JPH04206231A - Baking method of applied tube for fluorescent lamp and device therefore - Google Patents

Abstract

PURPOSE:To bake a straight applied tube for fluorescent lamp with slit, which is longer than standard size by adhering a band-like adhesive tape on the inner side surface of a hollow glass tube, by evenly applying a fluorescent paint, and by putting the glass tube vertically so as to bake it for each length part. CONSTITUTION:An adhesive tape 7 is linearly adhered to the part of the inner side surface of a thin and long cylindrical hollow glass tube 1, which will be a slit, along the axis of the glass tube 1, and a fluorescent paint is evenly applied to the inner side surface 2 of the glass tube 1, and after the paint for fluorescent lamp is applied, the tube is put vertically, and is heated and baked in a furnace 3 for each length part from the lower end to the upper end. Namely, since the applied tube 1 is baked under a condition where the adhesive tape 7 is adhered thereto, there is no need to peel the adhesive tape 7, and an applied surface 2 is not damaged, and it is facilitated that the width of the slit is kept at a constant level. A long and thin cylindrical applied tube for fluorescent lamp with slit, which is longer than standard size can be baked appropriately, while an applied tube of standard size can also be baked appropriately.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a generally widely used method and apparatus for firing coated tubes for fluorescent lamps, and particularly relates to a method and apparatus for firing coated tubes for fluorescent lamps, which are generally widely used. The present invention relates to a method and apparatus for firing coated tubes for fluorescent lamps useful for firing coated tubes for dosimeter lamps.

(Prior Art) Currently, linear fluorescent lamps are widely used mainly as home and industrial lighting equipment.

Fluorescent lamps are made by coating the inner surface of a hollow glass tube with phosphor.
The phosphor is caused to emit light by the discharge inside the hollow glass tube,
It is used as a light source for lighting, etc.

Phosphors (for example, calcium halophosphate) are generally refined into powder, and it is not possible to directly and uniformly fix this powdered phosphor onto the inner surface of a hollow glass tube. Generally, this powdered phosphor is mixed with a viscous organic solvent (e.g. nitrocellulose) to make a liquid fluorescent paint, and then this fluorescent paint is uniformly applied to the inner surface of a hollow glass tube. A method is used. The hollow glass tube coated with fluorescent paint is called a fluorescent lamp coated tube.

However, since this organic solvent is no longer needed after coating, it must be removed by some method after coating. Therefore, taking advantage of the property that phosphors do not deteriorate even at high temperatures, but organic solvents burn and evaporate when heated to high temperatures, we heated the coated tubes for fluorescent lamps in a furnace, removed the organic solvents by combustion, and fluoresced. A commonly used method is to fix only the body to the inner surface of a hollow glass tube.

This method is called firing of coated tubes for fluorescent lamps.

Currently, the common method for firing is to simultaneously heat the entire coated tube for a fluorescent lamp, and for this reason, the firing furnace needs to be large enough to cover the entire coated tube.

As mentioned above, fluorescent lamps are widely used mainly for illumination, and therefore their demand is large. For this reason, fluorescent lamps are now mass-produced with standardized lengths and diameters, and firing furnaces are also made and used in sizes that suit the size of the fluorescent lamps.

On the other hand, when a fluorescent lamp is used not for illumination but for a special purpose such as technology for inspecting the dimensions of a product, a lamp longer than the width of the product to be inspected may be required. Moreover, a fluorescent lamp with a slit that can irradiate a product with strong linear light is sometimes used as the fluorescent lamp for inspection.

A fluorescent lamp with a slit is a fluorescent lamp in which light is emitted only from a slit that is provided in a straight line along the axial direction of the fluorescent lamp.For example, a slit on the inner surface of a hollow glass tube A conceivable solution would be to leave the phosphor uncoated on the glass tube and attach a reflective film from the outer surface of the glass tube to prevent light from passing through the coated surface.

Since such a slit fluorescent lamp with a long overall length cannot be made from conventional standardized fluorescent lamps, it may be necessary to specially manufacture such a fluorescent lamp.

