Colored ribbon with discrete color layers

Embodiments of the disclosure relate to an optical fiber ribbon. The optical fiber ribbon includes optical fibers arranged in a row having a first width. Indicator fibers are provided at the edges of the row. The indicator fibers have different color fiber jackets. The optical fiber ribbon also includes a primary matrix into which the plurality of optical fibers is embedded. The optical fiber ribbon also includes an opacifying layer having a second width and a color layer, distinct from the opacifying layer, having a third width. The optical fiber ribbon further includes a layer of printing disposed on an outer surface of the primary matrix. In the optical fiber ribbon, the first width is greater than at least one of the second width or the third width such that the indicator fibers extend past at least one of the opacifying layer or the color layer.

BACKGROUND

The disclosure relates generally to optical fibers, and specifically to optical fiber ribbons having an opacifying and/or color layer with exposed indicator fibers. A single optical fiber cable may contain many optical fibers (indeed, hundreds of optical fibers), and during installation of a fiber optic cable network, managing the connections between the optical fibers can be difficult. Thus, various portions of the optical fiber cable, such as individual optical fibers, buffer tubes, or ribbons, may be color coded for the purposes of identification when making such connections.

SUMMARY

Embodiments of the disclosure relate to an optical fiber ribbon. The optical fiber ribbon includes a plurality of optical fibers arranged in a row having a first width. A first indicator fiber is provided at a first edge of the row, and a second indicator fiber is provided at a second edge of the row. The first indicator fiber has a first fiber jacket of a different color than a second fiber jacket of the second indicator fiber. The optical fiber ribbon also includes a primary matrix into which the plurality of optical fibers are embedded. The primary matrix has an outer surface. The optical fiber ribbon also includes an opacifying layer having a second width and being composed of a first base resin and an opacifier. The optical fiber ribbon also includes a color layer distinct from the opacifying layer. The color layer has a third width and includes a second base resin and a colorant. The colorant is different from the opacifier. The optical fiber ribbon further includes a layer of printing disposed on the outer surface of the primary matrix. In the optical fiber ribbon, the first width is greater than at least one of the second width or the third width such that the first indicator fiber and the second indicator fiber each extend past at least one of the opacifying layer or the color layer.

Additional embodiments of the disclosure relate to an optical fiber ribbon. The optical fiber ribbon includes a plurality of optical fibers arranged in a row having a first width. The plurality of optical fibers includes a first indicator fiber provided at a first edge of the row, a second indicator fiber provided at a second edge of the row, and at least a first interior fiber disposed between the first indicator fiber and the second indicator fiber. The first indicator fiber has a first fiber jacket of a different color than a second fiber jacket of the second indicator fiber. The optical fiber ribbon also includes a primary matrix into which the plurality of optical fibers are embedded. The primary matrix has an outer surface. The optical fiber ribbon includes a first color layer having a first base resin and a first colorant. The first color layer defines a first continuous coating over at least the first interior fiber. The optical fiber also includes a layer of printing disposed on the outer surface of the primary matrix. Further, the optical fiber includes a secondary matrix surrounding the primary matrix such that the layer of printing is disposed between the primary matrix and the secondary matrix.

Further embodiments of the disclosure relate to a method of preparing an optical fiber ribbon. In the method, a plurality of optical fibers are arranged in a row. The plurality of optical fibers includes a first indicator fiber at a first end of the row, a second indicator ribbon at a second end of the row, and at least one interior fiber disposed between the first indicator fiber and the second indicator fiber. In a first applicator, the at least one interior fiber is coated with an opacifying layer comprising a first base resin and an opacifier. A primary matrix is applied around the plurality of optical fibers in the first applicator during the step of coating. Information regarding characteristics of the optical fiber ribbon is printed onto the primary matrix, and a secondary matrix is applied around the primary matrix in a second applicator such that the printed information is disposed between the primary matrix and the secondary matrix.

Still further, embodiments of the disclosure relate to a method of preparing an optical fiber ribbon. In the method, a plurality of optical fibers is arranged in a row. The plurality of optical fibers includes a first indicator fiber at a first end of the row, a second indicator ribbon at a second end of the row, and at least a first interior fiber disposed in the row between the first indicator fiber and the second indicator fiber. In a first applicator, the first interior fiber is coated with a first color layer made up of a first base resin and a first colorant. A primary matrix is applied around the plurality of optical fibers in the first applicator during the step of coating. Information regarding characteristics of the optical fiber ribbon is printed onto the primary matrix. Further, a secondary matrix is applied around the primary matrix in a second applicator such that the printed information is disposed between the primary matrix and the secondary matrix.

