Machining resilient foams, requires that their pores shall first be filled with liquid and subsequently frozen, optionally also embrittling the plastic, before e.g. precision automatic machining

摘要

Gas removed from the pores is replaced by liquid. The workpiece is frozen solid and machined. Preferred features: The foam framework reaches a temperature embrittling it. The liquid sets. Cooling results from external heat removal. Freezing is induced by evaporation of a liquid with high enthalpy of vaporization. Reduced pressure removes gas or vapor from the pores. Water is introduced into the pores in the form of steam, the workpiece being subsequently cooled to minus (e.g. deg C) temperatures. Cooling results from shock freezing. Pores are filled under applied pressure, which is removed for its gasification or evaporation.