What This Test is Used For:
This test is used to cover the resistance to the formation of pills and other related surface changes on the textile fabrics using the random tumble pilling tester. The procedure is generally applicable to all types of woven and knitted fabrics.
How This Test Works:
Textile samples are placed into the random tumble pill tester for a specified amount of time and tumbled. The samples are then evaluated for the degree of pilling.
Scientific Testing Requirements:
Bring specimens to moisture equilibrium for testing in standard atmosphere for testing textiles according to ASTM D-1776, conditioning Textiles for Testing.
-Cork Cylinder Liners: about 5 3/4” wide by 17.81” long cut from 0.063” thick flat sheets
of Type P2117A material conforming to Classification System F104, Appendix X2.
-Air Injection Device to give 14-21 kPa (2-3 psi) air pressure in each test chamber
-Adhesive: white all-purpose, for sealing the edges of the specimen
-Twelve 4.13” squares cut on the bias approximately at a 45° angle to the warp and filling
- Cut a 4.13” square on the bias at approximately a 45° angle to the warp and filling directions.
One sample needed per person. (Avoid cutting samples in areas with wrinkles & other distortions. Avoid getting oil, water, grease, etc. on the sample while handling.)
- Condition sample and cork liners by bone drying and then bring them to moisture equilibrium in the controlled chamber.
Loading the Random Tumble Pill Tester
- Place Specimen and a 25 mg of a 5 mm (0.2”) gray colored cotton fiber into the test chamber.
- Place the cover on the chamber and set the timer for a running time of 30 minutes. (10 minute
intervals for up to 30 minutes may be more indicative for certain knits or soft-woven fabrics.)
- Turn the motor switch to “on,” and push the “start” button, and start the airflow.
- During the run check each chamber at frequent intervals. (If the specimen becomes wedged around the impeller without tumbling or lies on the bottom or side of the chamber, shut off the air, stop the machine, remove the face plate, and free the specimen. Record on a data sheet any abnormal behavior or hang ups of the specimen.
- After each run, rake out each specimen and clean off excess cotton fiber using the vacuum cleaner.
Preparation for Evaluation
- Place each specimen on the double faced tape in the viewing cabinet.
- Using suitable rating standards, and the apparatus for fabric evaluation, subjectively rate the face of each specimen, looking down on the specimen at a 45° angle and using the rating standard and the following scale. When the appearance of a test specimen falls between that of 2 rating standards, assign the half value (i.e. 3.5).
5- no pilling
4- slight pilling
3- moderate pilling
2- severe pilling
1- very severe pilling
- Average the ratings for the 3 specimens from each laboratory sampling unit and the average for the lot.
- Take note if one strip in either fabric direction, or in any one portion of a specimen, report this condition. This indicates that different yarns may have been used in the construction of the fabric being tested.
- Check the pilled specimens for evidence of irregular tumbling. If specimens show a high concentration of pills in a general line not parallel to either fabric direction, assume a specimen is wedged around the impeller for one or more periods during the test. Discard these and repeat test with new specimens.
- Evaluate the fabric for other surface effects such as fuzzing. It is advisable to have a separate set of in-house fabric rating standards for each surface effect to be rated.
The level of satisfaction the sample fabric displays will be determined by the specification written for the fabric. For the Quality Assurance class, this is the specification the group wrote for the textile material.
For reference in the industry the level of satisfaction determined by the amount of color change is as follows:
Satisfactory – If the test specimen exhibits a color change of less than or equal to Step 4.
Unsatisfactory – If the test specimen exhibits a color change or more than Step 4.
- State that the specimens were tested as directed in Test Method D-3512. Describe the material or product sampled and the method of sampling used.
- Report the following information for the laboratory sampling unit and for the lot as applicable to a material specification or contract order.
– Ratings of each individual specimen, the average rating of the 3 specimens from each laboratory sampling unit, and the average for the lot.
– If the fabric was washed before testing and laundering conditions used.
– Running time
– Type of viewing apparatus and rating standard used.
Basically, rubbing surface of fabrics in a certain time and then evaluating degree of pilling can be used as a test method of common evaluating pilling performance. The following is serval methods to measure pilling performance: random tumble pilling test method, box pilling test method, elastic pad method, Martindale abrasion and pilling test method, brush and sponge abrasion test method, accelerated abrasion test method, inflatable mode abrasion test method, appearance retention abrasion test method, reciprocating test method, HATRA pilling test method.
At present, random tumble pilling tester, box pilling tester, Martindale abrasion and pilling tester, circle pilling tester are common used in laboratory and factory.
- Random Tumble Pilling Test Method
Fabric sample tumbles in a cylinder with a stirring rod, rubbing with another sample or cylinder wall to produce pilling. Movement of fabrics is random and irregular; fabric surface undertakes a large external pressure. Sometimes fabric sample gotten stuck behind the stirring rod results in weak repeatability of this pilling test.
Figure 3 Random Tumble Pilling Tester
- Box Pilling Test Method
Fabric sample is covered on a rubber sample tube, put in a square wood box with rubber cork, and it tumbles in rotating wood box to make sample pilling. With random movement of fabric and bearing a little pressure, this test has a better repeatability, but the factors influencing pilling test is many, such as the superficial condition of rubber cork and rubber tube. This test method is suitable for fabrics easy to pilling.
Figure 4 Box Pilling Tester
Fabric, mounting on the clamp head, is rubbed and pilling with the same fabric set on grinding table in a prescribed pressure. Fabric rotates around axis, and the track of relative movement between clamp head and grinding table is pre-set Lissajous figure.
Figure 5 Martindale Pilling Tester
There introduces an improved Martindale Abrasion and Pilling Tester later. This test method is appropriate for wool fabrics and other fabrics easy to pilling, especially woven fabrics. Pattern standards or evaluation tables are used to evaluate the degree of pilling. Each sample is put on a dual platen of evaluating box. To evaluate grade of each sample’s positive should adopt proper evaluating conditions, proper standard fabrics or standard photos. Tested sample’s appearance is measured by two standard grades or cards when evaluated. The specified grades are as follows:
|4||Mild surface fluff and/or isolated pilling unformed|
|3||Form middle-level fluff and/or pilling. Around surface of the test specimen is covered with hair balls of different sizes and distributed densities.|
|2||Form obvious fluff and/or pilling. A large area of surface of the test specimen is covered with pilling of different sizes and distributed densities.|
|1||Densely covered fluff and/or obvious pilling. The surface of the test specimen is covered fully with pilling of different sizes and distributed densities.|
- Circle Pilling Test Method
Fabric sample pilling with nylon brush at a track of circle motion under a certain pressure, then rubbed relatively with a standard fabric to pilling, or with a fabric abrasive to pilling directly. This test method is suitable for chemical fiber filament fabrics and chemical fiber short fabrics, but if fabrics are used as abrasives, it can apply to fabrics easy to pilling.
Figure 6 Circular Locus Tester