WO1999026095A1

WO1999026095A1 - Coating and filling of cable cores using photocurable polymers

Info

Publication number: WO1999026095A1
Application number: PCT/IB1998/001995
Authority: WO
Inventors: Richard F. Zopf; Brian D. Thiffault
Original assignee: The Stewart Group, Inc.
Priority date: 1997-11-14
Filing date: 1998-11-11
Publication date: 1999-05-27
Also published as: AU1347699A

Abstract

The present invention provides a cable comprising a core (20) having at least one transmission medium (24), which is surrounded by a sheath (26) and a cable filling material (28), which is disposed either within the sheath and surrounding the core or disposed about the sheath, which comprises a single component, curable polymer matrix. The cable core can contain either optical fibres or electrical conductors as the transmission medium. The cable filling/coating material is preferably an ultra violet (UV) curable polymer matrix, which offers the versatility of ambient liquid application and rapid through cure using UV light. The cable is manufactured by forming a core having at least one transmission medium, surrounding the core with a sheath, filling either the core within the sheath or coating the sheath with a single component, curable polymer matrix cable/filling material, and curing the cable filling/coating material. Preferably, inert filling materials or flame retardant additives are also included in the polymer matrix.

Description

COATING AND FILLING OF CABLE CORES USING PHOTOCURABLE POLYMERS

FIELD OF THE INVENTION The present invention relates to wires and cables. More particularly, the present invention relates to a single component, ultra violet light curable polymer matrix, which is used as an interstitial filling compound for optical fiber cables .

BACKGROUND OF THE INVENTION Typically, one or more optical fiber leads for the transmission of optical signals or lightwaves are disposed within a protective casing to define an optical fiber transmission cable. Each optical fiber serves as a light waveguide and typically consists of a fiber that is coated to protect and preserve the strength of the optical fiber, to prevent damage during handling and to prevent moisture from attacking the glass fiber. In addition, coatings are applied to decrease the microbending of optical fibers, which can reduce their efficiency in transmitting optical signals. Examples of optical fiber coating systems that are well known in the art are disclosed in U.S. Pat. Nos. 5,664,041; 5,595,820; 5,502,145; 5,383,342; and 5,336,563.

One or more coated fibers are then typically surrounded by a protective sheath to form a "buffer tube". Buffer tubes may be either "loose" or "tight" buffered. In a loose buffer tube,^" an example of which is shown in Figure 1 and is generally designated as 10, there is a substantial volume 16 intermediate an optical fiber 12 or fibers and the buffer tube sheath 14. This volume is typically filled with a gel- type buffer tube filling material 18, which allows the optical fiber (s) to "float" within the buffer tube 10. This greatly reduces the stresses applied to the optical fibers, themselves, as the buffer tube is handled during manufacturing, installation, operation and maintenance processes. Examples of loose buffer tubes and methods of their manufacture are taught, for example, in U.S. Patent Nos. 4,839,970; 4,705,571; and 4,370,023. On the other hand, in a tight buffer tube, substantially the entire volume within the protective sheath is occupied by an optical fiber or fibers and no gel-type filling compound is employed.

Another type of buffer tube is a central, ribbon tube, within which a plurality of fiber optic ribbons are stacked. The stacked optical fibers themselves form an optical fiber matrix that is substantially square in cross section. Thus, when this square matrix is surrounded by a substantially round tube, a large unoccupied volume is created around the optical fiber matrix. This volume is filled with a gel-type buffer tube filling material of the same variety used with loose buffer tubes and serves substantially the same purpose. Thus, loose buffer tubes and central ribbon tubes are treated interchangeably herein, the only difference being that in practice, a plurality of loose buffer tubes are generally combined, in conjunction with a strength member, to form a cable core while a cable utilizing a central ribbon tube would typically employ only a single central ribbon tube and rely upon a strength member disposed about the core itself . A cable is then manufactured by combining one or more buffer tubes with additional cable components, such as strength and protection members. Typically, buffer tubes and strength members are bound together to form a cable core. The core may then be further protected by placing it within a core sheath, which may further be surrounded, for example, by a corrugated metallic sheath to prevent the possibility of rodents chewing through a buried cable. Finally, a cable will be jacketed with an outer jacket to protect the cable from exposure to the environment.

