| 摘要 |
<p>Anticorrosive coatings are applied tot he bores of pipes, moulded tubes, or fittings of steel, iron, concrete or asbestos-cement, using a mixt. of cement mortar with wt. ratio cement:additive of 1:1.5-1:3.5, esp. 1:1.5-2. The mixt. contains (by wt.) 3-25%, esp. 5-10% (w.r.t. the wt. of cement) of resin dispersions which are difficult or impossible to saponify, esp. acrylic resins; together with the usual antifoamants and/or thinners. The mixt. may also contain pozzolana and/or mineral- and/or organic fibres, esp. asbestos, glass, or plastic fibres as reinforcement; and the water/cement ratio is 0.25-0.45, esp. below 0.4. The mixt. is fed by compressed air through a nozzle onto a spinning dish so it is thrown radially by centrifugal force against the bore of a pipe to obtain a coating of 1-5, esp. 2-3mm. The pref. spraying plants use either one or four spraying nozzles specially designed for spraying.</p> |
