GB1571607A - Method of preparing glass fibre strand - Google Patents

Description

(54) METHOD OF PREPARING GLASS FIBER STRAND (71) We, PPG INDUSTRIES, INC, a corporation organized and existing under the laws of the State of Pennsylvania, United States of America, of One Gateway Center, Pittsburgh, State of Pennsylvania 15222, United States of America (Assignee of WARREN WENDELL DRUMMOND), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a method of preparing glass fiber strand.

In the manufacture of textile strand and yarns many operations are involved from the basic fonnation of the fibers constituting the strand to the finished strand packaged for use by the customer. In general the more handling that is required to produce a particular strand of yarn, the more costly the product becomes. Similarly, the more processing that is required to produce a given strand product, particularly one made of glass fibers, the weaker the fiber becomes.

In handling glass fibrous strands due to the fact that glass fibers have nearly perfect elasticity, it is found that considerable tension is exerted on the forming tubes used to collect these strands as they are wound from a glass source. This results in a strand which is often quite difficult to remove from a forming package in the wet or the dry state.

Still further, in many strand making processes where speciality yarns are desired, the strand source for the process is a bobbin which because of size and space limitations of commercial twist frame equipment is quite small. Since the preparation of the bobbin itself is a costly operation, the use of bobbins as the strand source for speciality yams renders these speciality yarns quite costly.

Often textile strands are sized during forming with special chemicals to render them useful for a particular end use. Since it is conventional, particularly in the fonnation of glass fibers, to utilize aqueous solutions of chemicals to apply the desired coatings, binders and sizes to textile strands, it is also common practice to dry the packages of strand so formed by placing them in suitable drying - sources such as ovens. This latter operation however often results in migra- tion of binder or coating from one layer of strand on a package to the next. The ultimate result of this undesirable, but often inevitable migration, is uneven binder or coating distribution along - the strand as it is used by the customer in weaving or as reinforcement material for resin or rubber use.

By practice of the present invention there may be provided a texturizing process in which glass fiber from a forming package may be utilized directly in a texturizing operation.

According to the present invention there is provided a method of preparing a glass fiber strand, which comprises feeding a glass fiber strand from a forming package having less than 0.5 percent by weight moisture therein to a zone of fluid turbulence, passing the strand through said zone of fluid turbulence at a speed of at least 500 feet (152.4 meters) per minute, introducing gaseous fluid into said zone of fluid turbulence and passing the fluid circumferentially around the interior of said zone at rates of 20,000 to 1,070,000 revolutions per minute continuously to thereby produce a false twist in said glass fiber strand, removing the glass fiber strand from said zone of fluid turbulence, passing the glass fiber strand from the zone of fluid turbulence into a fluid texturizing zone, contacting said glass fiber strand in the texturizing zone with a gaseous fluid introduced thereto at pressures of 20 to 80 pounds per square inch gauge (1.406 to 5.624 kilograms per square centimeter) to thereby bulk said glass fiber strand, removing the resulting bulked glass fiber strand from the texturizing zone and collecting said bulk strand.

The present invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of one -embodiment of a blower suitable for use in the method of the present invention, the blower having a slotted strand entry and two rows of fluid inlets, Fig. 2 is a cross-section of Fig. 1 showing the internal air chamber and fluid inlet communication therewith, Fig. 3 is a cross-section of another embodiment of a slotted blower suitable for use in the method of the present invention, the blower having an elliptical central cavity with two rows of fluid inlets positioned therein, Fig. 4 is a longitudinal front elevation view of the blower of Fig. 3 showing the arrangement of the fluid inlets and internal fluid chambers, Fig. 5 is a longitudinal side elevational view of the blower of Fig. 3 showing the arrangement of the fluid inlets and internal fluid chamber, Fig. 6 is a cross-section of a further embodiment of a blower suitable for use in the method of the present invention, the blower having an elliptical central cavity and no longitudinal slot, Fig. 7 is a longitudinal front elevational view of the blower of Fig. 6 showing the arrangement of the fluid inlets to the central cavity and the internal fluid chamber, Fig. 8 is a cross-section of another embodiment of a blower suitable for use in the method of the present invention, the blower having a cylindrical yarn passageway and a single row of fluid inlets, Fig. 9 is a longitudinal view of the blower of Fig. 8 showing the arrangement for the fluid inlets and the internal fluid chamber, Fig. 10 is a cross-section of still another embodiment of a blower suitable for use in the method of the present invention, the blower having a cylindrical yarn passageway and two rows of fluid inlets, Fig. 11 is a longitudinal view of the blower of Fig. 10 showing the arrangement of fluid inlets and internal fluid chambers, and Fig. 12 is an elevation in perspective of a fluid texturing process employing two blowers to permit feeding strand to the system from a forming package source.

