JP3416659B2 - How to seal the developer supply container - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry electrophotographic copying machine in which a container is filled with a powder developer and the container is sealed by using a heat welding film. The present invention relates to a method of sealing a developer supply container used by peeling off a film when replenishing a printer or a printer. 2. Description of the Related Art Conventionally, a developer supply container has a container body having a developer discharge port mainly made of synthetic resin, paper or the like, a synthetic resin film as a base, and a welding layer provided thereon. In general, the heat-welding film is heat-welded to a flange or the like around the developer discharge port to seal the developer accommodating portion. As shown in FIG. 4, the developer is replenished by fitting the developer supply port of the developer supply container downward into a developer supply section of a copying machine or the like, and pulling the film with a hand or the like to reduce the welded portion between the film and the container. Replenishment was performed by opening the developer outlet while peeling. [0003] In addition, high impact polystyrene resin (HIPS) or acrylonitrile / styrene / butadiene copolymer resin (AB) may be used as the material of the container body.
S), a material using plastic such as polypropylene resin (PP), and a flexible film material such as biaxially stretched polypropylene film (OPP), polyethylene terephthalate film (PET), stretched nylon film (ONy), etc. There is a base material which is laminated with an adhesive layer. The above-mentioned adhesive layer in such a conventional device is required to adhere to the container body and at the same time to be smoothly peeled when opened, and is usually called an easy peel type. As an adhesive layer that satisfies this,
Ethylene vinyl acetate copolymer resin (EVA), ethylene
Ethyl acrylate copolymer resin (EEA), ionic copolymer (ionomer) and the like are known, and a method of heat-welding them to a plastic or paper container body is adopted. The method of heat welding is hot plate seal, impulse seal,
Although there is a method such as a high frequency welder, a hot plate seal is the most common. Further, in the above-described known image forming apparatuses, a developer (hereinafter, referred to as toner) is consumed for each image forming apparatus. Therefore, toner is replenished as needed to a developing apparatus which stores toner in the apparatus. There is a need to. Various proposals have been made for the toner replenishment method. However, since toner is composed of extremely fine particles, toner replenishment is easy and can be easily operated by a user. A configuration that does not cause inconvenience is essential. [0006] However, according to each of the above conventional examples, there are the following problems. First,
The surface to be welded becomes uneven due to heating and pressurization of the container flange and the like by the heat welding jig at the time of film heat welding, and once the film is peeled off at the time of replenishing the developer, it is tried to heat weld again using a new film. However, since the surface to be welded has no flatness, the contact with the heat welding jig is poor, and the stability of the film heat welding is low, so that it is difficult to completely seal the developer. Therefore, the container after the replenishment of the developer has no other use except for disposal. Further, in the above-mentioned conventional example of the easy peel type, a problem has occurred if the adhesive strength is too high or too low. In other words, the developer supply container contains the developer in the form of fine black powder inside, and can be delivered to the user under various harsh environments and under logistics conditions. The film peels off during storage and the developer leaks. [0008] On the other hand, if the adhesive strength is too strong, the peeling strength at the time of opening the user is increased, and the operability is deteriorated.
In addition, when the peeling strength is high, problems such as the film being torn or being cut off during the peeling of the film have also occurred. For example, in the case of a hot plate sealing method, there are three manufacturing conditions relating to such adhesive strength: a surface temperature of the hot plate, a hot plate pressing time, and a pressure. In order to keep the adhesive strength within a range that does not cause the above problems, three manufacturing conditions must be strictly controlled. [0010] However, the temperature can be controlled by a temperature sensor and a temperature controller, and the time can be controlled with a timer by using a timer. The pressure can be controlled by an air cylinder and a regulator. Local pressure fluctuations have been a major cause of the above-mentioned problems. Also, there is only a method of measuring the adhesive strength of the film by actually peeling off the film (destructive inspection).
Plastics are manufactured by injection molding, hollow molding (blow molding), extrusion molding, etc. for sampling inspection. There is a possibility that unevenness and sink marks etc. may be different for each molded product, so sampling inspection is It was not a reliable measure. Further, according to the above-mentioned conventional example, the toner container is placed in various environments in the distribution stage before it reaches the user's hand, and is also exposed to impacts such as dropping. For this reason, in the conventional toner container, there has been a problem that the toner leaks. An object of the present invention is to solve the above-mentioned problems and to provide a method of sealing a developer supply container without toner leakage. According to the present invention, in order to solve the problem] The object covers the opening of the developer supply container body for accommodating a developer a heat seal film, heat from the top of the heat seal film the heat-sealing film around the opening in the sealing method of the developer supply container to the heat welded to the developer supply container main body by causing pressure contact with the sealing jig, provided to the pressure contact portion of the heat seal jig
