Method of manufacturing an inside-to-outside flow filter tube

Claim 2

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) forming a filter tube comprising a wet mat of the glass fibers from the water slurry on a cylindrical mandrel; (c) during the forming of the wet mat of fibers into a filter tube, encapsulating an open-scrim, reinforcing sheet material within the internal wall thickness of the wet mat of fibers forming the filter tube, the sheet material extending generally the length of the filter tube and at least about one and one-half revolutions of the filter tube diameter; (d) drying the filter tube containing the scrim sheet material within the filter tube wall; (e) bonding the dried filter tube with a bonding agent at the junction of the glass-fiber crossover points and with and through the scrim sheet material; and (f) recovering an integral filter tube having a high burst strength.

Claim 3

The process of claim 1 wherein the scrim material comprises a glass-fiber scrim material characterized by regular and uniform openings therein, and wherein the bonding agent is a resin material.

Claim 4

The process of claim 1 which includes forming a helical coil of the scrim sheet material within the filter tube wall.

Claim 5

The process of claim 1 which includes: (a) depositing the wet mat of fibers from the slurry onto the surface of a cylindrical vacuum mandrel; (b) wrapping an overlapping layer of the scrim material about the wet mat of fibers on the mandrel; and (c) depositing an additional wet mat of fibers from the slurry onto the wrapped scrim material, whereby the scrim material is positioned within the inner 50 percent of the filter tube wall thickness from the internal surface diameter of the filter tube.

Claim 6

The process of claim 1 which includes: (a) placing a layer of pretreatment material about and adjacent the internal wall surface of the integral filter tube; and (b) placing a porous, coalescing sleeve element about and adjacent the external wall surface of the integral filter tube.

Claim 7

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) forming a wet mat of the glass fibers from the water slurry on the surface of a flat screen; (c) placing an open scrim reinforcing sheet material on the wet mat of fibers, the sheet material extending generally the length of the filter tube to be formed, and having a width to provide for at least about 11/2 revolutions of the filter tube diameter, but insufficient to provide for the scrim sheet material to form a portion of the external wall surface of the filter tube; (d) rolling the wet mat and the scrim sheet material onto the external surface of a cylindrical vacuum mandrel to form the wet mat into the filter tube, with noncontacting layers of scrim sheet material in a helical form within the filter tube walls, with layers of glass fibers of selected depth separating each layer of the helical scrim sheet material, and to form a continuous filter tube wall of the fibers; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.

Claim 8

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) forming a wet mat of the glass fibers from the water slurry on the surface of a flat screen; (c) placing an open scrim reinforcing sheet material on the wet mat of fibers, the sheet material extending generally the length of the filter tube to be formed, and having a width to provide for at least about 11/2 revolutions of the filter tube diameter, but insufficient to provide for the scrim sheet material to form a portion of the external wall surface of the filter tube; (d) rolling the wet mat and the scrim sheet material onto the external surface of a cylindrical vacuum mandrel to form the wet mat into the filter tube, with noncontacting layers of scrim sheet material in a helical form within the filter tube walls, with layers of glass fibers of selected depth separating each layer of the helical scrim sheet material, and to form a continuous filter tube wall of the fibers; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.

Claim 9

The process of claim 6 wherein the glass fibers are borosilicate glass fibers having a diameter of from about 0.03 to 8 microns.

Claim 10

The process of claim 6 wherein the bonding agent is a hardened resin.

Claim 11

The process of claim 8 wherein the bonding agent is a phenol-formaldehyde resin, an epoxy resin or a silicone resin.

Claim 12

The process of claim 6 wherein the scrim sheet material comprises a glass-fiber scrim material.

Claim 13

The process of claim 6 wherein the scrim sheet material is characterized by regular and uniform openings of from about 1/8 to 1/2 inch in dimension.