With reference to Figs. 1 and 2 of the accompanying drawings there is shown a blower 10 which is provided with a central bore or passageway 13 formed by the walls of the blower 10. An elongated slot 19 is provided to permit the passage of strand 14 into the chamber 13 from the exterior of the blower 10. A plurality of fluid inlets 17 are positioned in a row on the lip of the blower 10 and the inlets 17 are machined to direct all fluid exiting from the inlets to the underside of the chamber 13 positioned above the inlets 17.A similar row of inlets 11 are provided at the back of the chamber t3 are machined to direct fluid emanating from the inlets 18 against the surface of the back wall of the chamber 13 toward the inlets 17 and in a path around the chamber surface which is perpendicular to the strand 14 passing longitudinally through the chamber 13. Inlets 17 are fed from a common header 1-6 - located on the interior of the blower 10. This is typically provided by boring a hole parallel to the longitudinal axis of the bower 10, drilling holes 17 into the side of the chamber or header 16 and sealing both ends of the chamber by brazing a plug on each end.An inlet for fluid is provided on one end of each chamber so that fluid inlets 11 and 12 can be connected thereto to provide for the feeding of fluid under pressure to the chambers 16 and 15, respectively. The strand 14 travelling through the device 10 is thus subjected to tangential contact with high velocity fluid, e.g. air, as it travels through the blower.

Typically the central bore 13 of the blower 10 is of a diameter which is at least ten times the diameter of the stand passing through the bore.

Figs. 3 and 4 show another embodiment of a blower suitable for use in the present invention. In this embodiment the blower 20 is provided with an elliptical shaped central cavity 23. A longitudinal slot 29 is provided for the purpose of passing a strand 24 into the central cavity 23. Fluid inlet lines 21 and 22 are provided to introduce texturizing fluid into the chambers 25 and 26 which are located inside the walls of the blower 20 at each side thereof. The chamber 25 is provided with a plurality of outlet passages 28 which are machined at their end which communicates with the cavity 23 to direct fluid emanating from these passages along the interior wall of the cavity 23 toward the second set of inlets 27.The fluid passages 27 communciate with the fluid chamber 26 and are machined at their ends communicating with the chamber 23 to direct fluid along the wall of the chamber in a direction toward the inlets 28. The fluid entering the chamber 23 from inlets 27 and 28 is thus directed in circumferential fashion around the wall of the chamber 23.

Although inlet lines 21 and 22 are shown entering blower 20 at one end thereof, they may enter blower 20 on either side i.e. inlet line 21 on the same side of blower 20 as fluid chamber 26 and inlet line 22 on the same side of blower 20 as fluid chamber 25.

The blower may be made of metal, brass being the preferred metal. However, the blower may also be made of a fired ceramic, hard plastics or other suitable structural material.

Figs. 6 and 7 show still another embodiment of a blower suitable for use in the present invention. In this embodiment the chamber 63, in which the strand 67 is posi tioned during operation of the blower 60 shown, is elliptical in shape. The blower is provided with two fluid inlet lines 61 and 62 which communicate with two chambers 65 and 66, respectively, these chambers being located inside of the blower 60, one at each side thereof. Chamber 65 has a plurality of fluid passages 68 in communication therewith and each of these passages terminate in chamber 63. At this termination point in chamber 63 the passages 68 are machined to direct fluid along the wall of the chamber 63 toward fluid passages 69. Chamber 66 is provided in a similar manner with fluid passages 69 which are in communication therewith and which terminate in chamber 63.These passages at the termination point in chamber 63 are machined to direct fluid along the wall of chamber 63 to the fluid passages 68.

