- Email: [email protected]
Quadrant launches temperature-resistant materials for machined parts
NEWS As a result, the permeation volume of Phase III fuel through the seal wall of Viton has dropped to less than 1/20th of the previous level – from 1908 gms-mm/m2/day to less than 96 gms-mm/ m2/day, meeting the tough PZEV requirement. In addition, oil resistance is also improved. Because Viton is stiffer and has better compression set characteristics than HNBR at a low temperature, a greater compression force could be used with Toyota’s metal fuel tank locknut than before, yielding a tighter seal with less permeation. In other news, DPP says that recent testing of its Vamac Ultra ethylene acrylic elastomers (AEM), and new grades of Zytel nylon resins and semi-aromatic Zytel HTN, in AdBlue aqueous urea solution has demonstrated their effectiveness in selective catalytic reduction (SCR) systems that are used to reduce NOx emissions from diesel engines. AdBlue is a 32.5% aqueous urea/demineralised water solution (currently termed ‘‘diesel exhaust fluid (DEF)’’ in North America). The technology has already been successfully used in commercial vehicles equipped with SCR systems, which carry AdBlue on board, in specially designed tanks, ready for dosing into the catalytic system at a rate of 3–5% of diesel consumption. This technology in now being applied in the automotive sector. Audi has recently started to provide the same beneficial technology for one of its production-series vehicles, the Q7 3.0-litre TDI Clean Diesel. Other automotive manufacturers are currently preparing similar models, or have already introduced them to the market place. Along with these developments, there is a growing requirement for polymer components that are able to resist the corrosive liquid, which must be stored and transported in separate tanks. For elastomeric and plastic materials that are used in contact with AdBlue, additional resistance to diesel or engine oils is generally required. The selected material must be able to resist the chemically-aggressive urea contained within the solution as well as the potential swell effect of the water. The effect of the material on the urea solution must remain below very low, industrydefined limits in order to prevent the release of substances from the polymer which could impair the catalytic effect, or even go as far as significantly affecting the catalyst. Additional requirements include the high stiffness and strength of the material and, in the case of elastomers, its flexibility, because AdBlue will freeze at –11°C, causing it to expand. Contact: DuPont Performance Polymers SA, 2 Chemin du Pavillon, CH-1218 Le Grand-Saconnex, Geneva, Switzerland. Tel: +41 22 717 4000, Fax: +41 22 717 4001, Email: [email protected], Web: www.dupontelastomers.com
September 2010
Quadrant launches temperature-resistant materials for machined parts
W
ith the launch of Duratron D7000 PI polyimides and modified PEEK Semitron MP370, Quadrant EPP Ag is expanding its range of materials available for machined parts that are used in high-temperature applications. Duratron D7000 PI and the new bearing grade Duratron D7015G PI are high-performance polyimide materials that bring the benefits of polymer materials to applications operating in the region of 315°C (600°F). Duratron D7000 PI materials are available in a wider range of sheet sizes and tube configurations than other polyimides, says the company. Quadrant recently re-branded its existing portfolio of PAI, PBI and PEI high-performance advanced engineering plastics under the umbrella brand ‘‘Duratron’’ in order to simplify the choice of products available and make them easier to identify, based on their performance attributes. New, homogenous, ceramic-filled PEEK Semitron MP370 gives semiconductor test-socket designers a stable platform for developing innovative design ideas by enabling builders to more closely tailor the socket material to the application environment. Semitron MP370 PEEK is not subject to the ‘‘soft centre’’ or inconsistent physical properties that are often associated with injection-moulded shapes. The material’s excellent machinability enables engineers to create holes with very small diameters and tight hole patterns, compared with generic, ceramic-filled PEEK.
