JPH04206230A - Baking method of applied tube for fluorescent lamp and device therefore - Google Patents

Abstract

PURPOSE:To keep an application surface from being damaged by adhering an adhesion tape on a part of the inner side surface of a long and thin cylindrical glass tube, which will be a slit, by applying fluorescent paint on the inner side surface of the glass tube, and then by baking the applied tube under a condition that an adhesive tape is adhered thereto. CONSTITUTION:An adhesive tape 8 of band shape is linearly adhered to the inner side surface of an application tube 1 for fluorescent lamp, along the axial direction of the application tube 1, while a fluorescent paint is evenly applied to the inner side surface of the application tube 1 after the adhesive tape 8 is adhered thereto. After the fluorescent paint is applied, the applied tube 1 is put laterally, and is heated at least until the adhesive tape 8 is completely burned and until an organic solvent can be removed, in a furnace 3 for each length part from one end to the other end of the applied tube 1. An applied surface 2 of fluorescent paint can thus be kept from being damaged.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method and apparatus for firing coated tubes for fluorescent lamps, which are generally widely used, and in particular to fluorescent lamps with slits that are linear and have a long overall length. The present invention relates to a method and apparatus for firing coated tubes for fluorescent lamps, which are useful for firing coated tubes for fluorescent 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, fluorescent lamps are not used for lighting purposes! When used for special purposes, such as technology used to inspect the dimensions of products, a lamp that is 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 method would be to leave the phosphor uncoated only on the area where the phosphor is to be coated, and attach a reflective film to the outer surface of the glass tube so that light does not pass 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.

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, turn the coated fluorescent lamp sideways, and apply it from one end. It is characterized by heating and firing each partial length up to the other end in a furnace.

Further, in order to solve the above problems, a first baking device for a coated tube for a fluorescent lamp according to the present invention includes a furnace having a substantially annular shape and having a heating means such as a gas burner or a heating wire on the inner surface thereof, and a fluorescent lamp. The furnace is mutually connected to the holding means so that the holding means for holding the coating tube laterally and the coating tube held by the holding means pass through the center of the annular furnace in the axial direction. The method is characterized in that it has a moving means for moving, and performs the first firing method.

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. With the application tube lying on its side, air is fed into the application tube so as to flow from the unfired end to the firing start end, and the application tube is first fired for each partial length from one end to the other end. Next, air is fed into the once-fired application tube in a direction from the firing start end to the firing end end, and the firing is carried out for each partial length from one end to the other end. be.

Moreover, in order to solve the above-mentioned problem, a second baking device for a coated tube for a fluorescent lamp according to the present invention includes a furnace having a substantially circular shape and having a heating means such as a gas burner or a heating wire on the inner surface thereof; A holding means for horizontally holding a coating tube for a fluorescent lamp, a blower means for blowing air into the coating tube, and a coating tube held by the holding means so as to pass through the center of the annular furnace in the axial direction. Further, the apparatus is characterized in that it has a moving means for mutually moving the furnace and the holding means, and performs the second 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 placed horizontally and heated in a furnace from one end to the other end, 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.

Therefore, it is suitable for firing coated tubes for fluorescent lamps with slits that are longer than standard dimensions, and is also applicable to firing coated tubes for fluorescent lamps with standard dimensions.
Moreover, it has various remarkable effects such as being able to be realized with low-cost equipment.

(Example) Examples 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 (1) of a baking apparatus for fluorescent lamp coated tubes according to the present invention, FIG. 2 is a view seen from the top, and FIG. Figure III-
It is a II+ sectional view.

First, the configuration of the firing apparatus of Example (1) will be explained. As shown in FIGS. 1 to 3, the baking device of Example (1) includes a large number of rotating rollers 5 that hold a linear fluorescent lamp coating tube 1 horizontally, and a substantially annular roller. , a furnace 3 having a heating zone 7 on its inner surface, a support pedestal 4 that supports the furnace 3 and the rotating roller 5, one end of which is wound around a winding means (not shown), and the other end of which is wrapped around the coating tube 1. Wire 6 attached to
It consists of

The rotating roller 5 is formed to be thinner at the center than at both ends, and can stably hold the coating tube 1. Also, the rotating roller 5
are pivotally supported by a support plate (not shown), and the respective rotating rollers 5 are installed with their axes parallel to each other at predetermined intervals.

