Antistatic flotation body and pontoon containing such body

Abstract

A hollow plastic body, particularly a plastic ball, has antistatic properties and a melting temperature above that found in floating covers of petrochemical storage tanks, therefore, enabling use of the body in flotation of oil tank covers without danger of melting and without danger of developing a static charge followed by subsequent hazardous discharge. The balls are constructed of a non-foamed high-density plastic resin, HDPE (high density polyethylene), mixed with an antistatic additive or agent. The antistatic agent is effective to convert the electrically insulating plastic to an electrically conductive material which does not develop a static electrical charge. Only a relatively small amount of the antistatic agent, less than one percent by weight, is sufficient to provide the desired antistatic property to ball while having no more than a minimal effect on the melting temperature, thereby to retain the integrity of the flotation in the presence of the elevated temperature.

What is claimed is:  
     
         1 . A flotation body constructed of high density non-foamed plastic material; and 
 wherein the plastic material includes a mix of plastic and antistatic material to inhibit development of static electric charge.    
     
     
         2 . A flotation body according to    claim 1    wherein the body is a ball.  
     
     
         3 . A flotation body according to    claim 1    wherein the body is a hollow ball.  
     
     
         4 . A flotation body according to    claim 1    wherein the antistatic material has a melting temperature and the plastic has a melting temperature higher than the melting temperature of the antistatic material.  
     
     
         5 . A flotation body according to    claim 4    wherein the ratio of weight of the antistatic material to the weight of the flotation body is less than 10 percent to inhibit a reduction of a melting temperature of the plastic material from the melting temperature of the plastic.  
     
     
         6 . A flotation body according to    claim 4    wherein the ratio of weight of the antistatic material to the weight of the flotation body is less than one percent to inhibit a reduction of a melting temperature of the plastic material from the melting temperature of the plastic.