Furukawa Electric North America, Inc.

Lucent Technologies Inc.

Jennifer R Meeks

Peter A Weimann

Harold P Debban

Luis M Bocanegra

Kenneth L Taylor

Jim Jenqtsong Sheu

Wayne McCall Newton

Mark I Shmukler

Carla Green Wilson

The specification describes an improved optical fiber cable wherein the cable cross section is round and contains a plurality of bundled optical fibers. The bundle may comprise randomly spaced fibers or fibers aligned in a ribbon configuration. The bundle is encased in a polymer encasement that couples mechanically to each optical fiber. Preferably, the fibers are spaced from the nearest neighbor to improve coupling. In some embodiments the encasement is relatively hard, and is deliberately made to adhere to the optical fiber bundle. Consequently the encasement medium functions as an effective stress translating medium that deliberately translates stresses on the cable to the optical fibers. The cable construction of the invention is essentially void free, and provides a dry cable with water blocking capability.

Optical fiber cables

The specification describes an improved optical fiber cable wherein the cable cross section is round and contains a plurality of bundled optical fibers. The bundle may comprise randomly arranged optical fibers or optical fibers aligned in a ribbon configuration. The bundle is encased in a polymer encasement that couples mechanically to the optical fibers. In some embodiments the encasement is relatively hard, and is deliberately made to adhere to the optical fiber bundle. Consequently the encasement medium functions as an effective stress translating medium that deliberately translates stresses on the cable to the optical fibers. The cable construction of the invention is essentially void free, and provides a dry cable with water blocking capability.

The specification describes an improved optical fiber ribbon cable. The cable design addresses the problem of wrinkles in the cable coating that occur on the interior bend radius on moderate bending of the cable. The wrinkles are much smaller than the bend radius, and are, relatively speaking, microbends. These may cause microbending losses in the fibers even where the bend radius is relatively large. The cable design of the invention has a combination of three important features. The cable cross section is round. The encasement for the optical fiber stack is relatively hard, and is deliberately made to adhere to the optical fiber stack. Consequently the encasement medium functions as an effective stress translating medium that deliberately translates stresses on the cable to the optical fibers. The optical fibers function as compressive strength members to retard longitudinal strain on the cables, and thereby reduce wrinkling of the encasement.

The present invention generally is directed to compositions, products and methods that utilize superabsorbent polymers for flame-retarding. A preferred method includes improving flame-retarding characteristics in products by adding SAPs to the product. Prior to the step of adding the SAPs, the product exhibits a first limiting oxygen index and after the step of adding the SAPs, the product exhibits a second limiting oxygen index, with the second limiting oxygen index being higher than the first limiting oxygen index. Preferably, the SAPs can be pre-loaded with moisture, thereby potentially further increasing the flame-retarding characteristics of the product. In a preferred embodiment, the product is configured as a cable, with the outer jacket of the cable incorporating the SAPs.

Methods for flame-retarding and products produced therefrom

A preferred embodiment of the cable of the present invention incorporates a core, an outer jacket surrounding the core, and a tape disposed between the core and the outer jacket. The tape includes a first layer and superabsorbent polymers (SAPs) which are applied to the first layer. Preferably, the first layer is formed of spun bonded non-woven polyester material, nylon spun bonded fabric, non-woven glass, polypropylene melt blown non-woven fabric, polyurethane spun bonded fabric, or TCF cellulose fabric, among others. Additionally, the SAPs preferably are provided with a moisture content of greater than approximately 2 percent, by weight, thereby improving the flame-retarding characteristics of the tape.

Growing community of inventors

Lawrenceville, GA, United States of America

Jennifer R Meeks