Since a cable core itself is made up of a number of individual components, which are typically circular in cross section, the core will have a number of interstices between the core components once they are encased within a core sheath. It is these interstices to which the disclosed invention is directed.

A great deal of effort has been expended, on the part of cable industry personnel, to deal with the problems that can be created by cable core interstices. The most common problem associated with cable core interstices is the migration of moisture through a cable, which could have a detrimental effect on the transmission of light waves through the cable. In order to reduce or eliminate the migration of water, cable core interstices are typically filled with a core filling compound. However, prior art filling compounds have not been entirely satisfactory.

It is desirable for a filling compound to exhibit the following properties :

(a) The filling compound should be resistant to aging both in a chemical sense and in a physical sense;

(b) The filling compound should be compatible with and not exhibit a detrimental effect on any of the materials the filling compound will contact, i.e. buffer tube sheathing, fiber optic strength members, of core sheaths;

(c) The filling compound should exhibit an optimally low moisture absorption;

(d) The filling compound must retain its properties over a wide temperature range, for example from -60°C. to

+90°C; accordingly the filling compound should not exhibit excessive hardness at low temperatures that will cause a mechanical stressing of the cable components due to an excessive increase in the viscosity nor should the filling compound exhibit a phase separation at high temperature and resultant drip-out of the filling compound from the cable;

(e) The filling compound should avoid the buildup of tensile or compressive forces on the cable to the greatest possible degree, so as to minimize the degree of associated optical signal attenuation; and

(f) The filling compound should have a low viscosity at room temperature in its unprocessed condition in order to enable the filling of the cables with the filling compound during the cable core manufacturing operation. Although many attempts have been made to develop filling compounds which satisfy all of the desired characteristics, all known filling compounds are deficient in one or more areas. Thus, there is a need for an improved cable core interstitial filling compound for optical fiber transmission cables.

Recent industry trends of providing optical fiber transmission cables in more diverse locations has further exacerbated the problems associated with prior art filling compounds. Where, in the past, optical fiber transmission cables were typically utilized for major trunk lines having a limited number of junction locations, the introduction of broadband services employing optical fiber cables has made cable splicing and termination environments more diverse in terms of hardware and procedures. Thus, splicing operations are occurring in more unusual locations such as from a bucket truck at an aerial Optical Network Unit (ONU) location. These changing environments are placing increased demands on crafts people in the field and on the products with which they must work. Thus, there also exists a requirement for an optical fiber transmission cable which provides field personnel with an easy, craft friendly and efficient method of accessing the cable core. Nonetheless, although attempts have been made to provide more user-friendly filling compounds, which facilitate the splicing operation, the use of gel-like filling materials, even those of the greaseless variety, still results in cables, which are deficient in one or more of the above- identified characteristics.

SUMMARY OF THE INVENTION The present invention provides an improved cable comprising a core having at least one transmission medium, which is surrounded by a core sheath and a cable filling material, which is disposed within the sheath and filling the interstices in the core. The same material may also be applied about the core sheath. The core filling and coating compound comprises a single component, curable polymer matrix. The cable core filling and coating material is preferably an ultra violet (UV) light curable polymer matrix, which offers the versatility of ambient liquid application and rapid through cure using UV light.

The present invention further provides a method of manufacturing an improved cable, which includes the steps of forming a cable core having at least one transmission medium, surrounding the core with a core sheath, filling either the core interstices or coating the core sheath with a single component, curable polymer matrix cable filling and coating material, and curing the cable filling and coating material.

In an alternative embodiment of the invention, the cable core filling and coating material itself provides the cable core sheath.