Claim 14

The process of claim 6 wherein the scrim sheet material is positioned on the wet mat of fibers so that, on rolling into a filter tube, the scrim forms all or a portion of the internal wall of the filter tube.

Claim 15

The process of claim 6 wherein the scrim sheet material has a width sufficient to provide from about 11/2 to 5 revolutions of the scrim sheet material in the wall of the filter tube.

Claim 16

The process of claim 6 which includes placing a layer of pretreatment material about the internal wall surface of the recovered filter tube.

Claim 17

The process of claim 6 which includes: (a) rolling a batt of coarse glass fibers about a perforated mandrel; (b) inserting the mandrel and the rolled batt of glass fibers snugly within the interior of the recovered filter tube; and (c) placing means to retain the rolled batt of fibers at each end of the filter tube to form a filter tube assembly.

Claim 18

The process of claim 15 which includes forming a porous outer sleeve over the external surface of the filter tube as a coalescing filter.

Claim 19

The process of claim 6 which includes packing a coarse, particulate, pretreatment material about a porous, internal tube within the filter tube, and inserting end cap means to prevent the particulate material from being dislodged from between the filter tube and the porous tube.

Claim 20

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) forming a wet mat of the glass fibers from the water slurry on the surface of a flat screen; (c) placing a glass-fiber open scrim reinforcing sheet material on the wet mat of fibers, the sheet material characterized by regular and uniform openings of from about 1/8 to 1/2 inch in dimension and extending generally the length of the filter tube to be formed, and having a width to provide from about 11/2 to 5 revolutions of the filter tube diameter, but insufficient to provide for the scrim sheet material to form a portion of the external wall surface of the filter tube; (d) rolling the wet mat and the scrim sheet material onto the external surface of a cylindrical vacuum mandrel to form the wet mat into the filter tube, with noncontacting layers of scrim sheet material in a helical form within the filter tube walls, with layers of glass fibers of selected depth separating each layer of the helical scrim sheet material, and to form a continuous filter tube wall of the fibers; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a hardened resin bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.

Claim 21

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) forming a wet mat of the glass fibers from the water slurry on the surface of a flat screen; (c) placing a glass-fiber open scrim reinforcing sheet material on the wet mat of fibers, the sheet material characterized by regular and uniform openings of from about 1/8 to 1/2 inch in dimension and extending generally the length of the filter tube to be formed, and having a width to provide from about 11/2 to 5 revolutions of the filter tube diameter, but insufficient to provide for the scrim sheet material to form a portion of the external wall surface of the filter tube; (d) rolling the wet mat and the scrim sheet material onto the external surface of a cylindrical vacuum mandrel to form the wet mat into the filter tube, with noncontacting layers of scrim sheet material in a helical form within the filter tube walls, with layers of glass fibers of selected depth separating each layer of the helical scrim sheet material, and to form a continuous filter tube wall of the fibers; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a hardened resin bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.

Claim 22

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) forming a wet mat of the fibers of selected depth onto the surface of a cylindrical vacuum mandrel; (c) wrapping an open scrim reinforcing sheet material about the surface of the wet mat of fibers on the mandrel, the scrim sheet material extending generally the length of the filter tube to be formed and at least about 11/2 revolutions about the mandrel; (d) forming a wet mat of fibers of selected depth over the wrapped scrim sheet material on the mandrel to encapsulate the scrim sheet material within the wall of the filter tube so formed; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.

Claim 23

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) forming a wet mat of the fibers of selected depth onto the surface of a cylindrical vacuum mandrel; (c) wrapping an open scrim reinforcing sheet material about the surface of the wet mat of fibers on the mandrel, the scrim sheet material extending generally the length of the filter tube to be formed and at least about 11/2 revolutions about the mandrel; (d) forming a wet mat of fibers of selected depth over the wrapped scrim sheet material on the mandrel to encapsulate the scrim sheet material within the wall of the filter tube so formed; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.

