Patents by Inventor Dunstan H. Peiris

Dunstan H. Peiris has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5415830
    Abstract: The disclosure relates to a binder, and the method of formulating the said binder, which is suitable for shaping parts from metallic and/or ceramic particles by injection molding. The binder comprises materials that are mainly thermoplastics, each of which having a percentage that is determined by its thermogravimetric analysis (TGA) profile and a weight loss versus highest binder removal rate from a green body by progressive heating. The removal of this binder from the green body is performed within a much shorter period of time than those published in the prior art. An example binder comprises 40-70% HDPE, 18-30% Paraffin wax, 10-25% microcrystalline wax and 2-5% stearic acid. Another binder comprises 35-65% PP, 23-35% paraffin wax, 10-25% microcrystaline wax and 2-5% stearic acid.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: May 16, 1995
    Assignee: Advanced Materials Technologies Pte Ltd
    Inventors: Jian G. Zhang, Dunstan H. Peiris, Jun W. Zhao, Sow W. Loh
  • Patent number: 5401462
    Abstract: The disclosure relates to a binder, and the method of formulating the said binder, which is suitable for shaping parts from metallic and/or ceramic particles by injection molding. The binder comprises materials that are mainly thermoplastics, each of which having a percentage that is determined by its thermogravimetric analysis (TGA) profile and a weight loss versus highest binder removal rate from a green body by progressive heating. The removal of this binder from the green body is performed within a much shorter period of time than those published in the prior art. An example binder comprises 40-70% HDPE, 18-30% Paraffin wax, 10-25% microcrystalline wax and 2-5% stearic acid. Another binder comprises 35-65% PP, 23-35% paraffin wax, 10-25% microcrystaline wax and 2-5% stearic acid.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: March 28, 1995
    Assignee: Advanced Materials Technologies Pte Ltd
    Inventors: Jian G. Zhang, Dunstan H. Peiris
  • Patent number: 5397531
    Abstract: Metal injection-molded green bodies (2) are formed from a granulated feedstock comprising metal powder and a binder comprising:a) 15-25 volume % paraffin waxb) 20-30 volume % microcrystalline waxc) 45-60 volume % polyethylene.The paraffin wax has two melting regions around 45.degree. C. and 63.degree. C. and the microcrystalline wax exhibits four melting regions in the range 62.degree. C. and 144.degree. C. By raising the temperature of the oven in a controlled manner, first the paraffin wax and then the microcrystalline wax melts and is vapourised and entrained in a flow of carrier gas which flows over supporting trays (5), as indicated by the horizontal arrows (a). The requirement for wicking powder is eliminated by the staged removal of the wax and the polyethylene can subsequently be removed at a higher temperature by thermal depolymerisation in the same apparatus.
    Type: Grant
    Filed: June 2, 1993
    Date of Patent: March 14, 1995
    Assignee: Advanced Materials Technologies Pte Limited
    Inventors: D. Dunstan H. Peiris, Jian G. Zhang
  • Patent number: 5332543
    Abstract: The disclosure relates to a binder, and the method of formulating the said binder, which is suitable for shaping parts from metallic and/or ceramic particles by injection molding. The binder comprises materials that are mainly thermoplastics, each of which having a percentage that is determined by its thermogravimetric analysis (TGA) profile and a weight loss versus temperature profile that is designed for the binder to allow highest binder removal rate from a green body by progressive heating. The removal of this binder from the green body is performed within a much shorter period of time than those published in the prior art. An example binder comprises 40-70% HDPE, 18-30% Paraffin wax, 10-25% microcrystalline wax and 2-5% stearic acid. Another binder comprises 35-65% PP, 23-35% paraffin wax, 10-25% microcrystaline wax and 2-5% stearic acid.
    Type: Grant
    Filed: August 26, 1992
    Date of Patent: July 26, 1994
    Assignee: Advanced Materials Technologies Pte Ltd
    Inventors: Jian G. Zhang, Dunstan H. Peiris, Jun W. Zhao, Sow W. Loh