Utilizing a UV-curable polymer matrix, the above method offers significant advances over the prior art, including an advanced ability to conform to intricate core and cable structures and totally encapsulate the cable, the ability to formulate and design specific UV curable compounds to conform to specific cable requirements and an improved cure method, which can be accomplished at ambient temperatures and at accelerated times so as to be compatible with current cable manufacturing hardware at common cable manufacturing speeds . Furthermore, the disclosed invention can eliminate a number of prior art cable manufacturing steps, such as core binding and taping operations.

In addition, the present invention offers a number of advantages over conventional water-blocking materials, including but not limited to ease of removal, the absence of chemical residue after removal, non-melting characteristics, flame retardant capability, superior shear stability, non- migration into cable polymers, and ease of application.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein :

Figure 1 is a cross-section of a prior art loose buffer tube showing a single optical fiber encased within the buffer tube and surrounded by a gel-type buffer tube filling material; Figure 2 is a cross-section of an optical fiber transmission cable showing the cable core interstices intermediate a central strength member, a plurality of buffer tubes and a core sheath; Figure 3 is a cut away perspective view of the cable of Figure 2 showing the cable core and surrounding protective cable components;

Figure 4 is a cross section of a ultra violet (UV) light source which is used in a curing station for a fiber optic cable core manufactured in accordance with the teachings of the present invention;

Figure 5 is one embodiment of a production line for manufacturing tight buffered fiber optic cables in accordance with the teachings of the present invention; Figure 6 is a production line layout for manufacturing loose tube fiber optic cables in accordance with present invention;

Figure 7 is a typical production line layout for manufacturing buffer tube cables in accordance with the present invention; and

Figure 8 is a production line layout for manufacturing fiber optic cables incorporating interstitial filling, sheath coating and corrugated tape application.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The principles of the present invention are particularly useful in optical fiber transmission cables of the type illustrated in Figures 2 and 3. However, while the following description will refer to optical fiber transmission media, it is understood that the principles of the present invention may be utilized with other transmission media, such as electrically conductive media, which could range from low voltage control wires to high voltage power transmission cables. A typical fiber optic cable comprises a cable core, generally designated as 20 and a cable protection system, generally designated as 30. The cable protection system 30 may comprise a corrugated metal sheath 32, which would offer rodent protection for cables that are to be buried. Alternatively, other types of sheathing may be utilized, such as aramid fiber or other composite sheaths. In addition, one or any number of protection layers may be included. In any event, the protection system is surrounded by an exterior jacket 34, which is typically an extruded polyethylene material .

The cable core 20 comprises at least one optical fiber transmission medium 22, which may be of the loose buffer tube, tight buffer tube or central, ribbon tube variety as discussed above. The core 20 is disposed within the interior of the cable protection system 30.

Cable core 20 comprises at least one strength member 22, which to provide the requisite tensile stress characteristics for the cable. The strength member is combined with at least one optical fiber transmission medium 24, which may be, for example, a plurality of loose buffered fiber optic tubes. The combined buffer tube(s) and strength member (s) are surrounded with a core sheath 26. The portions of the interior space within the sheath that are not occupied by the optical fiber transmission media, including but not limited to the interstices between the optical fiber transmission media and the strength member (s), is filled with a cable filling material 28. The cable filling material 28 comprises a single component, curable polymer matrix. It should be noted that the drawings are illustrative only and the principles of the invention are applicable to a variety of cable constructions and geometries such as those having a plurality of core sheaths containing either one or more buffer tubes, which are arranged in an outer jacket with the interior space between the plurality of core sheaths also having the cable filling material of the disclosed invention disposed therebetween. Preferably the single component, curable polymer matrix is an ultra violet (UV) light curable polymer matrix. While UV light curable polymers are well known in the cable industry, heretofore they have not been utilized for cable filling applications since it is generally accepted in the industry that gel-type cable core filling materials are more compatible with existing cable manufacturing processes and manufacturing line speeds. In this regard, the use of a cured core filling material comprising 100% solids has not been considered to be compatible with current cable construction techniques since cured materials generally require extended cure times, which are not compatible with current production line speeds. However, by using UV light curable cable filling materials, rapid through cure can be accomplished at current production line speeds. In fact, the use of UV curable cable filling compositions can even allow for increased cable manufacturing speeds.

