A method of producing a capillary tube from glass includes zonally softening a tubular preform having an outer diameter D.sub.OD, an inner diameter D.sub.ID and a diameter ratio D.sub.relwith D.sub.rel=D.sub.OD/D.sub.IDin a heating zone heated to a draw temperature T.sub.draw and drawing off continuously from the softened region a capillary strand having an outer diameter d.sub.AD, an inner diameter d.sub.ID and a diameter ratio d.sub.relwith d.sub.rel=d.sub.OD/d.sub.IDat a draw speed v.sub.draw and cutting the capillary to length therefrom. For cost-effective production of a thick-walled capillary by drawing from a preform without strict requirements for the geometry and dimensional accuracy of the preform, the capillary bore is subjected in the heating zone to a shrinkage process based on the action of draw temperature T.sub.draw and surface tension, such that the diameter ratio d.sub.rel of the capillary strand is adjusted to a value greater than the diameter ratio D.sub.rel of the preform by at least a factor of 5.

Apparatus and method for producing elongated glass components with low bow. The apparatus may include a heating element to heat a bulk glass component where a strand may be drawn from the bulk glass component in a downward direction and a gripper device including a clamping element to support the strand while pulling or drawing it from the bulk glass component in a linear motion, and a low-friction mounting element attached to the clamping element which allows translational movement of the clamping element in an x-y plane. The gripper device may further be used to reduce bow in the strand while it is being drawn by moving the clamping element on the mounting element in a direction opposite the direction of any measured transverse acceleration.

Apparatus and method for producing elongated glass components with low bow. The apparatus may include a heating element to heat a bulk glass component where a strand may be drawn from the bulk glass component in a downward direction and a gripper device including a clamping element to support the strand while pulling or drawing it from the bulk glass component in a linear motion, and a low-friction mounting element attached to the clamping element which allows translational movement of the clamping element in an x-y plane. The gripper device may further be used to reduce bow in the strand while it is being drawn by moving the clamping element on the mounting element in a direction opposite the direction of any measured transverse acceleration.

A lathe-based system may include chucks to retain a glass core rod, an arm, a slip joint, an actuator system, and a control system. The slip joint may couple the arm and a first chuck in fixed relation against relative axial motion with respect to an axis of rotation. The slip joint may also couple the arm and the first chuck in two-dimensionally movable relation with respect to a plane normal to the axis of rotation. The actuator system may be configured to two-dimensionally adjust a position of the first chuck in the plane. The control system may measure straightness of the glass core rod and control the actuator system in response to optical measurements of the straightness. In this manner, the system may straighten the glass core rod. The system may simultaneously elongate the glass core rod as it straightens the glass core rod.

In a method of manufacturing a tube of quartz glass by molding a hollow cylinder having a wall thickness of at least 20 mm, the cylinder is continuously fed under rotation about a rotational axis into a heating zone at a relative feed rate V.sub.C, softened and radially expanded under the effect of a gas pressure. A tube strand is continuously formed and is withdrawn at a withdrawal rate V.sub.T. In order to mold thick-walled initial hollow cylinders of quartz glass into tubes with larger diameter, the gas pressure is used as an actuating variable of a diameter regulation for the tube outer diameter or for a geometrical correlated parameter thereof, and in a pressure build-up phase the gas pressure is gradually increased from a lower initial value to a higher final value, and that the following applies to the ratio of V.sub.C and V.sub.T:V.sub.T=V.sub.C0.2.Math.V.sub.C.

In a method of manufacturing a tube of quartz glass by molding a hollow cylinder having a wall thickness of at least 20 mm, the cylinder is continuously fed under rotation about a rotational axis into a heating zone at a relative feed rate V.sub.C, softened and radially expanded under the effect of a gas pressure. A tube strand is continuously formed and is withdrawn at a withdrawal rate V.sub.T. In order to mold thick-walled initial hollow cylinders of quartz glass into tubes with larger diameter, the gas pressure is used as an actuating variable of a diameter regulation for the tube outer diameter or for a geometrical correlated parameter thereof, and in a pressure build-up phase the gas pressure is gradually increased from a lower initial value to a higher final value, and that the following applies to the ratio of V.sub.C and V.sub.T:V.sub.T=V.sub.C0.2.Math.V.sub.C.

Provided herein are measurement systems including a micrometer assembly for receiving a length of tubing, the micrometer assembly including a plurality of non-contact optical micrometers disposed around the length of tubing for measuring an outer diameter (OD) at a first plurality of positions along a circumference of the length of tubing. The measurement system may further include a displacement gauge assembly for receiving the length of tubing from the optical micrometer assembly, the displacement gauge assembly including a plurality of non-contact gauges disposed around the length of tubing for measuring a wall thickness at a second plurality of positions along the circumference of the length of tubing. A controller receives the OD measurements and thickness measurements, and determines an inner diameter and a concentricity of the length of glass tubing based on an index of refraction of the length of glass tubing, the OD measurements, and the thickness measurements.

A method for production of a photo-structurable glass element is provided. The method includes the steps of: fixing a blank of photo-structurable glass at a first end; heating of a deformation zone of the blank; and drawing the blank. The glass includes Si.sup.4+, a crystal-agonist, a crystal-antagonist, and a pair of nucleating agents. The crystal-agonist is selected from the group consisting of Na.sup.+, K.sup.+, Li.sup.+, and any combinations thereof. The crystal-antagonist is selected from the group consisting of Al.sup.3+, B.sup.3+, Zn.sup.2+, Sr.sup.2+, Sb.sup.3+, and any combinations thereof. The pair of nucleating agents include cerium and an agent selected from the group consisting of silver, gold, copper, and any combinations thereof. The crystal-agonist has a molar proportion cat.-% in relation to a molar proportion of Si.sup.4+ that is at least 0.3 and at most 0.85.

A method for production of a photo-structurable glass element is provided. The method includes the steps of: fixing a blank of photo-structurable glass at a first end; heating of a deformation zone of the blank; and drawing the blank. The glass includes Si.sup.4+, a crystal-agonist, a crystal-antagonist, and a pair of nucleating agents. The crystal-agonist is selected from the group consisting of Na.sup.+, K.sup.+, Li.sup.+, and any combinations thereof. The crystal-antagonist is selected from the group consisting of Al.sup.3+, B.sup.3+, Zn.sup.2+, Sr.sup.2+, Sb.sup.3+, and any combinations thereof. The pair of nucleating agents include cerium and an agent selected from the group consisting of silver, gold, copper, and any combinations thereof. The crystal-agonist has a molar proportion cat.-% in relation to a molar proportion of Si.sup.4+ that is at least 0.3 and at most 0.85.

A redrawing method for the production of thin glasses is provided that allows redraw of high refractive index optical glasses. The includes the steps of providing a vitreous preform with a mean width B, a mean thickness D, and a refractive index n.sub.D of at least 1.68 in a redrawing device, heating at least a part of the preform, redrawing of the preform to a thin glass with a mean width b and a mean thickness d. The heated part of the preform exhibits, for the duration of at most 30 minutes, a temperature above a lower limit of devitrification of the glass. The glass of the preform exhibits a dependence of the viscosity on the temperature, which is characterized by a mean decrease of the viscosity with increasing temperature in an viscosity range of 10.sup.8 to 10.sup.5 dPas of at least 3*10.sup.5 dPas/K.