Abstract: A device for severing flexible polymeric tube, pipe, or tubular extrudate, such as flexible light pipe, reproducibly, cleanly, and safely is described. The device comprises a block with two specially aligned cylindrical devices for holding the pipe and a slot between the devices for guiding the severing blade with minimum deviation from its path, and a pivot and mounting upon which a blade in a holder is mounted to give even more accurate and uniform control of the path of the severing action.

Abstract: The present invention relates to a process for making glass by the sol-gel process. A mixture of silicon alkoxide, at least two other metal alkoxides, and alcohol in a solution sufficiently acidic to hydrolyze partially the silicon alkoxide is formed. Water is then added under agitation to convert the metal alkoxides to a network of corresponding metal oxides suitable for gelation. The mixture containing the network of metal oxides is then molded for a sufficient time to form a gel. Substantially only oxides of one of the at least two other metals is then removed from the gel, which is then fixed in a liquid capable of arresting such additional removal. The fixed gel is then dried and sintered to form a glass. The step of removing the at least one other metal oxide from the gel can be followed with a step of withdrawing partially oxides of one of the remaining at least two other metals in order to form a transparent gradient-index glass after sintering.

Abstract: The present invention relates to a process for making glass by a sol-gel process. The process is initiated by forming a mixture of silicon alkoxide and an alcohol in a solution sufficiently acidic to partially hydrolyze the silicon alkoxide. An index modifying metal alkoxide selected from the group consisting of alkoxides of titanium and zirconium is then added to the mixture. Water is next added to convert the metal alkoxides to a network of corresponding metal oxides suitable for gelation. The mixture containing the network of metal oxides is then contained for sufficient time to form a gel. The gel is acid leached for enough time to remove some of the index modifying metal oxide. To prevent further removal of index modifying metal oxide from the gel, the gel is fixed. The fixed gel is then rinsed with a solvent to remove precipitates from the gel, dried, and sintered into a transparent gradient-index glass.

Abstract: Gradient-index glass is produced in a sol-gel process by utilizing water or a mixture of water and alcohol. This technique is particularly suitable for production of glass bodies with a ternary system of metal alkoxides, including silicon alkoxide, an index modifying metal alkoxide, such as alkoxides of titanium and zirconium, and an additional metal alkoxide, such as an alkoxide of aluminum, boron, or germanium.