Figs. 8 and 9 show another embodiment of a device utilizing a single row of fluid passages. In this embodiment a blower 80 is provided with a chamber 85 in which the strand 84 is treated. Chamber 85 is circular in shape. A fluid inlet line 82 is provided to introduce fluid into a chamber 86 housed in the wall of blower 80. The chamber 86 is provided with a plurality of fluid passages 87 which are in fluid communication with chamber 86 at one end and which terminated in chamber 85. The passages 87 at their termination point in chamber 85 are machined to direct fluid around the wall of the chamber 85.

Figs. 10 and 11 show a still further embodiment in which a circular chamber is employed in the blower. In these figures the blower 90 is provided with a central cavity 93 in which a strand 99 is treated. Two fluid inlets 91 and 92 are provided to introduce fluid into chambers 95 and 96, respectively, these chambers being formed in the wall of the blower 90. The chamber 95 has a plurality of fluid passages 98 provided therein which pass from chamber 95 to the cavity 93 in the blower 90. At their point of termination in cavity 93 the passages 98 are machined to direct fluid around the interior wall of the cavity 93. In like fashion a plurality of passages 97 are provided in chamber 96 in fluid communication therewith and terminate in chamber 93. These passages are also machined to direct fluid around the wall of the chamber 93.

Referring now to Fig. 12 there is shown a process, in accordance with the present invention, for producing textured glass fiber strand. In this system forming packages 120 121 are used as the glass strand feed source.

These packages are preferably formed by drawing molten glass from a molten glass source into a multiplicity of filaments, applying a binder or size to the filaments, gathering the filaments into a strand and winding the strand to produce a forming package. The packages 120 and 121 have less than 0.5 percent by weight moisture therein and, if necessary, are dried prior to use.

As shown in Fig. 12 the strands 124 and I25 are removed from packages 120 and 121, respectively. The strands 124 and 125 pass over the exterior of the wheels 122 and 123, respectively, so that strand can be removed from the outside of the packages without snagging. The strands 124 and 125 are passed over the surface of a drive roll 129 coupled for rotation to a suitable drive source, not shown, and subsequently over nip roller 130 journalled for rotation with its outer cylindrical surface in frictional contact with the outer cylindrical surface of roll 129.

The strands 124 and 125 are passed from the surface of the nip roll 130 through blowers 131 and 132 respectively. Blowers 131 and 132 are preferably the blowers of Figs. 1, 2, 3, 4, and 5 since these blowers are equipped with a longitudinal slot for ease in threading. While these blowers are preferred blowers having the configuration of the blowers of Figs. 6, 7, 8, 9, 10 and 11 may also be employed. Using the blowers of Figs. 1, 2 and 3 as the blowers 131 and 132, air (the preferred fluid), is fed to the blowers through a suitable supply line (not shown) and the air is passed circumferentially around the interior cavity or channel running lengthwise of the blowers 131 and 132. The air is fed from a pressurized air source, not shown, at about 20 to about 80 pounds per square inch (1.406 to 5.624 kilograms per square centimeter) or more.

The whirling air inside of the blowers 131 and 132 resulting from the air feed and its passage around the cavity of the blowers 131 and 132 through which strands 124 and 125 are passing, tends to create in those strands a false twist leaving them in a more receptive state for the air texturizing that follows than is normally encountered by a twisted strand from a bobbin source fed to a similar air texturizing system.

Strands 124 and 125 after emerging from blowers 131 and 132 are passed through texturizing jets 133 and 134, respectively.

These jets are standard jets used to texturize yarn surfaces and are described in detail in U.S. Patents 2,783,609, 3,328,863 and 3,381,346. The strands are contacted in the texturizing zone with a gaseous fluid introduced to the texturizing zone at pressures of 20 to 80 pounds per square inch gauge to thereby bulk the strands. After being texturized, strands 124 and 125 are passed over the roll 135 which is coupled to a power source for rotation. The strands 124 and 125 pass from roll 135 over the surface of nip roll 136 which is journalled for rotation with its outer cylindrical surface in frictional contact with the outer - cylin- drical surface of roll 135.

The strands 124 and 125 are then passed over guide bar 138 mounted on the bracket 137 and both strands are passed under the binder spray head 141 which applies binder 142 to the strands. Binder 142 is pumped to the spray head 141 by pump 144 through pipe 140 from a binder reservoir 143. Ex cess binder is collected continuously in reservoir 143 by a suitable drain arrange ment in the bottom of the binder appli cation zone.

