Belcoro Yarn Fact Sheet

Transcription

1 Introducing Belcoro yarn Ray Wright, Fruit of the Loom s European Fabric Technologist and QA Lab Manager, explains why the company s Belcoro fabrics herald a major advance in the quality of imprint garments and how they render the traditional distinctions between open-end and carded ring-spun fabrics virtually redundant. Fruit of the Loom has over 150 years experience of manufacturing textiles. During that time the company has witnessed major advances in both fabric technology and quality, (not to mention customers demands and expectations). One of the most important of these advances is the company s introduction of Belcoro accredited fabrics in the manufacture of its core, in-house T-shirt and Sweat fabrics. Fabric quality is an important property of any imprint T-shirt or sweatshirt. And fabric quality begins with the qualities of the cotton yarn the fabric is knitted from. In particular, the yarn will influence the fabric s hand-feel and its printability. Historically, there has been a trade-off between the two: carded ring-spun yarns were preferred for fabrics with a softer hand-feel, at the expense of some loss of print quality; open-end yarns were chosen for fabrics that promoted superior printed results, but at the expense of a slightly harsher hand-feel. Fruit of the Loom s Belcoro open-end yarns render such distinctions virtually redundant: the company s Belcoro licensed fabrics, which are knitted from Belcoro yarns, are a close match for carded ring-spun fabrics for softness, whilst advancing the traditional printability advantages of conventional open-end fabrics. What s more, the company has the numbers to prove it. What is Belcoro? Belcoro is a proprietary trademark of Oerlikon Schlafhorst, manufacturers of Autocoro automatic rotor spinning machines. Fruit of the Loom has installed Autocoro machines in its new Moroccan factory to produce yarn for its in-house T-shirt and sweatshirt fabrics. Fabrics that use yarns produced on Autocoro machines may be submitted to TexLab Oerlikon Schlafhorst s laboratory, which is accredited to DIN ISO/IEC Here, they are tested against the Belcoro Quality Standards. The Standards are based on international testing criteria for a wide range of both yarn and fabric parameters. These include yarn tensile strength, elongation, and IPI values

2 (imperfections); and fabric wash fastness and crocking fastness (fastness to rubbing). Fabrics that conform to the rigorous requirements of the Standards are awarded a Belcoro licence a globally recognised fabric quality guarantee. All of the Fruit of the Loom fabrics used for the company s in-house T-shirt and Sweats programme are Belcoro licensed. The high quality of the Fruit of the Loom Belcoro fabrics can, in large part, be attributed to the spinbox on the Autocoro spinning machines. In very simple terms, to produce openend yarn, cotton fibres are first formed into a sliver a thick cord in which the cotton fibres are placed next to and parallel with each other. The sliver is then fed into the machine s spin box. This smooth metal box is rotated (spun) at high speed (up to 120,000 revolutions per minute on the Autocoro machines), generating a powerful centrifugal force that lifts the cotton fibres apart. The fibres are then pulled out of the other end of the spin box via the spinning head as lengths of cotton yarn. To the naked eye, the inside of a conventional spin box looks smooth. However, the metal is actually covered in minute imperfections (visible only under an electron microscope). When the spin box is rotated at high speed, the cotton fibres catch on these imperfections, which roughen and damage them. Oerlikon Schlafhorst addressed this challenge by fabricating the spinbox on the Autocoro machines from high-grade surgical steel. This has an incredibly smooth surface with very few imperfections. The difference is significant: comparing the metal from an Autocoro spinbox with that from a conventional spin box could be likened to comparing rolling grassy downlands with the jagged peaks of the Himalayas! The use of surgical steel means that the cotton fibres suffer no damage during the spinning process. The resulting yarns are far softer and retain more loft; they are more even (with the fibres remaining parallel to one another); they have fewer imperfections (the yarn is more uniform); and they are less hairy there are fewer loose and broken fibres standing out from the surface of the yarn. Quantifying quality TexLab s testing procedures provide hard data that illustrates the quality advantages that result from the Belcoro spinning technology. For example, Fruit of the Loom s Belcoro yarns register a reading of 5 on the scale of yarn hairiness; in comparison, conventional open-end yarn measures in excess of 7, whilst the ring-spun yarns that are most commonly used for imprint apparel measure 6.2. (Higher readings indicate greater hairiness).

