WO2002008106A2

WO2002008106A2 - Method and apparatus for producing cylindrical packages of glass fiber strands

Info

Publication number: WO2002008106A2
Application number: PCT/US2001/022744
Authority: WO
Inventors: Douglas Brian Mann
Original assignee: Advanced Glassfiber Yarns, Llc
Priority date: 2000-07-24
Filing date: 2001-07-19
Publication date: 2002-01-31
Also published as: WO2002008106A3; TW524769B; AU2001276998A1

Abstract

An improved method and apparatus is disclosed for winding cylindrical glass fiber packages using the benefits of precision builders at high speeds to form high quality glass fiber packages wherein the precision builder comprises at least one guide eye able to oscillate at a rate independently from the oscillation rate of the precision builder.

Description

METHOD AND APPARATUS FOR PRODUCING CYLINDRICAL PACKAGES OF GLASS FIBER STRANDS

FIELD OF THE INVENTION The present invention relates generally to packaging glass fiber strands. More particularly, the present invention relates to an improved method for making a glass fiber package having the improved strand control of a precision builder along with a sufficient oscillation to build a package having predetermined characteristics.

BACKGROUND OF THE INVENTION In the glass fiber field, continuous fibers, such as glass fibers, are made by mechanically drawing fiber material from a feeder of molten glass. The feeder has a bottom plate, or bushing having a plurality of orifices through which the molten glass feeds. In the forming process, the strand is drawn, solidified, treated, and then wound on a rotating drum or collet to form progressively and build a package. The completed package consists of single or multiple long strands formed from a collection of glass fibers. This method also can be used to make and package fibers of other materials, such as other mineral materials or organic polymer materials. Often, a protective coating, or size, is applied to the fibers which allows them to move past each other without breaking as the fibers are collected to form a single strand. The size also can improve the bond between the strands since the size may also include bonding agents which allow fibers to stick together to form an integral strand. It is preferable that the package be wound in a manner that enables the strand to be easily unwound by an end user.

One conventional winding pattern consists of a series of helical courses laid on a rotating collet to build a package that can be easily unwound. Such helical, or spiral, pattern prevents adjacent loops or wraps of strand from fusing or trapping together. The helical courses or patterns are wound around the collet as the package begins to build. Successive courses are laid on the outer surface of the package continuously increasing the package diameter, until the winding is complete and the package is removed from the collet. According to known methods, a strand reciprocator guides the strand longitudinally back and forth across the outer surface of the package to lay each successive course. Known reciprocators include spiral wire-type strand oscillators that consist of a rotating shaft containing two outboard wires approximating a spiral configuration. The spiral wires physically strike the advancing strand and are directed back and forth along the outer surface of the package. The shaft is also moved longitudinally so that the rotating spiral wires traverse across the package surface to lay the strand on the package surface. While building the package, the spiral wire strand oscillator does not contact the package surface. This aforementioned method is well known and commonly used.

Packages produced according to the spiral wire method have been used to accomplish high speed (e.g. in excess of 4000 fpm) packaging, but have produced fiber having inconsistent diameters due to the oscillating helical wind that produces packages with uneven diameters. In addition, such spiral built packages often are not built with the desired precision with respect to strand throw since the package outer diameter is inconsistent, which affects the location of the strand on the spiral wire. A more consistent package building process results in greater fiber consistency over then entire length of the fiber.

Precision builders meanwhile are known which use guide eyes to direct the fiber to the collet. In these systems the guide eyes oscillate relative to the precision builder. While the precision of these systems is superior to the spiral builders, the known precision systems have serious design limitations with respect to winding speed for certain materials, such as glass fibers. The desired glass fiber processing requirements of a greater than 4000 fpm manufacturing speed can not be achieved successfully with common precision building systems.

