This relates to laminated preforms, the method of forming such preforms and products which may be beneficially formed utilizing such preforms. Most particularly, this relates to a preform which has formed as part of the injection molding thereof two layers of barrier material which are disposed within...http://www.google.co.uk/patents/US4781954?utm_source=gb-gplus-sharePatent US4781954 - Preform with internal barrier and products made from the same
