It is no doubt that the use of bicomponent fibers, both staple and filament, has increased in recent years. In China, bicomponent filaments are used in traditional textiles e.g. suede and chamois as well as in nonwovens. In fact, bicomponent staple fibers have become one of most important fibers in nonwovens. Capacity and consumption of bicomponent staple fibers has increased steadily at approximately 10% per year since 1990 and about 200,000 tons are used in China each year. Chinese fiber suppliers supply about 136,000 tons per year and the rest, mainly CoPET/PET, is supplied by Korea’s Huwis and Far East Textile in Taiwan. Chinese fiber suppliers supply not only the domestic market but also export to southeast Asia, Japan, the U.S.and Europe.
It is well known that there are four basic types of bicomponent fibers: sheath/core, side-by-side, orange and islands in the sea. Now, all of the four kinds of bicomponent staple fibers can be produced in China. Currently, the output of bicomponent staple fibers is nearly 136,000 tons per year. This output has increased three times since 2000.
In China, the sheath/core PE/PP and PE/PET bicomponent fiber types are mainly bicomponent fibers and the capacity of this type is about 136,000 tons per year. Apart from 38-51 mm for carding nonwovens, China also makes bico fiber tow for Swiffer-type cleaning products and short cuts for airlaid and wetlaid nonwovens. The bicomponent tow fiber output is 3000-5000 tons per year.
Some special bicomponent fibers are mainly used by foreign companies with manufacturing operations in China. For example, Fiberweb (China), imports short cut bicomponent fibers for its airlaid from Europe because their fibers have better bonding properties.
Liaoning Deli in North China has produced PA/CoPA and PE/PA fibers. Up until now, locally made CoPET/PET fibers in China have not been priced competitively because the melting point is too low and they dry out and stick together. This is why local producers like YCTEX have focused on making PTA. YCTEX is a leader of bicomponent fiber technology in China. It has cooperated with a Danish company to develop airbond-777 bico fibers for airlaid nonwovens. These bicomponent staple fibers range from 3-8 mm and are better able to bond with pulp than fibers currently made in China. YCTEX has also developed a new bicomponent fiber BL255 and BL-Adhesive-C for airlaid. The airlaid with new bicomponent fiber is very soft and has no-pulp-drop.
SHCR is a pioneer of bicomponent fibers in China, having made staple fibers for 20 years and more recently filaments. It was SHCR in the 1980s that designed bicomponent technology, bicomponent spinning beams and bicomponent spinerette. Research into bico fibers and improvements on old chemical fiber machines have allowed Chinese manufacturers to start making bicomponent fibers, but their staple fiber machines are too old to continue production so they transferred the technology to Jiaxin to set up new machines. In fact, SHCR is not alone. In the past 10 years, five other companies including Baling, Dacheng and SHPC, have closed their bicomponent staple fiber production lines.
Of course, there are a few new companies entering this market—Jiangnan, Zhetai, HXN and Qixi to name a few. Jiangnan has replaced Jiaxin as the biggest supplier of bicomponent staple fibers with a capacity of 45,000 tons per year after they imported two bicomponent fiber production lines from Neumag, Germany in 2005. One produces sheath/core and another makes island-in-the-seafibers. Based in Shanghai,China Jiangnan also makes polyester fibers from both crude oil and recycled materials as well as PET filament tow. In fact, bico fiber is only a small percentage of Jiangnan’s sales. Meanwhile, Zhetai, using technology from Baling, German’s key spinneret technology to make bicomponent fiber, exports nearly 100% of its product. HXN is a brother company of U.S.-based Fiber Innovation Technology. YCTEX-Zhonglian mainly produces bicomponent tow fiber for dust wipes. The Qixi company produce not only bicomponent staple fibers but also hot air-through, airlaid and spunbond nonwovens.
Mankelong Produce Orange Bicomponent Fibers
Jiaxin always uses machines made by Chinese manufacturers.They try again and again to make S/C bico fiber as the same quality as fibers made from German machines.
