On-line pH value measurement of solution on the removing support material process

Removing support material from rapid prototyping (RP) part fabricated by fused deposition modeling is essential once the physical model is completed. Removing the support material from RP parts efficiently is an important concern because the product life cycle is shorter than before. In this study, a new on-line optical measurement system was developed to measure the pH value of solution during removing support material from fused deposition molded parts. The pH value of the solution can be predicted directly from the obtained maximum peak intensity according to the linear regression equation. The maximum discrepancy can be controlled within 4.37%. The time saving in removing the support material from RP parts up to 70.3% can be obtained by means of using the on-line measuring system for measuring the pH value of solution and compensating the pH value of solution immediately during the removing support material process.