Toray Industries, Inc.

Haruki Morikawa

Makoto Endo

Eiichi Yamamoto

Keizo Ono

Toshiyuki Miyoshi

Shuichi Yamanaka

Mikiya Takechi

Toshinori Kawamura

Jun Yamazaki

Masakatsu Shinto

Seiji Mizukami

Process for producing a precursor fiber bundle and a carbon fiber bundle

Precursor fiber bundle for production of a carbon fiber bundle, a process for producing the precursor fiber bundle, a carbon fiber bundle, and a process for producing the carbon fiber bundle

By using carbon fibers having a fineness of 25,000 deniers or more, the present invention provides a carbon fiber package including a cheese winding package or a coreless package in which an outside diameter of the package, a diameter of a bobbin or an inside diameter of the package, and a winding width are regulated in the specific ranges, a square-end type package in which a yarn width per fineness, wind angles at the start of winding and at the end of winding, and shifting of the yarn are regulated in the specific ranges, and a carbon fiber packed member in which an average bulk density is regulated in a specific range. Those carbon fiber packages and the carbon fiber packed member solve troubles and inconveniences during use, and also packages which have a high winding density and which do not break easily can be obtained.

Carbon fiber package and carbon fiber packed member

A heat treatment furnace for fiber for heat-treating a fiber bundle (yarn) formed of many continuous filaments in hot gas while running the yarn. The heat treatment furnace has a plurality of heat treatment chambers provided in a furnace body. The temperature in each individual heat treatment chamber is independently adjusted to a temperature which is different from the temperatures in the other heat treatment chambers. Thereby, the heat treatment furnace can be made small and is able to heat-treat fiber efficiently. This heat treatment furnace is useful, particularly, as a heat treatment furnace (an oxidizing heat treatment furnace, or a oxidizing furnace) for producing an oxidized fiber needed to produce a carbon fiber. A polyacrylonitrile-based fiber bundle (yarn), that is a precursor fiber bundle for producing an oxidized fiber, passes through a zigzag yarn path, and passes through the heat treatment furnaces, in each of which temperature is independently adjusted to a temperature that is different from the temperatures in the other furnaces. An oxidized fiber bundle (yarn) is thereby produced. The zigzag yarn path in the heat treatment chambers for the oxidizing heat treatment is established by a combination of a plurality of yarn guide rollers provided outside the furnace body. Each yarn guide roller has, on its peripheral surface, a yarn guide groove for guiding a yarn. The yarn guide grooves have a specific cross-sectional shape whereby the cross-sectional shape of the yarn to be supplied into the heat treatment chambers for the oxidizing heat treatment is adjusted into a flat generally rectangular shape. Heat accumulation in the yarn being heat-treated is thereby reduced.

Yarn guide roller

Heat treatment furnace for fiber

Growing community of inventors

Shiga, Japan

Haruki Morikawa