Unfortunately, theyhave suffered an important decrease in the last years, as upvc foot valve manufacturers a consequence of thecurrent economic and financial crisis. However, lately there have been little signsof recovery, giving hope to workers and entrepreneurs. With regard to therubber and plastic manufacture and other non-metallic mineral products, the dataconcerning the production in April 2009 is positive (+2,6%), although it lostthe 21,9% in comparison with the same month last year. There is also a negativeindex (-26,1%) comparing the first five months of this year with the sameperiod last year. Plasticfilms, although little known, are essential nowadays to various industrialsectors. They are the result of specific manufactures of plastic, such as thermoforming andextrusion processes, which are the best method to create polyethylene rolls. One of the widestapplications of polyethylene is [...]