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Compression Test

The compressive stress-strain curve is similar to the tensile stress-strain curve up to the yield strength. Thereafter, the progressively increasing specimen cross section causes the compressive stress-strain curve to diverge from the tensile curve. Some ductile metals will not fail in the compression test. Complex behavior occurs when the direction of stressing is changed, because of the Bauschinger effect, which can be described as follows: If a specimen is irst plastically strained in tension, its yield stress in compression is reduced and vice versa.

Mark's Standard Hanbook For Mechanical Engineers, P. 5-5

Cold Rolling

Cold Rolling is practical in production of thin coil stock with the more ductile metals. The number of passes or amount of reduction between anneals is determined by the rate of work hardening of the metal. Successive stands of cold-rolling help to retain heat generated in working. Tension provided by mill reels and between stands helps to increase the practical reduction per step. Bright annealing in a controlled atmosphere avoids surface pockmarks, which are difficult to get out. For highfinish stock, the rolls must be maintained with equal finish.

Mark's Standard Hanbook For Mechanical Engineers, P.13-16

Polycarbonate

     Polycarbonates show excellent dimensional stability, with good impact resistance and ductility. They are employed as a base for photographic film and also for lenses. Their toughness makes them appropriate for the manufacture of safety helmets.     ( John Martin, Materials For Engineering, Third Edition, P.160 )

      Polycarbonates, one of the strongest, toughest, and most rigid thermoplastics, are not generally considered good barrier materials. It is possible to use polycarbonate as the structural layer in a composite (co-extruded) film for use in barrier application. In such cases, polycarbonate contributes
toughness and heat resistance to the final product while other components in the composite film may provide the barrier properties
Processing Methods: Injection molding, extrusion, blow molding, and rotational molding
Applications:
• Packaging. Milk bottles, baby bottles, food containers.
• Medical. Dialysers, artery cannulas.
• Electrical. Distribution box lids, fuses, sockets, lamp holders, and covers.

Liesl K. Massey, Permability properties of Plastics And Elastomers. Chapter 26




Process Flow Chart

        Process Flow Charts are to manufacturing as road maps are to drivers. They provide detailed view of the process, and increase understanding of how the process flow. With a process flow chart teams repetitive steps, bottlwnecks, and inefficiencies in the process wich in turn helps the team identify potential failures, effects and solutions.
        The best way to create a flowchart  is to walk through the process as if you were the thing being processed or created. the process steps should be followed sequentally and notes should be taken during walk through.
         once the walk through is complate each steps should be listed on a self stick-stick note. It helps to have several people do this as each will contribute  ideas  that others missed. The steps should then be grouped and organized according to their order in the process
        For complicated process  with a several steps  and substeps it helps to create a top-down flowchart, where each of major steps in the process listed in order of flow across the top of the chart and sub-steps are listed underneath each major steps

Robin E. McDermott,Raymond J. Mikulak,Michael R. Beauregardi The Basics of  FMEA, P. 59