Thin-wall applications

The production of thin-walled parts is one of the major challenges of the plasticprocessing industry today. Thin-wall applications are found mainly in packaging, casings and housings, but also in technical devices and articles (medical, optical, electronic, and telecommunications technologies). 

High pressure in loop can result in relatively high hydrogen concentrations and a wide range of MFR (wider than others), which is especially important for thin wall applications within the packaging industry. Obtaining good utilization of propylene because unreacted propylene from the loop is apparently fed to gas phase reactor. 

Gammagraphic weld inspection in the lower range of steel thicknesses has been done with Iridium and Ytterbium isotope sources throughout the past. The large majority of applications has been using Iridium due to the unfavourable economical parameters of Ytterbium, obviously with non-optimal results at thin wall inspections. 

The higher transparency coupled with the rigidity expected of a conventional polypropylene homopolymer is of particular interest in thin-wall moulding applications. 

One method that can be used to overcome most of the environment-induced problems is to use plastic tubing to shield the beam. This tubing can be placed between the transmitter and receiver of the optical-alignment fixture. It should be sized to permit transmission and reception of the light beam, but small enough to prevent distortion caused by atmospheric or environmental conditions. Typically, 2-inch, thin-wall tubing provides the protection required for most applications. 

Intergranular Oxidation Intergranular penetration of oxide can be a serious problem particularly when thin-walled components are used in load-bearing applications such as cooled turbine blades. Mass change data often do not adequately reflect the extent of this type of attack, and examination... 

Resistance to puncture is another type of loading. It is of particular interest in applications involving sheet and film as well as thin-walled tubing or molding and other membrane type loaded structures. Hie surface skins of sandwich panels are another area where it is important. A localized force is applied by a relatively sharp object perpendicular to the plane of the sheet of material being stressed. If the material is thick compared to the area of application of the stress, it is effectively a localized compression stress with some shear effects as the material is deformed below the surface of the sheet. 

A common pressure vessel application for pipe is with internal pressure. In selecting the wall thickness of the tube, it is convenient to use the usual engineered thin-wall-tube hoop-stress equation (top view of Fig. 4-1). It is useful in determining an approximate wall thickness, even when condition (t < d/10) is not met. After the thin-wall stress equation is applied, the thick-wall stress equation given in Fig. 4-1 (bottom view) can be used to verify the design (Appendix A PLASTICS DESIGN TOOLBOX). 

Spray 0.1 ohm per square foot hard, dense coating. mechanical bonding to plastic special applications equipment required requires special applicator safety procedures for dust and fumes warps thermoplastics not suitable for thin-walled designs not field repairable. 

Etringer, M.D., Mumford, N.A. In Composite Case Subcommitee Conference (1987) JANNAF Thin-Wall Composite Case Development for SDI Application JANNAF Joint Army, Navy, NASA, and Air Force... 

Thin-walled (approximately 0.010-0.040 in., or 0.25-1.0 mm) tubing is usually selected by continuous service temperature, which may range from 90°C (194°F) for some PVC tubing up to 250°C (482°F) for tubing made from PTFE. The main use of thin shrink tubing is in electrical and electronic applications. 

A very high price and performance family of polymers called liquid crystal polymers (LCPs) exhibit extremely high mechanical and thermal properties. As their ease of processing and price improve, they may find application in thin-wall, high strength parts such as nails, bolts, and fasteners where metal parts cannot be used for reasons of conductivity, electromagnetic characteristics, or corrosion. 

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