The binder used can be of any desired composition, consistency and viscosity so long as it can be applied through the spray head 141. Thus, binders containing starches, oils, resins, hot melt or solvent type ma terials and the like including emulsion, suspensions, solutions and the like may be used.

The strands 124 and 125 pass to the winding operation after binder 142 is applied thereto over rolls 146 and 145, respectively.

The strands are then passed over the tension rolls 148 and 147 which maintain constant tension on the strands 124 and 125 during winding. The strands 124 and 125 are wound in two packages on winder 150 which is equipped with a roller bail 149 to maintain the packages smooth on the surface and square ended. The texturizing and binder application to strand is more-fully described in our U.S. Patent 3,730,137 and the winder 150 employed with the tension rolls 148 and 147 is the winder more fully described in our U.S. Patent 3,814,339.

The texturized strands produced in this embodiment of the present invention are more rounded in shape than strands norm ally produced practicing the process of U.S.

Patent 3,730,137 and texturizing can be accomplished from a forming package strand supply rather than the bobbin feed of that patent. The strands after - passing through the blower are at low tension with a false twist rendering them more receptive to texturizing than the twisted strands norm ally used. The use of the blower does not hinder the operation in any way and the strands 124 and 125 may be fed at the 500 to 1,000 yards per minute rate or higher in the same fashion as the process described in U.S. Patent 3,730,137.

The zone of turbulence is usually of small diameter and the central cavity of the zone is typically from about i inch to about t inch (0.3175 to 1.91 centimeters) in dia meter, preferably from X inch to t inch (0.610 to 1.27 centimeters). Generally, the blower is of a length sufficient to impart a false twist to the strand during its passage *ough the block and its central cavity.

thus of 1 to 6 inches (2.54 to 15.24 centi are are typical with 1 to 3 inches (2.54 to 7.26 centimeters) being preferable for proper traversing of strand.

Using high pressure air to the zone of turbulence as a teed through the rows of inlets arranged in vertical alignment on the wall of the cavity - and with the small diameter of the cavity defining a small circumference over which the air travels, air revoles around the circumference of the cavity at values of between about 20,000 to 1,070,000 revolutions per-minute. Usually with cavities of itoi inch (0.610 to 1.27 centimeters) in diameter the zone of turbulence has air flowing around it at 150,000 to 310,000 revolutions per minute.

The fluids utilized in the zone of fluid turbulence are typical gases such as air, nitrogen, oxygen, carbon dioxide and other similar gases inert to the glass strand fed thereto. Steam may also be utilized. In the preferred embodiment of the present invention air is utilized as the gaseous source.

While the process constituting the present invention has been described with reference to certain specific illustrated embodiments, it is not intended that the invention be limited thereby except insofar as appears in the accompanying claims.

WHAT WE CLAIM IS: 1. A method of preparing a glass fiber strand, which comprises feeding a glass fiber strand from a forming package having less than 0.5 percent by weight moisture therein to a zone of fluid turbulence, passing the strand through said zone of fluid turbulence at a speed of at least 500 feet (152.4 meters) per minute, introducing gaseous fluid into said zone of fluid turbulence~ nd passing the fluid circumferentially around the interior of said zone at rates of 20,000 to 1,070,000 revolutions per minute continuously to thereby produce a false twist in said glass fiber strand, removing the glass fiber strand from said zone of fluid turbulence, passing the glass fiber strand from the zone of fluid turbulence into a fluid texturizing zone, contacting said glass fiber strand in the texturizing zone with a gaseous fluid introduced thereto at pressures of 20 to 80 pounds per inch gauge (1.406 to 5.624 kilograms per square centimeter) to thereby bulk said glass fiber strand, removing the resulting bulked glass fiber strand from the texturizing zone and collecting said bulked strand.

2. A method as claimed in claim 1, wherein said gaseous fluid is air.

3. A method as claimed in claim 1, or claim 2, wherein said bulked glass fiber strand has a binder applied thereto prior to being collected.

4. A method of preparing glass fiber strand as claimed in claim 1 and substantially

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   in frictional contact with the outer - cylin- drical surface of roll 135.

   The strands 124 and 125 are then passed over guide bar 138 mounted on the bracket

   137 and both strands are passed under the binder spray head 141 which applies binder

   142 to the strands. Binder 142 is pumped to the spray head 141 by pump 144 through pipe 140 from a binder reservoir 143. Ex cess binder is collected continuously in reservoir 143 by a suitable drain arrange ment in the bottom of the binder appli cation zone.