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 Example (1). Fourth
The figure shows the configuration during firing.A band-shaped adhesive tape 8 is applied linearly along the axial direction of the glass tube to the portion of the inner surface of a linear hollow glass tube that will be slit. Coat fluorescent paint (a mixture of trocellulose and calcium halophosphate) uniformly on the inner surface of this glass tube, and apply coating tube 1.
make. The coating tube 1 is placed horizontally on a rotating roller 5, as shown in FIGS. 1 to 3.

As clearly shown in FIG. 4, the applicator tube 1 held by the rotating roller 5 is moved in the direction of arrow A by a wire 6 attached to the right end, and is moved by a partial length from the right end to the left end. Then, it is heated and fired by the heating zone 7 of the furnace 3. The adhesive tape 8 attached to the inner surface of the application tube 1 is
There is no need to remove the tape as it will burn. In this way, the firing of the coated tube for a fluorescent lamp with a slit is completed. In addition,
As shown in FIG. 4, it is more preferable to install the application tube 1 so that the surface to which the adhesive tape is attached is facing upward during baking than to place the coating tube 1 with the surface to which the tape is attached downward.

The method and apparatus for firing a coated tube for a fluorescent lamp according to the present invention have been described above based on Example (1).
The present invention is not limited to such Example (1). For example, in the embodiment (1), the applicator tube 1 is pulled by the wire 6, but if the rotary roller 5 is provided with a driving means and the applicator tube 1 is moved by the rotation of the rotary roller 5, the wire 6 is not necessary. Further, in Example (1), the rotating roller 5 has a shape that is narrower at the center than at the ends, but if the shape is such that it can stably hold the application tube 1,
It may also be of other shapes.

Further, in Example (1), the application tube 1 is not rotated around its axis, but if the application tube 1 is fired while being rotated around its axis, the application tube 1 will be This is more preferable because it can prevent bending at high temperatures. Hereinafter, as a second embodiment of the method and apparatus for firing a coated tube for a fluorescent lamp according to the present invention, a case where the coated tube 1 is fired while being rotated around its axis will be described based on the drawings.

Figure m5 is a perspective view showing the overall configuration of Example (2) of the firing apparatus for fluorescent lamp coated tubes according to the present invention, Figure 6 is a view seen from the top, and Figure 7 is the same as that of Figure 6. Vll-VTI
The cross-sectional view and FIG. 8 are taken from Vllll-Vl11 in FIG.
FIG. 3 is a schematic end view.

As shown in FIGS. 5 to 7, the baking device of Example (2) consists of a large number of rotating rollers 5 that hold a linear coating tube 1 for fluorescent lamps horizontally while rotating, and a substantially circular coating tube 1. circular,
A furnace 3 having a heating zone 7 on the surface of the crucian carp, a support pedestal 4 that supports the furnace 3 and the rotating roller 5, one end of which is wound around a winding means (not shown), and the other end of which is wrapped around the coating tube. 1 and a wire 6 attached to the wire 6.

The rotating roller 5 is supported by a support means (not shown) so that its axial direction is horizontal, and a rotational force is applied around the axis by a driving means (not shown).

The rotating rollers 5 are supported in sets of two with their outer peripheral surfaces close to each other, and each set of rotating rollers 5 is arranged in a row in the axial direction at a predetermined interval.

As shown in FIG. 8, the coating tube 1 has two outer peripheral surfaces.
It comes into contact with the outer peripheral surface of each of the rotating rollers 5 of the set, and is held by the rotating rollers 5 while rotating in the direction of arrow C as the rotating rollers 5 rotate in the direction of arrow B. Further, as shown in FIGS. 5 to 7, a connecting member 9 is provided on the coating tube 1 side of the wire 6 to prevent twisting of the wire 6 due to rotation of the coating tube 1.

