Coating device having first and second temperature controlled flow paths for coating a glass fiber and coating method

A coating device comprising:

• a fiber passage through which a glass fiber passes downward in a vertical direction;
• an inner sleeve, an outer sleeve, and a die having a first die and a second die;
• said die is disposed in the inner space of the inner sleeve;
• the first die shares a shaft with a main body portion of the inner sleeve;
• the second die shares the shaft with the main body portion of the inner sleeve;
• a concave portion is formed on the outer peripheral surface of the inner sleeve and between a first annular body and a second annular body;
• the outer sleeve is fixed to an outer peripheral surface of the inner sleeve;
• the outer sleeve includes the first annular body and the second annular body;
• the first annular body has an inner diameter of a same size as the outer diameter of the inner sleeve;
• the second annular body has an inner diameter of a same size as the outer diameter of the inner sleeve;
• a first flow path which is a flow path allowing a primary resin to flow toward the fiber passage and includes a first branch path only horizontally dividing the primary resin moving in a horizontal direction;
• a first temperature controller which is disposed along the first flow path and controls a temperature of the first flow path;
• a second flow path which is a flow path allowing a secondary resin to flow toward the fiber passage, includes a second branch path only horizontally dividing the secondary resin moving in the horizontal direction, and is located below the first flow path;
• and
• a second temperature controller which is disposed along the second flow path and controls a temperature of the second flow path,
• wherein each of the first flow path and the second flow path is formed into four-branch flow paths by being branched into two twice, and each flow path of the four-branch flow paths is arranged with respect to each other at an interval of 90° in a circumferential direction,
• the first flow path and the first temperature controller form the first annular body disposed around the fiber passage and having an annular shape,
• the second flow path and the second temperature controller form the second annular body disposed around the fiber passage, disposed below the first annular body, and having an annular shape,
• the first annular body and the second annular body are separated from each other in the vertical direction and a heat shield layer formed by an air layer or a heat insulation material is formed between the first annular body and the second annular body, said heat shield layer is formed along a position of the concave portion formed on the outer peripheral surface of the inner sleeve;
• and
• the temperature of the first flow path controlled by the first temperature controller is higher than the temperature of the second flow path controlled by the second temperature controller.