Statistical Investigation of Maintenance Effects on Quality of Formed Glass Tube Dimensions

Process quality control utilizes inspection of a product while it is being produced through testing periodic samples of products. After this, if product quality characteristics have been changed, the process is stopped, and a search is made for an assignable cause. The objective of a process-capability study is to assess the ability of a process to meet product specifications. During a quality improvement initiative, capability-estimates are obtained at start and at end of study to reflect the occurred improvement. Several capability-estimates show how a process is capable of meeting its specification limits. Essentially, capability-estimates reflect the non conformance rate of a process in a single number form. This involves calculating some ratio of process specification limits. In this study, the production of a fluorescent lamp consisting of a glass tube is considered. Tube quality is affected by the production line conditions. So, the maintenance of the production line is an important stage to increase tube quality. In this paper glass tube quality is studied. Minitab is a statistical software was used to analyze obtained data. The results showed an obvious improvement of part quality after maintenance stage. All measurements were done in Toshiba factory for fluorescent lamp manufacturing.

Design and Development of Integrated System on CAD/CAE /CAPP for Tube-Bending in Power Plants Boiler

Quality control is very important in the manufacturing process of cold tube-bending, but most of enterprises can only verify tube quality by the tube bending machine. Based on the platform of commercial software, an integrated system on CAD/CAPP/CAE for bending tube in power plants boiler is developed. The system is carried on re-development under the VC++ language environment, and data is transferred in Pro/E, Ansys and designing module through a reasonable data structure and interface. So we can share data and realize flexibility and standardization of the processing. The application result indicated that the integrated system can offer a whole set of solution from building a CAD model, forecasting tube bending quality and structure optimization by CAE methods to programming CAPP processes.