Nov 7 2012
British technology innovator Mantec Technical Ceramics owns the world renowned Bullers brand - whose Bullers Rings were introduced in 1900, making them among the very earliest pyrometric devices for this industry. Now Mantec has introduced its high temperature Bullers Process Control Discs.
Important in all ceramic manufacturing, when it comes to technical ceramics, ferrites, MLCCs, refractories, grinding wheels, compacts and powder injected components then ensuring a uniform and controlled 'Heat Work' profile is seen as absolutely critical. The consistent performance of Bullers Process Control Discs makes them an essential tool in this thermal monitoring and controlling exercise.
Increased interest in these discs - manufactured to ISO 9001:2008 quality standards - has really taken off since Mantec introduced higher temperature versions. These are the BPCD-HT, for firing/sintering temperatures between 1200°C and 1550°C and the BPCD-VHT, covering 1500°C up to 1770°C.
As with Bullers Rings, accurate and reliable pyrometry is guaranteed because the ceramic discs (unlike thermocouples, for instance) experience the same thermal effects as the payload. So, for any particular point in any zone, measuring the disc shrinkage after firing/sintering will tell the user exactly what quantity of heat - from all sources - has been absorbed through the kiln, furnace or oven cycle.
Both the BPCD-HT and BPCD-VHT discs are only 20mm diameter by 7mm thick, thus making them ideal for placement in a whole host of high temperature and ultra-high temperature combustion environments, right down to small footprint sintering and test furnaces. They are simple to use because they are easily placed and quick to measure.
After the firing process, the operator just uses a micrometer to measure the outside diameter of the disc and note whether there are any changes to that diameter from the norm. Here, Mantec's discs provide an advantage to the user and speed up the process. For other similar products the norm is established by a temperature correlation chart or calibration curve which has to be issued with each set of discs supplied to the customer. The user must read off this new chart each time after making measurements.
Mantec, however, has developed the required technology to manufacture its discs to a set of consistent principles and keep them harmonised against internal standards for any of its given temperature ranges. Mantec makes the very smallest of changes to the discs to ensure that they perform to this established standard. This means that there is just one standard temperature correlation chart for the BPCD-HT and one for the BPCD-VHT. Batch to batch, customers know they can simply check against just these two charts all the time. They are then immediately able to make adjustments to their firing programmes.
Adrian Wake, Mantec's Sales Manager, commented: "Heat Work evaluation is vital in all technical ceramic manufacturing processes and there are very few pyrometry products on the market which offer consistent and accurate measurement up to 1770°C. Product quality can easily be compromised if this evaluation process is not carried out and association with peak firing temperatures is not being monitored and controlled.
"Early reaction to our HT and VHT discs has been extremely encouraging - customers have recognised that our closely controlled manufacturing technique has made life a lot easier for them, in addition to which the discs are very competitively priced. They help maximise yields, increase productivity, minimise waste and improve profitability. Each batch of materials is pre-tested to our exacting standards before discs are manufactured. This consistency ensures a reliable, consistent and reproducible product quality time after time."
Disc Number to Temperature Comparison Chart available here: http://www.mantectechnicalceramics.com/sites/default/files/7mm_ht_data_sheet.pdf