this invention the crystallinity of the pellets shall increase to the normally observed value after correcting for the presence of the blowing agent for the polymer in question however such crystallization does not have the same detrimental effect on the loading of the gaseous blowing agent in the polymer as it would have in the event that the polymer had been permitted to fully crystallize as it passed from molten to solid state as per its natural tendency owing to the gaseous blowing agent being effectively trapped within the bulk of the pellet such reasoning is inapplicable to amorphous polymers which retain gaseous blowing agents well upon solidification blowing agents are generally well known to those of ordinary skill in the polymer art a blowing agent employed herein may include any of those well known in the foamed polymer art as being useful for this purpose including but not limited to gases including hydrocarbons nitrogen carbon dioxide halogenated hydrocarbons fluorinated hydrocarbons chlorocarbons chlorofluorocarbons solid substances such as azodicarbonamide and other well known compounds which similarly evolve gases suitable for use as blowing agents in polymers when subjected to thermal energy are also herein indicated as being suitable blowing agents for inclusion in the polymer melt preferably though for purposes.