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Asbestos-free sealing material gains approval
Static sealing developing the world’s first realistic testing standards for joint sealants - the materials which fill the gap between external panels on the average office block. The research team will determine scientifically why sealed joints fail, develop a novel testing system and produce guidelines for designers and specifiers. “The majority of post- 1960s commercial buildings have some sort of panelled cladding system, where the
joints between panels are filled with sealant,” explains Dr Allan Hutchinson, from Oxford Brookes. “The
failure of sealants is commonplace; in 1990, for example, 100 000 kilometres of joints were resealed in the UK, at a cost of f500m! Further afield, the Sydney Opera House cost a staggering s42m to reseal.” The main causes of sealant failure are movement caused by temperature change, settlement and moisture, plus weathering and chemical attack. Movement whilst the sealant is curing - a process which can take several weeks - can also have a dramatic effect, especially on one-part seakmts. Yet there are no scientific measurements of these effects, and no established test methods. Oxford Brookes, with industrial partners Taywood Engineering, Bovis Program Management, Morton International and Fosroc International, aims to bridge this gap. The team’s two-year project is funded by a s95.000 grant from the EPSRC. In the first year they will develop a test rig to impose movement and environmental exposure on a variety of sealed joints. These will be measured regularly to establish failure patterns, durability and during characteristics, especially of one-part sealants. In addition, large one-storey panels will be tested on cladding rigs at Taywood Engineering. The team will also record joint movements on two prestigious buildings in Central London, an aluminium-clad office block in New Bridge Street and a concrete-clad block in Broadgate, before using their findings to introduce real variables in comprehensive tests. Oxford Brookes believes the new testing standards will have a real impact on the construction industry, the owners of commercial properties and sealant manufacturers. The production of well-tested and better materials could mean that joints could last up to 25 years, rather than ten or less. Property owners will be able to insist that construction firms use sealants that are tested to set standards, and people working in well-sealed buildings won’t have to put up with damp and mould. Contact: Dr Allan Hutchinson, Joining Technology Research Centre, Oxford Brookes University, Gipsy Lane Campus, Oxford OX3 OBP, UK. Tel: +44 1865 463506.
Klingersil C4324; a low-cost, asbestos-free sealing material. The company says that with excellent gas-tight properties, C4324 also has good resistance to oils, fuels, hydrocarbons and refrigerants, and can be used in steam at temperatures up to 150°C. It is coloured black on one side and green on the other. Suitable for potable water, food and food processing applications, C4324 complies with BS5753 Grade Y - the non-asbestos standard. It is mixture of 100% recycled flbres, with a nitrile rubber binder an effective anti-stick finish on both sides. Developed in 1990, C4324 was the world’s first asbestos-free, recycled gasket material. Prior to submitting it for WRC approval in September, the formulation had to be modified to improve its release properties. It is now being produced for the European market at Sidcup, and is available in standard 2.0 m x 1.5 m sheets or as cut gaskets. Contact: Richard Klinger Limited, Sidcup, Kent DA14 5AG, UK. Tel: +44 161 300 7777; Fax: +44 161 302 6145.
Durable PTFE form-in-place gasketing A new expanded PTFE form-in-place
Asbestos-free sealing material gains approval Water Research Council (WRC) approval has been given to Richard Klinger Limited, UK, for its new
gasketing has been launched by Chesterton, providing life sealing of most industrial equipment. The gasketing’s micro-fibrillated internal structure turns ordinary PTFE into a dimensionally strong, durable gasketing material tough enough to resist creep and cold flow yet soft and pliable enough to easily conform to worn or uneven surfaces and create a tight seal. Expanded PTFE is unaffected by all common chemicals in the entire pH range 0 to 14. The gasketing handles pressures from full vacuum up to 2 10 bar and temperatures from 268°C up to 3 15°C. Installation is quick, easy and clean for most sealing surfaces. Type
Sealing TechnologyNo. 22
joints between panels are filled with sealant,” explains Dr Allan Hutchinson, from Oxford Brookes. “The
failure of sealants is commonplace; in 1990, for example, 100 000 kilometres of joints were resealed in the UK, at a cost of f500m! Further afield, the Sydney Opera House cost a staggering s42m to reseal.” The main causes of sealant failure are movement caused by temperature change, settlement and moisture, plus weathering and chemical attack. Movement whilst the sealant is curing - a process which can take several weeks - can also have a dramatic effect, especially on one-part seakmts. Yet there are no scientific measurements of these effects, and no established test methods. Oxford Brookes, with industrial partners Taywood Engineering, Bovis Program Management, Morton International and Fosroc International, aims to bridge this gap. The team’s two-year project is funded by a s95.000 grant from the EPSRC. In the first year they will develop a test rig to impose movement and environmental exposure on a variety of sealed joints. These will be measured regularly to establish failure patterns, durability and during characteristics, especially of one-part sealants. In addition, large one-storey panels will be tested on cladding rigs at Taywood Engineering. The team will also record joint movements on two prestigious buildings in Central London, an aluminium-clad office block in New Bridge Street and a concrete-clad block in Broadgate, before using their findings to introduce real variables in comprehensive tests. Oxford Brookes believes the new testing standards will have a real impact on the construction industry, the owners of commercial properties and sealant manufacturers. The production of well-tested and better materials could mean that joints could last up to 25 years, rather than ten or less. Property owners will be able to insist that construction firms use sealants that are tested to set standards, and people working in well-sealed buildings won’t have to put up with damp and mould. Contact: Dr Allan Hutchinson, Joining Technology Research Centre, Oxford Brookes University, Gipsy Lane Campus, Oxford OX3 OBP, UK. Tel: +44 1865 463506.
Klingersil C4324; a low-cost, asbestos-free sealing material. The company says that with excellent gas-tight properties, C4324 also has good resistance to oils, fuels, hydrocarbons and refrigerants, and can be used in steam at temperatures up to 150°C. It is coloured black on one side and green on the other. Suitable for potable water, food and food processing applications, C4324 complies with BS5753 Grade Y - the non-asbestos standard. It is mixture of 100% recycled flbres, with a nitrile rubber binder an effective anti-stick finish on both sides. Developed in 1990, C4324 was the world’s first asbestos-free, recycled gasket material. Prior to submitting it for WRC approval in September, the formulation had to be modified to improve its release properties. It is now being produced for the European market at Sidcup, and is available in standard 2.0 m x 1.5 m sheets or as cut gaskets. Contact: Richard Klinger Limited, Sidcup, Kent DA14 5AG, UK. Tel: +44 161 300 7777; Fax: +44 161 302 6145.
Durable PTFE form-in-place gasketing A new expanded PTFE form-in-place
Asbestos-free sealing material gains approval Water Research Council (WRC) approval has been given to Richard Klinger Limited, UK, for its new
gasketing has been launched by Chesterton, providing life sealing of most industrial equipment. The gasketing’s micro-fibrillated internal structure turns ordinary PTFE into a dimensionally strong, durable gasketing material tough enough to resist creep and cold flow yet soft and pliable enough to easily conform to worn or uneven surfaces and create a tight seal. Expanded PTFE is unaffected by all common chemicals in the entire pH range 0 to 14. The gasketing handles pressures from full vacuum up to 2 10 bar and temperatures from 268°C up to 3 15°C. Installation is quick, easy and clean for most sealing surfaces. Type
Sealing TechnologyNo. 22