine can be defined as a stente finishing process in which the open width form of the fabric is treated to set up the required width, weight, and fabric texture as per customer’s specification. These requirements from the customer are achieved by a single Stenter machine process (i.e. Chemical application, Overfeeding-Compaction, Drying- Curing and setting of Width and Yield).

Stenter Machine Process Requirements

  • Equipment used
  • Following equipment is used for Stenter Finishing process
  • Bruckner stenter machine

Key Accessories

  • Following equipment is used for Stenter Finishing process :
  • pH papers,
  • Buckets,
  • Sewing machine,
  • Measuring balance,
  • Measuring tape,
  • Scissors, and

Materials / Chemicals Used

The materials and chemicals used in the stenter machine process for TC fabric, 100% Cotton fabric, CVC fabric and for Water Repellent fabric are described below.

Types of FabricMaterials/Chemicals Used
TC FabricSoftener

 

Additive

Stiffener

Acetic acid to adjust the pH

100 % Cotton Fabric (soft)Softener

 

Additive

Acetic acid to adjust the pH

100% Cotton Fabric (anti shrinking)Softener

 

Additive

Resin

Catalyst

Wetting agent (when chemical absorbency is poor)

Acetic acid to adjust the pH

CVC Fabric (medium touch)Softener

 

Additive

Stiffener

Acetic acid to adjust the pH

CVC Fabric (soft)Softener

 

Additive

Acetic acid to adjust the pH

Water Repellent FabricHydrophobic agent

 

Stiffening agent

Softener

Additive

Acetic acid to adjust the pH.

Safety

  • Following Do’s and Don’ts are to be followed during operation:
  • Do not wear loose dress that may entangle with the machine parts while running.
  • Always wear rubber shoes.
  • Never touch the uncurling roller while running the machine.
  • Be careful in manual pinning of fabric.
  • Do not insert hands between the rollers during running the machine.
  • Wear an eye goggle and hand gloves during preparation of chemical solution.
  • Do not touch the padder during operation.
  • Be careful about the selvage cutting blade.
  • Be familiar about volatile chemicals.
  • Be careful in handling the trolley of fabrics.
  • Be aware of the first aid treatment procedure.

Operation Procedure of Stente Machine

  • Operation Staff for stente machine
  • Operation stuffs of Finishing Process includes:
  • Manager
  • Textile Technologist / Production Executive
  • Production Co-ordinator
  • Operator
  • Assistant Operator for stente machine

Checklist Before Production

  • Operator must check the following items before finishing, re-finishing, heat setting and stretching process in Stenter machine process:
  • Machine parameters are set according to program.
  • Required manpower is available for feed side and delivery side.
  • Required chemicals are available.
  • Batch for Feed side is set.
  • Lead cloth is guided up through passage point to operator station.
  • Empty trolley is set at delivery side.
  • Ensure the the Stenter machine parts as spare

Operation Procedure for 100% Cotton Fabric (Soft Finish)

Calculation of Solution Amount

Production officer or shift in-charge will provide the recipe with the process flow. The finishing procedure begins with the calculation of solution amount for a particular batch. The formula is as follows :

Solution Amount = Total Weight of Fabric ´ Pick-up Percentage (%) + Trough Content + 3% Wastage.

Suppose, we have 500 kgs of fabric, which are to be finished, and for that we need to prepare the solution.

Required Solution Amount     = (500 x 80%) + 50 + (500×3%)

= 400+50+15

= 465 litre

(where 80% is the average pick up of knit fabric, and 50 litre is the trough content of machine trough).

Operation Procedure

Chemicals are measured using the electronic balance and taken in buckets separately. Chemicals are diluted with hot or normal water based on the references of the chemical literature provided by the chemical company.

Mixing tank is filled up with 50% of water to the required solution level and then chemicals are poured separately into the tank through a piece of filter cloth. Then water is added to get the target solution.

Chemicals are stirred for five to seven minutes by the electrical mixer impeller in the mixing tank and then send to the machine through. Then operator will run 1-meter fabric as a trial run to check the parameter(s), softness and hardness, shade match, etc. which is required by the customer. A small piece of fabric from that trial portion is given to the shift in-charge to check the parameter(s).