3 Yarn hairiness has a profound effect on a fabric s printability: loose, damaged fibres sticking up from the surface of the fabric will lead to fibrillation; they may also prompt the printer to use a heavier ink deposit to matt down the broken fibres during the print stroke. Just as importantly, broken fibres will easily become detached from the fabric and build up on the underside of the screen during a print run. This will require the printer to stop the press more often to clean the screens and remove the broken-off fibres, resulting in increased downtime, longer print runs and reduced profitability. The Belcoro fabrics, which have very low hairiness, provide an incredibly clean print surface that encourages high quality printing and will minimise disruption and downtime. Yarn hairiness will also affect a fabric s propensity to pill. So-called surface fuzz, (the loose fibres on the fabric before it is washed or worn), is regarded as the first stage of the pilling process. It follows, therefore, that the hairier a yarn, (and the greater a fabric s surface fuzz), the more likely the fabric is to pill. The Fruit of the Loom Belcoro fabrics, (including the company s next-generation sweatshirt fabrics), score 4 on TexLab s pilling test, (measured against the DIN EN ISO T02 Standard). The scale runs from 1-5, with 1 representing an unacceptable degree of pilling, 5 indicating no evidence of pilling, and 3-4 representing the minimum pass grade. For comparison purposes, conventional polycotton sweatshirt fabrics score either 1 or 2 on the pilling scale. A canvas for print The Belcoro Quality Standards also set tight tolerances for yarn strength, elongation and imperfections, plus fabric stability. Stability is a measure of the degree of shrinkage after washing and tumble-drying. The standards set a maximum shrinkage rate of just 6% and Fruit of the Loom Belcoro fabrics are regularly showing shrinkage rates as low as 4%. Older-style open-end yarns could be expected to shrink by 7% or more. Similarly, the standards limit the number of thick and thin areas that occur along a length of yarn (that is, the uniformity of yarn shape and diameter), and the permissible number of neps (minute blobs of thread caused by fibres gathering together on the yarn) fewer than 12 per kilometre are allowed. The result is a remarkably uniform yarn that produces fabrics with a smooth, uniform surface that s perfect for print. Viewing the Belcoro yarns under an electron microscope also reveals that they are considerably thicker, with greater loft, than conventional open-end yarn of a similar yarn

4 count. This causes the Belcoro yarns to better fill the gauge (the loops in the fabric) for a denser, less transparent looking fabric: this is easy to demonstrate simply by holding up a garment to the light. Fruit of the Loom has augmented this yarn property on its Valueweight T styles by knitting the fabric on 28 gauge knitting machines: by comparison, old-style open-yarn tends to be knitted on 22 gauge machines, and the majority of modern T-shirt jersey fabrics are knitted on 24 gauge machines. By using a finer yarn count and finer knit gauge the company is able to produce a fabric that boasts 40% more stitches (up to 1700 per square inch). The end result is a close-knit fabric with a remarkably smooth, uniform surface that could justifiably be described as a print canvas. Environmental benefits In addition to the quality advantages, Fruit of the Loom s Belcoro open-end yarn production delivers significant environmental benefits, in terms of reduced energy consumption and waste. The Autocoro machines operate at speeds in excess of 100,000 (and up to 120,000) revolutions per minute, compared with the 19,000 revolutions per minute of ring-spun spinning machines. This means that the Autocoro machines can produce four, five or even six times as much yarn over a given period of time, and using the same power consumption. With fewer manufacturing steps involved in the spinning of open-end yarn compared with ring-spun yarn means less electricity is used, which further increases energy savings. The net result is energy savings of up to 30%. Belcoro open-end yarn manufacture also reduces waste. The minimum fibre length for spinning open-end yarn is shorter than that for ring-spun yarn. This means that more of the cotton fibres can be used and converted to open-end yarn. By using more of the fibres, fewer bales of cotton are needed, which reduces the consumption of diesel fuel. Similarly, less land is required to produce a given amount of open end yarn compared with ringspun yarn, so the use of fertilizers, insecticides, and herbicides is also reduced. Using more of the available cotton fibre even relieves the burden on landfill, by reducing the volume of bale wraps and packaging. Based on Fruit of the Loom s annual cotton consumption, it is estimated that over 6 million litres of diesel fuel, 1.5 million litres of insecticide and over 420 tonnes of bale ties are saved by using open end yarn. The company calculates that, overall, the production of Belcoro open-end yarns delivers a 23% reduction of the waste associated with ring-spun yarns.

5 Summary The advent of Fruit of the Loom Belcoro fabrics represents a major advance in the quality and performance of open-end cotton yarns, and it means that printers no longer need to compromise between a fabric s hand-feel and its printability. It can be difficult, if not impossible, to discern any significant difference in the hand-feel between a Fruit of the Loom fabric made from Belcoro yarns and a similar weight fabric made from carded ringspun yarns; whilst TexLab s data, plus real-world print trials, show that Fruit of the Loom Belcoro fabrics provide a clean, smooth, tight knit and uniform surface that provides a perfect canvas for print. Below are some visuals highlighting the differences between the 3 yarns: Ringspun, traditional open end yarn and Belcoro yarn: 100% CARDED COTTON STANDARD OPEN END SPUN

6 100% CARDED COTTON RING SPUN There is noticeably a larger amount of surface fibre (technically known as hairiness ) evident on the face of the carded ring spun fabric in comparison to the standard open end fabric and particularly with the fabric knit from Belcoro spun yarn. 100% CARDED COTTON BELCORO OPEN END SPUN Fabric knit using Belcoro spun yarn gives better clarity when screen printed in comparison with standard open end spun and carded ring spun fabrics because of its clean surface. Fruit of the Loom 2010