Method for controlling polymer shrinkage

Abstract

It is herein disclosed a method for controlling the shrinkage of parts formed from semi-crystalline polyolefin involving the addition of a suitable nucleant(s), in a suitable amount. This method results in reduced processing costs primarily due to reduced processing cycle time and to greater flexibility in the use of processing equipment.

What is claimed is: 
     
       1. A method for controlling the shrinkage of parts formed from nucleated semi-crystalline polyolefins comprising adding from about 0.0001 to 5 weight percent of at least one nucleant to said semicrystalline polyolefin during processing. 
     
     
       2. A method as in claim 1 wherein said nucleant is present in an amount of from 0.1 to 1 wt. %. 
     
     
       3. A method for controlling the shrinkage of parts formed from nucleated polybutene-1 comprising adding from about 0.0001 to 5 weight percent of one or more nucleant to said semi-crystalline polyolefin during processing. 
     
     
       4. A method as in claim 3 wherein said nucleant is present in an amount of from 0.1 to 1 wt. %. 
     
     
       5. A method as in claim 4 wherein said polybutene is isotactic polybutene. 
     
     
       6. A method as in claim 3 wherein said nucleant is an organic nucleant.