New & Improved PSR Refractory Compositions

Over the last few years PSR have worked closely with the School of Chemical and Process Engineering at the University of Leeds to develop new refractory compositions to enhance our range of products for the glass container industry. After comprehensive development, testing and field trials, we are now able to offer the following superior feeder expendable refractory compositions.

Spout Bowls PSR Refractories
PSR-930 – 24.9% ZrO2

PSR-930 is the latest material development to come out of PSR’s research and development department. It has a higher zircon content, but of equal importance is the particle packing density which we were able to achieve through detailed analysis of the refractory microstructure. With a porosity as low as 13% and a density as high as 3200 kg/m3, compared to typical values of 18-20% and 2900-3000 kg/m3 respectively for competitive high zircon containing refractories, we were able to achieve excellent glass corrosion resistance whilst maintaining the thermal shock resistance inherent in our traditional refractory compositions.

Results to date have shown an increase in the life of feeder expendable parts of 30-50% over our standard refractory compositions in most standard soda lime container glass operations.

Our full range of feeder expendable refractories are now available in PSR-930 material.

PSR-925 – 24.1% ZrO2, 74% Al2O3

PSR-925 was developed initially as a spout insert material as an alternative to other options such as fused cast AZS inserts or, more common in recent years, Chrome-Oxide inserts.

Using Zirconia, a highly refractory material, as the base for the material (as opposed to the usual ingredient Zircon, more accurately known as Zirconium-Silicate) and adding only alumina grains and powders, we were able to achieve exceptionally high corrosion resistance.

By manufacturing the material ourselves, using our usual slip-casting method, we are able to cast PSR-925 as a single piece ‘uninserted’ spout. This eliminates the joint which would otherwise be present between the spout insert and the spout body, and ensures the entire spout bowl is highly resistant to glass corrosion.

PSR-925 spouts and spout inserts have proven to operate for in excess of 3 or 4 years in most typical soda-lime container glass applications, matching or even surpassing the life expectancy of a chrome-oxide inserted spout.

PSR are also able to offer Chrome-Oxide inserts, inserted in a PSR-315 spout bowl. However Chrome-Oxide material comes with its own drawbacks of; being expensive to produce; the special environmental considerations inherent with some Chromium containing refractories; and the potential to discolour some glasses.

PSR-925 has none of these considerations, can be offered at a fraction of the price of a Chrome-Oxide inserted spout and represents the optimum solution for a spout bowl.

PSR-925 is now available and is recommended for supply as a complete spout bowl.

Please contact our sales team for any enquiries at

See article written by our Company Chairman, in conjunction with our Research and Development Manager, as published in the Glass International industry magazine for further details.

Glass International Article – October 2020