The feature of Example (2) is that it is equipped with a rotating roller 5 that holds the coating tube 1 while rotating it around its axis, and bakes the coating tube 1 while rotating it around its axis. By doing so, it is possible to prevent the application tube 1 from being bent or warped. In this way, Example (2) differs from Example (1) in that the coated tube 1 is fired while rotating around its axis, but the method for firing a coated tube for a fluorescent lamp according to the present invention is carried out. In that respect, there is no difference.

In the embodiments (1) and (2), the furnace 3 has a support frame 4.
Although the furnace 3 is fixedly installed and the coating tube 1 is moved, it is also possible to make the furnace 3 movable. Embodiment (3) in which the furnace 3 is made movable will be described below based on the drawings.

FIG. 9 is a perspective view showing the overall configuration of implementation PI (3) of the firing apparatus for fluorescent lamp coated tubes according to the present invention.

As shown in FIG. 9, the baking device of Example (3) includes four rotating rollers 5 that hold the linear coating tube 1 for fluorescent lamps while rotating it horizontally, and a substantially annular roller. It consists of a furnace 3 having a heating zone on its inner surface, and a support pedestal 4 that rotatably supports the rotary roller 5 around an axis and supports the furnace 3 so as to be movable in the direction of arrow AB in the figure.

The characteristics of Example (3) are the same as those of Examples (1) and (2).
In this case, the furnace 3 is fixedly installed on the support frame 4, whereas the furnace 3
is installed movably on the support frame 4,
Compared to the embodiments (1) and (2), the device itself can be made smaller and save space.

The method of firing the coating tube 1 is as described in Examples (1) and (2) above.
In Example (3), the coating tube 1 was fired while moving, whereas in Example (3), the furnace 3 fired the coating tube 1 part by length from one end to the other end while moving. ,
There is no difference in that the method for firing a coated tube for a fluorescent lamp according to the present invention is carried out.

Above, in Examples (1) to (3), cases were explained in which fylucium halophosphate was used as the phosphor and nitrocellulose was used as the organic solvent. phosphors or other organic solvents may also be used. Hereinafter, a case where polyethylene oxide is used as an organic solvent will be described as Example (4) based on the drawings.

FIG. 10 is a perspective view showing the overall configuration of Example (4) of the firing apparatus for fluorescent lamp coated tubes according to the present invention, and FIG. FIG. 11B is a schematic cross-sectional view showing the configuration at the time of second firing.

As shown in FIG. 1O, the baking device of Example (4) is equipped with a blower pipe 10 inserted into one end of the application tube 1, and a filler 11 filled in the inserted part. is an example (
It has exactly the same configuration as 1). As will be described later, this blower pipe 10 is provided to generate a flow of air in a fixed direction inside the application pipe 1 during firing, and the filler material 11 is provided to prevent air leakage. It is provided.

As shown in FIGS. 11A and 11B, the application tube 1
is fired twice. The coating tube 1 is made by pasting an adhesive tape 8 on the inner surface of a hollow glass tube along the axial direction of the glass tube, and then uniformly applying a fluorescent paint using polyethylene oxide.

As shown in FIG. 1LA, first, the coating tube 1 is moved in the direction of the arrow by the wire 6 attached to the right end, and the heating zone 3 of the furnace 3 is moved from the right end to the left end by partial length. is heated, and the first firing is performed. During this time, air is sent from the blower tube 10 inserted into the left end of the coating tube 1, and the air flows in the direction of arrow B inside the coating tube 1. Therefore, the polyethylene oxide evaporated during firing flows toward the right end of the coating tube 1 that has been fired for the first time, so the polyethylene oxide vapor flows into the unfired part and corrodes the surface coated with the fluorescent paint. prevent. During this first firing, a portion of the evaporated poly-ethylene oxide may cool down and adhere to the inner surface 2, so a second firing is performed.

