Polylactic acid fiber is a kind of green embracing fiber. After analyzing the research status of polylactic acid fiber nonwovens at home and abroad, it is proposed to use polylactic acid fiber as a raw material. According to the performance characteristics of the fiber, we choose carding and spunlace reinforcement technology to develop a new type of environmentally friendly nonwoven fabric, the product can be completely degraded naturally.

Key words: polylactic acid fiber; spunlace; nonwoven fabric; natural degradation

Research Status of Polylactic Acid Fiber Nonwovens

Research Status Abroad

The booming global wiper market is driving the upsurge in the continued adoption of natural fibers in Asia and Europe. Asia is experiencing the development of cotton fiber spunlace wipes, while Europe uses more cotton fiber nonwoven products due to the rise of the cosmetic cloth market. The University of Tennessee has been conducting research on the development of polylactic acid fiber spunbond and meltblown nonwovens. French company, Fiberweb, revealed the development of Deposa, a meltblown and spunbond brand name nonwoven made of 100% polylactic acid. Japan's Zhongbo Synthetic Fiber Co., Ltd. and Wu Yu Synthetic Fiber Co., Ltd. jointly developed a three-dimensional non-woven fabric structure made of the biodegradable fiber "Lactron" produced by polylactic acid. Unijica has successfully made polylactic acid spunbonded nonwovens through melt spinning technology using polylactic acid produced from corn by Cargill Dow Polymers. Blechschmidt et al. of the Saxon Textile Research Institute in Germany also spunbonded nonwovens for polylactic acid.

Domestic Research Status

Due to the cost of domestic corn fiber and the special requirements of natural fibers on the process, the proportion of non-woven fabrics made of polylactic acid fibers is very small for the time being. Ren Yuanlin and others from the School of Textile and Clothing of Tianjin University of Technology have also conducted some research on polylactic acid fiber nonwovens, and they mainly use the spunbond method.

Polylactic acid fiber spunlace nonwoven fabric process.

Polylactic acid fiber and its process principle

The raw material of polylactic acid fiber comes from natural plants and is easy to biodegrade. The degradation products are lactic acid, carbon dioxide and water. It is a new generation of environmentally friendly degradable fiber. Its moisture absorption rate (0.6%), strength g/d (4.5-5.5), elongation % (25-40) are similar to polyester, crystallinity % (above 70) is larger than polyester, and polyester modulus is poly Lactic acid modulus kg/mm2 (400 ~ 600) more than twice. The cohesion of polylactic acid is poor, so it is suitable to choose air-laid net when forming a net. Polylactic acid has much lower moisture absorption and modulus than polyester. The strength is higher than other natural fibers, but the moisture absorption rate is lower than other natural fibers, showing medium strength and good hydrophobicity, and can be reinforced by spunlace.

At present, there are already products with a specification of 1.5D×38mm, and the length and fineness meet the requirements of spunlace reinforcement.

Basic process: polylactic acid staple fiber → opening → air-laid web → spunlace reinforcement → post-processing (drying) → finished product winding and other processes.

Polylactic acid is a new type of biodegradable material made of cornstarch. The development and application of this product plays a huge role in reducing "white pollution" and promoting green environmental protection. Select a suitable spunlace process parameter to develop polylactic acid nonwovens. This polylactic acid spunlace nonwoven material has undoubted advantages, such as better air permeability, hand feel, appearance, lint-free, and wicking properties. , elasticity, skin affinity, good degradability and biocompatibility, etc., must have broad research and application prospects in today's society. But its shortcomings greatly hinder its practical application. In view of these defects of polylactic acid materials, future research work can be carried out from the following aspects: simplify and shorten the process flow, reduce the cost of polylactic acid materials; open up ideas, try to modify polylactic acid with new materials; Strength, so that polylactic acid spunlace nonwovens have good application prospects in more aspects.