   The binder used can be of any desired composition, consistency and viscosity so long as it can be applied through the spray head 141. Thus, binders containing starches, oils, resins, hot melt or solvent type ma terials and the like including emulsion, suspensions, solutions and the like may be used.

   The strands 124 and 125 pass to the winding operation after binder 142 is applied thereto over rolls 146 and 145, respectively.

   The strands are then passed over the tension rolls 148 and 147 which maintain constant tension on the strands 124 and 125 during winding. The strands 124 and 125 are wound in two packages on winder 150 which is equipped with a roller bail 149 to maintain the packages smooth on the surface and square ended. The texturizing and binder application to strand is more-fully described in our U.S. Patent 3,730,137 and the winder

   150 employed with the tension rolls 148 and 147 is the winder more fully described in our U.S. Patent 3,814,339.

   The texturized strands produced in this embodiment of the present invention are more rounded in shape than strands norm ally produced practicing the process of U.S.

   Patent 3,730,137 and texturizing can be accomplished from a forming package strand supply rather than the bobbin feed of that patent. The strands after - passing through the blower are at low tension with a false twist rendering them more receptive to texturizing than the twisted strands norm ally used. The use of the blower does not hinder the operation in any way and the strands 124 and 125 may be fed at the 500 to 1,000 yards per minute rate or higher in the same fashion as the process described in U.S. Patent 3,730,137.

   The zone of turbulence is usually of small diameter and the central cavity of the zone is typically from about i inch to about t inch (0.3175 to 1.91 centimeters) in dia meter, preferably from X inch to t inch (0.610 to 1.27 centimeters). Generally, the blower is of a length sufficient to impart a false twist to the strand during its passage *ough the block and its central cavity.

   thus of 1 to 6 inches (2.54 to 15.24 centi are are typical with 1 to 3 inches (2.54 to 7.26 centimeters) being preferable for proper traversing of strand.

   Using high pressure air to the zone of turbulence as a teed through the rows of inlets arranged in vertical alignment on the wall of the cavity - and with the small diameter of the cavity defining a small circumference over which the air travels, air revoles around the circumference of the cavity at values of between about 20,000 to 1,070,000 revolutions per-minute. Usually with cavities of itoi inch (0.610 to 1.27 centimeters) in diameter the zone of turbulence has air flowing around it at 150,000 to 310,000 revolutions per minute.

   The fluids utilized in the zone of fluid turbulence are typical gases such as air, nitrogen, oxygen, carbon dioxide and other similar gases inert to the glass strand fed thereto. Steam may also be utilized. In the preferred embodiment of the present invention air is utilized as the gaseous source.

   While the process constituting the present invention has been described with reference to certain specific illustrated embodiments, it is not intended that the invention be limited thereby except insofar as appears in the accompanying claims.

   WHAT WE CLAIM IS: 1. A method of preparing a glass fiber strand, which comprises feeding a glass fiber strand from a forming package having less than 0.5 percent by weight moisture therein to a zone of fluid turbulence, passing the strand through said zone of fluid turbulence at a speed of at least 500 feet (152.4 meters) per minute, introducing gaseous fluid into said zone of fluid turbulence~ánd passing the fluid circumferentially around the interior of said zone at rates of 20,000 to 1,070,000 revolutions per minute continuously to thereby produce a false twist in said glass fiber strand, removing the glass fiber strand from said zone of fluid turbulence, passing the glass fiber strand from the zone of fluid turbulence into a fluid texturizing zone, contacting said glass fiber strand in the texturizing zone with a gaseous fluid introduced thereto at pressures of 20 to 80 pounds per inch gauge (1.406 to 5.624 kilograms per square centimeter) to thereby bulk said glass fiber strand, removing the resulting bulked glass fiber strand from the texturizing zone and collecting said bulked strand.
2. 2. A method as claimed in claim 1, wherein said gaseous fluid is air.
3. 3. A method as claimed in claim 1, or claim 2, wherein said bulked glass fiber strand has a binder applied thereto prior to being collected.
4. 4. A method of preparing glass fiber strand as claimed in claim 1 and substantially

   as hereinbefore described with reference to the accompanying drawings.
5. 5. Glass fiber strand whenever prepared by a method as claimed in any of claims 1 to 4.