] The present disclosure relates to optical fiber cables, and in particular, relates to an optical fiber cable with flexible wrapping tubes.
5 BACKGROUND
[0002] Optical fiber cables are a critical component of modern communications networks across the globe. For high density optical fiber cables, intermittently bonded ribbons (IBRs) are broadly used, wherein the IBRs are bound/bundled together by coloured binder yarns for easy identification of optical
10 fibers and the bunched IBRs are put together to form the optical fiber cables. Typically, the binder yarns are applied with tension directly on the IBRs, which can increase attenuation of the optical fibers and hence reduces optical performance of the optical fiber cables. Additionally, the binder yarns can also unwind that creates difficulty in identification of the optical fibers while end preparation.
15 [0003] One way to address the aforesaid drawbacks is to use wrap/wrapping
tubes. In the same context prior art references "JP5789630B2" and "EP0733925B1" disclose such wrapping tubes. However, the conventional wrapping tubes are wound around loose optical fibers, i.e., the scope and use of the conventional wrapping tubes are limited to loose optical fibers only. Due to such limitation, one cannot achieve
20 the optical fiber cables with high filling coefficient, for example IBRs. Additionally, other conventional wrapping tubes are extruded over the optical fibers and are not flexible, thereby imparting mechanical stress/tension and heat stress on the optical fibers, which further results in degradation of the optical performance as well as increase in the attenuation.
25 [0004] Therefore, an improved technique is required that can help in
achieving optical fiber cables with high filling coefficient, improved optical performance and reduced attenuation.
[0005] Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or
30 form part of the common general knowledge.

OBJECT OF THE DISCLOSURE
[0006] A primary object of the present disclosure is to provide an optical fiber cable with flexible wrapping tubes.
[0007] Another object of the present disclosure is to provide the flexible
5 wrapping tubes (i.e., non-extruded film) that can hold optical fibers without
imparting any stress, thereby improving optical performance and reducing
attenuation of the optical fibers and to provide the optical fiber cable with high filling
coefficient.
10 SUMMARY
[0008] Accordingly, an optical fiber cable with flexible wrapping tubes is disclosed. The wrapping tube is formed using a non-extruded film. The optical fiber cable comprises a plurality of unit bundles packed in the optical fiber cable, wherein each unit bundle has a plurality of optical fibers enveloped by the non-extruded film,
15 wherein at least one of the plurality of unit bundles takes a non-circular shape in a packed configuration. The plurality of optical fibers has bonded and unbonded regions along a length of adjacent optical fibers. The plurality of unit bundles is arranged in the optical fiber cable with a packing density in a range of 0.3 to 0.6. Each of the plurality of unit bundles has a filling coefficient in a range of 0.5 to 0.7.
20 Each unit bundle is formed by wrapping the non-extruded film around the plurality of optical fibers. The non-extruded film is wrapped around the plurality of optical fibers such that width edges of the non-extruded film overlap along length of the optical fiber cable. An overlap ratio of the non-extruded film is in a range of 0.05 to 0.3, wherein the overlap ratio is a ratio of an overlapped area and total area of the
25 non-extruded film. Alternatively, the non-extruded film is wrapped around the plurality of optical fibers helically. The non-extruded film is coated with at least one of a water blocking material, a water absorbent material, a fire retardant material, a low friction material and a cushioning material. The non-extruded film has a width in a range of 5mm to 100mm and an elasticity modulus less than or equal to 5 GPa.
30 The optical fiber cable further comprises a sheath enveloping the plurality of unit bundles and one or more elements like binders, water blocking tape, fire retardant

tape, metal tape, rip cords, water swellable yarns, water blocking gel, strength yarns, dielectric armouring, ECCS (Electro Chrome Coated Steel) tape.
[0009] These and other aspects herein will be better appreciated and understood when considered in conjunction with the following description and the 5 accompanying drawings. It should be understood, however, that the following descriptions are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the invention herein without departing from the spirit thereof.
BRIEF DESCRIPTION OF FIGURE
[0010] The invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the drawings. The invention herein will be better understood from the following description with reference to the drawings, in which:
15
[0011] FIG. 1 illustrates a non-extruded film.
[0012] FIG. 2 illustrates overlapping portions of the non-extruded film.
[0013] FIG. 3 illustrates helical wrapping of the non-extruded film.
[0014] FIG. 4 and FIG. 5 illustrate example optical fiber cables having non-extruded films.
[0015] It should be noted that the accompanying figures are intended to present illustrations of few examples of the present disclosure. The figures are not intended to limit the scope of the present disclosure. It should also be noted that accompanying figures are not necessarily drawn to scale.