DETAILED DESCRIPTION

Referring generally to the figures, various embodiments of an optical fiber ribbon having exposed indicator fibers are provided. That is, in an optical fiber ribbon, the optical fibers between the two outside optical fibers (i.e., the “interior fibers”) are partially or totally obscured by an opacifying layer and/or a color layer. Because the indicator fibers at the edge are not obscured or at least not obscured to the level of the interior optical fibers, a technician can discern the polarity (direction that light signals travel through an optical fiber) of the optical fiber based on the observable color-coded order of the optical fibers in the ribbon. The interior optical fibers are obscured using at least one of an opacifying layer or a color layer. The optical fibers are also embedded in a primary matrix and a secondary matrix with a printed layer therebetween. The printed layer provides another means of identification in addition to the indicator fibers. Advantageously, the opacifying layer and the color layer can be applied at the same time as the primary matrix and/or the secondary matrix using the same applicator.

As described herein, embodiments of the optical fiber ribbon have an opacifying layer applied over the optical fibers or over a primary matrix into which the optical fibers are embedded. Thereafter, printing is applied to the outside of the primary matrix, and a secondary matrix is applied over the printing to protect it from smudging. In embodiments, the secondary matrix acts as the color layer. In other embodiments, the color layer is applied over the fibers or over the opacifying layer. In still further embodiments, both an opacifying layer and a color layer are applied to one or both sides of the optical fibers, and the primary and secondary matrices are applied around the optical fibers with the printing contained therebetween. In still another embodiment, two or more color layers are applied to the optical fibers with an overlap region between at least two of the color layers. In this way, a first color region is provided over certain optical fibers, a second color region is provided over other optical fibers, and a third color region is provided in the overlap region over still other optical fibers. Each of these exemplary embodiments will be described in greater detail below, and these exemplary embodiments are provided by way of illustration, and not by way of limitation. These and other aspects and advantages will be discussed in relation to the embodiments provided below.

FIG. 1depicts an exemplary embodiment of an optical fiber ribbon10according to the disclosure. The optical fiber ribbon10includes a plurality of optical fibers12arranged in a substantially planar row. The number of optical fibers12contained in the row varies by embodiment. In embodiments, the number of optical fibers12in a row is from four to thirty-six. Further, in embodiments, the optical fibers12may be divided into subunits15of from two to twelve optical fibers12. In the embodiment shown inFIG. 1, the optical fiber ribbon10includes a single subunit15of twelve optical fibers12. In the optical fiber ribbon10, the optical fibers12are coated with an opacifying layer14and a color layer16. As will be described more fully below, the optical fiber ribbon10has indicator fibers12a(generally, at least the optical fibers12located at the edges of the row of optical fibers12) that are used to provide a reference polarity. In order to provide reference polarity, the indicator fibers12aare left at least partially uncovered by at least one of the opacifying layer14and the color layer16. That is, the optical fibers12between the indicator fibers12a(referred to as “interior fibers”12bas shown inFIG. 3), are more obscured than the indicator fibers12a, allowing the indicator fibers12ato more readily stand out visibly on the optical fiber ribbon10.

As can also be seen inFIG. 1, the optical fiber ribbon10includes a printing layer18, which is made up of ink dots20. The ink dots20may be used to provide identifying characteristics of the optical fiber ribbon10in the printing18layer.

As shown inFIG. 2, a primary matrix22holds the plurality of optical fibers12such that they are substantially parallel, adjacent, and are disposed, at least at a given cross section of the optical fiber ribbon10, in substantially the same planar row. In embodiments, the longitudinal axis of each optical fiber12is substantially parallel to and coplanar with its adjacent optical fiber12. The primary matrix22is coated with a secondary matrix24. As can be seen in the embodiment ofFIG. 2, the optical fiber ribbon10has a “dog-bone” structure in which the primary matrix22is thicker at the end regions. In these regions, the thickness of the secondary matrix24may reduce to approximately 0 μm. In the embodiment depicted, the printing layer18is contained between the primary matrix22and the secondary matrix24. As mentioned briefly above, by placing the printing layer18between the primary matrix22and the secondary matrix24, the printing layer18is advantageously protected from accidental removal or abrasion, especially during installation, thereby preserving the legibility of the printing layer18.

