Coefficient of linear thermal expansion CLTE

When materials with different coefficients of linear thermal expansion (CLTE) are bolted, riveted, bonded, crimped, pressed, welded, or fastened together by any method that prevents relative movement between the products, there is the potential for thermal stress. Most plastics, such as the unfilled commodity TPs, may have ten times the expansion rates of many nonplastic materials. However there are plastics with practically no expansion. Details are reviewed in Chapter 2, THERMAL EXPANSION AND CONTRACTION. 

Like metals, plastics generally expand when heated and contract when cooled. Usually, for a given temperature change many TPs have a greater change than metals. The coefficient of linear thermal expansion (CLTE) is the ratio between the change of a... 

URPs generally have much higher coefficients of linear thermal expansion (CLTE) than conventional metal, wood, concrete, and other materials. CLTEs also vary significantly with temperature changes. There is RPs that does not have these characteristics. With certain types and forms of fillers, such as graphite, RPs can eliminate CLTE or actually shrink when the temperature increases. 

Coefficient of linear thermal expansion (CLTE) ASTM D696 ASTM E831 ISO 11359-1, -2... 

The change in length per unit length of a material per degree of temperature change is called the coefficient of linear thermal expansion (CLTE). The measurement of the CLTE is covered by several ASTM and ISO methods ... 

Table 2-19. Examples of the Coefficient of Linear Thermal Expansion (CLTE) for... 

Thermal Expansion of Polymeric Materials In addition to the glass transition and melting temperature measurements, the other major application of TMA is determination of the thermal expansion of polymeric materials. The coefficient of linear thermal expansion (CLTE or a) is the slope of the relative change in the length (AL/Lo) with respect to the temperature range of interest, as defined by Eq. (4.2) (see Fig. 4.2b). CLTE measurements are important for many reasons. For example, mismatch in CLTE values may cause dimensional change or delamination in composites and adhesives due to the thermal stresses. 

ETPs can be formulated to give coefficient of linear thermal expansion (CLTE) of comparable to many metals. The lower CLTE would decrease stresses from differences in thermal expansion and potentially reduce product failure and extend product life. 

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