DETAILED DESCRIPTION
[0016] In the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be obvious to a person skilled in the art that the invention 5 may be practiced with or without these specific details. In other instances, well known methods, procedures and components have not been described in details so as not to unnecessarily obscure aspects of the invention.
[0017] Furthermore, it will be clear that the invention is not limited to these alternatives only. Numerous modifications, changes, variations, substitutions and
10 equivalents will be apparent to those skilled in the art, without parting from the scope of the invention.
[0018] The accompanying drawings are used to help easily understand various technical features and it should be understood that the alternatives presented herein are not limited by the accompanying drawings. As such, the present disclosure
15 should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
20 [0019] FIG. 1 illustrates a non-extruded film 100. The non-extruded film
100 may comprise a first layer 102 and a second layer 104. The first layer 102 may be a tape layer. The first layer 102 may be made up of polyolefins, polyesters or polypropylene. Alternatively, the first layer 102 may be made of any other suitable material. The second layer 104 may be an adhesive layer such as adhesive coating.
25 The second layer 104 may be made from polyurethane, acrylic, rubber, glue, for example. The second layer 104 may have a width in a range of 1mm to 20mm.
[0020] A plurality of optical fibers 106 may be wrapped in the first layer 102 such that on one edge, the second layer 104 is applied extending longitudinally along the length of the first layer 102, which when formed in a cylindrical shape
30 adheres to other edge of the first layer 102 thus forming a wrapping tube containing the plurality of optical fibers 106. The first layer 102 may be a colored layer that

helps in easy identification of the plurality of optical fibers 106 and the second layer may be applied on the first layer 102 before wrapping (offline) or may be applied during wrapping process (online).
[0021] The non-extruded film 100 acts like the wrapping tube that uses the 5 second layer 104 to wrap the first layer 102 and form the wrapping tube. The non-extruded film 100 may be coated with, such as, but not limited to, a water blocking material, a water absorbent material like super absorbent polymer, a fire retardant material like inorganic fillers, a low friction material and a cushioning material. Advantageously, the non-extruded film 100 is not extruded over the plurality of
10 optical fibers 106 but wrapped around them utilising the second layer 104, thus is flexible and easy to manufacture and does not pose any stress on the plurality of optical fibers 106 contained within.
[0022] FIG. 2 illustrates overlapping portions of the non-extruded film 100. The non-extruded film 100 may have a rectangular shape (as shown in FIG. 1) that
15 surrounds the plurality of optical fibers 106 by overlapping width ends/edges of the non-extruded film 100 along a length of an optical fiber cable. Such overlapping is shown using reference numeral 108. The overlapping 108 may have an overlap ratio in a range of 0.05 to 0.3 as below 0.05, the non-extruded film 100, when wrapped, may open up during manufacturing or handling and beyond 0.3, the cost and
20 thickness of the non-extruded film 100 will be increased. The overlap ratio may be defined as a ratio of an overlapped area and total area of the non-extruded film 100. [0023] Alternatively, the non-extruded film 100 may be wrapped around the plurality of optical fibers 106 helically as shown in FIG. 3. The helically wrapped non-extruded film 100 may not have the second layer 104.
25 [0024] The non-extruded film 100 may be characterized by a width and
Young's modulus (or modulus of elasticity), wherein the width may be in a range of 5mm to 100mm and the Young's modulus may be less than or equal to 5 GPa, so that the non-extruded film 100 can be flexible enough and can take a deformed non-circular shape to enhance packaging/packing density of the optical fiber cable.
30 Alternatively, the width and Young's modulus may vary. Typically, the Young's modulus is a property of a material that tells how easily it can stretch and deform and

is defined as a ratio of tensile stress to tensile strain, where stress is the amount of
force applied per unit area and strain is extension per unit length and the elasticity is
an ability of an object to resist a distorting influence or force and to return to its
original size and shape when that influence or force is removed.
5 [0025] Now, simultaneous reference is made to FIG. 4 and FIG. 5 that
illustrate example optical fiber cables 400, 500 having a plurality of non-extruded films 100. The optical fiber cable 400, 500 may include the plurality of optical fibers 106, the plurality of non-extruded films 100 and a sheath 404, 504.
[0026] The plurality of optical fibers 106 may be present in form of, but not
10 limited to, a group of loose optical fibers, a group of optical fiber ribbons or a stack of optical fiber ribbons, a group of rollable ribbons, a group of corrugated ribbons, a group of partially/intermittently bonded optical fiber ribbons, a group of flat ribbons. Generally, an optical fiber refers to a medium associated with transmission of information over long distances in the form of light pulses. The optical fiber uses
15 light to transmit voice and data communications over long distances when encapsulated in a jacket/sheath. The optical fiber may be of ITU.T G.657.A2 category. Alternatively, the optical fiber may be of ITU.T G.657.A1 or G.657.B3 or G.652.D or other suitable category. The ITU.T stands for International Telecommunication Union-Telecommunication Standardization Sector, is one of the
20 three sectors of the ITU. The ITU is the United Nations specialized agency in the field of telecommunications and is responsible for studying technical, operating and tariff questions and issuing recommendations on them with a view to standardizing telecommunications on a worldwide basis.
[0027] The optical fiber may be a bend insensitive fiber that has less
25 degradation in optical properties or less increment in optical attenuation during bending of the optical fiber cable. Thus, the bend insensitive fiber further helps to maintain the optical properties during multiple winding/unwinding operations of the optical fiber cable. The optical fiber may be coloured fiber. The optical fiber may be a single-core optical fiber, a multi-core optical fiber, a single-mode optical fiber, a
30 multimode optical fiber or the like. The single mode optical fiber carries only a single mode of light and the multimode optical fiber carries multiple modes of light to

