Seamless belt forming die and manufacturing method thereof

Abstract

The invention provides a seamless belt forming die and a manufacturing method thereof capable of inhibiting the generation of fusion traces of a resin interflow portion. The seamless belt forming die comprises an inner core rod (21), an outer core rod (31) and a resin inlet (41) for injecting fusion resin inside the gap between the inner core rod (21) and the outer core rod (31). The outer circumferential surface of the inner core rod (21) is equipped with a hanger type resin flow path (51) for the diffusion of the injected fusion resin in the gap between the inner core rod (21) and the outer core rod (31) along the circumferential direction thereof. With the shaft of the inner core rod (21) as the center, the S part of the hanger type resin flow path (51) at the approximately opposite direction of the resin inlet (41) is equipped with a flow-stopping part (52) for stopping the flowing of the resin inside the flow path. The circumferential length t1 of the flow-stopping part (52) is 0.050-0.400% of the length of the outer circumference L of the inner core rod (21).

Description

technical field [0001] The present invention relates to a molding die and method for producing an endless seamless belt by extrusion molding a thermoplastic resin. In particular, the present invention relates to a molding die and method for producing a seamless belt having performances such as an intermediate transfer belt suitable for use in image forming apparatuses such as electrophotographic copiers and printers. Background technique [0002] In conventional image forming apparatuses such as electrophotographic copiers and printers, a photoreceptor is uniformly charged and an image thereon is exposed to form a latent image. Then, the formed image latent image is developed with toner to form a toner image of the image, the toner image is transferred to the intermediate transfer belt, and then transferred to the recording medium, and the transferred image is transferred by the fixing device. The toner image is heated and fixed to form an image. [0003] Since the interme...

AI Technical Summary

Problems solved by technology

As a result, the thickness uniformity and surface smoothness of the film at the fusion mark portion are poor, so that the dispersion uniformity of additives, especially conductive fillers is poor, and the quality required as an intermediate transfer belt cannot be fully satisfied.

For example, the fusion line part contained in the film produced by the above-mentioned coat hanger mold, in particular, the thickness of the fusion line part is 5% or even 8% thicker than other parts on the circumference, in the film containing at least polyphenylene sulfide and nylon. When a resin composition is used as a raw material, it is particularly difficult to form a film with a uniform thickness

If an intermediate transfer belt composed of such a film is used for image formation, image impurities after transfer to recording paper due to protrusions on the intermediate transfer belt, local resistance, and film thickness uniformity, transfer efficiency Inferior phenomenon

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