In embodiments, the optical fibers12embedded in the primary matrix22are color coded as shown by the color abbreviations inFIG. 2. For example, the optical fibers12going from left to right are color coded as follows: BL—blue; OR—orange; GR—green; BR—brown; SL—slate; WH—white; RD—red; BK—black; YL—yellow; VI—violet; RS—rose; and AQ—aqua. In embodiments containing more than twelve optical fibers12, the pattern of colors may be repeated. The optical fibers12are color coded in this way to help organize and identify specific fibers12when making connections or splices. Further, as mentioned above, the indicator fibers12aare less obscured by the opacifying layer14and/or color layer16than the interior fibers12b. In this way, a technician can use the color coding of the optical fibers12to determine polarity of the optical fiber ribbon10based on the indicator fibers12b.

The color of the optical fibers12can make reading the printing layer18between the primary matrix22and the secondary matrix24difficult. In particular, the darker colored fibers12tend to limit the contrast between the ink of the printing layer18and the background. Thus, the opacifying layer14(or, in embodiments, the color layer16) creates a contrasting background for the printing layer18. In a particular embodiment, the opacifying layer14includes a pigment, ink, dye, or other colorant as an opacifier. In embodiments, the pigment provides the opacifying layer14with a color of white, gray, or black.

In terms of the CIE L*c*h* color space, using a white opacifier causes the lightness (L*) values for all of the optical fibers12to increase, which makes the color whiter, and the saturation (chroma—c*) decreases, which decreases the intensity of the colors. The hue angle h* for the colors remains the same. By increasing lightness and decreasing chroma, the optical fibers12become less visible through the opacifying layer14. In this way, the printing layer18is able to contrast more with the underlying opacifying layer14. In some embodiments, the color layer16is provided below the printing layer18. In such embodiments, the color layer16may contain an opacifier to enhance contrast.

As can be seen inFIGS. 1 and 2, the printing layer18is comprised of a plurality of dots20of ink. In embodiments, the ink dots20are printed using inkjet printing on the opacifying layer14or primary matrix22. In embodiments, the ink dots20are substantially circular and have a diameter of from 200 μm to 350 μm. In embodiments, the dots have a thickness of 2 μm to 10 μm. In embodiments, the color of the ink dots20is selected to provide good contrast with the color of the opacifying layer14. For example, when the opacifying layer14is white, the ink dots20may be selected to be black. An example of a black ink suitable for use for the ink dots20is MB175 (available from Markem-Imaje, Switzerland). In another example, when the opacifying layer14is black or gray, the ink dots20may be selected to be yellow. An example of a yellow ink suitable for use for the ink dots20is Yellow MC258 (available from Markem-Imaje, Switzerland). Other color combinations between the ink dots20and the opacifying layer14are possible, and these examples are provided by way of illustration only and not by way of limitation.

FIG. 3provides an enlarged view of a portion of the optical fiber10. InFIG. 3, the structure of the optical fibers12is depicted. The optical fibers12are comprised of a core26surrounded by a cladding 28. Optical signals are carried by the core26, and the cladding 28 substantially prevents the optical signals from escaping the core26during transmission. In embodiments, the cladding 28 is coated with a primary coating30that is made of a relatively softer, cushioning material. The primary coating30is further coated with a secondary coating32that is made of a harder material to provide abrasion resistance. Disposed outside of the secondary coating32is a fiber jacket34that comprises, e.g., a dye, an ink, or a pigment that provides one of the color-coded identifying colors discussed above for the fiber12.

As can be seen inFIG. 3, the primary matrix22is provided above and below the optical fibers12as well as in the spaces between optical fibers12(although, in practice, the primary matrix22may not entirely fill the space between optical fibers12and air gaps may be present between adjacent optical fibers12). In embodiments, the optical fibers12are embedded in the primary matrix22, which forms a continuous and contiguous layer of polymer material around the optical fibers12. In various embodiments, substantially all of the outer surface of the fiber jacket34contacts the primary matrix22. In the embodiment depicted inFIG. 3, the opacifying layer14is coated over the primary matrix22and is embedded in the secondary matrix24, which serves as the color layer16.

