Search

It is sometimes observed that the rust of the base metal appears on the surface through probable pinholes of the rust-proof coating.This report is intended to explain the method to detect pinholes by the use of electrolysis of ZnSO4 solution.As a result, it was known that the electrolysis for pinhole detection should be made with the bath having undermentioned condition (A), and procedures (B) should be followed in order to eliminate the pinholes.(A) Condition of electrolysis.Bath composition-10% ZnSO4 sol.Bath temperature-Room temp.Time-3-5sec.Terminal voltage-3V D. C.(B) B-1. Thickness of coating should be increased.B-2. Slow vapourized thinner should be used.B-3. Setting time should be extended.

Pulps made from Kozo (paper mulbery, Broussonetia kajinoki Sieb 29), one of the most essential fiber materials of the Japanese papers, were coated or impregnated with synthetic Latex resin emulsions and their mechanical and physical strength characteristics were tested.Good results in the strength test were obtained when coating was done with acryl amide water soluble resin.With regard to applying the synthetic resin in general, it was found that the results brought about by the internal addition into the fiber suspension were better than those resulted from outside addition, i. e. after the sheet is formed (and dryed to a certain degree).It was also revealed that the so-called nagashi-zuki (worker's own sheet forming motion on the mould along with his dipping out suspended fibers from the stock chest), which implies the most significant characteristic of the hand-made Japanese paper making techniques, becomes considerably difficult when the amount of the added resin exceeeds its maximum limit.

heat-transfer coefficient of condensing vapour [kcalim*hdegC]; EDWARDS and Doolittle [I], Le Fevre and Rose [?.I, and Butcher and Honour [3] have discussed the promotion of combined conductance of tube wall and resin coating [kcal!m2 hdegC] ; dropwise condensation of steam with tetrafluoroethylene coatings. Their data shows that the overall heat-transfer heat-transfer rate [kcal/m* h] ; coefficient for dropwise condensation is increased from 16