International Journal of Precision Engineering and Manufacturing

Korean Society for Precision Engineering (한국정밀공학회)
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Time-dependent Optimal Heater Control in Thermoforming Preheating Using Dual Optimization Steps

  • Li, Zhen-Zhe (Department of Mechanical Engineering, Chonnam National University) ;
  • Heo, Kwang-Su (Department of Mechanical Engineering, Chonnam National University) ;
  • Seol, Seoung-Yun (Department of Mechanical Engineering, Chonnam National University)
  • Published : 2008.10.01
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Abstract

Thermoforming is one of the most versatile and economical processes available for shaping polymer products, but obtaining a uniform thickness of the final product using this method is difficult. Heater power adjustment is very important because the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the steady-state optimum distribution of heater power is first ascertained by a numerical optimization to obtain a uniform sheet temperature. The time-dependent optimal heater input is then determined to decrease the temperature difference through the direction of the thickness using the response surface method and the D-optimal method. The optimal results show that the time-dependent optimum heater power distribution gives an acceptable uniform sheet temperature in the forming temperature range by the end of the heating process.

Keywords

References

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