Grade selection

Although less known than diatomite, these products have been in wide use for many years so that there exists a sound body of applications knowledge upon which to base grade selection, dosage, and procedures. Perlite and Solka-floc have the same availability in bagged, semi-bulk, or bulk formats as diatomite. 

Framework of load compensator on plane wings injection moulding of carbon fibre reinforced PEEK replaces the aluminium alloy previously used. This part plays a critical role in plane safety and must resist the static and dynamic stresses and hydraulic fluids. The grade selected after many tests has a high fluidity allowing the manufacture of parts with dimensions of 200 mm by 400 mm. With 30% carbon fibre reinforcement, this PEEK grade ... 

Note that there are two distinct steps in negative creation—expose and develop. The same distinction applies to printmaking—exposure and contrast control. Thus, our axiom for printmaking is expose (exposure time) for the highlights and contrast control (VC filters or paper grade selection) for the shadow areas. 

Particle size distribution the particle size distribution of xylitol depends upon the grade selected. Normal crystalline material typically has a mean particle size of 0.4-0.6 mm. Milled grades are commercially available that offer mean particle sizes as low as 50 pm. Individual suppliers literature... 

Table 14.2 Typical properties of EVOH copolymers (For purposes of comparison the grades selected all have a MFI (2.16kg, 190°C) of 1.7-1.8. Grades with other MFl values are also available)...

Table 8.3 Plain bearing ISO viscosity grade selection [34]...

Saipem S.p.A. Butene-1, polymerization grade Selectively prehydrogenated Raffinate-2 from MTBE Butene-1 recovery via superfractionation 4 2010... 

PVC is a complex raw material and all its attributes determine its different applications, but its morphology is most likely more influential on PVC grade selection for a particular task than all other parameters combined. This will be become clear... 

Knives chip Too much vertical overlap Incorrect horizontal clearance Incorrect passline Incorrect stripper ring practice Speed mismatch Incorrect knife grade selection... 

Shear knives are manufactured from a variety of tool steels. The tensile strength and thickness of the metal being sheared determines the type of tool steel selected. Grade Selection is a function of balancing the variables of wear resistance, toughness, thermal properties, and cost. 

Fig. 12-3. The cabinet, access door, motor assembly and drum assembly of Lennox s central humidifier is molded from polyphenylene oxide (PPO) to solve corrosion problems that exist with metal components when exposed to the various water conditions across the country. The grade selected is rated SE-1 according to U.L. Bulletin 94 on flammability.,This and the material s high heat resistance of 265° F enabled the units to be certified by the Air Conditioning Refrigeration Institute as passing all requirements of their standard 610 which measures capacity and ability to withstand a 200-250°F temperature. (Courtesy Lennox Furnace Co. Mar-shalltown, Iowa)...

In addition, a change in a specific polymer parameter may affect both processability and basic physical properties and both of these can interact in governing the behaviour of a fabricated article. Comprehensive experimental data are therefore necessary to understand effectively the behaviour of plastic materials and to give a realistic and reliable guide to material and grade selection. 

Based on their need for reliability, the customers may request in the product specification that the system has a strictly defined high confidence level (e.g., 98 %). The predetermined level of confidence impacts the choice of product s components and selection between different available component grades, balancing cost with quality. The component grade selection is also dependent on how the system is designed, i.e., how many units of a specific component are used and if there is any component redundancy. Equations that are used to calculate the reliability factors are as follows ... 

The door-mounted rear view mirror with a plastic body, now a virtually universal feature, was a French innovation, introduced with the Renault 14 in 1976. The great majority of today s mirror housings are moulded in glass reinforced nylon, in a variety of formulations based on both PA 6 and PA 66. Black UV-stabilized grades are normally used, with body colours an added refinement for high series models (see Fig. 5.20). Reinforced nylon is used because of the mechanical performance requirements of remote-controlled mirrors, especially the creep resistance needed for the mechanisms to survive the touch-up ovens. The precise grade selection depends on whether die-castings are used for any of the structural elements (still the... 

Shenoy, A. V, Estimation of compounding conditions and grade selections in the prq -ration of fliermoplaslic melt blends, Pofym. Plastics TedmoL Eng., 24,27-41 (1985). Saini, D. R. and Shenoy, A. V., A new method for the determination of flow activation energy for polymer melts,/. MacromoL ScL—P /s., B22,437-449 (1983). Speed, C. S., Formulating blends of LLDPE and LDPE to design better film, Plastics Eng. (July 1982), p. 39. 

Today, with the proliferation of plastics types and grades, selection of the best plastics material to use is frequently not a simple problem. In the main this has to take into account not only the functionality of the end product, but the possible life span of the article to be produced and its material and production cost. Even more fundamental is of course the basic question, why plastics However, it must be assumed that for very good reasons the designer has satisfied himself that on all these counts plastics can offer advantages over traditional materials. 

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