SUMMARY OF THE INVENTION

According to one embodiment, the present invention is directed to high speed winding method for making a glass fiber package comprising the steps of providing a winding assembly including a cylindrical collet having an outer diameter and in communication with a direct drive mechanism capable of driving the collet at speeds in excess of about 3000 fpm, preferably from about 3000 to about 15,000 fpm, and more preferably from about 3500 to about 12,000 fpm. A cylindrical tube is provided having an inner diameter substantially equal to the outer diameter of the collet such that the tube fits onto the collet. A continuous glass fiber strand made from a molten preform is provided and directed to a preferably substantially cylindrical precision builder having at least one guide eye. The precision builder is preferably in communication with a second drive mechanism, preferably comprising an assembly, such as a cam or ball screw assembly, for oscillating the builder in a direction along the builder's longitudinal axis. The guide eyes are in communication with a third drive mechanism, preferably a mechanism driven by a cam mechanism, such as a barrel cam, for oscillating the guide eyes independently from the builder at an oscillation frequency that is preselected to be the same as or different from the oscillation frequency of the builder. The present invention also contemplates a single drive assembly that regulates the oscillation of both the builder and the guide eye, assuming that the single drive can be customized to deliver varying oscillation rates, or frequencies, or phases to the builder with respect to the guide eyes. Finally, the collet is rotated at a predetermined speed to maintain a predetermined tension on the strand to achieve a high quality package of a fiber having a consistent fiber diameter. In another embodiment, the present invention is directed to a method for improving the uniformity of precision built glass fiber packages comprising providing a winding assembly including a cylindrical collet having an outer diameter, said winding assembly in communication with a first drive mechanism. A cylindrical tube having an inner diameter substantially equal to the outer diameter of the collet is provided such that the tube intimately contacts the collet. A precision builder is provided in communication with a second drive mechanism preferably comprising a cam or ball screw mechanism, and having at least one guide eye, with said guide eye attached to a third drive mechanism, preferably comprising a cam mechanism, and said builder having a longitudinal axis. A fiber strand is provided and directed to the guide eye of the precision builder. The precision builder is then oscillated in the longitudinal axis of the builder at a first adjustable frequency while the guide eye is oscillated in the longitudinal axis of the builder at a second adjustable frequency while also rotating the collet at a predetermined speed in excess of about 3000 fpm to maintain a predetermined tension on the strand.

In yet another embodiment, the present invention is directed to an apparatus for making a glass fiber package comprising a winding assembly including a cylindrical collet having an outer diameter, said assembly in communication with a rotating drive mechanism. A cylindrical tube is provided having an inner diameter substantially equal to the outer diameter of the collet such that the tube intimately contacts the collet. A precision builder is provided in communication with a first oscillating drive mechanism, preferably comprising a cam or ball screw assembly, said builder having a longitudinal axis and located proximate to the winding assembly. At least one guide eye is in communication with the precision builder, said guide eye attached to a second oscillating drive mechanism, preferably a cam mechanism. The drive rotating mechanism drives the winding assembly at a predetermined rotational speed and the first oscillating drive mechanism oscillates the precision builder along the longitudinal axis at a first preselected frequency while the second oscillating drive mechanism oscillates the guide eye along the longitudinal axis at a second preselected frequency. The preselected frequencies may be the same or different, and in or out of phase with respect to one another.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows an end or longitudinal perspective view of a conventional spiral winding process for building a cylindrical glass fiber package onto a spiral-built tube;

Figure 2 shows an end or longitudinal perspective view of the precision build winding apparatus of the present invention;

Figure 3 shows an overhead plan view of the apparatus of the present invention;

Figure 4 shows a longitudinal schematic view of the spiral build apparatus of Figure 1 showing the angle of attack of the fiber being wound; Figure 5 shows a longitudinal schematic view of the apparatus of Figure 2;

Figure 6 shows a partial overhead plan view of the guide eye of the precision builder of Figure 5; Figure 7 shows an overhead plan view of the apparatus of the present invention used to wind multiple strands;

Figure 8 shows an enlarged side view of the guide eye of the precision builder; and Figure 9 shows an enlarged plan view of the guide eye of the precision builder.

DETAILED DESCRIPTION OF THE INVENTION The glass fiber package method and apparatus of the present invention is designed to replace spiral builders that are generally used for high speed fiberglass winding that is wound at a rate of greater than about 4000 fpm. Spiral built packages are not adequately uniform due to inconsistencies in package diameter, which affects fiber diameter. By contrast, the rotational rate of precision built packages traditionally have been relatively slow (less than 4000 fpm) due to inherent process limitations affecting various parameters such as throw length.

Building a predictably shaped precision built fiber glass package at high speeds is complex and has not met with success in the glass fiber packaging industry. It has now been discovered that glass fiber packages can be built at high speeds by oscillating not only the guide eyes within the precision builder, but also the builder itself; both in the longitudinal axis.

