Nippon Sheet Glass Company, Limited

Unitika Ltd.

Unitika Glass Fiber Co., Ltd.

Yoshiyuki Inaka

Hiroyuki Tanaka

Yukihito Nagashima

Shigeki Nakagaki

Takashi Sunada

Koji Hayashi

Seiichiro Manabe

Takaharu Miyazaki

Yoshito Nawa

Riku Sawai

Daisuke Nishinaka

Kouichi Sakaguchi

Tomoki Sekida

A glass composition of the present disclosure includes, in wt %, 50&#x2264;SiO&#x2264;56, 20&#x2264;BO&#x2264;30, 10&#x2264;AlO&#x2264;20, 3.5&#x2264;MgO+CaO&#x2264;10, and 0&#x2264;RO&#x2264;1.0, further includes FeO, and has a permittivity of less than 5.0 at a frequency of 1 MHz. R is at least one element selected from Li, Na, and K. The glass composition of the present disclosure is a low-permittivity glass composition with which the occurrence of fiber breakage during fiber forming can be reduced even when glass fibers to be formed have a small fiber diameter, and the occurrence of defects such as fiber breakage and fluffing during processing of the glass fibers can be reduced.

Glass composition, glass fibers, glass cloth, and method for producing glass fibers

A vertical glass melting furnace of the type having an inlet for raw materials at the top thereof, an outlet for molten glass at the bottom thereof, and a tabular electric resistance heating element for melting which is immersed at some level in molten glass, has at least one opening, and covers almost entirely the cross-section of the furnace at that level, the vertical glass melting furnace comprising a stirrer which extends from above the furnace and passes through the batch layer and the tabular heating element so that the stirrer brings about forced circulation for homogenization of the molten glass which has passed through the tabular heating element and stays in the region below the tabular heating element.

Vertical glass melting furnace

Growing community of inventors

Mie, Japan

Yoshiyuki Inaka