Process for surface finishing insoluble plastics
AssigneeBaxter Travenol Laboratories, Inc.
InventorsHerbert M. Cullis, Frederick Klaiber
Life of this patent
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Abstract
A fluid medium is used in a process for polishing all surfaces of plastic components made of a material which is insoluble or inert within that fluid medium unless subjected to a temperature at which the insoluble plastic would deform. The process, which is particularly suitable for polishing the internal surfaces of tubing components for medical equipment, includes applying a vaporized solvent at an elevated pressure to liquify or melt the insoluble plastic component surfaces without deforming the component, followed by solidifying or freezing the surfaces by removing the component from the presence of the vapors.
Claims12
A process for surface finishing inert, insoluble plastic component parts, comprising:
- selecting a component part made of an inert, insoluble plastic material, said plastic material being substantially insoluble in organic solvents including a selected fluid medium at room temperature and being soluble in organic solvents including said fluid medium at standard, substantially atmospheric pressure only when heated to a temperature at which the part will deform;
- preheating said component part to a selected temperature;
- placing said preheated component part within a substantially gas-tight environment;
- adding said selected fluid medium into said substantially gas-tight environment;
- said fluid medium being liquid at room temperature and being vaporizable within said environment at a treatment temperature below said temperature at which the component part will deform, and said selected fluid medium being a fluid in which the inert, insoluble plastic component is insolubilizable at room temperature and at all temperatures below said temperature at which the component part will deform;
- heating said added selected fluid medium to said treatment temperature while said environment is maintained gas-tight to vaporize said fluid medium and to develop a positive vapor pressure within said substantially gas-tight environment, said vapor pressure forming a treatment pressure within said substantially gas-tight environment that is greater than said standard, substantially atmospheric pressure, said treatment pressure being between about 31/2 to 15 pounds per square inch (gauge);
- contacting the preheated component part, while at a temperature less than the treatment temperature, with said fluid medium at said greater than atmosphere treatment pressure to liquify the surfaces of said part while within said gas tight pressurized environment;
- and
- solidifying said liquified surfaces of said component part.
Dependencies are inferred from the claim text.