Plastic logs

Abstract

Plastic logs having a smooth, textured, glossy surface with a nominal diameter greater than 2 inches and a flexural modulus at 40° F. of at least 70,000 psi. Thermoplastic material comprising such logs is preferably substantially polyolefin and other plastic materials having a higher melt temperature, e.g. a melt temperature at least 20° C. higher than the melt temperature of the polyolefin component. Such logs are produced by extrusion through a circular die to a heat transfer medium Such extruded logs are especially useful for durable fencing.

What is claimed is:  
     
         1 . A plastic log having an average diameter greater than 2 inches, a flexural modulus at 40° F. of at least 70,000 psi and a diameter deviation in the range of 2 to 60%.  
     
     
         2 . A log of claim comprising at least 80% of thermoplastic material.  
     
     
         3 . A log of  claim 2  wherein said thermoplastic material comprises at least one polyolefin selected from the group consisting of polyethylene and polypropylene.  
     
     
         4 . A log of  claim 3  further comprising at least one other polymeric material having a melt temperature at least 20° C. higher than the melt temperature of said polyolefin.  
     
     
         5 . A plastic log having deviations in diameter simulating a natural wood log comprising at least 80% polypropylene and having an average diameter greater than 2 inches, a flexural modulus at 40° F. of at least 90,000 psi and a diameter deviation defined by the algorithm ((D−d)/D)×100 in the range of 2 to 60%, where D is the maximum diameter and d is the minimum diameter.  
     
     
         6 . A method of producing a plastic, cylindrical log comprising extruding through a circular die a plastic material to form a cylindrical mass with a molten surface and cooling said molten surface with an air stream from an annular nozzle proximate to said die.  
     
     
         7 . A method of  claim 6  wherein said shape is further cooled by contacting with an aqueous fluid.  
     
     
         8 . A method of  claim 7  wherein said shape is further cooled by natural air convention around a supported length of log.  
     
     
         9 . A method of  claim 8  further comprising pulling said shape from said die.