02701nas a2200253   4500008004100000022001400041245011900055210006900174260009300243300001200336490000700348520178100355100001602136700001502152700002202167700001902189700001902208700001802227700001402245700001702259700002302276700002102299856012702320       2016                        eng d  a0930-777X00aEffect of plug temperature on the strain and thickness distribution ofcomponents made by plug assist thermoforming0 aEffect of plug temperature on the strain and thickness distribut  aKOLBERGERSTRASSE 22, POSTFACH 86 04 20, D-81679 MUNICH, GERMANYbCARL HANSER VERLAGcMAY  a166-1780 v313 a<p>Plug temperature is a key parameter affecting the thickness distribution of thermoplastic components made by plug assist thermoforming. For a specified pair of plug and plastic sheet, the variation in plug temperature can alter the coefficient of friction (COF) between the pair. We show here how the temperature dependence of COF influences the nature and extent of biaxial stretching of the sheet and consequently the thickness distribution of the thermoformed component. In the present study, high impact polystyrene (HIPS) sheets were thermoformed into axisymmetric cups using a plug-assist process in which the aluminum plug temperature (T-plug) was varied from ambient to above the glass transition temperature of HIPS (similar to 100 degrees C). Biaxial strain maps on the surfaces of the formed cups were measured and quantified using Grid Strain Analysis (GSA). Thickness distributions of the cups were also measured. Temperature dependent COF between HIPS and aluminum was determined independently using a rotational rheometer. The measured COF was low for T &lt; 100 degrees C, whereas it increased appreciably at and above 100 degrees C. We conclude that when T-plug &lt; 100 degrees C the HIPS sheet slips on the plug during forming, and this results in biaxial stretching of the base and walls of the formed cup. In contrast for T-plug &gt; 100 degrees C, a significant reduction in the magnitude of slip is expected. Here the sheet is gripped at the clamp and by the plug during forming which causes reduced biaxial stretching of the base and increased uniaxial stretching of the walls of the cup. Simulations of plug-assist thermoforming using a temperature dependent COF showed qualitative agreement with the GSA data thereby supporting our inferences.</p>1 aMarathe, D.1 aRokade, D.1 aAzad, Lal, Busher1 aJadhav, Kishor1 aMahajan, Sunil1 aAhmad, Zubair1 aGupta, S.1 aKulkarni, S.1 aJuvekar, Vinay, A.1 aLele, Ashish, K.  uhttps://library.ncl.res.in/content/effect-plug-temperature-strain-and-thickness-distribution-ofcomponents-made-plug-assist