FIG. 3depicts a midline40of the cross-section of the optical fiber ribbon10. The midline40divides the optical fiber ribbon10into a first portion42and a second portion44. With respect to the orientation of theFIG. 3, the first portion42is shown as the upper portion of the optical fiber ribbon10, and the second portion44is shown as the lower portion of the optical fiber ribbon10. In the embodiment ofFIG. 3, the opacifying layer14is located only in the first portion42, but in other embodiments, the opacifying layer14may additionally or alternatively be located in the second portion44.

In embodiments, the average thickness T1of the secondary matrix24is from 10 μm to 35 μm. The average thickness T2of the opacifying layer14is from 20% to 100% of T1, or from 2 μm to 35 μm. As mentioned above, the average thickness T3of the ink dots20is from 2 μm to 10 μm. As described, opacifying layer14is able to obscure a portion of the color of the fiber jacket34so as to provide a contrasting background for the ink dots20of the printing layer18. Further, the color layer16, which is incorporated in the secondary matrix24, provides identification of the optical fiber ribbon10. In the embodiment depicted, the primary matrix22is uncolored and unopacified.

As discussed above, the indicator fibers12aare left at least partially uncovered by the opacifying layer14. In embodiments, each optical fiber12has a diameter D, and the optical fibers12are arranged in a planar row and in an edge-to-edge fashion such that the number N of optical fibers12defines a width of approximately D*N (with some small gaps potentially existing between adjacent optical fibers12). In each of the embodiments described here, at least one of the opacifying layer14or the color layer16has a width that is less than the width of the planar row of optical fibers12. In this way, the indicator fibers12awill extend (at least partially) past one or both of the opacifying layer14and the color layer16. In this way, the interior fibers12bwill be obscured by both the opacifying layer14and the color layer16, whereas the indicator fibers12awill have at least a region that is only obscured by at most one of the opacifying layer14or the color layer16.

With respect to the embodiment shown inFIG. 3, the color layer16is incorporated into the secondary matrix24, and thus, the color layer16has a width wider than the width of the planar row of optical fibers12. As can be seen, though, the opacifying layer14has a width that is less than width of the planar row of optical fibers12. In embodiments, the width of the opacifying layer14is selected to be at least about D(N−2). In such embodiments, the opacifying layer14may be substantially centered over the interior fibers12bsuch that equal amounts (about an entire diameter D) of the indicator fibers12aat the edge of the row are exposed. In other embodiments, the width of the opacifying layer14is selected to be no more than D(N−0.5). In such embodiments, the opacifying layer14may be centered over the interior fibers12bsuch that about 0.25D of each indicator fiber12aat the edge of the row is exposed. In the other embodiments described below, either one or both of the opacifying layer14or the color layer16may, in embodiments, have a width of from D(N−2) to D(N−0.5).

FIG. 4depicts another embodiment of an optical fiber ribbon10that is substantially similar to the embodiment shown inFIG. 3with the exception that, in the embodiment ofFIG. 4, the opacifying layer14is coated onto the optical fibers12instead of the primary matrix22. As shown inFIG. 4, the opacifying layer14is coated onto the interior fibers12band is located in the first portion42above the midline40. However, in other embodiments, the opacifying layer14may be located additionally or alternatively in the second portion44below the midline40. In embodiments, the opacifying layer14has an average thickness T4proximal to the midline40(i.e., in the region between adjacent optical fibers12) of 5 μm to 50 μm and an average thickness T5over the remainder of the optical fibers12of from 5 μm to 50 μm.

In the embodiment ofFIG. 4, the primary matrix22is provided around the optical fibers12and the opacifying layer14. That is, the optical fibers12and opacifying layer14are embedded in the primary matrix22, which forms a continuous and contiguous layer of polymer material around the optical fibers12and the opacifying layer14. As with the previous embodiment, the printing layer18is applied in ink dots20over the primary matrix22, and the secondary matrix24, which incorporates the color layer16, is applied around the printing18and primary matrix22. In the embodiment depicted, the primary matrix22is uncolored and unopacified.

