Multiple layer hose, method of producing a multiple layer hose and apparatus therefor

Abstract

In one aspect the present invention provides a multilayer hose comprising an inner layer surrounded by a first layer of reinforcement material around which is formed a second layer of reinforced material and over which is placed an outer cover, in which the two reinforcement layers have an intermediate layer of elastomeric material applied as a water-based emulsion. In another aspect of the invention there is a method of producing a multilayer hose of the type comprising internal and external flexible resilient layers between which is located a reinforcement layer, in which inner and outer reinforcement layers have an intermediate bonding layer; the said method comprising the steps of: providing a first reinforcement layer over the said internal flexible resilient layer; applying a water-based elastomeric emulsion over the said first reinforcement layer to form an intermediate layer; drying the said water-based emulsion to reduce the moisture content thereof; providing a second reinforcement layer over the said elastomeric layer and subsequently curing the said elastomeric layer to bond the two reinforcement layers together.

1 . A multilayer hose comprising an inner layer surrounded by a first layer of reinforcement material around which is formed a second layer of reinforced material and over which is placed an outer cover, in which the two reinforcement layers have an intermediate layer of elastomeric material applied as a water-based emulsion.  
     
     
         2 . A hose as claimed in  claim 1  wherein the intermediate layer has a moisture content substantially in the range 0.5 to 1.5%.  
     
     
         3 . A hose as claimed in  claim 2  wherein the moisture content is substantially 1%.  
     
     
         4 . A hose as claimed in  claim 1  wherein the intermediate layer comprises a water based rubber.  
     
     
         5 . A hose as claimed in  claim 4  wherein the intermediate layer comprises a water based neoprene rubber.  
     
     
         6 . A hose as claimed in  claim 1  wherein at least one of the said first and second reinforcement layers comprises a layer of braided filamentary material.  
     
     
         7 . A hose as claimed in  claim 1  wherein the said first and second reinforcement layers comprise the same or similar material.  
     
     
         8 . A hose as claimed in  claim 1  wherein the said inner layer and outer cover comprise internal and external flexible resilient layers.  
     
     
         9 . A hose as claimed in  claim 8  wherein the internal and external flexible resilient layers comprise an elastomeric material.  
     
     
         10 . A method of producing a multilayer hose of the type comprising internal and external flexible resilient layers between which is located a reinforcement layer, in which inner and outer reinforcement layers have an intermediate bonding layer; the said method comprising the steps of: 
 providing a first reinforcement layer over the said internal flexible resilient layer;    applying a water-based elastomeric emulsion over the said first reinforcement layer to form an intermediate layer;    drying the said water-based emulsion to reduce the moisture content thereof;    providing a second reinforcement layer over the said elastomeric layer and subsequently curing the said elastomeric layer to bond the two reinforcement layers together.    
     
     
         11 . A method as claimed in  claim 10  wherein the said drying step comprises the step of passing air over the said emulsion.  
     
     
         12 . A method as claimed in  claim 10  wherein the moisture content of the said intermediate layer is reduced to lie substantially in the range of 0.5 to 1.5% by weight in the drying step.  
     
     
         13 . A method as claimed in  claim 10  wherein the said emulsion comprises a water based rubber.  
     
     
         14 . A method as claimed in  claim 13  wherein the said emulsion comprises a water based neoprene rubber.  
     
     
         15 . A method as claimed in  claim 10  wherein the step of applying the said water based emulsion comprises the step of feeding the said internal resilient layer and said first reinforcement layer into a reservoir of the said emulsion.  
     
     
         16 . A method as claimed in  claim 10  wherein at least one of the said first and second reinforcement layers comprises a layer of filamentary material braided and the step of applying the said reinforcement layer(s) comprises the step of braiding the said filamentary material over the surface of a respective adjacent inner layer.  
     
     
         17 . Apparatus for producing a multilayer hose having inner and outer flexible resilient layers with two braided filamentary layers between them and an intermediate water-based elastomeric emulsion bonding layer between the said braided layers, the said apparatus comprising: a first braiding station, an application station at which water-based elastomeric emulsion is applied, a drying station at which moisture content of the said elastomeric bonding layer is reduced to a pre-determined level, and a second braiding station at which a further filamentary braided layer is formed over the intermediate layer.  
     
     
         18 . Apparatus as claimed in  claim 17  wherein the said application station comprises a reservoir for the said water based emulsion and means for feeding the inner layers of the hose through the said emulsion.  
     
     
         19 . Apparatus as claimed in  claim 17  wherein the said drying station comprises air drying means for reducing the said moisture content from the said intermediate layer.  
     
     
         20 . Apparatus as claimed in  claim 18  wherein the said drying station further comprises infrared drying means for further reducing the moisture content from the said intermediate layer.