Raw Materials of Nonwovens | Fiber Requirement in Nonwovens | Fiber Consumption in Nonwovens

1. Introduction
Fibers are the basic element of Nonwovens. Manufacturers of Nonwovens products can make use of almost any kind of fibers. These include traditional textile fibers, as well as recently developed hi-tech fibers. The selection of raw fibers, to considerable degree, determines the properties of the final nonwoven products. The selection of fibers also depend on customer requirement, cost, process ability, changes of properties because of web formation and consolidation. The fibers can be in the form of filament, staple fiber or even yarn. The following table shows the significant fibers used in the Nonwovens industry all over the world.
Table 1 - Fibers used in Nonwoven industry
TRADITIONAL TEXTILE FIBERS

HI-TECH FIBERS
PET

Aramid (Nomex/Kevlar)
Polyolefin (PP/PE)

Conductive Nylon
Nylon

Bi-component (side-by-side, sheath-core, segmented pie and sea-island)
Cotton
Melamine (heat & flame resistant)
Rayon
Superabsorbent
Wool
Hollow fibers
Lyocell
Spandex fibers (polyether)
Modacrylic
Fusible co-PET fiber

PA-6 support/matrix fiber

Glass micro-fiber

Chlorofiber

Antibacterial fiber

Stainless steel

Rubber thread

PTFE

Nanofibers
 
Although there are several natural fibers available for nonwovens, wood pulp - which is far shorter in length than  the conventional textile fibers - is the only natural fiber used in very large amounts because of its high water absorbency, bulk and low cost. Cotton has excellent inherent properties for nonwovens fabrication. Viscose rayon has been widely used in the nonwovens industry in the area of disposables and sanitary products. Rayon fibers can be easily made into webs and readily bonded into nonwovens fabrics. All these cellulosics such as cotton, rayon and acetate are absorbent, act as carriers for microbial agents, and give strength combined with biodegradability [1]. Among the synthetic fiber polypropylene (PP) is widely used. PP is inexpensive and has very good rheological characteristics to form fine fibers. PP fibers are hydrophobic, voluminous, and thermoplastic in nature. Polyethylene terephthalate (PET) is used where strength and mechanical properties are of prime importance. Nylon fibers are used for their excellent recovery (resiliency) properties. Bicomponent fibers with different polymers in the core and sheath are widely used in thermally bonded nonwovens [2]. Recent developments in bi-component fiber structure include segmented pie, islands in sea structures.Fiber requirements for nonwovens depend on the product being produced and the fabrication process being used. Since each process leads to a different range of fabric properties, all available fibers cannot be used equally well in all nonwoven processes.
With nonwovens products successfully moving into more technical end-uses, the fiber requirements have also become more exacting with regard to the fiber properties. The cooperation between fiber supplier and fabric producers is now seen as important criteria for additional advancements to come about in the nonwovens field.
Although a large number of fibers are available, commercially important nonwoven fabrics have been limited to relatively few types, the dominant fibers include polyolefins, polyester, and rayon. These three fiber types made up a substantial part of the overall nonwovens markets for fibers. The increasing importance of olefin-based fibers is well illustrated by data from major nonwovens-producing regions that show increasing shipments of PP and PE at the expense of some natural fibers, rayon and polyester [3]. Much of this shift in fiber consumption can be attributed to the growing use of olefin-based nonwovens in absorbent products around the world.
Rayon was a major fiber used in the nonwovens industry until 1985 [4]. Over the past decade, production of rayon has decreased considerably in the US and Western Europe because of the increasing cost of the fiber. Since cost of PP and PET dropped compared to that of rayon, and yet they provide superior strength there was big drop in 1989, after which the shipment of rayon staple kept declining slowly. Nonwovens made of rayon are mainly found in medical/surgical/sanitary products and wipes. The cleanliness and absorptive properties made rayon popular in these fields. Similarly, cotton is the preferred fiber in tampon and incontinence products. Its consumption is stable at 40-45 million pounds. Nylon, which is more expensive than most other fibers, is used in a lesser extent. The other "special fibers" listed in table 1 has only a limited market share, probably no more than 15 percent of the whole Nonwovens market.
2. US consumption
The North American nonwovens industry is the largest in the world and accounts for just under a third of the worldwide sales of roll goods - around $2.8 billion - in 1997, according to estimates from the Association of the Nonwoven Fabrics Industry (INDA). This is up by 17% from its 1992 value. Table 2 from the Fiber Economics Bureau shows that the increase in shipments of staple fiber for nonwovens was led by olefin fibers, dominated by polypropylene, which further cemented its domination of shipments in 1998. Polyester staple fiber shipments were also up slightly from 1997 to 1998. Rayon shipments increased slightly in 1998, but their share of overall fiber consumption continued to be the same. The figures for rayon may have been affected by a rise in rayon prices while polyester and olefin prices generally fell in 1998, but historical figures show a long-term pattern of decline in rayon consumption. In 1989, rayon staple shipments for nonwovens were almost 100 million lb, almost double their 1998 level [5].
Table 2 : US producer’s shipments of staple to Nonwoven (1989-1999) (million lb, % of total)
YEAR
RAYON
POLYESTER
OLEFIN
TOTAL
1989
98(17)
272(48)
195(35)
565
1990
72(13)
240(44)
233(43)
545
1991
70(12)
237(41)
272(47)
579
1992
70(12)
244(43)
259(45)
573
1993
70(11)
263(43)
276(46)
609
1994
64(10)
280(45)
280(45)
624
1995
60(10)
280(46)
267(44)
607
1996
57(9)
285(45)
295(46)
637
1997
58(9)
285(43)
314(48)
657
1998
60(9)
292(42)
339(49)
691
1999
64(8)
276(35)
434(57)
774
Source: US Fiber Economics Bureau
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Fig. 1: US producers shipments staple to nonwovens
Olefin staple, became the dominant fiber in the nonwovens business in 1996. In the latest figures olefin had 49% of sales while polyesters share of the business dropped to 57%. The balance of 9% each year represented the estimated rayon staple sales. Looking back over the 10-year period covered by Table 3, the increase in olefin market share at the expense of polyester and rayon has been striking. Ten years ago, olefins participation in the business was a mere 35% compared with 65% for the two competitive fibers. Since then, as noted above, olefin has risen to over 49% with polyester and rayon dropping to 51%.

