After spinning, polylactic acid can be obtained into polylactic acid fiber. Polylactic acid fiber combines the advantages of natural fiber and chemical synthetic fiber. It has weak acidity similar to human skin, is naturally skin-friendly, antibacterial, anti-mite, anti-allergic, has good drape, smoothness, breathability, and is glossy. At the same time, textile products made of polylactic acid fiber are also self-extinguishing and safe to use.
Classification
Common polylactic acid fibers can be divided into two categories: polylactic acid staple fiber and polylactic acid filament.
1. Polylactic acid staple fiber Polylactic acid staple fiber is a fiber product with certain mechanical properties such as strength and elasticity. Its product types include pure spinning products and blended products with cotton, wool, linen, lyocell, modal and other fibers.
2. Polylactic acid filament Polylactic acid filament is a fiber aggregate formed by stretching, twisting or deformation of multiple long monofilaments. One strand contains dozens of monofilaments, which is called polylactic acid composite yarn, which can be spun into differentiated polylactic acid fiber. At the same time, it also includes polylactic acid monofilament, which is widely used in medical suture, fishing, tea bags and other fields due to its unique properties.
Performance
1. Mechanical properties
The breaking strength of polylactic acid fiber is 3.2~4.9cN/dtex, which is higher than natural cotton fiber. The breaking elongation in dry state is similar to that of nylon and wool, and the elongation in wet state increases, indicating that polylactic acid fiber products have the advantages of high strength and good extensibility.
2. Biodegradability
Polylactic acid product waste can be completely decomposed into carbon dioxide and water in 3-6 months under industrial composting conditions (58 degrees Celsius, humidity 98% and microorganisms). At normal temperature and humidity, polylactic acid fiber and its products are quite stable. When in a natural environment with a certain temperature and humidity (such as sand, silt, seawater), polylactic acid will be completely degraded into carbon dioxide and water by microorganisms. If polylactic acid fiber is buried in the soil, the natural degradation time is 2~3 years; if polylactic acid fiber is mixed with organic waste and buried, it will degrade in a few months.
3. Biocompatibility and anti-allergy
The raw material of polylactic acid, lactic acid, is an endogenous substance in the human body, which makes polylactic acid fiber have good biocompatibility, excellent affinity with the skin, non-allergenicity, and good product safety performance. Therefore, it has been widely used in the field of biomedicine.
4. Antibacterial and anti-mite, anti-mildew and anti-odor The surface of polylactic acid fiber is weakly acidic like lactic acid, which makes it have natural antibacterial properties, can effectively inhibit the breeding of mites, and has the effect of anti-mildew and anti-odor.
5. Safety of use Polylactic acid fiber is not easy to burn, extinguishes immediately when away from the fire, and has no black smoke and toxic gas emissions, which has good safety of use.
6. Wearability
① Drapability: The initial modulus of polylactic acid fiber is low, the drape coefficient is small, and the fabric has good drape performance.
② Wrinkle recovery: When the polylactic acid fiber is stretched and deformed by 5%, the elastic recovery rate is as high as 93%, so the wrinkle recovery of pure polylactic acid fiber fabric is very good.
③ Good thermal insulation performance. PLA fiber is a lightweight fiber that can quickly recover after being damp or soaked in water. PLA fiber-related products can play different functions in different seasons. When worn in winter, it has better thermal insulation performance than cotton and polyester fibers; when worn in summer, it has excellent moisture permeability and water diffusion, absorbs sweat and dries quickly, and can quickly take away body heat through evaporation.
④ Moisture conduction and quick drying: PLA fiber has a high porosity and good air permeability, so it can conduct moisture and dry quickly, keeping the skin dry and comfortable
