JPS59207540A - Manufacture of fluorescent lamp - Google Patents

Abstract

PURPOSE:To remove liquid film formed on the lower end surface of a glass bulb by means of a low pressure gas by supporting the glass bulb vertically, coating the internal surface with the phosphor suspension and blowing the gas in while closing the upper end of the glass bulb. CONSTITUTION:The glass bulb of a phosphor lamp whose both ends are open is supported in the vertical direction and the internal surface is coated with a film 2 by allowing the phosphor suspension to flow from the upper end surface using a nozzle. A plate-like closing member 4 made of rubber or the like is attached to the upper end surface 1b of the glass bulb 1 in order to hermetically sealing it and the dry air is blown into the inside from the nozzle 5 penetreating the closing member 4 in order to blow out the liquid film 3 formed on the lower end surface 1a of glass bulb 1. Accordingly, the total amount of air to be injected is useful for removing liquid film 3 downward, is and thereby air pressure can be lowered and moreover the liquid film 3 can be removed effectively without roughing the surface of film 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a fluorescent lamp, and more particularly to a method for removing a liquid film from the end surface of a tube during the phosphor coating process.

[Technical background of the invention and its problems] Conventionally, the suspension used to coat one glass tube for a fluorescent lamp with a phosphor is prepared by dissolving nitrified cotton as an adhesive in one part of an organic solvent such as butyl acetate. A required binder liquid is prepared, and the two phosphors are dispersed in this binder liquid 5 to form a suspension. Recently, aqueous phosphor suspensions have also been developed using water as a solvent, which is safer and cheaper than organic solvents.

These phosphor suspensions are applied to the inner surface of the glass tube. In this case, a thin liquid film is formed on the lower end surface f' of the glass tube, and if this liquid film is left as it is, there is a drawback that uneven coating of C2 occurs after drying.

Conventionally, in order to apply this liquid film, air was blown from below the glass tube to blow off the liquid film. However, this method has the disadvantage that the blown suspension may adhere to other coated surfaces, causing uneven coating, or staining the outer surfaces of other glass tubes and surrounding equipment. Therefore, as an improvement on this, a method was developed in which a gas such as air is blown from the upper end of the glass tube using a nozzle to blow the liquid film downward. In this case, since the gap between the nozzle and the upper edge of the glass tube is large, approximately 2 cm of trapped air blown from the nozzle leaks into the atmosphere. For this reason, the air pressure required to remove the liquid film is 3 to 5 particles/d, including this leakage, and this air pressure causes the paint film in the upper part of the tube to be directly exposed to air, which deteriorates the skin condition of the paint film. i! , from the nozzle to the inside of the glass tube C
When air is blown into the glass tube, negative pressure causes outside air to be sucked into the glass tube, and dirt and dust in the outside air adheres to the coating film, degrading the quality of the fluorescent lamp later on.

``Object of the Invention'' The present invention provides a fluorescent lamp which can effectively remove the saliva film formed on the lower end surface of a glass tube after applying a fluorescent suspension, and which does not cause uneven coating on the coating film. The purpose is to provide a manufacturing method.

[Summary of the invention] A glass tube with both ends open is supported in the vertical direction so that its inner surface C
After applying a suspension of two fireflies, the upper end of this glass tube is closed and gas is blown from the upper end to blow the liquid film formed on the lower end surface of the glass tube downward and remove it. ,
This method involves blowing in a relatively small amount of gas at low pressure to effectively remove liquid films.

[Embodiments of the invention] The details of the invention will be explained by means of illustrated embodiments.