Both types of builders (oscillating precision builders and oscillating spiral builders) create tapered edge packages because of their geometric nature. Figure 1 shows a conventional yarn package spiral builder. With a conventional spiral builder, the strand throw length (axial motion) is controlled by many variables including shape of wires, strand attention, package diameter, X & Y dimensions, angle of attack and free length. In the spiral building system, the strand throw length, the speed of the strand's turnaround, and the end of the throw are very imprecise due to the dependency upon strand tension and package shape. Therefore, it is difficult to make a consistent yarn package, because of the many variables that control strand throw. However, with the precision builder of the present invention, these inconsistencies are eliminated. Through the use of the precision builder, as has now been determined, strand placement onto the winding collet is more controlled. Further, the precise placement of the strand allows the production of heavier (larger diameter) packages without sacrificing product quality (yardage variation). As set forth in the present invention, a precision builder incorporates an oscillating guide eye as well as the builder itself oscillating in the same axis (longitudinal) as the guide eye. This increases the precision with which the package is built, leading to a more consistent fiber, which in turn creates a more consistently shaped package.

Known precision builder assemblies, as they are presently used, are stationary (i.e. only the guide eyes move) whereas spiral builder assemblies oscillate several inches at a relatively slow rate compared to the spiral throw rate. The present invention combines the strand control of a precision builder guide eye oscillation with second oscillation; that of the precision builder itself, to build a precision package. With the improved strand control of the precision builder of the present invention, a more consistent fiber is produced in terms of fiber dimension, including fiber diameter. Therefore precision packages can be produced with higher fiber quality than is presently known. This allows the production of larger packages of higher quality, and reduces production costs. It would be readily understood by one skilled in the field of fiberglass packaging that precision built taper-edged packages can be built for both single end and multiple end packages.

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

Figure 1 shows a conventional spiral fiber winding process. The winding apparatus 10 comprises a fiber strand 12 directed past a spiral builder 14 to a winding collet 16 on which is placed a tube 20. The collet preferably is rotated in a clockwise direction in order to wind the fiber and thereby "build" the package. The combined factors of yarn tension, spiral builder oscillation speed, as well as the free length between the spiral builder and the winding collet will determine the final features of the fiber strand, and consequently, the wound package. The collet is in communication with a drive mechanism (not shown), preferably a direct drive mechanism as would be understood by one skilled in the field of high speed glass fiber winding machines. The builder and guide eyes are in communication with drive mechanisms, preferably cam-type mechanisms suitable for producing oscillation. Preferably the builder and guide eyes are in communication with different drive mechanisms. However, the present invention contemplates the use of one drive mechanism to which both the builder and guide eyes are attached so long as the builder and guide eyes can be made to oscillate at differing frequencies, if desired. The present invention contemplates the use of controllers, which is preferably be computer assisted, in communication with the various drive mechanisms to control the frequencies of the oscillations during the package "build" cycle. The oscillation frequencies may be varied or held constant as desired to achieve the desired package characteristics. Similarly, a controller, which is preferably computer assisted, is contemplated in communication with the drive mechanism to enable the winder to achieve a preselected fixed or variable winding speed to work in concert with the oscillation frequencies to create a glass fiber package having desired characteristics. Figure 2 shows one embodiment of the present invention where the winding apparatus 28 comprises fiber strands 12 directed to the oscillating guide eyes (not visible) located on precision builder 29, which itself oscillates in the direction of its longitudinal axis. The fiber strands are directed to the winding collet 33 onto which is placed tube 30. The packages, shown as 35 on the tube 30 are built up as the collet 33 rotates to wind the fiber 12. Alternate tube 32, on collet 31 is shown awaiting its turn to be rotated into position, for filling, once the package being wound onto tube 30 is full. The strands 12 will then, in a continuous fashion, be directed to the locations shown on tube 32.

