摘要 |
A phosphor suspension is prepared by adding to an aqueous solution of a polyethylene oxide, a phosphor, a phosphate or a borate of an alkali metal and a phosphor bonding agent. After having passed through a filter, the phosphor suspension flows down on the inner surface of a glass bulb of a fluorescent lamp to form a phosphor layer thereon. The coated bulb is heated to a temperature which is not higher than its softening temperature while it is transported along two opposite guide rails by two endless conveyors by having both end portions supported by associated guide tips on the conveyors projecting above the guide rails.
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