(Problems to be Solved by the Invention) There are several problems in manufacturing a fluorescent lamp with a slit that is longer than standard dimensions. For example, when applying fluorescent paint to the inner surface of a hollow glass tube, leaving a slit,
It is difficult to make the width of the slit constant. Therefore,
One option is to attach adhesive tape to the part that will be slit and then peel off the tape after applying the fluorescent paint, but if the glass tube is long, there is a high possibility of damaging the fluorescent paint coated surface when peeling it off, so it is technically difficult to do so. Have difficulty.

In addition, as mentioned above, the conventional method of firing coated tubes for fluorescent lamps is to heat the entire coated tube in a special furnace according to the size of the fluorescent lamp. In order to fire a longer coated tube for a fluorescent lamp, it is necessary to make the firing furnace large enough to accommodate the length.

However, since there is little demand for such long fluorescent lamps, it is not desirable from a cost standpoint to prepare a large dedicated furnace.

Therefore, instead of the conventional firing method of firing the entire coated tube for fluorescent lamps at the same time, a method can be considered in which the coated tube for fluorescent lamps is laid horizontally and the coated tubes are fired section by length from one end to the other. .

According to this firing method, there is no need to increase the size of the furnace even when firing a long linear coated tube for a fluorescent lamp, and the equipment cost can be reduced. However, since the glass tube is heated to high temperatures (350 to 900 degrees Celsius) during firing, there is a risk that the glass tube may bend or warp. To prevent this, the glass tube is fired while rotating around its axis. methods such as these must be taken. Therefore, a means for rotating and holding the glass tube is required as firing equipment, which poses problems such as the firing apparatus becoming complicated.

In view of the above-mentioned problems, the present invention is suitable for firing coated tubes for fluorescent lamps with linear slits longer than conventional standard dimensions, and can also be applied to firing coated tubes for fluorescent lamps of conventional standard dimensions, and is simple. It is an object of the present invention to realize a method and apparatus for firing a coated tube for a fluorescent lamp, which can be realized using low-cost equipment.

(Means for Solving the Problems) In order to solve the above problems, a first method for firing a coated tube for a fluorescent lamp according to the present invention is to apply a slit to a portion of the inner surface of a hollow glass tube having a substantially elongated cylindrical shape. Adhere adhesive tape linearly along the axial direction of the glass tube, apply fluorescent paint evenly to the inner surface of the glass tube, hold the coated fluorescent lamp vertically, and apply it from the bottom end. It is characterized by heating and firing each section up to the upper end in a furnace.

Furthermore, in order to solve the above-mentioned problems, a second method for firing a coated tube for a fluorescent lamp according to the present invention is to apply powdered phosphor to 40%
Mixed with a viscous organic solvent (e.g. polyethylene oxide) that decomposes and evaporates below 0°C, this liquid fluorescent paint is uniformly applied to the inner surface of a straight hollow glass tube after it has been pasted with tape. This coating tube is held vertically, and the coating tube is first fired for each partial length from the upper end to the lower end.Then, this once fired coating tube is then fired for each partial length from the lower end to the upper end. It is characterized by this.

In addition, in order to solve the above-mentioned problems, the present invention provides a baking apparatus for coating tubes for fluorescent lamps. a holding means for vertically holding the furnace; and a moving means for mutually moving the furnace and the holding means so that the application tube held by the holding means passes through the center of the annular furnace in the axial direction. It is characterized in that it has the following, and performs the above-mentioned firing method.

(Operations and Effects) In the method and apparatus for firing a coated tube for a fluorescent lamp according to the present invention, an adhesive tape is pasted to the slit portion of the inner surface of a substantially elongated cylinder, and fluorescent paint is applied to the inner surface of the glass tube. After coating, the application tube is fired with the adhesive tape still attached, so there is no need to remove the adhesive tape and the coated surface will not be damaged, making it easy to maintain a constant slit width.

In addition, since the coating tube is held vertically and the entire length of the coating tube is heated and fired in a furnace from one end to the other, there is no need to heat the entire coating tube at the same time as in conventional firing methods.
There is no need to use a special furnace.

Moreover, since the coating tube is held vertically, the coating tube does not bend or warp during firing. Therefore, it is suitable for firing coated fluorescent lamp tubes with slits that are longer than standard dimensions, and is also applicable to firing coated tubes for fluorescent lamps with standard dimensions, and is simple and uses low-cost equipment. Various remarkable effects can be achieved.

