JPS5987071A - Manufacture of fluorescent lamp - Google Patents

Abstract

PURPOSE:To manufacture a fluorescent lamp with the saved consumption of resources at a low cost, while suppressing the deterioration of light flux as much as possible, by performing the sucking motion of a dust catcher only during spraying a powdery fluorescent substance through a nozzle. CONSTITUTION:A glass tube 1 is heated with a line burner 2, a nozzle 3 is inserted into the glass tube 1 through its opening,and fluorescent powder prepd. by mixing the predetermined amount of a powdery recovered fluorescent substance in a powdery unused fluorescent substance is sprayed through the top end of the nozzle 3 while retreating said nozzle 3. At the same time, high voltage is impressed on the line burner 2, the sucking motion of a dust catcher is performed by opening a closing valve 6, and clean air is injected from a clean air blower 7 into the glass tube 1 to perform electrostatic coating. Thereafter, said sucking motion is suspended until the next glass tube 1 is carried to the apparatus. Thus, the fluorescent lamp is manufactured with excellent efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a fluorescent lamp, and more particularly to a method for electrostatically coating the inner surface of a glass tube for a fluorescent lamp with phosphor powder.

Conventional structure and its problems Conventionally, to electrostatically coat the inner surface of a glass tube for a fluorescent lamp [9 luminous powder, the glass tube is a non-conductor, so the glass tube must be uniformly heated with a burner. Then, this electrical resistance is lowered, a high voltage is applied between the electrostatic coating nozzle and the burner, the nozzle is inserted into the glass tube through one opening, the glass tube is rotated, and the nozzle is turned on. Even in the midst of retreat, charged phosphor powder is injected from the injection hole of the nozzle, and this phosphor powder is painted on the inner surface of the glass tube, and at the same time, it is sprayed from the other opening of the glass tube and painted on the inner surface of the glass tube. A common method is to collect the unused phosphor powder using a dust collector.

However, this recovered phosphor is colored black, and the luminous flux of fluorescent lamps electrostatically coated using this recovered phosphor powder is significantly reduced, making it difficult to reuse the recovered phosphor. It was difficult.

OBJECTS OF THE INVENTION The present invention provides a method for manufacturing a fluorescent lamp that enables the reuse of recovered phosphors and suppresses deterioration in lamp characteristics, particularly luminous flux, even when recovered phosphors are used. It is.

Structure of the Invention The present invention reduces the amount of dust, dirt, etc. in the atmosphere that is sucked in by the dust collector by sucking the dust collector only while the fluorescent powder is being injected from the nozzle. This is a method of manufacturing a fluorescent lamp in which the coloring of the light body is weakened.

DESCRIPTION OF EMBODIMENTS The present invention has investigated various causes of discoloration of recovered phosphors, and found that the cause is +1 dust, etc. in the atmosphere where electrostatic coating is performed, which is collected together with phosphor powder. It became clear that this was because the device used suction.

In the past, the suction by the dust collector was constant, including during the indexing of electrostatic coating equipment, which resulted in the suction of a large amount of dust, etc. from the atmosphere, and as a result, the collected phosphor became strongly colored. 4. When the recovered phosphor was analyzed for dirt, the amount of carbon was 220 ppm.

On the other hand, if the dust collector performs suction only while the phosphor powder is being injected from the nozzle, the amount of carbon contained in the recovered phosphor decreases from 220 ppm to 100 ppffi, and the coloring of the recovered phosphor decreases. The intensity also became weaker.

Furthermore, in this case, by setting the suction flow rate of the dust collector to 4 times or more and 20 times or less than the phosphor powder injection air flow rate, the amount of carbon contained in the recovered phosphor can be reduced to 1100 pp.
It decreased from 80 ppm to 80 ppm.

Here, if the suction flow rate of the dust collector exceeds 20 times the flow rate of the phosphor powder injection air, a large amount of dust, etc. in the atmosphere will be suctioned, and the degree of coloring of the recovered phosphor will become strong. Moreover, if this is less than 4 times, the phosphor powder will accumulate in the phosphor powder pipe, resulting in insufficient suction, which is undesirable as the phosphor powder will scatter around the electrostatic coating device.

Furthermore, if the nozzle is inserted into the glass tube from one opening, and when the phosphor powder is jetted from the nozzle, clean air is blown into the inside of the glass tube from the glass tube opening on the side where the nozzle is inserted. The amount of carbon is so ppm to 6
It decreased to 0 ppm.

Thirty percent of the recovered phosphor was mixed into a new phosphor (hereinafter referred to as unused phosphor) to obtain a mixed phosphor, which was electrostatically coated on the inner surface of a glass tube for a fluorescent lamp. When we fabricated a fluorescent lamp using the usual method, we found that this fluorescent lamp had an initial luminous flux that was lower than that of a fluorescent lamp using unused phosphor. On the other hand, it was confirmed that the decrease was suppressed to about 2 inches.

Therefore, the method of the present invention allows the use of recovered phosphors.

Next, embodiments of the present invention will be described using the drawings.

The figure shows an example of an apparatus for carrying out the method of the present invention.
1 is a glass tube for fluorescent/pumping, 2 is a line burner that heats this glass tube 1, 3 is a nozzle for electrostatic coating, 4 is a suction of a dust collector, and 6 is an on-off valve installed therein. ,6
7 is a clean air blowing device, and 7 is a roller for rotating the glass tube.

In the above-described apparatus, the glass tube 1 is uniformly heated to about 300"C by the line burner 2, the nozzle 3 is inserted into the glass tube 1 through one opening, and while the nozzle 3 is retreated, At the same time, a high voltage of 20 KV is applied to the line burner 2, and the on-off valve 6 is opened. It is sucked by the dust collector, clean air is blown into the glass tube 1 by the clean air blowing device 7, and the fluorescent powder is electrostatically coated on the inner surface of the glass tube 1.

Then, the next glass tube 1 is sent to the device.
Stop suction by the dust collector until When the next glass tube 1 is sent to the device, exactly the same operation as above is carried out,
Fluorescent powder is electrostatically coated on the inner surface of the glass tube 1.

Thereafter, the above operations are repeated.

A 30 W round fluorescent lamp was prepared by a conventional method using the glass tube 1 for fluorescent powder, and the initial luminous flux was measured, and the results shown in the table below were obtained. Note that the number of samples is four each.

As is clear from the above table, the initial luminous flux of the fluorescent lamp obtained by the method of the present invention is significantly higher than that of the fluorescent lamp obtained by the conventional method. Recognize.

As described in detail, the present invention is capable of suppressing the decrease in luminous flux as much as possible even when using 1 [j] convergence) 0 bodies, and is therefore excellent in terms of cost and resource saving. A method for manufacturing a fluorescent lamp can be provided.

[Brief explanation of drawings]

The figure shows an example of an apparatus for carrying out the method of the present invention. 1...Glass tube, 2...Line burner, 3...Nozzle, 4...Suction,
5...Opening/closing valve, 6...Clean air blowing device.

Claims (1)

[Claims] A nozzle is inserted through one opening of the glass tube, and a phosphor powder containing recovered phosphor mixed with unused phosphor powder is injected from the nozzle to statically coat the inner surface of the glass tube. A method of electrically coating the inner surface of the glass tube and suctioning uncoated phosphor powder by a dust collector provided near the other opening of the glass tube, the method comprising: A method for manufacturing a fluorescent lamp, characterized in that suction is performed by the dust collector only while powder is being injected.