The heat seal off as the depth becomes shallower according to the welding surface of 5 ° to 45 ° <br/> the developer supply container body is pushed in correspondence with the tapered portion of which is it approaches the opening
This is achieved by heat welding the film . In the present invention, when a tensile force is applied to the heat seal film from the welding surface toward the central surface covering the opening due to a reduced-pressure environment, dropping, or the like, the welding surface is applied to the central surface. Since it has a predetermined angle with respect to the welded portion, shear stress acts as a reaction at the welded portion along the welded surface against the tensile force. Therefore, the component in the direction perpendicular to the welding surface, that is, the peeling force against the film does not work, and the developer does not leak. Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a plan view showing the configuration of a conventionally used general toner replenishing container. In FIG. 3, reference numeral 201 denotes a toner container main body, which is assumed to have a container portion for accommodating toner at the bottom of the paper. An opening 203 as shown by a dotted line is formed on the upper welding surface 205 of the container body.
Are formed, and the surface thereof is covered with a seal film 202, and the opening 203 is sealed by a sealing portion around the opening. FIG. 4 is a vertical sectional view of the sealing portion.
5 is adhered in a state where it is slightly pushed in as shown in the figure. Next, it is assumed that the conventional container is placed under a reduced pressure. Under reduced pressure, the film at the opening is pushed by the internal pressure 206 due to the pressure difference between the inside and outside of the container.
Swelling, and tension 207 is applied to the film,
A vertical peeling force 208 that decomposes the film tension is applied to the bonding surface. This peeling force 208 is applied to the film 20.
If the adhesive force 209 between the second and the container 201 is stronger, the toner leaks because the film 202 is peeled off from the main body of the container 201. The same phenomenon occurs when the toner container 201 is left in a high temperature and high humidity environment. Further, it is considered that the same thing occurs when the container is dropped because the impact due to the load of the toner is applied to the film 202. FIG. 1 shows a state of heat sealing in the present invention. The feature of the present invention is that the pressure contact portion of the upper heat sealing jig 211 at the time of heat sealing is inclined with an angle, and the state of the sealing surface of the film 202 after the heat sealing is as shown in FIG. It is in a state of being pushed in with a mark. According to the present invention, as shown in FIG. 2, even when a force 207 'is applied to the film 202 due to a reduced-pressure environment or a drop, the force 207' pulling the film 202 is applied to the bonding portion between the film 202 and the container body 201. However, the shear stress 210 'acts only as a reaction along the bonding surface with respect to'', but the component in the direction perpendicular to the bonding surface, that is, the peeling force against the film 202 does not work. Here, the shear stress between the film 202 and the container 201 is sufficiently large because it is a resistive force on the surface, and the film does not peel off. For this reason, the film peeling due to the above-mentioned factors is strengthened, and toner leakage hardly occurs. However, when replenishing the toner, the shape does not affect the peeling strength, so that the toner can be replenished smoothly. The angle of the press contact portion of the heat sealing jig in the present invention is suitably about 5 ° to 45 °. In order to clarify the effect of the present invention, heat sealing according to the conventional example and the present invention was performed, and the inside of the container was pressurized to give a peeling force to the film by a pressure difference between the inside and outside. Table 1 shows the results of measurement as to whether or not peeling of the seal occurred when the pressure was applied at the same pressure. [Table 1] As described above, according to the present invention,
Using a heat seal jig, the welding surface is pushed in according to the inclination angle of the press-contact part of the heat seal jig, so that the film is hard to peel off by a simple method using the heat welding of the film Can be. As a result, even if a peeling force is applied to the welded film, the film is less likely to peel off than before, and contamination of the inside of the image forming apparatus due to leakage of the developer and contamination of the operator's hands and clothes can be prevented. It is possible to prevent breakage during transportation and movement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a state of a welding surface of a heat seal film in an embodiment of the present invention. FIG. 2 is a diagram showing a relationship between forces applied to the heat seal film of FIG. FIG. 3 is a plan view showing a schematic configuration of an apparatus provided with a conventional heat seal film. FIG. 4 is a cross-sectional view showing a state of a welding surface of a heat seal film of the apparatus of FIG. 3; FIG. 5 is a diagram showing a relationship between forces applied to the heat seal film of FIG. [Description of Signs] 201 Toner container (developer container) 202 Heat seal film 203 Opening

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-136877 (JP, A) JP-A-1-310372 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 13/08 G03G 15/08

Claims (1)

(57) [Claims 1 Openings of the developer supply container body for accommodating a developer is covered with a heat seal film, it is pressed against the heat-sealing jig from the top of the heat seal film
In the method for sealing the developer supply container, wherein the heat seal film is heat-sealed around the opening with respect to the developer supply container main body, 5 is provided on the press-contact portion of the heat sealing jig. ° to 4
The developer replenishment pushed in corresponding to the 5 ° taper portion. As the welding surface of the container body approaches the opening, the depth increases.
Heat-sealed the above heat-sealing film to make it shallow
A method for sealing a developer supply container.