Determination of level of pilling in the woven fabric by the Martindale Method.

Pilling is the formation of bunches or balls of tangled fibers, which are held to the surface of a fabric by one or more fibers. The resistance to the formation of pills on the surface of a textile fabric is known as pilling resistance.

Pilling of yarn or fabric is due to the fiber mobility action with in the yarn. Yarn dimensional stability is very important because if our yarn is dimensionally stable less fiber mobility in the yarn and hence less pilling will occur on the fabric surface.

The pilling is divided into four stages:

• Fuzz formation
• Entanglement
• Growth
• Wear-off

Pilling normally happens on the parts of clothing that receive the most abrasion in day-to-day wear, such as the collar, cuffs, and around the thighs and rear on trousers.

The pilling of textile fabrics is a very complex property because it is affected by many factors that include:

• Type of fiber or blends
• Fiber dimensions
  • Fiber length plays important role in the pilling properties. Staple and filament fibers show totally different properties of pilling from each other.
• Yarn construction
  • Yarn construction includes the type of spinning system used like ring, rotor or vortex. If the yarn is more compact it will have a low level of pilling than a loose yarn (with low twist).
• Fabric construction
• Fabric finishing treatments
  • Fabric finishing treatments exerts a large effect on the pilling properties. As the surface of the fabric changes hence the pilling properties also changes after finishing.

Techniques used to avoid pilling includes:

• Using Filament fibers instead of staple or long staple fibers.
• Increase compactness of yarn by increasing the twist of the yarn during its manufacturing process.
• Singeing the loose protruding fibers on the fabric surface.
• Spinning the yarn with a high number of twists per inch.
• By the chemical treatment of fabric usually with the softeners finishes.
• Polymeric coatings are sometimes applied, to bind fibres into the fabric surface and prevent initial fuzz from forming.
• Polyester and cotton fibres are sometimes modified to be of lower-than-normal strength, which results in pills detaching easily from fabrics, once they are formed.
• The textile consumers can also reduce pilling of their fabrics by:
  • Turing their clothes inside out before washing.
  • Washing with laundry detergent containing enzymes will get rid of pills on cotton clothing. The enzymes eats away the cellulose of the exposed fibers, leaving the fabric looking fresh and new.

The pilling resistance of a specific fabric in actual wear varies more with general conditions of use and individual wearers than in replicate fabric specimens subjected to controlled laboratory tests.

The degree of fabric pilling is evaluated by comparing the tested specimens with visual standards, which may be actual fabrics or photographs of fabrics, showing a range of pilling resistance. The observed resistance to pilling is reported on an arbitrary scale ranging from 5 to 1.

ASTM 4970 – 02 test method was used for determining the pilling properties. This test method covers the determination of the resistance to the formation of pills and other related surface changes on textile fabrics using the Martindale tester. The procedure generally is applicable to all types of fabrics, being particularly suitable for woven fabrics.

Objectives:

• To study the test method used for determining pilling in the woven fabrics.
• To determine the pilling in the given sample of woven fabric.

Materials & Equipment:

• Martindale Tester.
• 100% pure cotton sample
• Fabric punches or fabric cutters.
• Standard felt of mass 750 g/m² and 3 mm thick.
• Apparatus for Fabric Evaluation.
• Photographic – A set of five photographs 105 mm, numbered 1 to 5, illustrating varying degrees of pilling from "very severe pilling" to "no pilling".

Method:

• The pilling test was performed before on the cotton fabric sample in order to assess the resistance to the formation of pills.
• The test was performed using ASTM D-4970 American Standard on Martindale Abrasion.
• Martindale tester is designed to give a controlled amount of rubbing motion between fabric surfaces at low pressures in continuously changing directions.
• Four circular samples of 120 mm for the abradent and 140 mm for the abrader was cut from each swatch.
• These samples then were loaded onto the Martindale tester.
• The test was performed using variant pressure for 1000 rubs according to the standard.
• The degree of pilling was visually assessed using pilling photograph 1-5, 1 means more pilling and 5 means no pilling.

Observations:

Sr. #	Fabric samples	Martindale Tester Results
1	Compact sample 01	3-4
	Ring sample 01	1-2
2	Compact sample 02	4
	Ring sample 02	2-3
3	Compact sample 03	4
	Ring sample 03	2

Table 1: Pilling test results on the Martindale tester.

Results & Discussion:

The pilling test results of the fabrics on the Martindale tester are presented in table 1. Woven fabrics made from compact yarns were significantly more pill-resistant than those made from ring yarns. This suggested that the hairier ring spun yarns caused the fabric surfaces to pill more. In other words, the well-aligned and compact structure of compact yarns did not allow easy fibre pull-out, which led to higher pilling resistances. In addition, the visual comparison of the fabric surfaces after pilling clearly showed the advantages of the compact yarn structure in which the marginal fibres were better integrated in the body of the yarn.

These findings supported the theory which indicates that the pilling properties of the fabric are highly related with the hairiness property of yarns used to construct the fabric. Moreover, an increase in the number of longer hairs in the yarn has a decisive influence on pilling formation.

With regard to the yarn count, the pilling rates of the fabrics tended to increase with finer yarn counts. This tendency was observed in a similar manner for both ring and compact yarns. The increased pilling rates in the fabrics with finer yarns can be attributed to the fact that finer yarns have lower hairiness values than the coarser yarns. The appearances of the fabrics woven from compact spun and finer yarns indicated that their tendency to pilling was lower than the fabrics woven from ring spun and coarser yarns.

After the rubbing action was completed, the appearances of the fabrics woven from ring spun yarns showed higher pilling tendency than the fabrics woven from compact spun yarns. Moreover, it is clearly visible that the pill formation has a tendency to decrease as the yarns get finer and less hairy.

Conclusion:

When pilling behavior was taken into account, it was observed that fabrics woven from compact yarns were found to have higher pilling resistances than those woven from ring yarns.

Reference:

1. http://books.google.com.pk/books?id=EIJXNyjx7bwC&pg=PA298&dq=pilling+prevention+fabric&hl=en&sa=X&ei=aYHtToydA4qKiALxt6TWBw&redir_esc=y#v=onepage&q=pilling%20prevention%20fabric&f=false
   
2. http://publications.muet.edu.pk/research_papers/pdf/pdf743.pdf
   
3. http://www.fibtex.lodz.pl/60_11_39.pdf