[0001] The present disclosure relates to the field of optical fiber cables and, in particular, relates to a heat resistant water blocking tape. The present application is based on, and claims priority from an Indian Application Number 202011033983 filed on 7th August 2020, the disclosure of which is incorporated herein.

BACKGROUND
[0002] Optical fiber cables have secured an important position in building optical network of modern communication systems across the world. The optical fiber cables are sensitive to a plurality of conditions. The plurality of conditions includes crushes, kinks, bends, presence of water and/or moisture, and the like. Specifically, the ingression of water in due course of time degrades the optical fiber cables. In addition, change in ambient conditions leads to vapour pressure difference between inner side and outer side of a sheath of the optical fiber cable. Further, the vapour pressure difference diffuses moisture in a unidirectional manner from the outer side to the inner side of the sheath of the optical fiber cable. Furthermore, this leads to undesirable high moisture level inside the optical fiber cable, specifically when the sheath is the only barrier to the ingression of water. Moreover, the ingression of water may be caused due to damages to the optical fiber cable because of a plurality of factors. The plurality of factors includes rodent attacks and mechanical impacts. In general, water blocking tape is used inside the optical fiber cable to protect the optical fiber cable from the ingression of water. In addition, the water blocking tape acts as a barrier to resist heat transfer between the sheath and a core of the optical fiber cable. The core comprises of a plurality of optical transmission elements either in a loose tube configuration or in a tight buffered configuration or the like. However, conventional water blocking tape deforms due to excess heat transfer during the sheath extrusion process carried out at high temperatures up to 250 degree Celsius. In addition, the deformation of the conventional water blocking tape leads to damage of the core of the optical fiber cable and results in degradation of optical properties of the plurality of optical transmission elements (optical fibers). Further, the conventional water blocking tape breaks during the extrusion process. FIG. 1 shows such conventional water blocking tape having a superabsorbent powder sandwiched between two non-woven tapes.
[0003] Further, few of the prior art water blocking tapes are disclosed in the patent documents having publication numbers JP2004071475 and KR102058013. The patent document JP2004071475 discloses a water barrier tape including polyethylene film layer. The patent document KR102058013 discloses a polyethylene film provided on both sides of elastomeric film to block water.
[0004] In light of the above-stated discussion, there exists a need for a water blocking tape that overcomes the above cited drawbacks of the conventional water blocking tape and can withstand high heat/temperature.

OBJECT OF THE DISCLOSURE
[0005] A primary object of the present disclosure is to provide a heat resistant water blocking tape that is resistant to water penetration and heat inside a core of an optical fiber cable.

SUMMARY
[0006] In an aspect, the present disclosure provides a heat resistant water blocking tape for use in an optical fiber cable. The heat resistant water blocking tape is wrapped around a core of any optical fiber cable. The heat resistant water blocking tape is made of one or more non-woven fabric and a polyethylene film. The heat resistant water blocking tape includes at least one fabric, a water absorbent material on the at least one fabric and a heat blocking/reducing/absorbing layer. The at least one fabric comprises of a non-woven fabric. The water absorbent material on the at least one fabric is a superabsorbent powder. The heat blocking/reducing/absorbing layer comprises a polyfilm or polyethylene layer. The at least one fabric is applied as a top layer and a bottom layer of the heat resistant water blocking tape, each with a thickness in a range of 0.05 millimeter to 0.25 millimeter. The heat blocking/reducing/absorbing layer is sandwiched between at least one fabric. The heat blocking/reducing/absorbing layer has a thickness in the range of 0.05 millimeter to 0.25 millimeter. The water absorbent material on the at least one fabric is applied on side facing the heat blocking/reducing/absorbing layer. The heat resistant water blocking tape can withstand temperature up to 250o C.
[0007] These and other aspects herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawing. 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.