Bicomponent staple fiber is used for thermal bonded, hot air-through and airlaid nonwovens. In thermal bonding, 100% bicomponent fiber nonwovens are mixed with polypropylene fibers because 100% bicomponent fiber nonwovens have better bondability between fibers and nonwovens. Nonwovens by air through is best made from 100% bicomponent staple fiber also and this technology consumes about 50% of bicomponent fibers in China. The bicomponent staple fiber in air-through has different quality needs from thermal bonded nonwovens. The nonwovens made with an air-through process need soft, loose handles. The material and finish of bicomponent fibers used in air-through is very important and different from bicomponent fiber used in thermal bonding.
Airlaid is another user of bicomponent fiber. It must be super-short length and highly decentralized. Its length is nearly equal to the length of pulp—about 3-5 mm. In China, nearly 90% of airlaid is thermal bonded, but our bicomponent fibers have low bondability with pulp— 25-35% bico fiber in airlaid. Such a rate is far higher than bicomponent fibers made by ES Fibervisions.
A few nonwovens makers have developed new drylaid nonwovens without latex. This new drylaid nonwovens is made of PE/PP bicomponent fibers and rayon and is bonded by flat bonding instead of point bonding. It looks very similar to latex bonded drylaid and is 15-20% cheaper than latex bonded drylaid nonwovens. In spunlace, orange-type bicomponent fibers are used to make nonwovens for micro fiber clean wipes.
Despite all of these developments, the market is too small to bear production of an entire bicompoent fiber production line. Thesituation is the same as an islands in the sea type bico fiber maker. Although JNGX has produced the 51-islands in the sea bicomponent microfibers, we import such bicomponent fibers from Huwis in Korea and Far East in Taiwan.
The spunlace cloth made with bicomponent microfibers cleans without streaks and is ideal for wet and dry cleaning. As for PA/PET Mixtro bicomponent staple fibers, they are used to make manmade leather with a needlepunch process. After defibration, the fibers split from each other and become superfine fibers of nearly about 0.1D.
In wadding, in order to get soft,lightweight, heat-insulating nonwovens, we mixabout 30% bicomponent staple fiber to make wadding. The CoPET/PET bicomponent staple fiber is in this wadding field. Unfortunately, theCoPET/PET can’t be produced in China and must be exportedfrom Korea andTaiwan as above. CoPET/PET is a good fiber and can be used to many useage as soft, hard, pad,wadding, wall decorationswall, thin, thick and so on. I think that the Chinese will produce it in future in some day.
Bicomponent Filament For Nonwovens
Four production lines of bicomponent filament nonwovens for use in China have been built in the past five years. Yaolong’s spunbond nonwovens technology uses an imported a bicomponent filament spunbond production line from the U.S. to produce PE/PET and PE/PP bicomponent filament spunbond with a capacity of 8000 tons per year in widths of 3.2 meters and weights of 10-150 gsm. This line uses narrow draw in advance.
The PE/PP sheath/core bicomponent spunbond for baby diape rsand laminating on foil use.
About 20 years ago, SHRC also set up a bicomponent filament spunbond production line that is 2.4 meters wide. It can make PE/PP and PE/PET sheath/core type. Afterwards, Sanjiang Superfine fiber nonwovens began a bico filament spunbond-spunlace production line with capacity 6000 of tons per year.Its drawn is tube-type. In July 2007, Tianjing Teda company started a bicomponent meltbrown machine (NanoPhase) with Nordson and it began operation in May 2009. Its width is 2400mm and its output is 2000 tons per year. As usual,it uses side-by side section and its fiber has up to 0.7µm diameter. It has better filter for liquid.
Bicomponent Fibers for Nonwovens in China: Now and in the Future
Market is growing but continues to represent a small percentage of total production.
By John Xuan, Yacheng Textile College, YCTEX IMP & EXP Co., LTD