Figure 3 is a close-up overhead plan view of one embodiment of the present invention. The builder 29 comprises an internal rod (not shown) that is engaged within the apparatus housing 40, preferably to a cam assembly (also not shown) that is responsible for oscillating the builder 29 in the longitudinal axis 51 according to a predetermined frequency. The oscillation of the builder is conducted in concert with the individual oscillation patterns of the guide eyes 53 which are connected or in communication with oscillation mechanisms such as, for example cams. Any mechanism that can achieve such oscillation in addition to a cam, such as for example pulleys, reciprocating pistons, hydraulic or pneumatic assisted assemblies, etc., is contemplated by the present invention. The guide eyes 53 are moveably connected to individual cams (not shown) located within the builder 29. The cams move the guide eyes 53 along the longitudinal axis 51 to effect the desired fiber coverage on the tube 30. It is the combined preselected and modifiable movements of the oscillations of the builder 29 and the guide eyes 53 that effect the many critical building characteristics, such as, for example, the desired throw length. In this way, the package is built up as desired. By winding a package using a precisely held strand, the package's shape and the strand placement on the package can be controlled so that the strand pull speed can be held nearly constant. This is accomplished by using a strand throw that is smaller than the builder's stroke, and decreasing the builder's stroke as the package builds. By maintaining a constant pulling speed, the fiber attenuation/diameter can be kept nearly constant. This allows for the production of larger packages without decreasing product quality.

Figures 8 and 9 show the guide eye in greater (enlarged) detail. Figure 8 shows a side view and Figure 9 shows an overhead plan view of guide eye 53. The guide eye 53 comprises a slot 44 bounded by two sides 40, 42. The fiber strand is retained within the slot 44 during the fiber winding attending the building of the package. In essence, the surrounding slot 44 creates a directing perimeter for the fiber being wound under tension to the package. In this way, the fiber is guided to predetermined positions on the take-up tube (package) by the oscillating guide eye 53, in combination with the oscillating precision builder. The oscillating action of the guide eye in combination with the oscillating builder has been found to be significantly less damaging to the fiber compared with the physical striking of the fiber that normally attends spiral building. Once again, anything that reduces impact (physical contact) on the fiber is desirable since such impact necessarily affects the fiber characteristics, such as fiber diameter. In a process that runs at rapid speeds (i.e. in excess of about 4000 fpm), any repetitive act that alters the characteristics of the fiber, results in fiber deviation which, in turn, leads to packaging deviation.

Figures 4 and 5 compare the enhanced control of the precision builder system (Fig. 5) as compared to the spiral builder 54 (Fig. 4). As shown in Figure 4, the very dimension and orientation of the spiral builder requires locating the builder 55 at a certain distance from the winding collet 56. This distance creates a "free length" of fiber represented by "y". The greater the free length, the less the control of placement of the strand 57 on the package. The "angle of attack" is represented by angle θ . Figure 5 shows that, through the use of the guide eyes 58 of the precision builder 59, the free length "y" is reduced, further contributing to a more consistent fiber product. Figure 6 is a partial overhead plan view of the precision builder of the present invention. This figure shows the oscillation of the guide eye 60 as travelling (oscillating) a distance "c" in the direction of the longitudinal axis. In addition, the precision builder 62 itself oscillates a distance "b" in the direction of the longitudinal axis. In this figure, "a" represents the distance over which the package is formed on the collet tube 64. The distance "x", (x=b-c), is the flat portion of the package (constant diameter). When the strand is pulled by this (x) portion of the package, the strand attenuation/fiber diameter is constant. With a large "b" dimension and a small "c" dimension, the short-term yardage variation (fiber diameter variation) can be kept at a minimum because "x" will be large. With spiral wire technology it is very difficult to have small "c" dimensions and still maintain control of the strand. With the precision builder, the yardage variation can be further minimized by building a package with a decreasing "b" dimension stroke so that the yarn is never placed/pulled upon the tapered edge of the package.

Figure 7 shows a further embodiment of the present invention where multiple fiber strands 71 are directed through guide eyes 73, 74 of precision builder 70 to form packages 75, 76 on tube 78 placed onto collet 80.

Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

THAT WHICH IS CLAIMED:

1. A high speed winding method for making a glass fiber package comprising the steps of: providing a winding assembly including a cylindrical collet having an outer diameter, said winding assembly attached to a first drive mechanism; providing a cylindrical tube having an inner diameter substantially equal to the outer diameter of the collet such that the tube intimately contacts the collet; providing a continuous glass fiber strand from a molten preform; providing a precision builder in communication with a second drive mechanism and having at least one guide eye, said guide eye attached to a third drive mechanism, said builder having a longitudinal axis; directing the strand to the guide eye of the precision builder; oscillating the precision builder in the longitudinal axis at a predetermined frequency; oscillating the guide eye in the longitudinal axis at a predetermined frequency; and rotating the collet at a predetermined speed to maintain a predetermined tension on the strand.