propagate. The multicore optical fibers comprise of multiple cores as opposed to the single-core optical fiber that comprise only a single core.
[0028] The plurality of optical fibers 106 may have bonded and unbonded regions along a length of adjacent optical fibers. The plurality of optical fibers 106 5 may be enveloped by the plurality of non-extruded films 100. That is, each of the plurality of non-extruded films 100 may envelop the plurality of optical fibers 106, thereby forming a plurality of unit bundles, where at least one of the plurality of unit bundles may take a non-circular shape in a packed configuration. Each of the plurality of non-extruded films 100 may be wrapped around the plurality of optical
10 fibers 106 such that width edges of each of the plurality of non-extruded films 100 overlap along length of the optical fiber cable 400, 500 as shown in FIG. 2. Alternatively, each of the plurality of non-extruded films 100 may be wrapped around the plurality of optical fibers 106 helically as shown in FIG. 3. It may be noted that the details of each of the plurality of non-extruded films 100 is already provided in
15 conjunction with FIG. 1, FIG. 2 and FIG. 3.
[0029] Each of the plurality of unit bundles may have a filling coefficient in a range of 0.5 to 0.7. Alternatively, the filling coefficient may vary. Generally, filling coefficient is a ratio of cross-sectional area of all the optical fibers inside a unit bundle to inner cross-sectional area of the non-extruded film. The plurality of unit
20 bundles may be arranged in the optical fiber cable 400, 500 such that a packing density is in a range of 0.3 to 0.6. Alternatively, the packing density may vary. Typically, packing density is a ratio of cross-sectional area of all the optical fibers to inner cross-sectional area of the sheath 404, 504.
[0030] The plurality of unit bundles may be enveloped by the sheath 404,
25 504. Usually, sheathing (extrusion) is done at a high temperature (preferably more than 100°C). The sheathing is a process of squeezing a molten sheathing material through a funnel of a die as a core runs through the center. The sheathing material for the sheath may include, but not limited to, polyvinylchloride, polyethylene (such as High Density Poly Ethylene (HDPE), Medium Density Poly Ethylene, and Low
30 Density Poly Ethylene), polyurethane, thermoplastic rubber/elastomer, thermoplastic chlorinated polyethylene or combination thereof.

[0031] The sheath 404 may comprise one or more strength members 402 (as shown in FIG. 4) embedded that may provide mechanical strength and stiffness to the optical fiber cable 400. The one or more strength members may provide enhanced tensile strength and excellent crush protection/resistance performance. The 5 crush resistance is an ability of a cable to withstand and/or recover from the effects of a compressive force. The one or more strength members 402 may be made of, but not limited to, FRP (Fiber Reinforced Plastic), ARP (Aramid Reinforced Plastic) or any other suitable dielectric/strength material. The one or more strength members 402 may have a round shape, a flat shape or any other suitable shape. The one or
10 more strength members 402 may be coated with EAA (Ethylene Acrylic Acid) or EVA (Ethylene-Vinyl Acetate) coating for better adhesion with the sheath 404, i.e., to enhance the adhesion of the one or more strength members with the sheath 404.
[0032] Alternatively, a strength member may be present in the form of a central strength member 502 as shown in FIG. 5 in the optical fiber cable 500, where
15 each of the plurality of unit bundles may be stranded around the central strength member 502. The central strength member 502 may provide mechanical strength and stiffness to the optical fiber cable 500. The central strength member 502 may provide enhanced break load and excellent crush protection/resistance performance. The central strength member 502 may be made of, but not limited to, FRP (Fiber
20 Reinforced Plastic), ARP (Aramid Reinforced Plastic) or any other suitable dielectric/strength material. The central strength member 502 may have a round shape, a flat shape or any other suitable shape.
[0033] It may be noted that the optical fiber cable 400, 500 may contain one or more elements depending upon requirement and implementation. Non-limiting
25 examples of the one or more elements are binders, water blocking tape, fire retardant tape, metal tape, rip cords, water swellable yarns, water blocking gel, strength yarns, dielectric armouring, ECCS (Electro Chrome Coated Steel) tape etc. Although FIG. 4 and FIG. 5 show various elements of the optical fiber cable 400, 500, but it is to be understood that other alternatives are not limited thereon. In other implementations,
30 the optical fiber cable 400, 500 may include less or more number of elements/components. Further, the labels or names of the elements/components are

