Crushing resistance

J. A. Laird and W. R. Beck. Ceramic spheroids having low density and high crush resistance. Patent EP 207668, 1989. 

CNC REZ 550 produces excellent crush resistance and shrinkage control on regular CRF or permanent press work. 

Costs of adsorption are limited by crushing resistance and abrasive strength of carbons. Losses of carbon may occur either in the filtration or regeneration process. Economical aspects limit losses of regeneration to the range of 2—5%. 

Selection of carbon is also limited by content of ash, absorbability, crushing resistance and abrasive strength, graining, and possibility of r eneration. 

Further reaction then builds up the polymer, which is called polyester and sold under trade names such as Dacron. The planar benzene rings in this polymer make it stiffer than nylon, which has no aromatic groups in its backbone, and help make polyester fabrics crush-resistant. The same polymer formed in a thin sheet rather than a fiber becomes Mylar, a very strong film used for audio and video tapes. 

Neutral sulfite semichemical" 6-8 Na+, NH4+ 1. Fluting board—provides stiffness, crush resistance to corrugated cardboard 2. Coarse wrapping papers... 

This is two to six layers of recycled paperboard which is treated with an adhesive between the layers and press-laminated together. The outside layer can be of Kraft paper to improve the strength and help better resist water and water vapour. It has good crush-resistant and anti-puncture properties. 

The selection of the carrier is relatively simple. It may be imposed by the type of reaction to be promoted. For instance, if the latter requires a bifunctional catalyst (metal + acid functions), acidic supports such as silica-aluminas, zeolites, or chlorinated aluminas, will be used. On the other hand, if the reaction occurs only on the metal, a more inert support such as silica will be used. In certain cases, other requirements (shock resistance, thermal conductivity, crush resistance, and flow characteristics) may dominate and structural supports (monoliths) have to be used. For the purpose of obtaining small metal particles, the use of zeolites has turned out to be an effective means to control their size. However, the problem of accessibility and acidity appearing on reduction may mask the evidence of the effect of metal particle size on the catalytic properties. 

Only in very rare cases can zeolites be used direetly in the form in which they were originally synthesized. For many larger-seale industrial applications, for instance, the synthetically obtained zeolite powders must be formed into larger attrition and crush-resistant partieles using inorganic binder materials [33]. In most cases a thermal treatment in air (calcination) is at least required to decompose the organic template, to dehydrate the zeolite and to desorb impurities [35]. This holds particularly true if the proton form of a zeolite is desired from the ammonium form for aeid eatalysis. 

Among the mechanical properties of greatest practical impact on catalysis applications is the attrition and crushing resistance of powdered or granular activated carbons, the most commonly used catalytic carbon materials, versus that of activated carbon fibers (ACFs) or of other, less-surface-active carbons (e.g.. 

To provide protection for the occupants in a frontal crash, there are two fore-and-aft tubular rails , which support the engine, then make an S bend and connect to the door sills. These rails have a crushing resistance of approximately 200 kN, so that the passenger cage of a 1 tonne car decelerates at approximately 20 g. To minimise the mass of these rails, a material with a high ratio of yield stress high strength steel is optimal for this component. For these two reasons, plastics are not used for the main structure of a car body. 

Safety Shoes Standard safety shoes (see Figure 28-4) have steel toes or toes containing crush-resistant materials. Safety shoes must meet certain standards. The standard calls for testing to demonstrate withstanding a 75-lb impact load and a 2500-lb compression load. Manufacturers offer safety shoes in many styles. Some come as boots. 

A series of crushing resistance tests consists in determining the stress at which the proppant material shows excessive generation of fines. Tests are conducted on samples that have been sieved. Four specific stress levels (i.e., 7.5,10,12.5, and 15 ksi) are used in the recommended practice (see API RP-61). 

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