Meltblowing of ethylene and fluorinated ethylene copolymers
AssigneeExxon Chemical Patents Inc.
InventorsLarry C. Wadsworth, Ahamad Y. Khan
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Abstract
High MI, high MP ethylene-fluorinated ethylene copolymers (preferably ECTFE) are meltblown through relatively large orifices. The web produced by the process is characterized by low fiber size and high strength.
Claims14
In a melt blowing process wherein thermoplastic polymer is extruded from a plurality of orifices, attenuating and stretching filaments formed by the thermoplastic polymer by converging air streams, and collecting the filaments, the improvement wherein the thermoplastic polymer is an ethylene-fluorocarbon copolymer having a melt index of at least of 100 and melting point of at least 200.degree. C. and wherein each orifice has a flow area greater than 0.31 mm.sup.2.
A meltblowing process which comprises:
- (a) meltblowing ethylene-chlorotrifluoro-ethylene through a plurality of orifices at a flow velocity of less than 150 cm/min/orifice forming a plurality of filaments, each orifice having a flow area of at least 0.36 mm.sup.2, said ECTFE having a melt index of greater than 300;
- (b) contacting the filaments with air to stretch the filaments to an average diameter of less than 3 um;
- and
- (c) collecting the filaments on a collector forming a nonwoven web of microsized filaments.
Dependencies are inferred from the claim text.