A significant limitation in cable manufacturing line speed results from the use of cable core binding fibers and/or polymeric core binding tapes . Due to the limitations found in prior art cable manufacturing methods and materials, including gel-type prior art cable filling compositions, a cable core incorporating any more than a single core component would require a cable stranding operation. A strander, such as an S-Z strander, is required to include sufficient excess length of each optical fiber transmission medium included in a cable to allow stresses to be applied to the finished cable, such as those imparted to a cable when it is bent, without imparting similar stresses on the optical fibers themselves, which would cause, at a minimum, degradation in optical signal transmissivity and at a maximum, fiber failure. Fiber and polymeric tape binders, each or both of which are required to physically hold a cable core configuration while the core is sheathed and filled with prior art gel-type interstitial filling materials, require an apparatus that circumscribes the cable as it speeds down a manufacturing line. Thus, the speed associated with the binding machines must be sufficiently greater than the speed of the production line in order to effectively bind the cable core .

However, by utilizing an appropriate UV light curable cable filling material, the use of binding fibers and/or polymeric binding tapes can be eliminated since the cable geometry imparted by the strander can be fixed when the UV light curable cable filling material cures. Since through cure can be accomplished nearly instantaneously when the UV light curable material is exposed to an appropriate UV light source, by locating a cable core filling and curing station immediately after a cable is stranded or even incorporating such a system into a strander, the stranded configuration can be fixed without requiring the use of binding fibers or tapes. Thus, this limitation on manufacturing speed would be eliminated. One such compound, which is suitable for cable filling applications is known as ZTX-1572A, which is manufactured by Zeon Technologies, Inc. of Londonderry, New Hampshire. ZTX- 1572A is composed of substantially 75-80% by weight urethane acrylate oligomer, 20-24% by weight monofunctional acrylate monomer and 0.2-1% by weight photoinitiator .

Compositions for UV light curable filling materials, such as ZTX-1572A, offer the versatility of ambient liquid application and rapid through cure via exposure to UV light. Thus, such materials offer an enhanced ability to conform to intricate structures and totally encapsulate the cable since they offer superior flow characteristics at ambient temperatures. Thus, their application can be incorporated into existing optical fiber cable production equipment without the necessity of exposing the cable being produced to temperature transients during the manufacturing process.

In addition, the inclusion of filling materials within the UV light curable polymer matrix provides the ability to formulate and design specific compounds to conform to specific cable requirements. Filling materials may be functional additives or inert fillers. For example, flame/fire resistivity capabilities can be incorporated into a UV light curable filling compound by the inclusion of flame/fire retardant materials in the UV curable polymer matrix. Examples of such flame retardant materials include aluminum trihydrate (ATH) , antimony oxide with halogen sinergists and phosphate esters. On the other hand, in certain applications it may be beneficial to include functionally inert organic or inorganic filler materials into the UV light curable polymer matrix. The use of inert fillers would add volume to the material on a cost effective basis. Thus, inert filled UV light curable polymers could provide cost effective solutions to cabling applications requiring large quantities of cable filling materials.

Examples of inorganic inert fillers include fumed silica, silica, talc, and mica. Examples of organic inert filler materials include hydrocarbon resins, terpene resins, tall oil ester resins, ethylene vinyl acetate, polyisobutylene and ethylene propylene copolymers.

An additional benefit of using curable cable filling materials is that they offer inherent stability. Thus, typical problems encountered with prior art cable filling materials, which involve the migration of chemical components, which can adversely affect the cable's transmission medium and its protective jacketing material are virtually eliminated. The use of UV light curable cable filling materials provide additional advantages to cables in which they are incorporated. First, a cured filling compound is non-melting. Therefore, even if a cable filled with such materials is exposed to ambient conditions exceeding the typical design characteristics of such cables (-60C - +90C) , the filling compound will not enter a flowable liquid state.

