Bulked continuous filaments

Polypropylene fibers are used in every aspect of carpet constmetion from face fiber to primary and secondary backings. Polypropylene s advantages over jute as carpet backing are dimensional stabiUty and minimal moisture absorption. Drawbacks include difficulty in dyeing and higher cost. Bulked-continuous-filament (BCF) carpet yams provide face fiber with improved crimp and elasticity. BCF carpet yams are especially important in contract carpets, characterized by low dense loops, where easy cleaning is an advantage. 

Fibers. Polypropylene fibers are extensively used in carpeting. Bulked continuous filament yams are commonly used in carpet facing in the level loop carpets used in commercial buildings however, nylon remains the dominant face yam in tufted household carpets. The advantages of polypropylene carpeting are superior stain resistance and low moisture absorbance. Polypropylene sHt tape fibers are heavily used in carpet backing. 

Because of its high strength and toughness, spun nylon yams tend to form unsightiy pihs, ie, balls of fiber on the fabric surface containing some short lengths of fiber, in flat woven and apparel fabrics. This is also why bulked continuous-filament yam (BCE) is preferred over spun yams for loop pile carpets. 

Some 50% of all nylon is in the form of carpets almost exlusively colored with acid dyes, and around 50% of the carpet manufacturing industry is located in the United States. The acid dyes from Group 1 are those most widely used because they exhibit the rapid diffusion needed to penetrate the bulky yams used in carpets, especially bulk continuous filament yam used in tufted constmctions, with high exhaustion. Their wetfastness properties are generally adequate for most oudets. 

PTT polymer pellets must be dried to a moisture level of <30 ppm, preferably in a close-loop hot air dryer, to avoid hydrolytic degradation during melt processing. Drying is carried out with 130 °C hot air with a dew point of < -40 °C for at least 4 h. Because of the faster crystallization rate, PTT pellets are already semicrystalline after pelletizing, and do not require pre-crystallization prior to drying as with PET. The dried polymer is extruded at 250-270 °C into bulk continuous filaments (BCFs), partially oriented yam (POY), spin-draw yam (SDY) and staple fiber. 

Chuah, H. H., Processing of Corterra Polytrimethylene Terephthalate Polymer for Bulk Continuous Filament Carpets, Technical Bulletin SC 2528-98, Shell Chemical Company, Houston, TX, 1998. 

Bulked continuous filament (BCF) carpet yarns are heavy decitex bundles of fiber that are bulked by passage through a turbulent blast of steam or hot air well above Tg. The turbulence blows the yarn about and entangles the filaments, and then heat sets them into place, giving them a permanent crimp. Polymers like PET do not have very good resilience as carpet fibers, but PTT (Eg = 45°C) lends itself very well to the BCF process and has excellent resilience [38]. 

Today, the carpet market is dominated by nylon-bulked continuous filament and staple fiber. A small market still exists in the United States and Europe, while in Japan acrylic carpets are still relatively popular. Numerous studies have been carried out to find ways of... 

Chiu FC, Ung MH (2007) Thermal properties rmd phase morphology of melt-mixed poly (trimethylene terephthalate)/polycarbonate blends-mixing time effect. Polym Test 26 338-350 Chuah HH (2004) Effect of process variables on bulk development of air-textured poly (trimethylene terephthalate) bulk continuous filament. J Appl Polym Sci 92 1011-1017 Chuah HH, Lin VD, Soni U (2001) PTT molecular weight and Mark-Houwink equation. Polymer 42 7137-7139... 

BCF yarns n. Bulked continuous filament yarns for carpet trade, usually nylon, polypropylene, or polyester. 

Bulked continuous filament (BCF) processes are similar to CF processes, but one main difference is that in BCF a texturizer is an integral part of the process, to impart bulk to the fibers, through crimps or kinks. Commonly, BCF fibers are of ca. 20 dpf, with yarns being in the vicinity of 2000 denier. Polypropylene homopolymer with MFRs in the range of 12-20 MFR and normal MWD is typically used. BCF yarns are mainly used as carpet face yarns and in fabrics for upholstery. 

The main production volume is given by transversally and longitudinally textured BCF (bulked continuous filament), which are used in the sector of home textiles, especially as ... 

Keywords use, application, chemical fiber, polypropylene fiber, monofilament, multifilament, staple fiber, tapes, spunbond, melt blown, split film, textile yarn, knitted fabrics, clothing, nonwoven fabric, home textiles, upholstery, geotextiles, agrotextiles, composites, medical textiles, automotive textiles, bulk continuous filaments (BCF), Eco-textiles, integrated fabric. 

Even when crimp is fully developed it is easy to pull out (low energy) and difficult to translate into noticeably bulkier woven and knitted fabrics. It does however improve the absorbency and the cohesion of the staple (important in spun-yarn and nonwoven making) and gives a subtly different texture to woven fabrics. Coarse crimped rayon was the leading synthetic carpet fiber in Europe in the 1960s, but has since been replaced by the highly durable bulked continuous filament nylon yams. Crimp is most important in rayon used for hygienic absorbent products. 

The dried polymer is extruded at 250-265° C into fibers using conventional processing machines for bulk continuous filaments (BCF), partially oriented yarn (POY), spin-draw yarn (SDY), and staple fiber. 

PLA can be melt-spun into various types of fibers including monofilaments, multifilaments, bulked continuous filaments. 

The initials BCF (bulked continuous filament) indicate a yam obtained with a continuous process of spinning, drawing and texturing in only one step. The final product is characterised by a bulky appearance, from which the name derives. 

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