Tensile strength longitudinal

A variation of the preceding process is used to produce oriented vinyUdene chloride copolymer films. The plastic is extmded into tube form and then is supercooled and subsequently biaxiaHy oriented in a continuous bubble process. The supercooled tube is flattened and passed through two sets of pinch roUs, which are arranged so that the second set of roUs travels faster than the first set. Between the two sets, air is injected into the tube to create a bubble that is entrapped by the pinch roUs. The entrapped air bubble remains stationary while the extmded tube is oriented as it passes around the bubble. Orientation is produced in the transverse and the longitudinal directions, creating excellent tensile strength, elongation, and flexibiUty in the film. The commercial procedure has been described (157). 

The longitudinal crack apparent in Fig. 12.21 resulted from stresses from internal pressure that exceeded the tensile strength of the metal in the greatly thinned tube wall. 

Figure 13. Fiber loading vs. longitudinal tensile strength for various fibers...

The materials tested were mainly unidirectional and bidirectional satin cloth laminate. Unsaturated polyester resin was used as a matrix. The tensile strength ratio of longitudinal fiber to transverse fiber was... 

The thickness t (inches) of shell for a working pressure of p (pounds per square inch) is given by t — aDp -r 2T, where T = tensile strength of plate, pounds per square inch D == shell diameter, inches a — factor of safety divided by efficiency of longitudinal-riveted joint. Thicknesses are rarely below % in. for small boilers or... 

Longitudinal and transverse tensile tests are prescribed in the case of aluminium and aluminium alloys of great strength of thickness greater than 1 mm., and involve the determination of Elastic Limit, Tensile Strength, and % Elongation. 

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