The influence of cutting heat on the processing of plexiglass
The thermal conductivity of plexiglass processing is only 1/4501/175 of that of ordinary metal materials, so the cutting heat generated during cutting cannot be quickly dissipated, due to the poor thermal conductivity of plexiglass. Heat accumulates in the contact part between the tool and the workpiece, causing increased tool wear. At the same time, the thermal expansion coefficient of plexiglass is 1.52 times larger than that of ordinary metals, and the glass transition temperature is about 100°C. Excessive cutting heat causes the volume of plexiglass to change and vitrification, which reduces the processing accuracy and fails to meet the processing requirements. At the same time, the volume expansion intensifies the friction between the tool and the workpiece, causing the cutting heat to rise further, forming a vicious circle.
The processing of plexiglass has a low melting point, only 160200℃, which is a thermoplastic material. Excessive cutting heat in the cutting process can easily cause fusion of the processed surface. Specifically, when the part is processed with the inner hole, the heat dissipation condition is poor, and the appearance is easy to 'grab' and show small tearing cracks. It is mistaken for the small cracks caused by the brittleness of the material during processing or the internal defects of the material itself, but it is transparent or transparent. During the water seepage inspection, there was no leakage, the transparency of the parts could not meet the technical requirements, and the surface of the workpiece was stained after processing and forming, which was far from the texture of the part material itself.
has good light transmittance and chemical stability, and its scientific name is polymethyl methacrylate. It is acid and alkali resistant, dimensionally stable, and easy to form, so it is widely used in aerospace, chemical and medical fields. In actual production applications, most of the product parts can be cast directly, but some parts with special shapes, high dimensional accuracy and surface roughness requirements often require mechanical processing. However, the mechanical properties of organic glass materials and metal materials are quite different. Their texture is brittle, notch-sensitive, and easy to crack under stress.