METHOD OF CLEANING SURFACES
First Claim
Patent Images
2. The method of removing deposits of soils from surfaces which comprises applying to said surfaces a caustic alkali having about 5 percent of more of free hydroxyl;
- applying an aqueous acidic solution containing an acid-base indicator that changes color at pH between about 4 and 11 to substantially neutralize the caustic.
0 Assignments
0 Petitions
Accused Products
Abstract
A method of removing deposits of soil from surfaces, which comprises applying to said surfaces a caustic alkali including an acid-base color indicator, and applying an aqueous solution which is sufficiently acidic to substantially neutralize the caustic and visibly change the color of the caustic. The method has particular efficacy for the cleaning of the interior surfaces of ovens and similar surfaces.
127 Citations
5 Claims
-
2. The method of removing deposits of soils from surfaces which comprises applying to said surfaces a caustic alkali having about 5 percent of more of free hydroxyl;
- applying an aqueous acidic solution containing an acid-base indicator that changes color at pH between about 4 and 11 to substantially neutralize the caustic.
-
3. The method of removing deposits of calcined food soils from surfaces, which comprises applying to said surfaces a highly caustic foam having about 5 percent or more of free hydroxyl and containing an amount of an acid-base indicator that will produce a cOlor change at a pH of about 4 to about 11;
- and then applying an aqueous acidic solution to substantially neutralize the caustic foam to produce a change in color of said foam.
-
4. The method of removing deposits of calcined food soils from surfaces which comprises applying to said surfaces an alkaline material containing a caustic alkali having about 5 percent or more of free hydroxyl and an acid-base indicator that produces a color change at a pH of about 4 to about 11;
- and then applying an aqueous solution which is sufficiently acidic to substantially neutralize the alkaline material and to change the color of the alkaline material.
-
5. The method of claim 4 in which said acid-base indicator is selected from the group consisting of phenolphthalein, thymolphthalein, brilliant yellow, meta cresol purple, thymol blue, neutral red, phenol red, methyl red, paranitro phenol and bromthymol blue.
Specification