Manufacture, post-forming

Post-forming type is an HPDL similar to the general-purpose type but is capable of being thermoformed under controlled temperature and pressure in accordance with the laminate manufacturer s recommendations. 

The type of varnish used in the process depends on the kraft paper manufacturer and basis weight of the papers the machine, temperature, and control (scraper bars, squeeze roUs) used the method of cutting the paper to size the laminate being produced (post-forming or regular) and the press-cure cycle (see Laminated materials, plastic). 

Plastic products are made by a variety of basic manufacturing processes. As an example a major method such as extrusion has subdivisions that include profile, pipe, tube, film, sheet, coating, post forming, etc. equipment In injection molding there are subdivisions such as coinjection, gas assist, foam, inmold decorating, etc. equipment. There are literally hundreds of processes used with only about the dozen, as reviewed in this chapter, that are principally used (2). 

Finishing Post-Forming Manufacturing of Zeolite Catalysts and Adsorbents 71... 

Hot Melt, Field-Extruded Sealants. Several butyl raw material manufacturers and sealant producers have recently developed butyl tapes. These are premasticated, high viscosity thermoplastic compositions that are fed as talced ribbons into a polymeric sealant applicator (PSA). Within the PSA, the compound is heated and extruded into the joint opening to form a smooth joint that cools rapidly with excellent adhesion claimed, even to oily or otherwise poorly prepared surfaces. These hot-applied, post-formed butyl tapes have been successfully used to seal insulated glass units, automotive windshields (Fig. 4), curtain walls, concrete pipes, precast concrete structural joints, and as bedding compounds in combi-... 

A.irbome Basic Chemical Contamination. A critical, and at-first pu22ling problem, was encountered during early manufacturing trials of CA resists. Sporadically, severely distorted resist profiles would be formed in positive-tone CA resists, displaying what seemed to be a cap on the upper surface of the resist image (Fig. 26). In severe cases this cap or T-top would appear as a kin or cmst over the entire wafer surface that prevented development of the pattern. The magnitude of the effect varied dramatically between laboratories and appeared to grow more severe as the time interval between exposure and post-exposure bake was increased. 

Although spray-dryiag accommodates relatively high content of surfactants, certain types, such as the alkanolamides and some nonionic surfactants are best added to the product after spray-dryiag. Post additioa aot only protects the surfactant from the heat of the tower but also prevents the formation of aerosols ia the exit gas. Aerosols are more difficult to trap ia the scmbbiag system than soHd fines. They are formed by unsulfonated matter from the manufacture of LAS and nonionic surfactants with short ethylene oxide chains (120). 

The surface of carbonaceous materials contains numerous chemical complexes that are formed during the manufacturing step by oxidation or introduced during post-treatment. The surface complexes are typically chemisorbed oxygen groups such as carbonyl, carboxyl, lactone, quinone, and phenol (see Fig. 3). 

CDER Guidance for Industry. SUPAC-IR Immediate-Release Solid Oral Dosage Forms Scale-Up and Post-Approval Changes Chemistry, Manufacturing and Controls, In Vitro Dissolution Testing, and In Vivo Bioequivalence Documentation US Food and Drug Administration, 1995. 

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