FIG. 5depicts another embodiment of an optical fiber ribbon10having just a color layer16. In this embodiment, the color layer16is coated onto the interior fibers12b, leaving the indicator fibers12bat the edge of the row exposed. In the embodiment shown inFIG. 5, the color layer16is located in the first portion42above the midline40. However, in other embodiments, the color layer16may be located additionally or alternatively in the second portion44below the midline40. The color layer16has an average thickness T4proximal to the midline40in the space between the optical fibers12of from 5 μm to 50 μm and an average thickness T5over the remainder of each optical fiber12of from 5 μm to 50 μm. In embodiments, an opacifier may be incorporated into the color layer16. That is, the color layer16can contain both a colorant and an opacifier, which is applied over the interior fibers12b.

In the embodiment ofFIG. 5, the primary matrix22is provided around the optical fibers12and the color layer16. That is, the optical fibers12and color layer16are embedded in the primary matrix22, which forms a continuous and contiguous layer of polymer material around the optical fibers12and the color layer16. As with the previous embodiments, the printing layer18is applied in ink dots20over the primary matrix22, and the secondary matrix24is applied around the printing18and primary matrix22. In the embodiment depicted, the primary matrix22and the secondary matrix24are both uncolored and unopacified.

FIG. 6depicts an embodiment having both the opacifying layer14and the color layer16, which are also both distinct from the primary matrix22and the secondary matrix24. As shown inFIG. 6, the opacifying layer14is applied over the interior fibers12b, and the color layer16is applied over the primary matrix22and is embedded in the secondary matrix24. In the embodiment depicted, the opacifying layer14and the color layer16both terminate at the last interior fiber12b, leaving the indicator fiber12aat each edge of the row unobscured. However, in other embodiments, the color layer16or opacifying layer14could extend further than the other layer. In embodiments, the opacifying layer14and the color layer16are located in the first portion42above the midline40. However, in other embodiments, the opacifying layer14and the color layer16may be located additionally or alternatively in the second portion44below the midline40. In embodiments, the opacifying layer14has an average thickness T6proximal to the midline40in the gap between adjacent optical fibers12of from 5 μm to 50 μm and an average thickness T7over the remainder of the optical fiber12of from 5 μm to 50 μm. In embodiments, the color layer16has an average thickness T8of from 2 μm to 15 μm.

In the embodiment ofFIG. 6, the primary matrix22is provided around the optical fibers12and the opacifying layer14. That is, the optical fibers12and opacifying layer14are embedded in the primary matrix22, which forms a continuous and contiguous layer of polymer material around the optical fibers12and the opacifying layer14. As with the previous embodiments, the printing18is applied in ink dots20over the primary matrix22, and the secondary matrix24, in which the color layer16is embedded, is applied around the printing18and primary matrix22.

FIG. 7depicts another embodiment in which the opacifying layer14and the color layer16are both contained in the primary matrix22. As shown inFIG. 7, the opacifying layer14is applied over the interior fibers12b, and the color layer16is applied over the opacifying layer14. In embodiments, the opacifying layer14and the color layer16are located in the first portion42above the midline40. However, in other embodiments, such as shown inFIG. 8, the opacifying layer14and the color layer16may be located additionally or alternatively in the second portion44below the midline40. In embodiments, the opacifying layer14has an average thickness proximal to the midline40in the gap between adjacent optical fibers similar to the average thickness disclosed with respect to the embodiments shown inFIGS. 4-6. In embodiments, the opacifying layer14has an average thickness T9over the remainder of the optical fibers12of from 2 μm to 10 μm, and the color layer16has an average thickness T10over the same region of the optical fibers12of from 2 μm to 10 μm.

In the embodiments ofFIGS. 7 and 8, the primary matrix22is provided around the optical fibers12, the opacifying layer14, and the color layer16. That is, the optical fibers12, the opacifying layer14, and the color layer16are embedded in the primary matrix22, which forms a continuous and contiguous layer of polymer material around the optical fibers12, the opacifying layer14, and the color layer16. As with the previous embodiments, the printing18is applied in ink dots20over the primary matrix22, and the secondary matrix24is applied around the printing18and primary matrix22.

