Integrated system for forming sheets and films of synthetic resins

An integrated commercial system for extruding a commercial end product from a polymer obtained directly from a polymerization reactor, in the absence of intermediate, energy-consuming process steps involved with the use of an intermediate product, comprising:

• (a) means for directly withdrawing substantially all of the molten polymer produced by a polymerization reactor, including transfer means for conducting said molten polymer from the polymerization reactor;
• (b) an extruder connected to said transfer means and receiving substantially all of said molten polymer withdrawn by said withdrawing means;
• (c) a film blowing extrusion die connected to said extruder for forming the extruded polymer into a tubular polymeric product so as to eliminate intermediate steps including cooling the polymer from the reactor, forming it into a suitable intermediate product, transferring the intermediate product to a processing plant and reheating and repressurizing the intermediate product to render the latter suitable for extrusion;
• (d) means for flattening said tubular product;
• (e) means for sensing the lateral dimension of the tubular product;
• (f) ventilation means for venting the interior of said tubular product to prevent undue concentrations of monomer from accumulating therein, whereby monomer dissolved in the extruded polymer which is released interiorly of said tubular product is prevented from building up to potentially explosive concentrations, said ventilation means comprising gas inlet means for introducing fresh gas into the tubular product including a first inlet passageway which is continually open during operation of the system for supplying gas into the tubular product and a second passageway communicating with said first passageway for venting fresh gas therefrom, and gas outlet means continually open during operation of the system for venting monomer-containing gas from said tubular product;
• and
• (g) means, responsive to said sensing means, for controlling said ventilation means to maintain the diameter of said extruded tubular product within predetermined limits, including a control valve arranged in said second passageway for regulating gas vented therethrough from said first passageway so as to control the amount of gas flowing through said gas inlet means into the tubular product.