A Rapid-Set Cement Suitable as a Molding Sand Binder for Small Ferrous Castings

Details

• Personal Author:
  Sanders SD ; Scott ED ; Sullivan, G. V.
• Description:
  The Tuscaloosa Research Center investigated using rapid-set cement as a suitable molding sand binder for small ferrous castings; currently petroleum-based binders are used. Substitution of a rapid- set cement would eliminate organic vapors associated with the petroleum-based binders; these vapors constitute occupational hazards and environmental pollutants. A binder containing 60 percent white portland cement (wpc) and 40 percent calcium aluminate (ca) would be an acceptable and economic substitute for petroleum- based binders where the foundry requirements are compatible with its limitations. It produced a set time and a pattern strip time of less than 1 hour. Cement, sand, and water mixtures developed compressive strengths from about 40 to 75 psi after 2 hours and from 120 to 130 psi after 24 hours. Tensile strengths of 18 to 22 psi were obtained after 2 hours, increasing to 30 to 35 psi after 24 hours. The addition of about 1 percent polyphosphate to the sand- cement-water mixture doubled the compressive strength and increased the tensile strength about 50 percent after 4 hours, but also increased the set time from 30 minutes to 1 to 1-1/2 hours. Polyvinylacetate (pva) resin latex additions resulted in rapid strength development. When castings were poured into the cement- bonded molds, the surface finish was fair to good on gray iron castings, but some areas of burn-on were present on steel castings. Using a graphite wash on the cement-bonded molds produced good surfaces on gray iron castings. [Description provided by NIOSH]
• Subjects:
  Occupational Health Safety
• Series:
  Mining Publications
• Subseries:
  Report of Investigations
• Document Type:
  Text
• Genre:
  Conference Publications ; Case Report
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  TURC - Tuscaloosa Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-16
• NIOSHTIC Number:
  nn:10006830
• Federal Fiscal Year:
  1980
• Peer Reviewed:
  False
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e143acc77034c18a92673cbc9939b7b023d93f3e28d5af26e5448f3042ac15b66ecafd15b99f23d392f2af3264aae058c83097f29becfddaf3ae635dae9f7093
• Download URL:
  https://stacks.cdc.gov/view/cdc/233947/cdc_233947_DS1.pdf
• File Type:
  [PDF - 5.50 MB ]