STATEMENT OF THE DISCLOSURE
[0008] The present disclosure provides a heat resistant water blocking tape for use in an optical fiber cable. The heat resistant water blocking tape is wrapped around a core of any optical fiber cable. The core of the optical fiber cable comprises a plurality of optical transmission elements. The heat resistant water blocking tape is made of one or more of a non-woven fabric and a polyethylene film. The heat resistant water blocking tape includes a first layer, super absorbent powder, a second layer and a third layer. The first layer is top layer of the heat resistant water blocking tape. The first layer is non-woven water blocking layer. In addition, the first layer is made of non-woven fabric. Further, non-woven fabric includes but may not be limited to polyester, nylon, acrylic and rubber. The first layer has one or more characteristics. The one or more characteristics include flexibility, absorbency, water resistance, and heat resistance. The second layer is middle layer of the heat resistant water blocking tape. The second layer is a layer made of polyethylene film. The second layer acts as heat barrier and prevents transferring of heat through the heat resistant water blocking tape. The second layer is positioned between the first layer and the third layer. The third layer is bottom layer of the heat resistant water blocking tape. The super absorbent powder is sandwiched between the first layer and the second layer. In addition, the super absorbent powder is sandwiched between the second layer and the third layer. The super absorbent powder has capability to absorb and retain extremely high volume of liquids. In an example, liquids include water.

BRIEF DESCRIPTION OF FIGURE
[0009] Having thus described the disclosure in general terms, reference will now be made to the accompanying figure, wherein:
[0010] FIG. 1 illustrates a double layer design of the conventional water blocking tape.
[0011] FIG. 2 illustrates an isometric exploded view of a heat resistant water blocking tape for use in an optical fiber cable.
[0012] It should be noted that the accompanying figure is intended to present illustrations of few examples of the present disclosure. The figure is not intended to limit the scope of the present disclosure. It should also be noted that accompanying figure is not necessarily drawn to scale.

