Transverse shrinkage

Boyd (39) has reviewed the published data and theories of anisotropic transverse shrinkage. He has concluded, in agreement with Bosshard s (40) contention, that the dominant factor is the greater degree of lignification in the radial walls. This characteristic reduces sorption of water (Figure 11). Boyd also attributes a significant effect to the preponderance of radially flattened thick-walled cells in the latewood of some woods, particularly conifers. 

The modulus of elasticity in tension shown here is the quotient of the tension (ti) and the elongation (c) in the case of bar elongation with unhindered transverse shrinkage. It was determined in accordance with DIN 53457. 

In such materials, transverse shrinkage is usually greater than shrinkage in the flow direction. When the polymer is cooled so rapidly that the polymer chains do not have sufficient time to relax, this orientation produces retained or molded-in stress. 

Tlm shrink of Icttilu al welds have been correlated by Sp ragen aad Etti r ( 2). For transverse shrinkage of buttwelds the follow ig relationship h[Pg.303]

Referring to Fig. 15.10, the total radial deflection due to transverse shrinkage of a number of seams in one layer is... 

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