Method for determining the natural value of stretching (NSR) of a Polymer composition suitable for Forming bottles, and apparatus for carrying out Said method

摘要

It provides a method and apparatus for determining the characteristics of stretching a Polymer composition suitable for use in the manufacture of Thermoplastic an article, e.g.A Bottle, and preferably a bottle that has a PET, Pen and their mixtures.The Method includes the steps of Heating Bottle Preform Polymer composition to at least its glass Transition Temperature.Then submit the free blowing to the Preform so that insufflation pressure varies inversely with respect to the expansion of the article during at least a portion of the passage of insuflacioN. unaparato free for blowing Thermoplastic articles according to the method of the invention.