Claim 24

The process of claim 19 wherein the glass fibers are borosilicate glass fibers having a diameter of from about 0.03 to 8 microns.

Claim 25

The process of claim 19 wherein the bonding agent is a hardened resin.

Claim 26

The process of claim 19 wherein the bonding agent is a phenol-formaldehyde resin, an epoxy resin or a silicone resin.

Claim 27

The process of claim 19 wherein the scrim sheet material comprises a glass-fiber scrim material.

Claim 28

The process of claim 19 wherein the scrim sheet material is characterized by regular and uniform openings of from about 1/8 to 1/2 inch in dimension.

Claim 29

The process of claim 19 wherein the scrim sheet material is wrapped about 11/2 to 5 revolutions about the mandrel.

Claim 30

The process of claim 19 wherein the wrapped scrim sheet material is wrapped and positioned within the inner 50 percent of the filter tube wall thickness from the internal surface diameter of the filter tube.

Claim 31

The process of claim 19 which includes the additional step of employing a number of scrim wrappings with additional layers of the fibers deposited between each scrim wrapping to provide a filter tube having a plurality of separate layers of scrim material contained within the wall of the filter tube.

Claim 32

The process of claim 19 which includes placing a layer of pretreatment material as a layer within and about the internal wall surface of the recovered filter tube.

Claim 33

The process of claim 19 which includes: (a) rolling a batt of coarse glass fibers about a perforated mandrel; (b) inserting the mandrel and the rolled batt of glass fibers snugly within the interior of the recovered filter tube; and (c) placing means to retain the rolled batt of fibers at each end of the filter tube to form a filter tube assembly.

Claim 34

The process of claim 19 which includes forming a porous outer sleeve over the external surface of the filter tube as a coalescing filter.

Claim 35

The process of claim 19 which includes packing a coarse, particulate, pretreatment material about a porous, internal tube within the filter tube, and inserting end cap means to prevent the particulate material from being dislodged from between the filter tube and the porous tube.

Claim 36

The process of claim 19 wherein the scrim sheet material is wrapped and positioned within from about 10 to 35% of the inner filter tube wall thickness from the internal surface of the filter tube.

Claim 37

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) depositing a wet mat of the fibers of selected depth from the slurry onto the surface of a cylindrical vacuum mandrel; (c) wrapping a glass-fiber open scrim reinforcing sheet material about the surface of the wet mat of fibers on the mandrel, the scrim sheet material characterized by regular and uniform openings of from about 1/8 to 1/2 inch in dimension and extending generally the length of the filter tube to be formed and from about 11/2 to 5 revolutions about the mandrel; (d) depositing a wet mat of fibers of selected depth from the slurry over the wrapped scrim sheet material on the mandrel to encapsulate the scrim sheet material within the wall of the filter tube so formed; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a hardened resin-bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.

Claim 38

A process of preparing an inside-to-outside flow filter tube, which process comprises: (a) dispersing a plurality of glass fibers in water to form a water slurry of the fibers, the glass fibers having a diameter range of from about 0.001 to 10 microns; (b) depositing a wet mat of the fibers of selected depth from the slurry onto the surface of a cylindrical vacuum mandrel; (c) wrapping a glass-fiber open scrim reinforcing sheet material about the surface of the wet mat of fibers on the mandrel, the scrim sheet material characterized by regular and uniform openings of from about 1/8 to 1/2 inch in dimension and extending generally the length of the filter tube to be formed and from about 11/2 to 5 revolutions about the mandrel; (d) depositing a wet mat of fibers of selected depth from the slurry over the wrapped scrim sheet material on the mandrel to encapsulate the scrim sheet material within the wall of the filter tube so formed; (e) drying the filter tube so formed; (f) impregnating and bonding the dried filter tube with a hardened resin-bonding agent at the junction of the fiber crossover points and cooperatively with and through the scrim sheet material; and (g) recovering an integral filter tube having a high burst strength.