This feature is especially advantageous when filled cables are utilized for long, vertically oriented transmission lines such as trunk lines in skyscrapers. As can be imagined, a long, vertically oriented cables filled with prior art, thixotropic core filling gels can exhibit filling compound drip-out resulting from hydraulic forces applied by the column of gel itself. As can be appreciated, this problem would be exacerbated at elevated ambient temperatures. Furthermore, as optical fiber transmission cables grow in popularity for use in more local applications, such as a skyscraper communications trunk line, the increasing need for splicing into such optical fiber transmission cables will create breaks in the cable jacketing material, which will provide additional openings from which a gel-type filling compound can drip-out of the cable core.

Not only does the use of UV lightcurable polymers for cable filling applications eliminate the possibility that such filling materials will drip out of the cable but they can also be formulated to provide varying degrees of flexibility in their cured states. Thus, by matching the flex-temperature characteristics of a UV light curable interstitial filling material to the characteristics of the other components used in a cable, such as sheathing and jacketing materials, the use of an appropriate UV curable filling material will avoid the buildup of tensile or compressive forces on the cable.

Additionally, since curable polymer matrices comprise 100% solids, they offer an inherent resistance to moisture permeability. Furthermore, once curable polymer matrices are cured, they exhibit inherent chemical resistance and excellent electrical resistance properties, and excellent oxidation resistance. They can also be formulated to exhibit excellent peel characteristics, which would facilitate cable splicing operations and eliminate the need to clean cable core components of tel-type interstitial filling compound residues during splicing operations. The use of UV curable polymer matrices also offers practical pot lives, long-term shelf storage and rapid, ambient temperature cure, which facilitates the manufacturing process.

Since UV curable polymer matrices can be applied and cured at ambient temperatures, they can be easily incorporated into typical cable manufacturing lines. Such materials can be applied using conventional pressure dies, drip tanks or the like to flood or fill core interstices. Any such conventional application system can be installed prior to a UV light source, which will be used to rapidly through cure the applied filling material. Furthermore, since the UV curable filling material is inherently stable and is a single component system, it can be delivered to a manufacturing site in a ready to be used state. Additionally, due to the inherent stability and shelf life of UV curable polymer matrices, they can be delivered in any quantity for which suitable storage space exists.

In order to effect the rapid cure of such UV curable polymer matrices, which would reduce the likelihood that gaps could form within the cable structure, a high intensity UV light source would be utilized at the curing station. Light sources with outputs of substantially between 350 and 400 nm are preferable to allow for maximum depth of cure while at the same time eliminating ambient cure due to exposure to visible light. Furthermore, the use of Fusion "D" bulbs, produced by Fusion Systems of Gaithersburg, Maryland, in the orientation shown in Figure 4 would be preferable to provide 360° exposure of the cable core. In Figure 4 a single Fusion D UV light source 40, having a lamp 41 located at first focus of an integral, elliptical reflector 42 is provided in conjunction with a second elliptical reflector 43. After filling the interstices between the cable core components, the cable core 30 passes through the focus of the second elliptical reflector. The reflectors are oriented such that their respective second foci are substantially co-located with the first focus of the opposite reflector. Thus, this arrangement will provide substantially uniform 360 degree exposure to the filling material applied to the cable core 30. Typical production line layouts for manufacturing optical fiber cables filled with UV curable filling materials are shown in Figures 5 through 8. Referring first to Fig. 5, a production line layout for manufacturing tight buffered fiber optic cable cores is disclosed and generally referred to as 50. Manufacturing line 50 includes a plurality of tight buffered fiber pay-offs 52. Tight buffered fibers from such pay-offs are pulled through a stranding machine 54, such as the S-Z strander discussed earlier, which adds excess fiber length to the finished cable. The stranded, tight buffered fibers are then pulled through reinforcement server 56, where they are merged with one or more strength member, such as aramid yarns, for the cable. Following the reinforcement server, the reinforced, stranded tight buffered fibers are pulled through a cable coating-interstitial filling and UV curing system 58 of the present invention. The cable coating/interstitial filling and UV curing system comprises a conventional polymer application device 60 of the type identified above. Immediately following the application device, is curing station 62 where the coated and/or filled reinforced, stranded optical fibers are exposed to a UV light source of the type indicated above to form a complete tight buffered optical fiber core. Following the cable coating, filling and curing system is capstan 64 which pulls the completed core through the various components of the production line and maintains a constant tension and speed through the production line. Subsequent to the capstan is a core take up system 66, where the cured cable core is wound on a reel where it will await additional manufacturing processes .

