about 25 and preferably at least about 40 thus causing the final composite product to have a stiffness comparable to natural wood the preferred polypropylene for use in the invention is reactor flake polypropylene i e the polymer flakes as they are produced in the reactor preferably without any further treatment e g without the addition of chemical additives or modifiers to the polypropylene the preferred polypropylene has a melt index at 230 u00b0 c of from about 0 10 g 10 min preferably from about 0 1 4 g 10 min and more preferably from about 0 1 1 g 10 min furthermore it is preferred that the polypropylene has a bulk density of from about 20 40 lbs ft 3 and more preferably from about 28 32 lbs ft 3 the average fiber length or particle size of the polypropylene flakes utilized should be from about 350 1 000 u03bcm and preferably from about 500 700 u03bcm the resulting composite product is in the form of a self sustaining body and has an astm d 6109 flexural modulus of from about 600 1 100 psi and preferably from about 800 1 100 psi the product should have an actual density of from about 40 60 lbs ft 3 and preferably from about 50 58 lbs ft 3 a number of optional ingredients can also be added to modify or.