Contact: Quadrant EPP Ag, Hardstrasse 5, 5600 Lenzburg, Switzerland. Tel: +41 62 8858 150, Fax +41 62 8858 401, Email: [email protected], Web: http://epp.quadrantplastics.com
FKM compounds are designed for semiconductor sealing applications
S
imrit is introducing two new fluorocarbon (FKM) compounds which have been created specifically for use in semiconductor fabrication processes. With high-purity and low metal-ion impurities – both of which are critical to ensuring that
BOB’S BIT
O
ur dishwasher was in need of a bit of attention this week. It had discovered a new programme setting which, after about two hours of rumbling and gurgling, delivered a machine full of cold, wet greasy plates. After the usual mutter about the situation I suddenly remembered that we had purchased this specific machine because it had a manufacturers’ five-year warranty. We run an impressive filing system, sometimes, and duly located the receipt. Well, you can guess the answer: we have been the proud owners for five years and one week. While the consumer and private individual in me thinks that this is a bit of a raw deal, as an engineer I have to be very impressed that someone can design a machine that lasts one week longer than the warranty period. Dishwashers are, I believe, just about the least reliable of all domestic white goods. This is perhaps not surprising as they have to handle large changes in water temperature and a variety of quite aggressive fluids and are also designed to meet stringent cost limits. Dealing with the complex requirements that enable us to produce components that meet an overall specification is often one of the most interesting parts of engineering. But how often do we meet them that closely? I know that it would be possible to build a dishwasher that would last indefinitely. But, would it fit in our kitchen or be within the sort of budget we would ever contemplate? The answer is probably no, to both questions. Thus the cycle of designing to reduce costs, weight and space starts. I am sure that every one of you has proposed a design for an application only to be told that it fails on at least one of these counts: space, weight or cost. A further interesting problem on occasions is the feasibility of fitting, or retro-fitting, the proposed design. And this is just what leads to the many interesting developments that help to fill these pages each month. Sometimes the inertia of large international organisations can impede progress a little. A few years ago I managed to propose a very simple modification to solve some serious random seal failures. Then the problems really started. Providing the modification with an international part number involved at least two orders of magnitude more effort than the solution. Bob Flitney
Sealing Technology
3
September 2010
Quadrant launches temperature-resistant materials for machined parts
W
ith the launch of Duratron D7000 PI polyimides and modified PEEK Semitron MP370, Quadrant EPP Ag is expanding its range of materials available for machined parts that are used in high-temperature applications. Duratron D7000 PI and the new bearing grade Duratron D7015G PI are high-performance polyimide materials that bring the benefits of polymer materials to applications operating in the region of 315°C (600°F). Duratron D7000 PI materials are available in a wider range of sheet sizes and tube configurations than other polyimides, says the company. Quadrant recently re-branded its existing portfolio of PAI, PBI and PEI high-performance advanced engineering plastics under the umbrella brand ‘‘Duratron’’ in order to simplify the choice of products available and make them easier to identify, based on their performance attributes. New, homogenous, ceramic-filled PEEK Semitron MP370 gives semiconductor test-socket designers a stable platform for developing innovative design ideas by enabling builders to more closely tailor the socket material to the application environment. Semitron MP370 PEEK is not subject to the ‘‘soft centre’’ or inconsistent physical properties that are often associated with injection-moulded shapes. The material’s excellent machinability enables engineers to create holes with very small diameters and tight hole patterns, compared with generic, ceramic-filled PEEK.
Contact: Quadrant EPP Ag, Hardstrasse 5, 5600 Lenzburg, Switzerland. Tel: +41 62 8858 150, Fax +41 62 8858 401, Email: [email protected], Web: http://epp.quadrantplastics.com
FKM compounds are designed for semiconductor sealing applications
S
imrit is introducing two new fluorocarbon (FKM) compounds which have been created specifically for use in semiconductor fabrication processes. With high-purity and low metal-ion impurities – both of which are critical to ensuring that
BOB’S BIT
O
ur dishwasher was in need of a bit of attention this week. It had discovered a new programme setting which, after about two hours of rumbling and gurgling, delivered a machine full of cold, wet greasy plates. After the usual mutter about the situation I suddenly remembered that we had purchased this specific machine because it had a manufacturers’ five-year warranty. We run an impressive filing system, sometimes, and duly located the receipt. Well, you can guess the answer: we have been the proud owners for five years and one week. While the consumer and private individual in me thinks that this is a bit of a raw deal, as an engineer I have to be very impressed that someone can design a machine that lasts one week longer than the warranty period. Dishwashers are, I believe, just about the least reliable of all domestic white goods. This is perhaps not surprising as they have to handle large changes in water temperature and a variety of quite aggressive fluids and are also designed to meet stringent cost limits. Dealing with the complex requirements that enable us to produce components that meet an overall specification is often one of the most interesting parts of engineering. But how often do we meet them that closely? I know that it would be possible to build a dishwasher that would last indefinitely. But, would it fit in our kitchen or be within the sort of budget we would ever contemplate? The answer is probably no, to both questions. Thus the cycle of designing to reduce costs, weight and space starts. I am sure that every one of you has proposed a design for an application only to be told that it fails on at least one of these counts: space, weight or cost. A further interesting problem on occasions is the feasibility of fitting, or retro-fitting, the proposed design. And this is just what leads to the many interesting developments that help to fill these pages each month. Sometimes the inertia of large international organisations can impede progress a little. A few years ago I managed to propose a very simple modification to solve some serious random seal failures. Then the problems really started. Providing the modification with an international part number involved at least two orders of magnitude more effort than the solution. Bob Flitney
Sealing Technology
3