Method for drying glass fiber forming packages

Claim 2

The method of claim 1 wherein a plurality of forming packages are conditioned in the manner set forth so as to substantially reduce the moisture on the strand in the forming packages to a uniform low level of moisture in each forming package.

Claim 3

The method of claim 1 wherein the strand forming package is postconditioned in a heated environment.

Claim 4

The method of claim 1 wherein the vacuum maintained within the chamber is at least 20 inches of mercury.

Claim 5

The method of claim 1 wherein the forming tube is a moisture permeable paper tube.

Claim 6

The method of claim 1 wherein the strand contains at least 400 individual fibers.

Claim 7

The method of claim 7 wherein the diameter of the individual fibers is at least 0.0002 inches.

Claim 8

The method of claim 8 wherein the thickness of at least a portion of the forming package is at least five-eighth inch.

Claim 9

The method of claim 1 which further includes the steps of periodically measuring the subatmospheric pressure of said gaseous environment while the moisture content of the package therein progressively decreases and the subatmospheric pressure in said environment progressively increases until the moisture content of the package reaches a desired level, then removing the package from said environment.

Claim 10

In the method of forming glass fiber strand which comprises forming individual continuous glass fibers from molten glass, applying an aqueous forming size to the individual fibers, said size being composed of water as the principal ingredient together with a binder, combining the fibers into a strand, winding the strand on a forming tube to form a cylindrical forming package, removing the strand from the tube and converting the strand into other forms such as chopped strand, roving, yarn, cord, mat and fabric, the improvement which comprises conditioning the strand forming package by preheating said package at an elevated temperature below that at which the nonaqueous size ingredients are chemically degraded, lowering the gaseous atmosphere within a chamber enclosing said package to subatmospheric pressure while radiantly heating said package from a radiant heat emitting source, the heating and drying rates being correlated so that a temperature above the freezing temperature of the moisture in the package but below the temperature at which the nonaqueous size ingredients are chemically degraded is maintained and the cylindrical forming package dries from both the interior cylindrical surface as well as the exterior cylindrical surface to keep migration of size to a minimum.

Claim 11

The method of claim 11 which further includes the steps of periodically measuring the subatmospheric pressure of said gaseous atmosphere while the moisture content of the package therein progressively decreases and the subatmospheric pressure of said atmosphere progressively increases until the moisture content of the package reaches a desired level, then removing the package from said atmosphere.