(Example) An example of the method and apparatus for firing a coated tube for a fluorescent lamp according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the overall configuration of an embodiment of the firing apparatus for coated tubes for fluorescent lamps according to the present invention, FIG. 2 is a longitudinal cross-sectional view thereof, and FIG. The schematic cross-sectional view shown and FIG. 4 are perspective views showing the overall configuration of another embodiment of the firing apparatus according to the present invention.

First, the configuration of the firing apparatus of this example will be explained. 1st
As shown in the figure and FIG. 2, the firing apparatus of this embodiment is
A wire 5 that hangs and holds a straight fluorescent lamp coating tube 1 vertically, a furnace 3 that is approximately annular and has a heating zone 6 on its inner surface, and this furnace 3 is movable in the vertical direction. The furnace 3 is made up of a support pedestal 4 that supports the furnace 3, and a drive system (not shown) that moves the furnace 3 vertically along the support pedestal 4.

The coating tube 1 held by the wire 6 is installed so that when the furnace 3 moves in the vertical direction, the coating tube 1 passes through the center of the furnace 3 in the axial direction. Fired in sections.

Next, a method for firing a coated tube for a fluorescent lamp according to the present invention will be explained based on the operation of the firing apparatus of this embodiment.

At the part that will be the slit on the inner surface of the straight hollow glass tube,
Strip-shaped adhesive tape 7 linearly along the axial direction of the glass tube
Paste. A coated tube 1 is prepared by uniformly applying a fluorescent paint containing trocellulose and calcium halophosphate to the inner surface of this glass tube. As described above, this application tube is suspended from the wire 5 and installed vertically at a predetermined position.

Next, as clearly shown in FIG. 3, while the furnace 3 moves from below to above (in the direction of arrow A), the coating tube 1 is baked from the lower end to the upper end part by length. The adhesive tape 7 stuck to the inner surface of the coating tube 1 is heated at approximately 350° C. to 900° C. by the heating zone 6 during baking and is completely burned, so there is no need to remove the tape before baking. In this way, the firing of the coated tube for a fluorescent lamp with a slit is completed.

Although the method and apparatus for firing a fluorescent lamp coated tube according to the present invention have been described above based on one embodiment, the present invention is not limited to this embodiment. For example, in the above embodiment, the applicator tube 1 is suspended and held by the wire 5, but if the applicator tube 1 can be installed so as to pass through the center of the furnace 3, other methods (for example, holding the lower end) may be used. , or holding the middle part).

Further, in the above embodiment, the furnace 3 is supported by the support frame 4, but as shown in FIG. 4, the furnace 3 may be suspended and held by wires 5' and moved up and down. . Further, in the above embodiment, the coating tube 1 is fixed and the furnace 3 is movable, but on the other hand, the furnace 3 is fixed and the coating tube 1 is moved.
Alternatively, both the furnace 3 and the coating tube 1 can be moved up and down.

Further, in the above embodiment, calcium halophosphate was used as the phosphor.
Although nitrocellulose was used as the organic solvent in each case, other phosphors and organic solvents commonly used for firing coated tubes may be used.

Next, a firing method according to the present invention in which polyethylene oxide, which has a property of decomposing and evaporating at about 200° C., that is, 400° C. or lower, is used as an organic solvent will be described below with reference to the drawings.

FIG. 5A is a schematic cross-sectional view showing the configuration at the first firing of another embodiment of the method for firing a coated tube for a fluorescent lamp according to the present invention, and FIG. 5B is a schematic cross-sectional view showing the configuration at the second firing. It is a cross-sectional schematic diagram.

As shown in FIGS. 5A and 5B, application tube 1
is fired twice. The coating tube 1 is a hollow glass tube with an adhesive tape 7 pasted on the inner surface along the axial direction of the glass tube, and then a fluorescent paint made of polyethylene oxide mixed with calcium halophosphate is uniformly applied. be.

