Melt spinning process for polymeric filaments
AssigneeE. I. Du Pont de Nemours and Company
InventorsBenjamin C. Sze, George Vassilatos
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Abstract
A melt-spinning process for spinning polymeric filaments at a spinning speed controlled by a positive mechanical withdrawal means that increases the speed of the filaments to above 7,000 meters/minute whereby a drawing and necking down of the filaments occur below the spinning pack, directing a gas into a zone extending from the spinning pack to a location between the spinning pack and the withdrawal means, maintaining the zone under superatmospheric pressure of less than 0.03 kg/cm2 and increasing the velocity of the gas as it leaves the zone to a level greater than the velocity of the filaments to reduce the extent of necking down of the filaments.
Claims6
In melt-spinning process for spinning continuous polymeric filaments in a path from a spinning pack at a spinning speed controlled by a positive mechanical withdrawal means that increases the speed of the filaments to above 7,000 meters/minute whereby a drawing and necking down of the filaments occur below the spinning pack, the improvement for increasing tenacity, elongation and spinning continuity of the filaments comprising:
- directing a gas into a zone enclosing said path, said zone extending from said spinning pack to a location between the spinning pack and the positive mechanical withdrawal means;
- maintaining said zone under superatmospheric pressure of less than 0.03 kg/cm.sup.2 and increasing the velocity of the gas as it leaves the zone to a level greater than the velocity of the filaments to reduce the extent of necking down of said filaments.
Dependencies are inferred from the claim text.