First, a glass tube with both ends open is supported vertically, for example, vertically, and the phosphor suspension in the ashiver tank is applied to the inner surface of the glass tube by flowing it down from the upper end surface using a nozzle. Then, as shown in the first diagram, a coating film (2) is formed on the inner surface of the glass tube (1), and a liquid film (2) is formed on the lower end surface (1a).
3) is formed. Therefore, as shown in FIG.
Dry air is blown from the nozzle (5) that penetrates through the 4th hole. Then, the air injected from the nozzle (5) flows through the glass tube (1
) acts on the liquid film (8) on the lower end surface (1a) and blows this film (8) away. At this time, since the upper end surface (1b) of the glass tube (1) is closed, the injected air does not leak upward, and the entire amount serves two purposes in removing the liquid film (8) facing downward. . In addition, since the direction of scattering of the liquid film (3) is downward, for example, placing a plate filled with water directly under the glass tube (1) may contaminate other glass tubes or manufacturing equipment. The liquid film (3) can be removed without any problems. Furthermore, the uniformity of the air flow means that the liquid film (8) can be removed in a short time even at low air pressure, making it possible to speed up production equipment, and also making it possible to roughen the surface of the paint film (2) due to the strong air flow. Nor. Furthermore, the paint film (2) is not contaminated by dirt or dust in the atmosphere.

By the way, when applied to a glass tube for a 20W fluorescent lamp using a manufacturing facility with an index of 4 seconds, the result was 05 to 2Kr10.
The liquid film was successfully removed by blowing air at a pressure of 1 for more than 1 second. Then, the glass tube (1
) is baked and mounted by conventional methods to form a fluorescent lamp.

Other examples of closures are shown in FIGS. 3 and 4 f.

The one shown in the third figure is similar to the one in which the nozzle (5) passes through the rubber stopper (4b) which is fitted into the upper end surface (lb) of the glass tube (1). This item can be easily sealed airtight.

Also, the one shown in Figure 4 is the upper end surface (1b) of the glass tube (1).
) f It is the same that the nozzle (5) penetrates through the cap body (4c) which is fitted with two crowns. This one is also easy to seal tightly.

Incidentally, the phosphor suspension used in the present invention can be applied either to one using the above-mentioned organic solvent or to one using water as a solvent. In this case, the pressure of the gas blown may be changed depending on the type of solvent. The application method is not limited to one in which the material flows in from above; it may also be applied by pushing it up from below.

Further, the gas blown into the glass tube in the final stage a) 4 (2) is not limited to air (2), but may be any other gas. The manufacture 52 of curved tube shaped fluorescent lamps, such as U-shaped, is also applicable.

Further, even if the closed substrate is not sealed, there may be some leakage as long as there is no large amount of gas leakage or outside air intake.

Furthermore, f2, the support direction of the glass tube is not limited to the vertical direction, but the effect of the present invention can be achieved even if the lower end surface j is tilted to some extent within the range where the liquid spoon is formed.

[Effects of the Invention] The method for manufacturing a fluorescent lamp of the present invention includes supporting a glass tube with both ends open in the vertical direction 52, applying a binary light suspension on the inner surface of the tube, and then closing the upper end of the glass tube. Gas is blown in from the upper end of the lever to blow away and remove the liquid film that has formed on the lower end of the glass tube, so there is no waste of gas and there is no risk of roughening or staining the paint film, allowing for successful removal of the liquid film. Can be done.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams showing one embodiment of the method for manufacturing a fluorescent lamp of the present invention in the order of steps, and FIGS. 3 and 4 show other examples using other closing bodies. It is an explanatory diagram. (1)...Glass tube (1a)...Lower end surface (
1b)...Top end surface (2)...Coating film (8)...
・Liquid film (4), (4b), (4C)...
Closed substrate (5)... Nozzle agent Patent attorney Mr. Inoue Figure 1 Figure 3 Figure 2 Figure 4 Figure 4

Claims (1)

[Claims] A glass tube with both ends open is supported 5 units in the vertical direction, and a phosphor suspension is applied to its inner surface.Then, the upper end of the ascending glass tube is closed and gas is blown from the upper end to the lower end surface of the glass tube. A method for manufacturing a fluorescent lamp, comprising removing a liquid film of the above-mentioned hanging kite liquid.