In addition, the ash from the adhesive tape burned during the first firing moves in the direction of arrow B and is discharged due to the air flow, so this ash does not adhere to the unfired part and attack the unfired part. It also has another effect: ephemerality.

As shown in Figure 1LB, the coating tube 1 that has been fired for the first time is moved in the direction of arrow C by the wire 6 attached to the left end, and is moved from the left end to the right end for each partial length. 2
The second firing is performed. During this time, air is sent in from the blower tube 10 inserted into the left end of the coating tube 1, and the air flows in the direction of arrow B inside the coating tube 1, as in the first firing. Therefore, even if the polyethylene oxide slightly adheres to the inner surface 2 during the first firing, it will not flow toward the left end where the second firing has been completed, so it will not remain on the inner surface 2 and will be completely removed. can be removed. In this way, high quality firing becomes possible.

Since polyethylene oxide has the property of decomposing and vaporizing at about 200° C., the firing temperature can be set low. Therefore, as in Examples (2) and (3), additional effects such as the ability to bake without bending or warping the coating tube 1 without rotating the coating tube 1 around its axis can be obtained. However, there is no difference in that the method for firing a coated tube for a fluorescent lamp according to the present invention is carried out. In addition, in Example (4), the furnace 3 is fixedly installed on a support frame, and the coating tube 1 is fired while moving, but in Example (3)
) It is also possible to move the furnace.

As described above in Examples (1) to (4), 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 Example (1) of the firing apparatus for fluorescent lamp coated tubes according to the present invention, FIG. 2 is a view seen from the top, and FIG. III-II+
4 is a schematic cross-sectional view showing the configuration during firing, FIG. 5 is a perspective view showing the overall configuration of the firing apparatus of Example (2), and FIG. 6 is a view from the top thereof. Figure 7 is a sectional view of Vll-V11 in Figure 6, and Figure 8 is a cross-sectional view of Figure 6 (7).
) Vllll-Vll+ end face schematic diagram, FIG. 9 is the example (3
FIG. 10 is a perspective view showing the overall configuration of the baking device of Example (4), and FIG. 11 is a perspective view showing the overall structure of the baking device of Example (4).
Figure A is a cross-sectional schematic diagram showing the configuration at the time of the first firing;
And FIG. 11B is a schematic cross-sectional view showing the configuration at the time of the second firing. 1... Coating tube for fluorescent lamp 2... Fluorescent paint coating surface 3... Furnace 4... Support frame 5...
・Rotating roller 6... Wire 7... Heating band 8... Adhesive tape 9... Connecting member
10-9. Air pipe 11...Filling material Fig. 4

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 placed on its side, and the length of the glass tube from one end to the other is heated in the furnace to a temperature at least at which the adhesive tape is completely burned and the organic solvent can be removed. 1. A method for firing a coated tube for a fluorescent lamp, the method comprising: 2) A furnace that is approximately annular and has a heating means on its inner surface; a holding means that holds the hollow glass tube horizontally; and the hollow glass tube held by the holding means is located at the center of the annular furnace. A fluorescent lamp, comprising: 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. Baking equipment for coating tubes. 3) 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 turned sideways, and air is introduced into the glass tube from the unfired end to the firing start end. While feeding the glass tube so as to flow in the direction of , heating and firing each part of the glass tube from one end to the other end in the furnace to a temperature at least at which the adhesive tape is completely combusted; The method is characterized in that air is fed into the glass tube so as to flow from the firing start end to the firing end end, and the glass tube is heated and fired in the furnace for each partial length from one end to the other end. A method for firing coated tubes for fluorescent lamps. 4) A substantially annular furnace having a heating means on its inner surface, a holding means for horizontally holding a hollow glass tube, a blowing means for blowing air into the hollow glass tube, and a furnace held by the holding means. The coating for a fluorescent lamp according to claim 3, further comprising a moving means for mutually moving the furnace and the holding means so that the hollow glass tube passes through the center of the annular furnace in the axial direction. A firing device for coated tubes for fluorescent lamps, characterized in that it performs a tube firing method.