Chapter 12. Plaster Mold Permeability vs Automatic Plaster Mixing

  1. William Smothers
  1. Douglas L. Hoge and
  2. Walter R. Mason

Published Online: 26 MAR 2008

DOI: 10.1002/9780470320303.ch12

A Collection of Papers Presented at the 86th and 87th Annual Meetings and the 1984 and 1985 Fall Meetings of the Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 6, Issue 11/12

A Collection of Papers Presented at the 86th and 87th Annual Meetings and the 1984 and 1985 Fall Meetings of the Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 6, Issue 11/12

How to Cite

Hoge, D. L. and Mason, W. R. (1985) Plaster Mold Permeability vs Automatic Plaster Mixing, in A Collection of Papers Presented at the 86th and 87th Annual Meetings and the 1984 and 1985 Fall Meetings of the Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 6, Issue 11/12 (ed W. Smothers), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470320303.ch12

Author Information

  1. Hoge-Warren-Zimmerman Co. 1701 Mills Ave., Cincinnati, OH 45212

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1985

ISBN Information

Print ISBN: 9780470374405

Online ISBN: 9780470320303

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Keywords:

  • microwave energy;
  • greenware;
  • quality control;
  • molecules;
  • ceramic industry

Summary

Automatic mixing of plaster slurry used for plaster molds used in ceramic casting introduces some interesting concepts concerning mold permeability. Permeability is in part a function of the uniformity or nonuniformity of the crystalline structure of the gypsum (or plaster) itself. The crystalline structure in turn depends largely on the degree of mixing imparted to the gypsum slurry. Since automatic mixing by its nature produces thorough mixing, it became evident that in certain instances the mixing was too efficient and that plaster with a uniform crystalline structure, but having fairly low permeability, was being produced. We undertook to redesign existing automatic mixing equipment to produce a largely nonuniform crystalline structured gypsum and plaster molds of high permeability. In other words, we undertook to build an inefficient mixer.