If the trial fabric matches with the customer-approved sample then production officer decides to go for the bulk production and operators starts the machine for production.

For the bulk production chemicals solution is prepared using the formula mentioned above and poured into the chemical trough.

The capacity of each tank is 400 litre.

Product Quality Check

Shade Check: During the processing of bulk production of any batch, operator checks the shade in the Stenter machine process. If any deviation is detected he informs the responsible shift officer who takes the necessary action to overcome the problem. If the officer fails to rectify the problem he informs the department head who finally gives the decision.

Fault Check in Stenter Machine Process: The operator checks for Knitting faults (i.e. double yarn, yarn contamination, fly yarn, etc.), Spinning faults (i.e. thick & thin yarn, barre mark, etc.) and other faults (i.e. dye resist mark, band line, chemicals spots, torn and hole, variation of shade, fabric structure, etc.) during the process.

In case minor faults occur within the half rolls of fabric (while running about 20-25 rolls of fabric) which is not resulted from previous process and also not recorded on the batch card the necessary action(s) to be taken is as follows :

Check the feed side to make sure that these faults didn’t occur from the previous process.

Stop the machine to identify whether these faults are occurring due to machine faults (i.e. from padder, chain bar, air duct, etc.) or the faults are due to the chemicals (check cleanliness, setting of machine parameter(s) and chemical composition).

If any spot on the fabric, which is not resulted from the previous process, is detected during processing, it indicates that the sequence of chemical pouring in the mixing tank is not correct which resulted in bad chemical reaction. If this happens, the process should be immediately stopped and responsible officer should be informed for investigation.

Width Check in Stenter Machine Process: Measure fabric width by using a measuring tape and compare it with the required width that is mentioned by production officer on the batch card or program.

Design, Fabric Bow and Slant Check in Stenter Machine Process: Check the design, bowing and slanting of fabric at the delivery side. Adjust the machine by straightening the courses line of the fabric for checking the bowing and slanting.

Pin Setting Check in Stenter Machine Process: Check at the delivery side whether the selvage of fabric is detached from pin and for minimum of 0.5″ each side pinning wastage is maintained, if any abnormality found, immediately inform the head operator.

Q.C. Sample Tests

1-meter sample is cut from each batch during processing and are sent to the Q.C. Department for lab testing. In Q.C laboratory, these samples are tested according to the quality requirement of the customer such as dimensional stability test, washing fastness, water fastness, light fastness, pilling test, crocking (dry & wet) etc.

After all necessary testing, the results are recorded on the Q.C. Sheet. Refer to Off Line QC Test Specification (Document No. 81-101) for details.

Applicable Forms & Documents

  • Forms & Documents Used
  • 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

 Document Flow

The document flow of Finishing Process is as follows :

Operator fills out the Batch Card and the concerned officer put his signature on it upon verification. The Batch Card moves with the fabric for the next step of finishing process(e.g. Tubular Compactor, De-water, Drying or Slitting).

The Daily Finishing Production Report is prepared to show shift wise daily production of finishing section of BK. Production officer prepares it and sign on it. The department head, Finishing verifies the facts and figures and put his signature on it. Finishing department records this report for future reference.

Machine Downtime Report is maintained to keep record of any stoppage in production due to machine break down or any other reason. Operator fills this and the responsible officer sign on it upon verification

Recipe Sheet is used to give recipe for a particular machine in each shift. It is also termed as the Chemical Consumption Report. Responsible officer prepares it and the Department Head, Finishing verifies and signs on it.

Identification Sticker is attached with every fabric roll that includes the Order number, Customer, Batch/Roll number, Quality, Colour/Shade, usable width and composition. This helps the stores personnel to easily store and locate a particular roll of fabric at Finished Goods Stores.

Program Register of Stenter Machine is maintained against Recipe Sheet to keep track of the production progress of a particular batch.

Production Register of Stenter Machine process is used to keep records of date wise production details. Operator fills this out along with his remarks (if any) and this report is recorded for future reference. Attachments: Examples of all applicable forms and documents are attached. Know more it