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.

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 glass container is provided that includes a tube, a circular bottom, and a longitudinal axis. A curved glass heel extends from an outer end the bottom to the first end of the tube. The two-dimensional distance h(x,y) between a contact plane and the outer surface. The two-dimensional distance is measured in a direction parallel to the axis. The slope magnitude of the outer surface at the given position x,y is given by

√{square root over ((dh/dx).sup.2+(dh/dy).sup.2)}.

The 75% quantile of values that have been determined for the term

√{square root over ((dh/dx).sup.2+(dh/dy).sup.2)}×d1/h(xy).sub.delta

for all given positions x,y within a circular area having a radius of 0.4×d2/2 and that correspond to the centre is less than 4100 μm/mm. The adjacent positions x,y increase stepwise by 200 μm, and h(x,y).sub.delta=h(x,y).sub.max−h(x,y).sub.min, h(x,y).sub.max is a maximum value for h(x,y) and h(x,y).sub.min is a minimum value for h(x,y) being determined in that circular area.

A glass container is provided that includes a tube, a circular bottom, and a longitudinal axis. A curved glass heel extends from an outer end the bottom to the first end of the tube. The outer surface has a topography defined by a function ĥ(x) that is an azimuthal average of a distance between a contact plane and the outer surface at any given position located on a circle having the centre and the radius |x|. The values ĥ for ĥ(x) are determined for a plurality of circles the radius of which increases stepwise by 500 μm starting with a circle around the centre having a radius of 500 μm. The values ĥ are determined in a range from x=−0.4×d2/2 to x=+0.4×d2/2, d2 having a size such that at least 4 values ĥ are determined and can be fitted with a curvature function

[00001]$\hat{h}\left(x\right)=\frac{-c\times x^2}{1+\sqrt{1-c^2\times x^2}}+h_0.$

A process for preparing a glass container that includes: providing a glass tube with a first portion, a second portion, and a longitudinal axis (L.sub.tube); holding the first portion in a first clamping chuck and the second portion in a second clamping chuck; rotating the glass tube around the longitudinal axis (L.sub.tube); heating, via a heater, the glass tube above a glass transition temperature; separating the first and second portions from one another by pulling apart along the longitudinal axis (L.sub.tube) while the heated glass tube is still rotating by moving the first and the second chucks away from each other; and moving the heater, while moving the first and second chucks away from each other, so that the heater follows a mass that remains at a circular end region of the first and/or second portion.

A process for preparing a glass container that includes: providing a glass tube with a first portion, a second portion, and a longitudinal axis (L.sub.tube); holding the first portion in a first clamping chuck and the second portion in a second clamping chuck; rotating the glass tube around the longitudinal axis (L.sub.tube); heating, via a heater, the glass tube above a glass transition temperature; separating the first and second portions from one another by pulling apart along the longitudinal axis (L.sub.tube) while the heated glass tube is still rotating by moving the first and the second chucks away from each other; and moving the heater, while moving the first and second chucks away from each other, so that the heater follows a mass that remains at a circular end region of the first and/or second portion.

The invention relates to a device for reshaping a rotating glass intermediate, in particular a glass tube, comprising at least one shaping roller, which is translationally displaceable into a shape-rolling contact with the glass intermediate for shaping, and comprising at least one linear motor for the translational positioning of the at least one shaping roller in such a way that the shaping roller directly follows a translational positioning movement of the translator of the linear motor.

The invention relates to a device for reshaping a rotating glass intermediate, in particular a glass tube, comprising at least one shaping roller, which is translationally displaceable into a shape-rolling contact with the glass intermediate for shaping, and comprising at least one linear motor for the translational positioning of the at least one shaping roller in such a way that the shaping roller directly follows a translational positioning movement of the translator of the linear motor.

A method and apparatus are provided for producing a tube of glass by zonewise heating and softening of a hollow cylinder by a movable heating zone while rotating about its rotation axis. The glass tube is continuously formed by radial expansion of the softened region under action of centrifugal force and/or internal overpressure applied in the hollow-cylinder bore. The method and apparatus make it possible to deform the hollow cylinder in a single or a small number of forming steps into a glass tube having a larger outer diameter and high dimensional accuracy by determining a circumferential position at which the wall thickness is comparatively small, and during heating and softening of the rotating hollow cylinder a coolant is dispensed from a coolant source onto the deformation zone only when or predominantly when the circumferential position having the comparatively small wall thickness passes the coolant source.

A method and apparatus are provided for producing a tube of glass by zonewise heating and softening of a hollow cylinder by a movable heating zone while rotating about its rotation axis. The glass tube is continuously formed by radial expansion of the softened region under action of centrifugal force and/or internal overpressure applied in the hollow-cylinder bore. The method and apparatus make it possible to deform the hollow cylinder in a single or a small number of forming steps into a glass tube having a larger outer diameter and high dimensional accuracy by determining a circumferential position at which the wall thickness is comparatively small, and during heating and softening of the rotating hollow cylinder a coolant is dispensed from a coolant source onto the deformation zone only when or predominantly when the circumferential position having the comparatively small wall thickness passes the coolant source.