A method for producing a glass sleeve having a first flattened portion and shaping tools for forming such glass sleeves. A method can comprise providing a substantially cylindrical glass tube—optionally polished or otherwise treated to reduce or remove interior imperfections—heating the glass tube to a temperature within the softening range of the glass, introducing one or more shaping tools having a generally D-shaped or generally rectangular cross-section into the enclosed space, and moving the one or more shaping tools against the inner curved surface to deform the tube, forming the first flattened portion. The one or more shaping tools can be made of any suitable material, for example: steel coated with boron nitride; porous graphite or carbon air bearings; or a nickel-based alloy (e.g., Inconel).

Methods for controlling a converter for converting glass tubes to glass articles include preparing condition sets including settings for a plurality of process parameters, operating the converter to produce glass articles, measuring attributes of the glass articles, operating the converter at each of the condition sets, associating each glass article with a condition set used to produce the glass article and the attributes measured, developing operational models from the attributes measured and the condition sets, determining run settings for each of the plurality of process parameters based on the operational models, and operating the converter with each of the process parameters set to the run settings determined from the operational models.

A method for homogenizing glass includes the method: providing a cylindrical blank composed of the glass having a cylindrical outer surface that extends along a longitudinal axis of the blank between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and displacing the shear zone along the longitudinal axis of the blank. To enable a radial mixing within the shear zone in addition to the tangential mixing with the lowest possible time and energy input, starting from this method, cylindrical sections of the blank are adjacent to the shear zone on both sides, the first cylindrical section having a first central axis and the second cylindrical section having a second central axis, the first central axis and the second central axis being temporarily non-coaxial with each other.

A method for homogenizing glass includes the method: providing a cylindrical blank composed of the glass having a cylindrical outer surface that extends along a longitudinal axis of the blank between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and displacing the shear zone along the longitudinal axis of the blank. To enable a radial mixing within the shear zone in addition to the tangential mixing with the lowest possible time and energy input, starting from this method, cylindrical sections of the blank are adjacent to the shear zone on both sides, the first cylindrical section having a first central axis and the second cylindrical section having a second central axis, the first central axis and the second central axis being temporarily non-coaxial with each other.

A method for homogenizing glass includes the method: providing a cylindrical blank composed of the glass having a cylindrical outer surface that extends along a longitudinal axis of the blank between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and displacing the shear zone along the longitudinal axis of the blank. The displacement of the shear zone along the longitudinal axis of the blank is superimposed by a simultaneous oscillating motion of the shear zone along the longitudinal axis of the blank. The first end of the blank is rotated at a first rotational speed and the second end of the blank is rotated at a second rotational speed. An oscillating motion of the shear zone is generated by periodically varying the first and/or second rotational speed.

A method for homogenizing glass includes the method: providing a cylindrical blank composed of the glass having a cylindrical outer surface that extends along a longitudinal axis of the blank between a first end face and a second end face, forming a shear zone in the blank by softening a longitudinal section of the blank and subjecting it to a thermal-mechanical intermixing treatment, and displacing the shear zone along the longitudinal axis of the blank. The displacement of the shear zone along the longitudinal axis of the blank is superimposed by a simultaneous oscillating motion of the shear zone along the longitudinal axis of the blank. The first end of the blank is rotated at a first rotational speed and the second end of the blank is rotated at a second rotational speed. An oscillating motion of the shear zone is generated by periodically varying the first and/or second rotational speed.

A glass tube element having a hollow cylindrical section with a shell having an outer diameter is provided. A first ratio is a difference value to a mean value. The difference value is a difference of a minimal and maximal value of the outer diameter. The mean value is a mean of the minimal and maximal values. A sub-section having a start, an end, and a distance of 1 meter measured along a straight line from the start to the end and intersecting with a center axis of the sub-section at the start and the end. The sub-section having, for every point of the center axis, a shortest distance to the straight line. A second ratio of a specific distance to 1 meter, the specific distance being defined as a largest of all shortest distances. A product of the first and second ratio is smaller than 4×10.sup.−6.

A borosilicate glass for a pharmaceutical container having high appearance quality, particularly a small number of air lines, and a glass tube for a pharmaceutical container are provided. The borosilicate glass for a pharmaceutical container contains, in mass %, from 70.0 to 78.0% of SiO.sub.2, from 5.0 to 8.0% of Al.sub.2O.sub.3, from 5.0 to 12.0% of B.sub.2O.sub.3, from 0 to 4.0% of CaO, from 0 to 4.0% of BaO, from 4.0 to 8.0% of Na.sub.2O, from 0 to 5.0% of K.sub.2O and from 0.001 to 1.0% of SnO.sub.2.

A borosilicate glass for a pharmaceutical container having high appearance quality, particularly a small number of air lines, and a glass tube for a pharmaceutical container are provided. The borosilicate glass for a pharmaceutical container contains, in mass %, from 70.0 to 78.0% of SiO.sub.2, from 5.0 to 8.0% of Al.sub.2O.sub.3, from 5.0 to 12.0% of B.sub.2O.sub.3, from 0 to 4.0% of CaO, from 0 to 4.0% of BaO, from 4.0 to 8.0% of Na.sub.2O, from 0 to 5.0% of K.sub.2O and from 0.001 to 1.0% of SnO.sub.2.

Methods for producing glass articles from glass tube includes securing a glass tube in a holder of a converter; rotating the glass tube; and passing the glass tube through processing stations, which include at least a heating station and a forming station, to form one or more features at a working end of the glass tube. An active time is an amount of time the glass tube is engaged with a heating element or a forming tool while in a processing station, and an exposure index for the processing station is the rotational speed of the glass tube multiplied by a number of heating elements or forming tools in the processing station multiplied by the active time. An absolute difference between the exposure index and a nearest integer is less than or equal to 0.30, which reduces temperature and dimensional inhomogeneity around a circumference of the glass tube.