DETAILED DESCRIPTION
[0013] 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 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.
[0014] Furthermore, it will be clear that the invention is not limited to these alternatives only. Numerous modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art, without parting from the scope of the invention.
[0015] The accompanying drawing is used to help easily understand various technical features and it should be understood that the alternatives presented herein are not limited by the accompanying drawing. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawing. 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.
[0016] FIG. 2 illustrates an isometric exploded view of a heat resistant water blocking tape 100 for use in an optical fiber cable. The heat resistant water blocking tape 100 is wrapped around a core of any optical fiber cable. The core may comprise of a plurality of optical transmission elements. The plurality of optical transmission elements presents in form of, but not limited to, a plurality of optical fibers, a group of loose optical fibers, a group of optical fiber ribbons or a stack of optical fiber ribbons, a plurality of buffer tubes, a plurality of tight buffered optical fibers over which a sheathing is done. The optical fibers may be a single mode optical fiber, a multicore optical fiber, a 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 mode optical fiber and the multimode optical fibers that comprises only a single core.
[0017] In an example, the heat resistant water blocking tape 100 may be positioned between a sheath and the core of the optical fiber cables requiring water blocking tape with better tensile strength or heat protection for the core.
[0018] As mentioned above, the plurality of optical transmission elements presents in form of, but not limited to, the plurality of optical fibers, the group of loose optical fibers, the group/bundle of optical fiber ribbons or the stack of optical fiber ribbons, the plurality of buffer tubes, the plurality of tight buffered optical fibers over which the sheathing is done. A loose tube from the group of loose tubes comprises the plurality of optical fibers. Further, the plurality of buffer tubes is an encasement tube used to encapsulate number of optical fibers or an optical fiber ribbon stack. The buffer tube is used in an optical fiber cable to provide mechanical isolation and protection from physical damages. The plurality of buffer tubes includes the plurality of optical transmission elements. The heat resistant water blocking tape 100 prevents damage to the the plurality of optical transmission elements present inside the plurality of buffer tubes.
[0019] The optical fiber ribbon bundle is a group of a plurality of optical fiber ribbons arranged together. The optical fiber ribbon includes a number of optical fibers arranged together within a matrix material. In addition, multiple individual optical fiber ribbons are stacked or grouped into bundle to form the optical fiber ribbon bundle. Further, optical fiber refers to a medium associated with transmission of information over long distances in the form of light pulses. Furthermore, the optical fiber uses light to transmit voice and data communications over long distances. The heat resistant water blocking tape 100 may surround the optical fiber ribbon bundle. The heat resistant water blocking tape 100 may surround the plurality of optical fibers. Alternatively, the optical fiber ribbon bundle or the plurality of optical fibers is placed inside the buffer tube and then surrounded by the heat resistant tape.
[0020] The heat resistant water blocking tape 100 is resistant to water penetration and heat. The heat resistant water blocking tape 100 is made of at least one fabric and a polyethylene film. The heat resistant water blocking tape 100 includes at least one fabric 102, 108, super absorbent powder 104, and a second layer 106. The at least one fabric is applied as a first layer 102 and a third layer 108 of the heat resistant water blocking tape 100.
[0021] The first layer 102 is top layer of the heat resistant water blocking tape 100. The first layer 102 is non-woven water blocking layer. In addition, the first layer 102 is made of non-woven fabric. Further, non-woven fabric includes but may not be limited to polyester, nylon, acrylic and rubber. The first layer 102 has one or more characteristics. The one or more characteristics include but may not be limited to flexibility, absorbency, water resistance, and heat resistance to some extent. The first layer 102 has a thickness in the range of 0.05 millimeter to 0.25 millimeter. The thickness of the first layer below 0.5 millimeter limits the manufacturing capabilities of the heat resistant water blocking tape. Further, the thickness beyond 0.25 millimeter may result in increase in the cable diameter by more than 0.25 millimeter which is not desired.
[0022] The second layer 106 is middle layer of the heat resistant water blocking tape 100. The second layer 106 may synonymously be called as a heat blocking/reducing/absorbing layer. The second layer 106 is a layer of polyethylene film or polyfilm. The second layer 106 prevents breaks in the heat resistant water blocking tape 100. The second layer 106 acts as heat barrier and prevents transferring of heat through the heat resistant water blocking tape 100 inside the core of the cable. In addition, the second layer 106 provides tensile strength to the heat resistant water blocking tape 100. Advantageously, the tensile strength of the heat resistant water blocking tape 100 is almost 3.5 times that of conventional tape (as shown in FIG. 1). The second layer 106 has a thickness in range of 0.05 millimeter to 0.25 millimeter. The thickness of the second layer below 0.05 millimeter may impose limitations in the manufacturing capabilities of the heat resistant water blocking tape. The thickness of the second layer above 0.05 millimeter results into increase in cable diameter by more than 0.25 millimeter, which is not desired. The thickness of the second layer up to 0.05 millimeter is sufficient to provide heat protection during a sheathing process. The second layer 106 may reduce transmission of thermal conduction across the heat resistant water blocking tape 100 at elevated temperature. The second layer 106 may produce insulating carbonaceous foam at the elevated temperature. The insulating carbonaceous foam reduces transmission of thermal conduction across the heat resistant water blocking tape 100 at the elevated temperature. The elevated temperature in the sheathing process can raise up to 250o C.
[0023] The second layer 106 is sandwiched between the at least one fabric. In other words, the second layer 106 is positioned between the first layer 102 and the third layer 108 of at least one fabric. The third layer 108 is bottom layer of the heat resistant water blocking tape 100. The third layer 108 has same properties as the first layer 102. The third layer 108 corresponds to a non-woven tape. The third layer 108 has a thickness in range of 0.05 millimeter to 0.25 millimeter. The thickness of the third layer below 0.05 millimetre may impose limitations in the manufacturing capabilities of the heat resistant water blocking tape. The thickness of the third layer above 0.25 millimeter may increase the cable diameter more than 0.25 millimeter, which is not desired. The third layer 108 has one or more characteristics. The one or more characteristics include but may not be limited to flexibility, absorbency, water resistance, and heat resistance.
[0024] The heat resistant water blocking tape 100 includes the super absorbent powder 104. The super absorbent powder 104 may synonymously be referred as a water absorbent material. The super absorbent powder 104 is applied on the at least one fabric. The super absorbent powder 104 on the at least one fabric is applied on a side facing the second layer 106. If applied outside, it may fall-off and create undesired powder dust. The super absorbent powder 104 is sandwiched between the first layer 102 and the second layer 106. In addition, the super absorbent powder 104 is sandwiched between the second layer 106 and the third layer 108. The super absorbent powder 104 has capability to absorb and retain extremely high volume of liquids. In an example, liquids include water.
[0025] Usually, the sheathing (extrusion) is done at high temperature (more than 100°C), which sometimes damages cable core and/or water blocking tape. The sheathing is a process of squeezing a sheathing material through a funnel of a die as the core runs through the center. The sheathing material may include, but not limited to, polyvinylchloride, polyethylene (such as High Density Poly Ethylene (HDPE), Medium Density Poly Ethylene, and Low Density Poly Ethylene), polyurethane, thermoplastic rubber/elastomer, thermoplastic chlorinated polyethylene, thermoset polyolefins or combination thereof. To prevent the damage, the heat resistance water blocking tape 100 is made in such a way that withstands temperature up to 250oC and may be used in any optical fiber cable to provide heat resistance and water blocking properties to the optical fiber cable. The core of the optical fiber cable may include the plurality of optical transmission elements. The plurality of optical transmission elements presents in the form of, but not limited to, the plurality of optical fibers, the group of loose optical fibers, the group/bundle of optical fiber ribbons or the stack of optical fiber ribbons, the plurality of buffer tubes, the plurality of tight buffered optical fibers over which the sheathing is done.
[0026] It will be apparent to those skilled in the art that other alternatives of 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 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.
[0027] 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 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 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.
[0028] Disjunctive language such as the phrase “at least one of X, Y, Z,” 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.
[0029] While the detailed description has shown, described, and pointed out 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 features can be used or practiced separately from others.

