Cellular polymer composites based on bi-component fibers

Traditionally, bi-component fibers are used as non-woven fabrics where stiffness is not a primary concern. In this work, we show that solvent activation of the polyethylene sheath leads to significant swelling that can induce and form entanglement gel structures between fibers. Fiber-reinforced cellular polymers are produced using bi-component fibers containing a polyester core and a HDPE sheath. Upon removal of the solvent from the gel, a polyethylene membrane structure forms between polyester cores, creating a cellular fiber composite. Swelling of the polyethylene sheath is analogous to a micro-scale “blowing” process. The reinforced cellular structure exhibits improved mechanical properties compared to hot-bonded systems based on similar bi-component fibers. Other possible variants of the micro-scale “blowing” process are discussed.