FIG. 9depicts an embodiment of an optical fiber ribbon10in which two color layers16a,16bare provided within the primary matrix22. In particular, a first color layer16ais provided over a first number of the interior fibers12b, and a second color layer16bis provided over a second number of the interior fibers12b. Further, the color layers16a,16boverlap over at least one of the interior fibers12b. In this way, the first color layer16aprovides a first region46of a first color, a second region48of a second color, and an overlap region50of a third color. For example, in an embodiment, the first color layer16ais blue, and the second color layer16bis red-orange. In such an embodiment, the overlap region50will be purplish in color when viewed from the exterior of the optical fiber ribbon10.

In embodiments, the color layers16a,16bare located in the first portion42above the midline40. However, in other embodiments, the color layers16a,16bmay be located additionally or alternatively in the second portion44below the midline40. In embodiments, the color layer16ahas an average thickness T9over the portion of the optical fibers12outside of the region between adjacent optical fibers12of 2 μm to 10 μm, and the color layer16bhas an average thickness T11over the portion of the optical fibers12outside of the region between adjacent optical fibers12of from 2 μm to 10 μm.

In the embodimentFIG. 9, the primary matrix22is provided around the optical fibers12and the color layers16a,16b. That is, the optical fibers12and the color layers16a,16bare embedded in the primary matrix22, which forms a continuous and contiguous layer of polymer material around the optical fibers12the color layers16a,16b. As with the previous embodiments, the printing layer18is applied in ink dots20over the primary matrix22, and the secondary matrix24is applied around the printing layer18and primary matrix22.

Similar to leaving the indicator fibers12aat least partially exposed, the color layers16a,16band overlap region50can help to identify various regions of the optical fiber ribbon10. In particular, in optical fiber ribbons10having twenty-four or more optical fibers12, the color layers16a,16band overlap region50can be alternated to set off particular groups of optical fibers12. Further, in embodiments, more than two color layers16a,16bcan be provided (e.g., three, four, five, or more different color layers16a,16b) to provide multiple different color regions and overlap regions.

FIG. 10depicts a schematic representation of a processing line100for producing an optical fiber ribbon10according to the embodiments of the present disclosure. As can be seen inFIG. 10, individual optical fibers12that are arranged in a planar row enter a first applicator110. In the first applicator110, the primary matrix22is applied around the optical fibers12to produce ribbon subunits15. In the first applicator110, any opacifying layers14and/or color layers16that are in contact with the optical fibers12or are embedded in the primary matrix22(such as the embodiments shown inFIGS. 4-9) are applied in the first applicator110. The 14 ribbon subunits15exit the first applicator110with the primary matrix22and any opacifying layer14and/or color layer16applicable to the particular embodiment. Thereafter, the ribbon subunits15are cured at first curing station120, depicted as a UV-curing lamp. After curing, the printing18is applied to the primary matrix22via one or more printheads130. In embodiments, the printheads130are inkjet printers that apply the ink dots20shown inFIGS. 1-9. After the printing18is applied, the subunits15enter a second applicator140for application of the secondary matrix24to form the optical fiber ribbon10. As described above, the secondary matrix24itself may be the color layer16(e.g.,FIGS. 3 and 4). Additionally, any opacifying layers14and/or color layers16that are in contact with the primary matrix22or embedded in the secondary matrix24(such as the embodiments shown inFIGS. 3 and 6) are applied in the second applicator140. Upon exiting the second applicator140, the optical fiber ribbon10is cured again at second curing station150, again depicted as a UV-curing lamp.

FIG. 11depicts an embodiment of the first applicator110. While the first applicator110is shown, the second applicator140is substantially similar in design, and the following discussion applies as well to the second applicator140. As can be seen inFIG. 11, the optical fibers12enter the first applicator110for application of the primary matrix22. The first applicator110is depicted with a substantially cubic housing160having a first entry port170for the material of the primary matrix22. The primary matrix22material is in a liquid form and is circulating within the housing160of the first applicator110. The optical fibers12enter the housing160and are submerged in the primary matrix22material. As the optical fibers12pass through the first applicator110, the primary matrix22material coats onto the outer surfaces of the optical fibers12.