3. West European consumption

In Western Europe, the three major fibers accounted for nearly 70% of staple fiber consumption by the nonwovens industry in 1997. Total Western European nonwovens production increased 11% in 1997 to reach almost 760,000 tones - almost doubling the 6% growth in 1996 - according to annual figures published by the European Disposables and Nonwovens Association (EDANA). Output of the 15 European Union countries plus Norway and Switzerland is forecast to top 800,000 tones in 1998, and could reach as much as 820,000 tones. Turnover of the nonwovens industry in Western Europe was estimated by EDANA to be 3 billion ECU in 1997. Although overall use of polypropylene in nonwovens increased over 10% from 1996 to 1997, the fastest rising market has been in spun-melt applications, where PP accounts for 61% of polymer granule consumption. PP staple fiber consumption in Europe increased less than 1% in 1997, and it accounted for only around 41% of staple fiber used in dry-laid nonwovens. By comparison, polyester staple consumption increased almost 5% and rayon by 8% for dry-laid nonwovens in 1997, respectively. The use of natural fibers other than wood pulp hardly grew in 1997, and cotton in particular is not a widely used fiber in the region.
Major global producers account for more than 75% of all roll goods production. US-owned firms, such as Dupont, PGI, Kimberly-Clark, Johns Manville, Ahlstrom, Lydoce, Foss and Synthetic Industries, and the European giants such as Freudenberg, BBA Group, BP Amoco, Fibretex and Pegas, still leading the global market. [6]
 
Table 3: EU fiber/polymer shipments for nonwovens (1000 tones)


1996

1997
PP polymer
181.2
215.4
PP staple
153.7
154.5
Polyester polymer
64.8
77.9
Polyester staple
68.1
72.8
Wood pulp
80.0
75.3
Rayon
59.0
67.3
Bi-component
33.2
29.1
Polyamide
13.5
12.5
Other man-made
33.5
54.7
Natural fibers
13.1
13.4
Other materials
6.5
8.6
Total
706.6
781.6
Source: EDANA
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Fig. 2: EU fiber shipments for nonwovens (1000 tones)
Source: EDANA
 Table 4: Nonwoven Production in thousand tones in West Europe [6].
Year
Production in 1000 Tones
1995
646
1996
684
1997
759
1998
836
1999
910
2000
1026
2001
1070
2002
1116


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Fig. 3: World Production in 2002[6]

Table 5 World Production of Nonwovens in thousand tones in 2002
Country
Production in Thousand tones
W.Europe
1208
U.S
1074
China
478
Japan
296
Other ANFA Members countries
245
Other
620

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Fig. 4: World production of nonwovens in 2002 (1000 tones)
4. Present and Future Fiber Requirements
The Nonwoven textile industry has made dramatic technical and commercial progress in recent years. Worldwide consumption of nonwovens by 2007 is likely to reach 4.0 million tons. Production of Nonwovens is still concentrated in the USA (41% of world total) West Europe (30%) and Japan (8%) and China produces 3.5%. By 2007, China will produce 7% of the world’s total. World consumption of fibers in nonwoven production is 63% polypropylene, 23% polyester, 8% viscose rayon, 2% acrylic, 1.5% polyamide and 3% other high performance fibers. Future advancements will be in bicomponent fibers, micro fibers (split bicomponent fibers or meltblown non- wovens), nano fibers, biodegradable fibers, super-absorbent fibers and high performance fibers. Also there will be more technological innovations such as 1) new, more efficient and economical processing technologies, 2) direct polymer to roll goods, 3) use of new types of composite nonwovens and laminates, and 4) new finishing techniques and novel additives. [8]
References
  1. William C. Smith, "Nonwovens Continue to Move Ahead", Textile World, Nov. 59-62 (1999).

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