The Lenzing Group stands for the environmentally responsible production of high-quality, specialty fibers derived from the renewable raw material wood. The production process of LENZING™ Lyocell fibers is distinguished by its conversion efficiency and closed loop design, which recovers, purifies and re-uses the process solvent and process water.

With a microfibrillar structure, good thermal stability and chemical resistance, LENZING^TM Lyocell fibers are well suited for use in various types of filter media. Their cellulosic composition contributes to compatibility with cellulosic and synthetic fiber types and binders. It also means these fibres are biodegradable in soil, freshwater and marine conditions or can be used for energy recovery by incineration at the end of the product lifecycle.

Commercial applications for LENZING^TM Lyocell fiber-based filter media range from lightweight papers for teabags and coffee filters, through pleatable media for industrial and automotive filters, to heavyweight depth filter sheets for food and beverage filtration. LENZING^TM Lyocell Shortcut fibres can be fibrillated in a separate step prior to the papermaking process. These fibrillated fibers provide a unique source of sub-micron diameter fibrils through wet abrasion within a refining process. Fibrillated LENZING^TM Lyocell Shortcut fibers may be directly incorporated into filter media formulations to increase wet web strength and sheet tear resistance, or for enhancement of fine particle filtration efficiency. Recent process enhancements by the Lenzing Group have resulted in LENZING™ Lyocell Enhanced Fibrillation (EF), Lyocell fibers which required less time and energy to reach a given degree of fibrillation, saving precious cost and valuable resources.

The work in this paper aims to:

• Outline current and future market trends in Filtration related to sustainability.
• Discuss the latest advances in LENZING^TM Lyocell fibers production and the commercial availability of fibrillated LENZING^TM Lyocell fibers, including Enhanced Fibrillation (EF) fiber.

The test sheets were subjected to physical tests to verify basis weight, thickness and air permeability prior to measuring filtration performance according to ISO 5011, ISO 16890 and ISO 19438 test methods. Laboratory tests show that...