What is Lyocell fiber?

Tencel Lyocell Short-Cut Fiber

Tencel® lyocell is produced from purified dissolving grade wood pulp and an amine oxide solvent. The pulp is a renewable resource and is dissolved directly into the solvent, filtered and extruded through spinnerets to form continuous fibers. These fibers are then washed to recover the solvent and then dried to form a continuous tow. The result is a pure, 100% alpha-cellulose fiber. The long chain molecules within the fiber are arranged in a highly oriented crystalline structure, resulting in high strength, absorbency and excellent retention of mechanical properties in the wet state.

When cut into short-fibers, lyocell, either used at one-hundred percent or in a blend, processes efficiently in all wet- laid papermaking technologies. Crimped short-cut fibers, with their inherently open nature, process efficiently in air- laid applications. In addition, lyocell can be fibrillated with mechanical refining to produce high surface area fibers with submicron fibrils that provide both mechanical binding and filtration efficiency for the production of specialty high performance papers.

Lyocell fiber is ideal for filtration applications that require highly uniform papers and for papers that are in contact with food. Lyocell can also be used for hot oil and beverage filtration and is suitable for uses defined under 21 CFR 176.170.

At the end of the product life, lyocell biodegrades completely during biological treatment, such as burial or anaerobic digestion, into carbon dioxide and water.

Some of the benefits of lyocell fibers are:

• High tensile strength (2X rayon dry / 3X rayon wet)
• Highly absorbent
• High wet and dry modulus
• Round Cross Section
• Swells radially when wet
• Easily dyeable to strong color-fast shades
• Does not melt
• Outperforms cotton and rayon at high temperatures
• Can be oxidized and carbonized

Comparison of Fiber Physical Properties

*At 5% strain

Property	Units	Lyocell	Polyester	Rayon	Cotton
Dry Tenacity	g/den	4.5 - 5.0	4.5 - 5.5	2.3 - 2.7	2.3 - 2.7
Elongation at break, dry	%	24 - 26	15 - 55	20 - 25	7 - 9
Wet Tenacity	g/den	3.9 - 4.3	4.5 - 5.5	1.4 - 1.8	2.8 - 3.4
Elongation at break, wet	%	16 - 18	15 - 55	23 - 35	12 - 14
Water Imbibition	%	65 - 70	N/A	90 - 100	44 - 55
Cellulose DP		550 - 600	N/A	250 - 350	2 - 3000
Initial Modulus, wet	g/den*	250 - 270	N/A	40 - 60	200

Typical Properties of Lyocell Fiber

Property	Units	Typical Values
Denier	g/9000m	1.25, 1.5, 2.2, 3.0
Cut Length	mm	0.5 - 25 (precision cut)
Cross-section		Round
Luster		Bright, dull
Crimp	per cm	0 - 2.5
Finish		Various
Dispersibility in water		Very good

Lyocell Short-cut Fiber Specialty Paper Applications

• Adhesive substrates
• Battery separators
• Cigarette filters and papers
• Electrical papers
• Filtration media
• Food casings
• Flushable wipes
• Fiberglass binder
• Medical papers
• Napkins, tablecloths, tissues
• Reinforcement papers
• Security / banknote papers
• Tea bags