Wet-laid nonwoven fabrics

JP Patent 2003,268,691, Wet-laid nonwoven fabrics comprising biodegradable fibers consisting of biodegradable polymers derived from sonrces other than wood and petroleum , Nakahara, Makoto, 2003. 

Melt blown, spunbond, air-through thermobond, and wet-laid nonwoven fabrics made from PP and polyethylene fibres are also widely used as a support layer in membrane filtrations and in filtration media where chemical resistance is cmcial they also have the potential to be recycled to make it environmentally fiiendly, but such possibility needs to be explored. They, as well as co-polyester fibres, are frequently used as binders in thermobond nonwovens for filtration applications. 

Fibrillated cellulosic fibres, such as LyoceU fibres, contain fibres having much smaller diameters and are thus promising resources of cellulosic micro- and nanoscale fibres for air, water, and hydraulic filtrations. They can be blended with nonfibril-lated synthetic staple fibres in a wet-laid nonwoven fabric to form high-efficiency and high-capacity glass fibre-free filtration media. ... 

Wet-laid nonwoven fabrics are produced from wet-laid webs, which are formed via filtering an aqueous suspension of fibres onto a screen conveyor belt or perforated drum, and they are then bonded by one or more techniques to provide fabric integrity. Wet-laid nonwoven technology is originated from papermaking process, but the resultant wet-laid nonwovens are different from paper. A wet-laid material is defined as nonwoven rather than paper if (1) more than 50% by mass of its fibrous content is... 

In 1992, as much as two-thkds of all spunlace fabrics were used in medical products other appHcations included wipes, industrial apparel, intedinings, absorbent components, filtration, and coating. Medical product appHcations also accounted for about one-thkd of all wet-laid nonwovens other appHcations included tea bags, meat casings, filter media, battery separators, and wipes. Most bonded-pulp fabrics were used as wipes or absorbent components. 

Paper-based processes Synthetic staple fibers as well as wood pulp libers are suspended in water and then formed into a paper-like nonwoven web on a perforated surface. The web is then bonded by interlocking the fibers by mechanical or chemical bonding techniques. Fabrics made by this type of process are known as wet-laid nonwovens. Such products can be made at very high speeds and are very uniform, but the process is capital-intensive. 

Wood pulp fibres are frequently less than 1 pm in fibre size and dominate wet-laid nonwoven filter media they are able to provide higher filtrafion efficiency and are environmentally fiiendly. Synthetic fibres (eg, polyolefin, polyester, and polycarbonate (PC) fibres) could work as electret fibres to provide additional electrostatic filtration mechanism, and also could be made binder-fitee, thermobond nonwoven fabrics if they are made Ifom thermoplastic polymers. 

Short-Cut Staple n Staple fiber less than 0.75-in. long. Typically used in wet-laid nonwoven processes to make fabrics, or as reinforcement in plastics, concrete, asphalt, and other materials. 

The basic concept employed in making a nonwoven fabric is to transform fiber-based materials into two-dimensional sheet structures with fabric-like properties. These are flexibility, porosity, and mechanical integrity. Their manufacturing processes can be split into four groups dry-laid webs, extrusion-formed webs, wet-laid webs, and web-bonding. 

Thus the target for biodegradable nonwovens is to replace synthetic fibers with biodegradable fibers in the disposable nonwovens. One group of disposable nonwovens is the wet laid pulp/polyester spunlaced fabrics mainly for industrial and professional wipe products. Another group of disposable nonwovens is... 

The three most commonly used nonwoven fabrics for surgical gowns are spunlace, SMS and wet-laid in weight range of 30—45 g/m. They are based on various forms of natural and manufactured fibres, that is, components such as wood pulp and cotton, or polyester, polyolefin, respectively. Based on the way the links between the fibres take place in the nonwoven — chemically, physically, mechanically, thermally — nonwovens are segmented in different categories. 

Clothing products, which include articles worn by both nursing staff and patients, have no specific requirements other than comfort and durability. In isolation wards and intensive care units, disposable protective clothing is worn to minimize cross infection. A wide range of designs in various types of nonwoven fabric is available as head coverings for male and female staff. These articles are made from composite fabrics that consist of tissue reinforced with a polyester or PP spunlaid web. SMS and wet-laid are the major nonwoven types used in sterilization wrap, laboratory coats, jackets and coveralls. 

Air filters have many different configurations in end use markets for both general dust filtration and high-efficiency filtration. The principal air filtration media for HVAC include melt blown and spunbond nonwoven fabric filters (around 825— 850 million m per year in North America) HEPA wet-laid fibreglass nonwoven filters account for another additional 90—100 million m. ... 

The milk filters in an automated milking system must work perfectly at all times. They have an important function in milk quality control. Professional disposable milk filters for on-farm milk filtration are nonwoven wet-laid and help to maintain high standards of hygiene in quality nulk production (Adanur, 1995 DeLaval, 2015). They come in a wide range of fabric weights, ranging from 20 to 160 gsm. 

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