,CLAIMS:CLAIMS
We Claim:

1. A heat resistant water blocking tape (100) for use in an optical fiber cable comprising:
at least one fabric (102, 108);
a water absorbent material (104) on the at least one fabric (102, 108); and
a heat blocking/reducing/absorbing layer (106).

2. The heat resistant water blocking tape (100) as claimed in claim 1, wherein the at least one fabric comprises of a non-woven fabric.

3. The heat resistant water blocking tape (100) as claimed in claim 1, wherein the at least one fabric is applied as a top layer (102) and as a bottom layer (108) of the heat resistant water blocking tape (100), each with a thickness in a range of 0.05 millimeter to 0.25 millimeter.

4. The heat resistant water blocking tape (100) as claimed in claim 1, wherein the water absorbent material (104) on the at least one fabric is a superabsorbent powder.

5. The heat resistant water blocking tape (100) as claimed in claim 1, wherein the heat blocking/reducing/absorbing layer (106) comprises a polyfilm or polyethylene layer.

6. The heat resistant water blocking tape (100) as claimed in claim 1, wherein the heat blocking/reducing/absorbing layer (106) is sandwiched between at least one fabric layers (102, 108).

7. The heat resistant water blocking tape (100) as claimed in claim 1, wherein the heat blocking/reducing/absorbing layer (106) has a thickness in the range of 0.05 millimeter to 0.25 millimeter.

8. The heat resistant water blocking tape (100) as claimed in claim 1, wherein the water absorbent material (104) on the at least one fabric is applied on sides facing the heat blocking/reducing/absorbing layer (106).

9. The heat resistant water blocking tape (100) as claimed in claim 1 withstands temperature up to 250o C.