Water blocking cable tape and methods for making the same

Abstract

The invention provides a water blocking tape for use in a variety of cable designs, such as power cable, data communications cable and telecommunications cable. A water blocking tape according to the invention includes layers of lightweight nonwoven fabric with one or more swellable water blocking compounds, such as water absorbent polymers, disposed between the layers. The nonwoven fabric layers are bonded in a pattern using an ultrasonic bonding technique. The bonding pattern helps to contain and to restrain movement of the water blocking compounds between the layers. The bonding pattern compartmentalizes the water blocking compounds to prevent pooling of the compounds and to facilitate a substantially consistent distribution of the compounds between the layers such that when a tape contacts water, the tape achieves a substantially consistent swell height. A substantially consistent swell height permits a tape to serve as a reliable water barrier to prevent damage and degradation of a cable and its components. Ultrasonic bonding of the multilayer tape eliminates the need and use of adhesives and bonding agents to form the tape that can have inhibiting effects on a swelling action of the tape.

1 - 34 . (canceled)  
   
   
       35 . A water blocking tape for use with a data or communications cable, the tape comprising: 
 at least a first layer of nonwoven material;    at least a second layer of nonwoven material disposed along the at least first layer of nonwoven material;    one or more water absorbent compounds disposed between the first and second layers, each of the first and second layers of nonwoven material having a low porosity and each of the one or more water absorbent compounds having a particle size such that the one or more water absorbent compounds do not permeate the layers of nonwoven material;    the first and second layers being ultrasonically bonded together along a pattern traversing the first and second layers such that the pattern defines the first and second layers with a plurality of compartments containing the one or more water absorbent compounds and being disposed to prevent or reduce loss of the one or more water absorbent compounds from between the bonded first and second layers;    the plurality of compartments being distributed across the first and second layers such that movement of the one or more water absorbent compounds between the bonded first and second layers is restrained; and    each compartment defining a volume to maintain a desired loading weight of the one or more water absorbent compounds between the bonded first and second layers.    
   
   
       36 . The water blocking tape of  claim 35 , wherein each compartment has dimensions such that each compartment contains a substantially equivalent amount of the one or more water absorbent compounds as contained by each other compartment.  
   
   
       37 . The water blocking tape of  claim 35 , wherein the pattern of ultrasonic bonding includes a repeating and substantially uniform bonding pattern.  
   
   
       38 . The water blocking tape of  claim 37 , wherein each of the plurality compartments has dimensions such that each compartment contains a substantially equivalent amount of the one or more water absorbent compounds as contained by each other compartment.  
   
   
       39 . The water blocking tape of  claim 36 , wherein the plurality of compartments is distributed substantially evenly across the first and the second layers such that when the water blocking tape is wetted, the water blocking tape swells to a substantially consistent swell height.  
   
   
       40 . The water blocking tape of  claim 38 , wherein the plurality of compartments is distributed substantially evenly across the first and the second layers such that when the water blocking tape is wetted, the water blocking tape swells to a substantially consistent swell height.  
   
   
       41 . The water blocking tape of  claim 37 , wherein the repeating and substantially uniform bonding pattern defines the plurality of compartments as a plurality of diamond-shaped compartments.  
   
   
       42 . The water blocking tape of  claim 41 , wherein each diamond-shaped compartment has dimensions of about 1.6 cm by about 1.6 cm.  
   
   
       43 . The water blocking tape of  claim 35 , wherein the one or more water absorbent compounds includes a loading weight of about 10 grams per square meter (gsm) to about 50 gsm of the bonded first and second layers.  
   
   
       44 . The water blocking tape of  claim 35 , wherein the nonwoven material of the bonded first and second layers includes a weight of about 10 grams per square meter (gsm) to about 40 gsm of the bonded first and second layers.  
   
   
       45 . The water blocking tape of  claim 35 , further comprising at least one layer of a shielding material disposed on a surface of at least one of the first layer and the second layer, the at least one layer of shielding material being ultrasonically bonded to the layer along the same pattern bonding the first and the second layers.  
   
   
       46 . The water blocking tape of  claim 35 , wherein the nonwoven material is selected from the group consisting of a spun-bonded nonwoven fabric, a spun-bonded melt-blown spun-bonded nonwoven fabric, a spun-bonded melt-blown melt-blown spun-bonded nonwoven fabric, a melt-blown nonwoven fabric, a nonwoven nylon, a carded nonwoven fabric, a plastic, a polyester, a polypropylene, a polyethylene terephthalate, and combinations thereof.  
   
   
       47 . The water blocking tape of  claim 35 , wherein the one or more water-absorbent compounds are selected from the group consisting of polyacrylate, polyacrylamide, polyvinyl alcohol, copolymer of polyacrylate, polyacrylamide and polyvinyl alcohol, copolymer of polyacrylate and polyacrylamide, copolymer of polyacrylate and polyvinyl alcohol, copolymer of polyacrylamide and polyvinyl alcohol, and combinations thereof.  
   
   
       48 . A water blocking tape for use with a data or communications cable, the tape comprising: 
 at least a first layer of nonwoven material,    at least a second layer of nonwoven material disposed along the at least first layer of nonwoven material:    one or more water absorbent compound disposed between the first and second layers, each of the first and second layers of nonwoven material having a low porosity and each of the one or more water absorbent compounds having a particle size such that the one or more water absorbent compounds do not permeate the layers of nonwoven material,    the first and second layers being ultrasonically bonded together by a plurality of intersecting bonding lines traversing the first and second layers such that the plurality of intersecting bonding lines defines the first and second layers with a plurality of compartments containing the one or more water absorbent compounds and being disposed to prevent or reduce loss of the one or more water absorbent compounds from between the bonded first and second layers;    the plurality of compartments being distributed across the first and second layers such that movement of the one or more water absorbent compounds between the bonded first and second layers is restrained; and    each compartment defining a volume to maintain a desired loading weight of the one or more water absorbent compounds between the bonded first and second layers.    
   
   
       49 . The water blocking tape of  claim 48 , wherein each compartment has dimensions such that each compartment contains a substantially equivalent amount of the one or more water absorbent compounds as contained by each other compartment.  
   
   
       50 . The water blocking tape of  claim 49 , wherein the plurality of compartments is distributed substantially evenly across the first and the second layers such that when the water blocking tape is wetted, the water blocking tape swells to a substantially consistent swell height.  
   
   
       51 . The water blocking tape of  claim 48 , wherein a loading weight of the one or more water absorbent compounds is distributed substantially evenly between the first and the second layers such that when the water blocking tape is wetted, the water blocking tape swells to a substantially consistent swell height.  
   
   
       52 . The water blocking tape of  claim 48 , wherein the plurality of intersecting lines defines a repeating and substantially uniform bonding pattern.  
   
   
       53 . The water blocking tape of  claim 52 , wherein each compartment has dimensions such that each compartment contains a substantially equivalent amount of the one or more water absorbent compounds contained by each other compartment such that when the water blocking tape is wetted, the water blocking tape swells to a substantially consistent swell height.  
   
   
       54 . The water blocking tape of  claim 48 , further comprising at least one layer of a shielding material disposed on a surface of at least one of the first layer and the second layer, the at least one layer of shielding material being ultrasonically bonded to the layer by the plurality of intersecting bonding lines.