Method of Smoothing Surface and Process of Lost Wax Precious Casting with Resin Model Having Its Surface Smoothing by the Method

Abstract

When a powder-sintered laminated resin model of powdery resin fabricated according to sintering / laminating shaping technique is applied to lost wax precision casting, casting products have rough finished surface causing a marked drop of commercial value. Thus, there is provided a method for smoothing the porous uneven surface of powder-sintered laminated resin model, comprising a resin impregnation step of dipping the powder-sintered laminated resin model (A) in a two-pack reaction hardening type urethane resin solution (B) with work time of 1 to 5 minutes and viscosity of 7 to 30 Pas and effecting pressure reduction so as to impregnate the surface of the resin model (A) with the two-pack reaction hardening type urethane resin solution (B) and a resin hardening step of updrawing the powder-sintered laminated resin model (A) having been impregnated with the two-pack reaction hardening type urethane resin solution (B) from the two-pack reaction hardening type urethane resin solution (B) and hardening the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for smoothing a surface of a powder-sintered laminated resin model (A) with a porous rough surface fabricated according to sintering / laminating shaping technique. In detail, a surface of a model obtained by burning and laminating impalpable powder of resin is made smooth by radiating a carbon dioxide gas laser beam controlled by a computer to it, the resulting model is adapted to a lost wax precision casting as an alternative model of a wax model. BACKGROUND OF THE INVENTION [0002] Firstly, a precision casting method achieved by adopting the lost wax process in the related art is explained. Next, a model used as a model for a lost wax precious casting is explained and then a powder-sintered laminated resin model is explained. Besides, we explain about prior arts that a resin layer is provided on a surface of the powder-sintered laminated resin model with porous roughness. [0003] Firstly, a lost wax precision casting me...

AI Technical Summary

Benefits of technology

"The present invention provides a method for smoothing a surface of a powder-sintered laminated resin model with a porous rough surface. The method involves dipping the resin model in a two-pack reaction hardening type urethane resin solution and then hardening it. The resulting resin model has a smooth surface and can be used in the lost wax precision casting method. The technical effect of this invention is to provide a smooth surface to the resin model, which improves its quality and accuracy in the casting process."

Problems solved by technology

However, in the case that the foundation has larger roughness than the above range, it is necessary to level the roughness or unevenness by applying putty.

As a prior art of a method so as to smooth a surface with porous roughness of the powder-sintered laminated model, EOS discloses a working mode so as to apply a wax component to a surface of the model, but there is no method which has been reported yet.

When the powder-sintered laminated model is adapted to the lost wax precision casting, because the roughness surface of the model is traced to the inner surface of the mold and the inner surface of the mold is traced to the surface of the molding article, a smooth surface, a sharpen edge and a smooth curved surface of the molding article is difficult to be achieved, so that the molding article is far from a visually superior molding article.

Thus, a big default of the powder-sintered laminated casting process is that lamination pitches appear on the model surface, that steps are produced on a curved surface because of stepped lamination and that a smooth surface, a smooth curved surface and a sharpen edge are difficult to be achieved because traces of the particle size are remained on the surface due to melting and fusing fine particles.

Images