- Title
- Optimisation of glass scoring operation
- Creator
- Bechoo, Durvesh Sookraj
- Subject
- Glass -- Mechanical properties
- Subject
- Glass manufacture
- Date Issued
- 2016
- Date
- 2016
- Type
- Thesis
- Type
- Masters
- Type
- MEng
- Identifier
- http://hdl.handle.net/10948/9283
- Identifier
- vital:26559
- Description
- The economic crisis and prior recession made a huge dent in many industries. Companies want a cheaper manufactured product with same quality to satisfy the customer in order be competitive yet profitable. Shatterprufe is a company that produces automotive glass. The company has a vast number of products and experience short production run lengths because of its order intake from customers. These short production run lengths require accurate setup to have a repeatable and stable process. An incorrect setup will produce a high scrap rate on production runs. Glass being very brittle and machining it incorrectly results in flaws, breakages or edge stresses that lead to latter process failures. The scoring operation of glass is key to achieve good edge quality to prevent such defects. The correct tools and machine parameters influence good edge quality during the setup procedure. Due to the process having many variables it is difficult to have a stable process and a repeatable stable process. This research will analyse the tool, parameters of the tool and machine parameters to achieve best edge quality and correlating these parameters that will lead to a repeatable stable process. An experimental analysis was conducted on 2.1mm and 2.5mm thick glass. These thicknesses are used predominantly at Shatterprufe automotive glass manufacturing company. The first sample and last sample was analysed during a production run. An average production run length is 36 pieces of glass. The edge quality was seen under a microscope and the fissure depth was measured. To achieve ideal edge quality, the fissure depth must be 15-20% deep of the glass thickness. A fissure is a crack propagated during the scoring of glass. A carbide wheel is used to score the glass. The carbide wheel parameters were varied being the wheel angle and wheel diameter. A 145 degree-4.1mm wheel, 145degree-5.6mm wheel and a 155 degree- 4.1mm wheel was used. The following relationships where observed being the wheel diameter and fissure depth. An increase in wheel diameter resulted in an increase in fissure depth but decreases the wheel life as the wheel becomes blunt. There was inconsistency on fissure depth with the larger diameter wheel. An increased in wheel angle from 145 degree to 155 degree promoted flaws in the glass. Larger wheel angles work better on glass thicknesses of 4-5mm as currently used in the Shatterprufe Struandale Company. An investigation on pressure variation in the pneumatic system was analysed using a pressure transmitter. The pressure transmitter measured the pressure per second versus the set pressure and recorded this data on a data logger. There was no pressure variation in the pneumatic system that can influence poor glass edge quality. A load cell analysis will investigate the physical applied pressure on the glass versus the set pressure. This analysis was to determine the relationship between set versus actual on the glass. It will indicate any mechanical fault. A mechanical fault could be a loose coupling or linkage that can influence the fissure depth. A direct proportional relationship was achieved between the set pressure versus the load cell readings. This indicates no mechanical fault on the system.
- Format
- x, 71 leaves
- Format
- Publisher
- Nelson Mandela Metropolitan University
- Publisher
- Faculty of Engineering, the Built Environment and Information Technology
- Language
- English
- Rights
- Nelson Mandela Metropolitan University
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