As mentioned above, opacifying layer14and/or color layer16are applied in the first applicator110along with the primary matrix22. As shown inFIG. 11, a second entry port180is provided for the material of the opacifying layer14and/or the color layer16. In the embodiment depicted, the second entry port180is arranged perpendicularly to the first entry port170, and on the interior of the housing160, slots190are formed such that the widths of the slots190are transverse to the longitudinal axis of the optical fiber12. Further, the width of the slots190are designed to substantially match the width of the opacifying layer and/or color layer16to be applied to the subunit15(or optical fiber ribbon10in the case of the second applicator140). Advantageously, the material for the opacifying layer14and/or color layer16simply be deposited from the slots190onto the optical fibers12as the circulation of the primary matrix22material within the housing160brings the material of the opacifying layer14and/or color layer16into contact with the surface of the optical fibers12.

FIG. 12depicts a cross-section of an optical fiber ribbon10of the type shown inFIG. 4produced in a processing line100as shown inFIG. 10, including using an applicator110as shown inFIG. 11. As can be seen inFIG. 12, the leftmost optical fiber is the indicator fiber12a, and the three other optical fibers depicted are interior fibers12b. The interior fibers12bare all coated with an opacifying layer14that is contained within the primary matrix22. The secondary matrix24is the color layer16.FIG. 12shows a sharp break in the opacifying layer14over the leftmost interior fiber12b, leaving the indicator ribbon12auncovered by the opacifying layer14. Because the indicator ribbon12ais only partially obscured by the color layer16of the secondary matrix24, the indicator ribbon12acan be more easily discerned for determination of the polarity of the optical fiber ribbon10.

Each of the opacifying layer14, the color layer16, the primary matrix22, and the secondary matrix24may have a base resin selected from the compositions described below. The opacifying layer14and the color layer16will contain a pigment, ink, or dye to provide the opacifying or coloring effect, whereas the primary matrix22and the secondary matrix24(unless used as the opacifying layer14or the color layer16) will not contain a pigment, ink, or dye and will be relatively clear or transparent. In embodiments, the base resin is a polymer material that is curable. In a particular embodiment, the base resin is a UV-curable resin comprising an oligomer component, a reactive diluent monomer component, and a photoinitiator. In embodiments, the oligomer is one or more acrylated, methacrylated, or vinyl functional oligomer, and in embodiments, the oligomer has an aliphatic urethane or epoxy backbone. In embodiments, the oligomer comprises 30 wt % to about 80 wt % of the UV-curable resin. In embodiments, the reactive diluent monomer component is one or more reactive diluent monomers having 1 to 5 functional groups of, e.g., acrylate, methacrylate, vinyl ether, or vinyl. In embodiments, the reactive diluent monomer comprises 5 wt % to 65 wt % of the UV-curable resin. In embodiments, the photoinitiator comprises from 0.1 wt % to 10 wt % of the UV-curable resin. In embodiments, the UV-curable resin may also include a variety of other additives in an amount of 0 wt % to 10 wt %, such as antioxidants, catalysts, lubricants, low molecular weight non-crosslinking resins, adhesion promoters, and stabilizers. In embodiments, the base resin comprises from 85 wt % to 99 wt % of the primary matrix22, and the pigment comprises the remaining 1 wt % to 15 wt % of the primary matrix22.

In embodiments of the UV-curable resin, the oligomers may be based on an aliphatic polyether polyol, which is reacted with an aliphatic polyisocyanate and then acrylated. In embodiments, the photoinitiator may include at least one photoinitiating compound selected from the group consisting of bis-acyl phosphine oxide; hydroxycyclohexylphenyl ketone; hydroxymethylphenylpropanone; dimethoxyphenylacetophenone; 2-methyl-1,4-(methyl thio)phenyl-2-morpholino-propanone-1; 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one; 4-(2-hydroxyethyoxy)phenyl-(2-hydroxy-2-propyl)ketone; 1-(4-dodecyl phenyl)-2-hydroxy-2-methylpropan-1-one; diethoxyacetophenone; 2,2-di-sec-butoxy-acetophenone; diethoxyphenyl acetophenone; bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide; and mixtures thereof.

A variety of suitable opacifiers can be dispersed in the UV-base resin to form the opacifying layer14. For a white opacifying layer14, exemplary opacifier includes such pigments as TiO2, BaSO4, ZnO or ZnS. For a black opacifying layer14, an exemplary opacifier pigment is carbon black. For a gray opacifying layer14, the opacifier may be a combination of white and black pigments.