As shown in FIG. 5A, the first firing is carried out by heating the coating tube 1 from the upper end to the lower end part by length while the furnace 3 moves from above to below (in the direction of arrow A). Since polyethylene oxyte decomposes and evaporates at about 200°C, the firing temperature is set at about 200°C. When baked at about 200° C., the adhesive tape attached to the application tube 1 is completely burned. Also, if the vapor of evaporated polyethylene oxide re-adheres to the unfired part, it may attack the surface coated with the fluorescent paint, but if the first firing is started from the upper end of the coating tube 1,
The polyethylene oxide vapor flows upward (
Since the steam moves in the direction of arrow C), the unfired portion is not attacked by this steam.

As shown in FIG. 5B, the second firing is carried out by heating the coating tube 1 from the lower end to the upper end part by length while the furnace 3 moves from below to above (in the direction of arrow B). The polyethylene oxide slightly attached to the rear side surface 2 after the first firing is completely removed during the second firing.

An example of a firing method using polyethylene oxide as an organic solvent has been described above, but this firing method can also be carried out using the firing apparatus shown in FIG. 1 or FIG. The present invention can also be carried out using a firing apparatus with various modifications as described above. Further, the organic solvent is not limited to polyethylene oxide.

As explained above, the method and apparatus for firing a coated tube for a fluorescent lamp according to the present invention can be modified in various ways without impairing its effects.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall configuration of an embodiment of the firing apparatus for coated tubes for fluorescent lamps according to the present invention, FIG. 2 is a longitudinal cross-sectional view thereof, and FIG. FIG. 4 is a schematic cross-sectional view showing the configuration during firing of the embodiment, and FIG. 5A is a perspective view showing the overall configuration of another embodiment of the firing apparatus according to the present invention.
The figure is a schematic cross-sectional view showing the configuration during the first firing of another embodiment of the firing method according to the present invention, and FIG. 5B is the second example.
FIG. 3 is a schematic cross-sectional view showing the configuration during the second firing. 1... Coating tube for fluorescent lamp 2... Fluorescent paint coating surface 3... Furnace 4... Support frame 5.5
'...Wire 6...Heating zone 7...Adhesive tape Figure 3 Figure 5A Figure 5B

Claims (1)

[Claims] 1) After uniformly coating the inner surface of a substantially elongated cylindrical hollow glass tube with a fluorescent paint consisting of a powdered fluorescent substance mixed in a viscous organic solvent, Heat the tube in a furnace,
A method for firing a coated tube for a fluorescent lamp, in which the organic solvent in the fluorescent paint is removed and only the phosphor is fixed on the inner surface of the hollow glass tube. A substantially belt-shaped adhesive tape is applied linearly along the axial direction of the tube, and the fluorescent paint is evenly applied to the inner surface of the hollow glass tube after the adhesive tape is applied. A hollow glass tube is held vertically, and the length of each section from the lower end to the upper end of the glass tube is heated in the furnace,
A method for firing a coated tube for a fluorescent lamp, comprising heating to a temperature at which at least the adhesive tape is completely burned and the organic solvent can be removed. 2) After uniformly applying a fluorescent paint consisting of a powdered phosphor mixed in a viscous organic solvent to the inner surface of an approximately elongated cylindrical hollow glass tube, the hollow glass tube is heated in a furnace. ,
A method for firing a coated tube for a fluorescent lamp, in which the organic solvent in the fluorescent paint is removed and only the phosphor is fixed on the inner surface of the hollow glass tube. A substantially belt-shaped adhesive tape is pasted linearly along the axial direction of the fluorescent paint, and an organic solvent that decomposes and evaporates at temperatures below 400°C is used as the organic solvent. is applied uniformly to the inner surface of the hollow glass tube after the adhesive tape has been applied, and the hollow glass tube after the fluorescent coating is held vertically, and the entire length of the glass tube is coated from the upper end to the lower end. , heating and firing in the furnace to at least a temperature at which the adhesive tape is completely combusted, and then heating and firing each partial length of the glass tube from the lower end to the upper end in the furnace. A method for firing coated tubes for fluorescent lamps, characterized by: 3) A furnace that is approximately annular and has a heating means on its inner surface, a holding means for vertically holding a hollow glass tube, and a hollow glass tube held by the holding means at the center of the annular furnace. and a moving means for mutually moving the furnace and the holding means so as to pass through the furnace in the axial direction, and carrying out the method for firing a coated tube for a fluorescent lamp according to claim 1 or 2. Firing equipment for coated tubes for fluorescent lamps.