In mechanical engineering, polyurethane is often used in the production of precise prototype tools, molds and models (control devices). These products have high requirements for dimensional accuracy. Thermal expansion of polyurethane can be the reason that products become dimensionally inadequate. Polyurethane test bodies were produced with the CNC machine. The change in body volume due to thermal expansion was determined experimentally utilizing the CMM machine. The assessment of the temperature influence on the dimensional accuracy of products was given. It has been shown that temperature, or its variation, has a major influence on the dimensional suitability of precision-manufactured polyurethane products, which is too often neglected in practice. The production of a test volume by bonding several equal sized pieces of polyurethane with a two-component adhesive has an effect on the final thermal expansion of the body so produced, but no effect on its temperature response over time. For products made from a homogeneous piece of polyurethane, it is assumed that the coefficient of volumetric thermal expansion can be taken to be three times the value of the linear thermal expansion (β ⡈ 3α).
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