used only for illustrative purpose and do not limit the scope of the present disclosure. The shape and size of the various elements in the optical fiber cable 400, 500 do not limit the scope of the present disclosure.
[0034] It will be apparent to those skilled in the art that other alternatives of 5 the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention. While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific
10 aspect, method, and examples herein. The invention should therefore not be limited by the above described alternative, method, and examples, but by all aspects and methods within the scope of the invention. It is intended that the specification and examples be considered as exemplary, with the true scope of the invention being indicated by the claims.
15 [0035] Conditional language used herein, such as, among others, "can,"
"may," "might," "may," "e.g.," and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain alternatives include, while other alternatives do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to
20 imply that features, elements and/or steps are in any way required for one or more alternatives or that one or more alternatives necessarily include logic for deciding, with or without other input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular alternative. The terms "comprising," "including," "having," and the like are synonymous and are used
25 inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term "or" is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term "or" means one, some, or all of the elements in the list.
[0036] Disjunctive language such as the phrase "at least one of X, Y, Z,"
30 unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any

combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain alternatives require at least one of X, at least one of Y, or at least one of Z to each be present.
[0037] While the detailed description has shown, described, and pointed out 5 novel features as applied to various alternatives, it can be understood that various omissions, substitutions, and changes in the form and details of the devices or algorithms illustrated can be made without departing from the scope of the disclosure. As can be recognized, certain alternatives described herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some 10 features can be used or practiced separately from others.

10

CLAIMS
We Claim:

1. An optical fiber cable (400, 500), comprising:
a plurality of unit bundles packed in the optical fiber cable (400, 500), each unit bundle has a plurality of optical fibers (106) enveloped by a non-extruded film (100), wherein at least one of the plurality of unit bundles takes a non-circular shape in a packed configuration; and
a sheath (404, 504) enveloping the plurality of unit bundles.
2. The optical fiber cable (400, 500) as claimed in claim 1, wherein each unit
bundle is formed by wrapping the non-extruded film (100) around the plurality
of optical fibers (106).

15 3. The optical fiber cable (400, 500) as claimed in claim 2, wherein the non-extruded film (100) is wrapped around the plurality of optical fibers (106) such that width edges of the non-extruded film (100) overlap along length of the optical fiber cable (400, 500).
20 4. The optical fiber cable (400, 500) as claimed in claim 2, wherein the non-extruded film (100) is wrapped around the plurality of optical fibers (106) helically.
5. The optical fiber cable (400, 500) as claimed in claim 1, wherein the non-
25 extruded film (100) has a width in a range of 5mm to 100mm.
6. The optical fiber cable (400, 500) as claimed in claim 1, wherein the non-
extruded film (100) has an elasticity modulus less than or equal to 5 GPa.
30 7. The optical fiber cable (400, 500) as claimed in claim 1, wherein each of the plurality of unit bundles has a filling coefficient in a range of 0.5 to 0.7.

8. The optical fiber cable (400, 500) as claimed in claim 1, wherein the optical
fiber cable (400, 500) has one or more elements like binders, water blocking
tape, fire retardant tape, metal tape, rip cords, water swellable yarns, water
5 blocking gel, strength yarns, dielectric armouring, ECCS (Electro Chrome
Coated Steel) tape.
9. The optical fiber cable (400, 500) as claimed in claim 1, wherein the plurality
of unit bundles is arranged in the optical fiber cable (400, 500) with a packing
10 density in a range of 0.3 to 0.6.
10. The optical fiber cable (400, 500) as claimed in claim 1, wherein the plurality
of optical fibers (106) has bonded and unbonded regions along a length of
adjacent optical fibers.
15
11. The optical fiber cable (400, 500) as claimed in claim 1, wherein an overlap
ratio of the non-extruded film (100) is in a range of 0.05 to 0.3, wherein the
overlap ratio is a ratio of an overlapped area and total area of the non-extruded
film (100).
20
12. The optical fiber cable (400, 500) as claimed in claim 1, wherein the non-
extruded film (100) is coated with at least one of a water blocking material, a
water absorbent material, a fire retardant material, a low friction material and
a cushioning material.