2. The method according to Claim 1, wherein at least one of the first, second and third drive mechanisms are direct drive mechanisms.

3. The method according to Claim 1 , wherein the precision builder and the guide eye are oscillated in the direction of the longitudinal axis of the precision builder at the same frequency.

4. The method according to Claim 1 , wherein the precision builder and the guide eye are oscillated in the direction of the longitudinal axis of the precision builder at different frequencies.

5. The method according to Claim 1, wherein the collet is rotated at a speed of from about 3000 to about 15,000 fpm.

6. The method according to Claim 1, wherein the collet is rotated at a speed of from about 3500 to about 12000 fpm.

7. The method according to Claim 1 , wherein the collet is rotated at a speed in excess of about 3000 fpm.

8. The method according to Claim 1, further comprising first second and third controllers correspondingly in communication with the first, second and third drive mechanisms.

9. The method according to Claim 8, wherein the second controller directs the second drive mechanism to oscillate the builder at a varying frequency during a package build.

10. The method according to Claim 8, wherein the third controller directs the third drive mechanism to oscillate the guide eye at a varying frequency during a package build.

11. A method for improving the uniformity of precision built glass fiber packages comprising the steps of: providing a winding assembly including a cylindrical collet having an outer diameter, said winding assembly attached to a first drive mechanism; providing a cylindrical tube having an inner diameter substantially equal to the outer diameter of the collet such that the tube intimately contacts the collet; providing a continuous glass fiber strand from a molten preform; providing a precision builder in communication with a second drive mechanism and having at least one guide eye, said guide eye attached to a third drive mechanism, said builder having a longitudinal axis; directing the strand to the guide eye of the precision builder; oscillating the precision builder in the longitudinal axis at a first frequency; oscillating the guide eye in the longitudinal axis at a second frequency; and rotating the collet at a predetermined speed of from about 4000 fpm to about 12,000 fpm to maintain a predetermined tension on the strand.

12. The method according to Claim 11, wherein the first frequency is different than the second frequency.

13. An apparatus for making a glass fiber package comprising: a winding assembly including a cylindrical collet having an outer diameter, said assembly in communication with a rotating drive mechanism; a cylindrical tube having an inner diameter substantially equal to the outer diameter of the collet such that the tube intimately contacts the collet; a cam assembly; a precision builder in communication with the cam assembly, said builder having a longitudinal axis and located proximate to the winding assembly, said builder in communication with a first oscillating drive mechanism; and at least one guide eye in communication with the precision builder, said guide eye attached to a second oscillating drive mechanism; wherein the drive mechanism drives the assembly at a predetermined rotational speed and the precision builder oscillates along the longitudinal axis at a first preselected frequency and the guide eye oscillates along the longitudinal axis at a second preselected frequency.

14. The apparatus according to Claim 13, wherein the builder is substantially cylindrical.

15. The apparatus according to Claiml3, wherein the rotating drive mechanism is a direct drive mechanism.

16. The apparatus according to Claim 13, wherein the drive mechanism is capable of driving the collet at preselected rotational speeds of from about 3000 to about 15,000 fpm.

17. The apparatus according to Claim 13, wherein the drive mechanism is capable of driving the collet at preselected rotational speeds of from about 3500 to about 12000 fpm.

18. The apparatus according to Claim 13, wherein the drive mechanism is capable of driving the collet at a preselected speed in excess of about 3000 fpm.

19. The apparatus according to Claim 13, wherein the first and second oscillating drive mechanisms oscillate at a substantially similar frequency.

20. The apparatus according to Claim 13, wherein the first and second oscillating drive mechanisms oscillate at differing frequencies.

21. The apparatus according to Claim 13, further comprising a first, a second and a third controller correspondingly in communication with the first, second and third drive mechanisms.

22. The apparatus according to Claim 21, wherein the second controller directs the second drive mechanism to oscillate the builder at a varying frequency during a package build.

23. The apparatus according to Claim 21 , wherein the third controller directs the third drive mechanism to oscillate the guide eye at a varying frequency during a package build.