Spirality Tester and Test Method
Fabric Spirality tester is a equipment for dimensional distortion in circular plain knitted fabrics. This In House Test Method describes the method of test in order to determine the spirality test method which occurs in a material resulting from laundering procedures. The correct number of test specimens are to be prepared and tested as specified within this test method in order to achieve a performance assessment of the product/fabric as described within the scope.
- Automatic Washing Machine
- Calibrated Tape or Ruler
- Conditioning/Drying Racks.
- Automatic Tumble Drier
- Make-weight 100% Polyester.
- Over-lock Sewing Machine.
Conditioning of Spirality Tester
The test specimens are to be conditioned in the standard atmosphere of 65% Relative Humidity (RH) +/- 2% and 20°C +/- 2°C for a minimum of 4 hours. Preparation of Test Specimens/Materials
- Fold the fabric along a Wale line.
- Place the marking template on the fabric parallel to the wales and drawn round.
- Cut out the double thickness specimen accurately g the knitted wale lines and cut at right angles to these to produce a “bag” square.
- Note: The second cuts are not necessarily parallel to the knitted courses.
- Sew the two pieces of fabric together to form an open ended bag i.e. similar to a garment. Overlock the single edges of the fabric to prevent unravelling.
- Test the garment in its finished state.
- Record whether any spirality test method is present in the garment prior to washing.
- Measure original length and width dimensions.
- Note: It is recommended that garments that already exhibit Spirality are not tested because deceptive results will be produced.
Carry out Washing/Drying procedure as agreed, or specified
Results of Spirality Test Method
- After conditioning, lay the specimen on a flat smooth surface so that the natural fold in the washed specimen is flat and free from wrinkles.
- Measure the distance “d” to nearest 1mm from the natural dried fold of the fabric square to the inner edge of the seam (see diagram). Repeat on the other edge by gently lifting back the opposite edge to the seam.
- On garments these measurements are made at the hem.
- Measure the length and width dimensions in order to determine the dimensional change.
Reporting Of Results
Determine the average of the two measurements (in cms), call this “D”.
Calculate the %Spirality
i.e. “D” x 100
L = Length of test Specimen (Fabric)
Or = Underarm to hem (Garment) (After Washing).
Effect of Yarn Twist On Spirality of A Fabric.
Finished fabric spirality may vary depending upon yarn twist.
Generally high twisted yarn may cause high spiraled of fabric and vise versa.
We know that,
TPI=TM*(Yarn Count) 1/2
Say for example 30 count yarn:
For Knit fabric yarn Lowest TM is 3.5 and the Highest TM is 3.7
For Viscose yarn TM is 3.5 because viscose is long staple fiber (near about 38 mm long, where as cotton is near about 28.5 mm long)
For woven fabric yarn, TM is given to 4.5 because woven fabric yarn needs more strength.
Skewness / Spirality Test Mechod
|Scope||To determine the Skewness/ Spirality /Torque of fabric Or Garment after repeated home laundering procedure|
|Precondition||2Hrs ( Temperature Below 50°C, 5%-25% RH)|
|Condition||4Hrs (Temperature 21°C ± 1° C, Relative humidity 65% ± 4%|
|spirality test method Method 1= (38×38cm)(Length & Width)|
|spirality test method Method 2 = (38×66cm) )(Length & Width)|
|Procedure A = (38×38cm)(Length & Width)Diagonal Marking Method|
|Procedure B = (38×66cm) Inverted Marking Method|
|580 ×510 mm , Mock Garment Marking Method|
|Procedure A = Within Garment Panel (Inverted Marking Method)|
|Procedure = B Garment Side Panel|
|Method 1 = Tow Pair’s of 250mm Benchmark Length & Width To Make a Squire Box (See Fig.)|
|Method 2 = Inverted Marking Method ( See Fig.)|
|Procedure A = Tow Pair’s of 250mm Benchmark Length & Width To Make a Squire Box (See Fig.)|
|Procedure B = Inverted Marking Method ( See Fig.)|
|Mock Garment Marking Method Face Side Together Length =580mm Width=510mm, Sew 12 mm from edge Tow Length and one Width wise .Turn Inside Out for making a Garment Mock.( See Fig.)|
|Procedure A = Within Garment Panel (Inverted Marking Method) See Fig.)|
|Procedure B = Garment Side Panel ( See Fig.)|
|Sewing & Note||Over Lock All Edges For Preventing Fray Effect|
Note Down Washing & Drying Condition & BGDT No.)
Prof. Jamps, South East University, Washington