| 摘要 |
A method of inspecting a structure for the presence of defects producing leakage comprises forming on the area of the structure to be tested a coating of a composition containing from 2 to 10% by weight of an adhesive agent, and from 0.2 to 2% by weight of a foaming agent, the balance comprising a solvent or dispersant for the adhesive agent, and applying gas pressure to said structure, whereby leakage of gas through a defect in the structure can produce a durable mass of foam at the location of the defect. The composition may also include an anti-rust agent, a hardening promoter, an antiseptic, a plasticizer, or a pigment filler. The composition may be brushed, sprayed, or rolled on to the structure. In one example, the composition comprises an adhesive agent of urea-formaldehyde resin solution and gelatine, the foaming agent is sodium dicotyl sulphosuccinate and water the solvent. In a second example, the adhesive agent consists of an emulsion of polyacrylic ester resin and glycerine, and the foaming agent is sodium dodecylbenzenesulphonate, water being the solvent. In a third example-the adhesive agent is a mixture of phenolic resin and gelatine, a hardener of phosphoric acid solution and an antiseptic of dodecylhydroxy-imidazoline are used. Alternatively, in the above examples, the adhesive agent may comprise synthetic resins, synthetic rubbers, proteins or bitumens; the foaming agent may consist of dodecylbenzenesulphonic acid, oleyldiethylethylenediane or polyoxyethylenesorbitan mondaurate; the rust inhibitors may comprise chromic acid, dichromic acid, benzoic acid, glycerol mono-oleate, sorbitan mono-oleate, N - dodecyl ammonium stearate, dicyclohexyl-ammoniumxylyl stearate or cetyldiethylammonium phenyl stearate; the hardeners may comprise chromic acid, dichromic acid or benzoic acid; and the antiseptics may comprise formalin, thymol, pentachloro phenol, phenol, dodecylhydroxy imidazoline or borax. In a fourth example, the adhesive agent is polyvinyl-acetate resin, the plasticizer is dibutyl phthalate and the foaming agent is sodium dioctylsulphosuccinate. In a fifth example, the adhesive agent is a copolymer of vinylchloride and vinylacetate, the plasticizer is tricresylphosphate and the foaming agent is polyoxyethylene-dodecylphenolether.
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