Spun-bonded sheet products

All sheet structures made directly from fibers and filaments without intermediate steps are classified under the term textile composites. In the English-speaking world, a general distinction is made between nonwoven fabrics made from stable fiber and spun-bonded sheet products manufactured from filaments. 

Tyvek DuPont s tradename for its spun bonded, tough, strong HDPE fiber sheet product. It is used in mailing envelopes (protects contents, etc.), medical devices, and wrapping around buildings. See fabric, nonwoven spun-bonded. 

PLA fibers, because of their natural wicking properties, are finding utility in the diaper and feminine hygiene markets, both in spun bond top sheets and acquisition/distribution layers. Again the ability to replace petroleum-based fibers with enhanced performance with a natural-based fiber has strong consumer appeal. An additional benefit is that since PLA fibers are fully compostable the products can be disposed of by composting if the infrastructure for disposal is in place. 

The key to the reverse osmosis (RO) process is a suitable semipermeable membrane. Improvements in membrane technology now mean that the process can apply to industrial-scale plants. Common contemporary membrane selections are made of cellulose-based polymer or a polyamide layer applied to a microporous poljmier fllm. This membrane is bonded to a porous polyester sheet for structural stiffiiess. This composite is rolled into a spiral. Spun hollow fine fibers are the finished product. The semipermeable layer is on the outside of the fibers. The total thickness of the composite is about 24 pm. The outside diameter of the tube is about 95 pm, making for a large surface area for rejecting salt. The fibers are made into bundles that are sealed with epo in a fiberglass pressure container. 

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