Figure 6 depicts a production line layout for the manufacture of fiber optic cable cores using loose buffered fiber optic tubes of the type generally known in the art, which is generally designated by the reference numeral 70. Production line 70 begins with a strength member pay-off 72 from which at least one strength member is pulled under tension through a plurality of loose buffer tube pay-offs 74 to add a desired number of loose buffered fiber optic tubes to the strength members. The combined strength member (s) and loose buffer tubes are then pulled through strander 76 and binder, 78, where the buffer tubes are stranded and bound together with the strength member. Once the buffer tubes and strength members are stranded and bound, they are pulled through cable coating/interstitial filling and UV curing system 80 which comprises the same components identified above with respect to cable coating-interstitial filling and UV curing system 58 discussed with respect to Figure 5 above and the cable core is formed.

However, as discussed earlier, one embodiment of the invention would eliminate the use of binder 78 and would rely on the cable filling composition to fix the stranded structure of the combined loose buffer tubes and strength member (s) . In this embodiment, the UV curing system 80 would preferably incorporated into the strander or be oriented immediately thereafter in the production line.

Capstan 82 provides the motive force to pull the cable core components through the production line, at the proper speed and tension. Finally, take-up reel 84 is used to wind the manufactured cable core onto a reel for storage prior to additional manufacturing processes.

Figure 7 shows a typical production line layout for manufacturing and coating buffer tubes using a UV curable cable coating material in accordance with the teachings of the present invention and is generally designated by the reference number 90. This production line begins with optical fiber payoffs 92, which provide the desired number of optical fibers to included in the loose buffered fiber optic tube to be manufactured. Guide 93 ensures that the selected number of optical fibers are oriented properly before they are pulled through extrusion system 94.

Extrusion system 94 is used to extrude a standard, prior art polyethylene or like tube around the selected number of fibers to form the loose buffer tube. Extrusion system 94 comprises an extruder 95, which melts raw polyethylene or the like and extrudes the melted polyethylene material into a tube around the optical fibers. Since the extrusion process uses heat to melt the polyethylene tubing material, following the extruder is a tubing cooling trough 96, through which the buffer tube passes in order to cool the tubing material into its solid phase. Once the buffer tube exits the cooling trough 96, it proceeds to buffer tube filling station 97, where a prior art, gel-type buffer tube filling material is inserted into the buffer tube. The preceding steps are all well known in the buffer tube manufacturing art. However, following the manufacture of the loose buffer tube, the buffer tube is pulled through guide 93' and into a coating/interstitial filling and UV curing system 98 of the present invention, where the buffer tube will be coated with a UV curable polymer matrix. The motive force used to pull the fiber optic cable through the various components of the production line is capstan 99, which applies the proper amount of tension to the cable and draws the cable at an appropriate speed through the production line after which the cable is taken up on cable take-up system 100. Figure 8 depicts a production line 110 for combining cable cores manufactured in accordance with the production line of Figure 5-7 above with cable protection system components to produce a completed fiber optic cable. Production line 110 begins with core payoff 115, from which a premanufactured cable core is drawn. As shown in Figure 8, the premanufactured core may be pulled through a UV coating and curing system 130 in a manner similar to that described above to apply an additional polymer sheath to the premanufactured core. The production line also comprises a corrugated tape application system 120. Corrugated tape application system 120 itself comprises a dual aluminum tape pay-off 121, from which two aluminum tapes can be taken simultaneously. Once the tapes are pulled from the dual aluminum tapes pay-offs, they are pulled through metal tape welder 122 which joins the tapes together along their longitudinal axes . The welded tape is then pulled through tape accumulator 123 and tape corrugater 124, which corrugates the tape in order to provide structural rigidity and allow for cable flexibility.

