Abrading – Abrading process – Utilizing fluent abradant
Patent
1994-06-09
1996-09-24
Meislin, D. S.
Abrading
Abrading process
Utilizing fluent abradant
451 75, 451 90, 451101, 451 39, B24B 100
Patent
active
055585620
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method of performing dry micro-cleaning by spraying abrasive powder having a very small grain size, the method enabling high cleaning speeds to be reconciled with exceptionally fine blasting.
There are numerous possible applications for the method of the invention. It is principally useful when various dirty stains and encrusted deposits are to be blasted off very finely from valuable, delicate, or fragile media.
In this way, a main application of the method of the invention is to blasting off pollutants and pollution that has become stuck to the surfaces of the outside faces of monuments and of buildings.
Industry releases numerous chemical pollutants into the atmosphere. Such pollutants (which comprise new types and new quantities of pollution) become stuck to the surfaces of the outside faces of monuments and of buildings, and they ultimately spoil the appearance of such monuments and buildings by gradually making them black and dirty.
Furthermore, in many cases, such pollution encrusted on the exposed stonework accelerates to a greater or lesser extent the degradation process of the stone used.
Under the action of such pollution, the surfaces of the exposed stonework of many monuments become weakened in a very non-uniform manner and to widely varying extents. Since the layer of pollution tends to become increasingly pellicular, it masks the weakened regions to a progressively increasing extent, thereby making the work of blast-cleaning the surfaces of such stone buildings an operation that is very fine and very fiddly.
Although exposed stonework has always been washed with water, today many scientists who are working on the problems of degradation in exposed stonework emphasize that cleaning off new pollutants by washing enables the pollutants to penetrate via capillary action, via joints that are faulty to various extents, or via surface points that have already been weakened, thereby contributing to accelerating the degradation process. Water, which in that case acts both as a chemical reagent and as a carrier of harmful salts, is becoming less and less suitable for cleaning off pollutants stuck to the surfaces of cut stone, especially if such surfaces have also been weakened (by flaking, pitting, etc.).
Unfortunately, in spite of the drawbacks of washing techniques using water, architects in charge of the upkeep and conservation of monument faces nevertheless hesitate to prefer cleaning by spraying abrasive particles, even fine particles, because of the risk (which varies in size) of subjecting the surface layer of the blast-cleaned stonework to abrasion.
In time, the surface layer of the cut stone used becomes covered with a fine crystallized layer that is harder than the inside of the stone and that protects the stone against external aggression of all kinds. The thickness of the fine protective layer varies in the range 2 millimeters to 5 millimeters, and such a layer forms a calcium-rich crust (or a sulfur-rich crust in an urban atmosphere). It is therefore essential to avoid subjecting the fine crystallized layer to abrasion if the stone is to be protected, especially since this fine film is progressively weakened under the action of pollution. In addition, such blackish pollution masks degraded regions and regions that are undergoing degradation, thereby making it difficult to see these weakened regions.
As a result, cleaning off pollution that has become encrusted on and stuck to cut stone surfaces is an operation that is becoming increasingly fiddly, requiring meticulous care and painstaking attention, and currently-used dry abrasive spraying techniques involve a risk of subjecting the material to abrasion and to aggression, which risk varies depending on the state, the hardness, and the uniformity of the hardness of the surface layer.
Sand-blasting is one of the basic abrasive spray techniques. It is very approximate, and very dusty, and it uses an arbitrary size of sand jet, which jet is fixed, unitary, and unidirectional, and is displaced manually by ope
REFERENCES:
patent: 1944404 (1934-01-01), Coble et al.
patent: 1951627 (1934-03-01), Pelk
patent: 2605596 (1952-08-01), Uhri
patent: 2644275 (1953-07-01), Hoguet
patent: 2669809 (1954-02-01), McGrath
patent: 2755598 (1956-07-01), Van Denburgh
patent: 2900851 (1959-08-01), Rutledge
patent: 3561163 (1971-02-01), Arnold
patent: 4045915 (1977-09-01), Gilbert et al.
patent: 4112535 (1978-09-01), Wild et al.
patent: 4439954 (1984-04-01), Bennett
patent: 4600149 (1986-07-01), Wakatsuki
patent: 4727687 (1988-08-01), Moore
patent: 4941298 (1990-07-01), Fernwood et al.
patent: 4986475 (1991-01-01), Spadafora et al.
Patent Abstracts of Japan, vol. 3, No. 7, 24 Jan. 1979 & JP-A-53132434 18 Nov. 1978.
Patent Abstracts of Japan, vol. 7, No. 189, 18 Aug. 1983 & JP-A-5809063 30 May 1983.
Patent Abstracts of Japan, vol. 9, No. 80, 10 Apr. 1985 & JP-A-59209768 28 Nov. 1984.
Banks Derris
Meislin D. S.
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