Abstract: A process for producing glass tubes includes: applying a glass melt onto an outer surface of a rotating conical mandrel by guiding the glass melt from a feed tank through an outlet; forming a hollow glass melt body on the conical mandrel; drawing the hollow glass melt body from the conical mandrel in a predetermined direction toward a front end for forming a glass tube, the outer surface having a wetting zone where the glass strand first contacts the conical mandrel, a spatial variation of the wetting zone of the applied glass melt being monitored by measuring a horizontal movement of an edge of the glass strand; reducing the spatial variation by adjusting one or more process parameters; cooling the hollow glass melt body; and cutting the cooled glass melt body into glass tubes.

Abstract: A glass tube, such as a glass tube for the production of containers for storage of pharmaceutical compositions, facilitates production of pharmaceutical containers with high quality. The glass tube has a relative cross-sectional area deviation defined as QF max - QF min 1.5 ? ? m . QF max - QF min 1.5 ? ? m is less than k*x+t. QFmax is the highest cross-sectional area and QFmin is the lowest cross-sectional area of at least two cross-sections of the glass tube, the cross-sections being spaced apart from each other along a length of the glass tube, and k is 0.0023 m?1, t is less than 0.15 mm2/m and x is QF max + QF min 2 .

Abstract: A glass tube, such as a glass tube for the production of containers for storage of pharmaceutical compositions, facilitates production of pharmaceutical containers with high quality. The glass tube has a relative cross-sectional area deviation defined as QF max - QF min 1.5 ? ? m . QF max - QF min 1.5 ? ? m is less than k*x+t. QFmax is the highest cross-sectional area and QFmin is the lowest cross-sectional area of at least two cross-sections of the glass tube, the cross-sections being spaced apart from each other along a length of the glass tube, and k is 0.0023 m?1, t is less than 0.15 mm2/m and x is QF max + QF min 2 .

Abstract: A method for optically inspecting a mold (10) for manufacturing ophthalmic lenses such as contact lenses for possible mold defects, including: generating a set of images of the mold (10) for different azimuthal illumination angles (?1, ?9) using an illumination system (20) and an imaging system (30), the latter being aligned such that its focal plane cuts through the mold (10) at a specific axial position along a center axis of the mold (10); generating a focal plane image by averaging pixelwise over the set of images after having masked out in each image those regions that include direct specular reflections from the mold (10); repeating the previous steps for one or a plurality of different axial positions of the focal plane such as to generate a plurality of different focal plane images; identifying one or more image features in the plurality of focal plane images indicative for a possible mold defect; determining for each identified image feature in which focal plane image the identified image feature app

Abstract: A method for optically inspecting a mold (10) for manufacturing ophthalmic lenses such as contact lenses for possible mold defects, including: generating a set of images of the mold (10) for different azimuthal illumination angles (?1, ?9) using an illumination system (20) and an imaging system (30), the latter being aligned such that its focal plane cuts through the mold (10) at a specific axial position along a center axis of the mold (10); generating a focal plane image by averaging pixelwise over the set of images after having masked out in each image those regions that include direct specular reflections from the mold (10); repeating the previous steps for one or a plurality of different axial positions of the focal plane such as to generate a plurality of different focal plane images; identifying one or more image features in the plurality of focal plane images indicative for a possible mold defect; determining for each identified image feature in which focal plane image the identified image feature app