Claims
- 1. A method for cleaning and drying the surface of non-absorbent articles to remove hydrophilic residues which comprises:
- (a) immersing an article in a boiling liquid azeotropic organic solvent bath which has a density greater than water and in which water is soluble in an amount not greater than 0.1 weight percent to displace or dissolve said hydrophilic residues:
- (b) lifting the article free from the liquid solvent;
- (c) reimmersing the article in a second, non-boiling bath of said azeotropic solvent which has a greater purity than the bath of step (a);
- (d) lifting the article from the solvent bath of step (c) and into a vapor phase of said azeotropic solvent in a vapor zone;
- (e) condensing liquid azeotropic solvent from said vapor phase, freeing the condensed solvent of moisture and rinsing the article while it is in said vapor phase with said liquid azeotropic solvent that is totally freshly condensed and is substantially freed of moisture;
- (f) retaining said article in the vapor zone of said azeotropic solvent until condensation of vapor on the article has ceased;
- (g) continuously removing and purifying said liquid azeotropic solvent from step (a) which has been contaminated with hydrophilic residues as a result of said cleaning, which purification comprises
- (i) filtering said contaminated liquid azeotropic solvent from step (a) to free it of particulates,
- (ii) subjecting the filtered liquid azeotropic solvent from step (ii) to distillation to separate therefrom the relatively high boiling components, and
- (iii) subjecting the distillate from step (ii) to drying to substantially remove any residual amount of moisture; and
- (h) regulating the return flow of said substantially dried, azeotropic solvent from step (iii) to the bath of step (c).
- 2. The method in accordance with claim 1 in which water is soluble in said azeotropic organic solvent in an amount not greater than 0.05 weight percent.
- 3. The method in accordance with claim 1 wherein organic solvent in the solvent bath of step (c) is used to replenish the solvent bath of step (a).
- 4. The method in accordance with claim 3 in which said replenishing is accomplished by overflow of solvent from the bath of step (c) to the bath of step (a).
- 5. The method in accordance with claim 1 in which the drying in accordance with step (g) (iii) is accomplished by flowing the distillate through a molecular sieve.
- 6. The method in accordance with claim 1 wherein agitation is provided in the reimmersion bath of step (c).
- 7. The method of claim 1 wherein the azeotropic mixture from step (g) (iii) is filtered before introducing it to step (h).
- 8. The method according to claim 1 wherein vapor condensed above the first and second baths is collected, dried and reintroduced to the baths.
- 9. The method according to claim 8 wherein the dried condensate is filtered prior to reintroducing it to said baths.
Parent Case Info
This application is a continuation of application Ser. No. 710,764 filed Mar. 11, 1985, now abandoned.
US Referenced Citations (18)
Non-Patent Literature Citations (1)
Entry |
Simon, Cleaning System Tailored for Water-Extendables, Industrial Finishing, pp. 44-45, 12/84. |
Continuations (1)
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Number |
Date |
Country |
Parent |
710764 |
Mar 1985 |
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