The corrugated tape is then pulled through core forming machine 132 where it is joined with the coated fiber optic cable core in order to circumscribe the cable to form a protected fiber optic cable. Alternatively, the locations of the core forming machine and UV coating and curing station may be interchanged should a coating be desired to be applied to the corrugated tape . Upon exiting the core forming machine, the corrugated tape encapsulated fiber optic cable is pulled through a jacket extrusion system 140, which comprises extruder 142 and cooling trough 144 in a manner similar to that described above with respect to Figure 7 in order to jacket the completed cable. Although not shown in Figure 8 the cable is pulled using a capstan similar to those described above and the completed cable is stored on a cable take-up reel.

Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention which is not to be limited except by the claims which follow.

What is claimed is:

Claims

1. An improved cable, said cable comprising: a core comprising at least one transmission medium; a core sheath disposed about said core; and a cable interstitial filling material disposed within said sheath, said interstitial filling material comprising a single component, curable polymer matrix.

2. The improved cable as claimed in claim 1, wherein said at least one transmission medium is an optical fiber transmission medium.

3. The improved cable as claimed in claim 1, wherein said at least one transmission medium is electrically conductive .

4. The improved cable as claimed in claim 1, wherein said single component, curable polymer matrix is an ultraviolet (UV) light curable polymer matrix.

5. The improved cable of claim 2 wherein said fiber optic transmission medium comprises at least one loose buffered fiber optic tube.

6. The improved cable of claim 2 wherein said fiber optic transmission medium comprises at least one tight buffered fiber optic transmission medium.

7. The improved cable of claim 2 wherein said fiber optic transmission medium comprises at least one central, ribbon tube fiber optic transmission medium.

8. The improved cable as claimed in claim 4, wherein said single component, curable, polymer matrix further comprises inert filler materials.

9. The improved cable as claimed in claim 4, wherein said single component, curable, polymer matrix further comprises at least one functional additive.

10. The improved cable as claimed in claim 9, wherein said at least one functional additive is a flame/fire resistivity additive.

11. A method of manufacturing an improved cable comprising the steps of : forming a core having at least one transmission medium; surrounding said core with a sheath; filling said core with a single component, curable polymer matrix cable filling material; and curing said cable filling material.

12. The method of manufacturing an improved cable as claimed in claim 11 further comprising the step of jacketing said cable in a polymer jacket.

13. A method of manufacturing an improved cable comprising the steps of: forming a core having at least one transmission medium; surrounding said core with a sheath; coating said sheath with a single component, curable polymer matrix cable coating material; and curing said cable coating material.

14. A method of manufacturing an improved cable comprising the steps of: forming a core having at least one transmission medium; surrounding said core with a sheath; filling said core with a first, single component, curable polymer matrix cable filling material; curing said cable filling material; coating said sheath with a second, single component, curable polymer matrix cable coating material; and curing said cable coating material.

15. The method of manufacturing an improved cable as claimed in claim 11, wherein said cable filling material comprises an ultraviolet (UV) light curable polymer matrix and said step of curing said cable filling material comprises exposing said cable filling material to a high intensity UV light source.

16. The method of manufacturing an improved cable as claimed in claim 13, wherein said cable coating material comprises an ultraviolet (UV) light curable polymer matrix and said step of curing said cable coating material comprises exposing said cable curing material to a high intensity UV light source.

17. The method of manufacturing an improved cable as claimed in claim 14, wherein at least one of said cable filling material and said cable coating material comprise ultraviolet (UV) light curable polymer matrices and said step of curing at least one of said cable filling material and cable coating material comprises exposing at least one of said cable filling and cable coating materials to a high intensity UV light source.