Patent · US Active

Process for production of glass tubes having at least one tube end section of reduced stress

US8474285B2 · kind B2 · utility

1Cited by

7References

31Claims

0Family size

Assignee

Schott AG · DE

Inventors

Reiner Bartsch · Tirschenreuth, DE
Jens Ahrens · Sulzbach-Rosenberg, DE
Markus Pappenberger · Wiesau, DE
Roland Fuchs · Mitterteich, DE

Key dates

Filing date	Jul 2, 2010
Grant date	Jul 2, 2013
Priority date	—
Expiry date	Apr 3, 2031

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC03B29/06
WIPO fieldOther special machines
WIPO sectorMechanical engineering

Abstract

In the process a glass tube line is drawn from a glass tube production plant and the glass tube is severed from the glass tube line. At the same time the still heated glass tube is subjected to a selective local heat treatment of the at least one tube end section prior to cooling down completely in order to reduce the stresses in the respective tube end section. Not the entire glass tube but instead only the respective tube end section is subjected to the selective local heat treatment. The heat treatment is performed in particular in such a manner that the mechanical tensile stress in the region between 7 mm and 20 mm from the tube end or ends is reduced to below 6.0 MPa, more preferably to below 4.5 MPa.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.