As discussed above, the color layer16is tinted with a colorant (e.g., one or more of dye(s), pigment(s), ink(s), etc.) so as to provide an identification element to the optical fiber ribbon10. However, the color layer16is also configured to be semi-transparent such that the printing18can be seen beneath the color layer16. As considered herein, the level of transparency of the color layer16is selected so as to achieve a desired contrast ratio according to ASTM D2805 of the color layer16. As used herein, “contrast ratio” is defined as “the ratio of the reflectance of a film on a black substrate to that of an identical film on a white substrate.” In performing a contrast ratio test according to ASTM D2805, the material tested is spread in an even layer over a test card having both a section of white background and a section of black background. Using reflectometry, the reflectance over the white section and the black section is measured. The ratio of these reflectances is the contrast ratio.

The contrast ratio can be adjusted by varying the amount of colorant used in the composition of the color layer16and by varying the thickness of the color layer16. For example, for a given composition, the contrast ratio of the color layer16will increase as the thickness of the color layer16increases. Additionally, for a given thickness, the contrast ratio of the color layer16will increase as the amount of colorant pigment in the composition of the color layer16increases. Table 1 provides the colors of the color layer16as defined according the CIE L*c*h* color space, and Table 2 provides the contrast ratio ranges to achieve the desired level of transparency to be able to clearly discern the printing18beneath the color layer16while still being able to identify the color of the ribbon10.

Taking as an example a blue color layer16of 30 μm thickness, the composition of the color layer16is selected to achieve a contrast ratio of no more than 0.7 as provided in Table 2 so as to maintain legibility of the underlying printing layer18. However, in order to clearly discern the blue color of the ribbon10, the composition of the color layer16is selected to achieve a contrast ratio of at least 0.5 as provided in Table 2. It is noted that the example of a blue color layer16was given, but performance of a contrast ratio measurement according to ASTM 2805 is the same for every color. That is, ASTM 2805 does not define different testing procedures on the basis of color analyzed.

In embodiments, the composition of the color layer16includes a colorant and a base resin. In embodiments, the colorant is one or more pigments dispersed in a base resin, such as the embodiments of the base resin described above with respect to the opacifying layer14. The colorant may be preferably a different composition form the opacifier. A variety of pigments are suitable for use in the pigment-based color dispersion. An exemplary black pigment includes carbon black. Exemplary white pigments include TiO2, BaSO4, ZnO or ZnS. Exemplary yellow pigments include diarylide yellow and diazo-based pigments. Exemplary blue pigments include phthalocyanine blue, basic dye pigments, and phthalocyanines. Exemplary red pigments include anthraquinone (red), napthole red, monoazo-based pigments, quinacridone pigments, anthraquinone, and perylenes. Exemplary green pigments include phthalocyanine green and nitroso-based pigments. Exemplary orange pigments include monoazo- and diazo-based pigments, quinacridone pigments, anthraquinones and perylenes. Exemplary violet pigments include quinacrinode violet, basic dye pigments and carbazole dioxazine based pigments. The colors of aqua, brown, gray, and rose can be formulated by combining the pigments of the other colors listed above.

In accordance with aspects of the present disclosure, fiber types for use in the ribbon may include G.652, G.657.B3, G.657.A2/B2, G.657.A1. These fiber types can have a 1310 μm MFD from 8.2 to 9.6 microns. Individual fiber diameters may range from 250 microns (or 258 microns if colored), 200 microns (or 208 microns if colored), or below. The higher cost, special bend fibers with MFDs at 8.8 μm or other lower MFDs may be used in cases where there is a particularly identified requirement, for example if the stripped fiber is stored outside the cable in a very tight splice tray. In addition, the special bend fibers may enable even smaller diameter cables with higher densities if the fibers are less than 200 microns in diameter, such as 185 microns or less. Moreover, the individual fibers in a ribbon may be set to have a core spacing set to match a predetermined core spacing. For example, individual fibers may not necessarily be abutting in planar alignment but may have gaps in between neighboring fibers, in particular if core spacing for smaller diameter fibers (e.g., 200 micron fiber ribbons) is desired to align with the higher core spacing of a larger diameter fiber ribbon (e.g., 250 micron fiber ribbons).