Chrome Plating - Adornment Of Objects and Protection From Corrosion
Just why are some metals coated with chromium? That is something I had always wondered and I guessed it had something to do with corrosion and rust protection. But why not make the item out of solid chromium to begin with?
For starters, some metals are coated with chromium to make them look more attractive. Chromium is shiny and sparkly – it is a good reflector and is bright. The metal is silver in appearance and can enhance all types of objects that it coats. And , sure, it certainly does protect from corrosion and tarnish.
It was discovered in 1798 and is a non-corrosive material which is very strong and resistant to heat. It is ideal for coating other metals in particular steel.
The coating process is done by electroplating – immersing the object in an electrolyte solution and passing an electric current through it. This is the only way it is done – there is no other reliable method and all other descriptions (such as “Chrome Dipping” and “Chroming”) refer to electroplating methods. The electrolyte contains chromium in a different form but the chromium is displaced onto the desired object during the electroplating process.
You will see chromium plating in lots of different places and in particular on appliances around the home (for example, taps) and on automobile and motorcycle parts. Other places you might find it commonly is in the tool shed – on tools of all kinds, and on electrical equipment. Virtually every object that is chromium plated is enhanced by its presence and can be polished up to a pleasing shine.
Asbestos - From Miracle Mineral To Mesothelioma Menace
During World War II Asbestos was hailed by many as a miracle mineral. Almost anything could be built or manufactured from this mineral. The building and construction industries used it as an additive to strengthen cement and plastics. Asbestos fibers can be separated into thin threads which do not conduct electricity and are not affected by heat or chemicals.
The four main types of asbestos are: Amosite with brown fibers, Anthophyllite with gray fibers, white Christie, and blue Crocidolite. Chrysotile has curly fibers while the other three have rod like fibers. These fibers break into dust quite easily and drift in the air. They can stick on skin, clothing, and can easily be swallowed or inhaled.
Use of asbestos skyrocketed during World War II. Shipbuilding used asbestos extensively in freighters and support vessels to insulate boilers, steam pipes and hot water pipes. Asbestos became the miracle construction material as it was easily obtained, processed, and transported.
After WWII cars used asbestos in break shoes and clutch pads. Asbestos found its way into residential and industrial building materials, water supply, sewage materials, ceiling and floor tiles, and vermiculite garden materials to name a few products.
In the 1970’s the U.S Consumer Product Safety Commission banned the use of asbestos in several products that could release asbestos fibers into the environment during use, following the discoveries of the health dangers of asbestos dust inhalation. Regulations governing the use of asbestos and concern of public opinion since 1970 have created a significant drop in the use of asbestos in the United States.
In 1989 all new uses of asbestos were banned by the Environmental Protection Agency while any old uses before that year were still permitted. The EPA suggested that schools inspect for damaged asbestos and eliminate any exposure or enclose it in protective barriers. Vermiculite, widely used in horticulture, became a concern of the EPA that recommended outdoor use, limiting the amount of dust used, and keeping vermiculite damp.
Asbestos may create serious health hazards such as coughing, lung damage, shortness of breath, and lung cancer. Most people do not become sick in the early stages of development, but usually need continued exposure, often on jobs such as mining, milling, manufacturing asbestos products, and building construction. Firemen, demolition workers, drywall removers, and any other workers in trades that involve destruction of buildings, ships, and automobiles are also exposed to the hazards and risks of asbestos.
Over a period of years continual exposure to asbestos can cause very serious health problems, such as mesothelioma. Mesothelioma is a rare type of carcinoma of the membrane that lines numerous cavities of the body, including the lungs, abdomen and heart, and has been associated with exposure to asbestos dust. In mesothelioma, the cells of the mesothelioma metastasize and damage adjacent organs and tissues.
Risk of developing mesothelioma takes a long period of time, often as long as twenty-five or thirty-five years before full blown symptoms appear. Not all workers who have been exposed will develop diseases caused by asbestos, but workers who have been exposed to it may bring fibers on their clothing, hair, shoes, and skin home to their families. To circumvent this risk, most industries require workers to bathe and change their clothing before they leave work.
Many studies have been conducted involving the risks of diseases caused by exposure to asbestos. The results of one such study involving the risks of smoking and exposure to asbestos proved extremely hazardous.
Coating reduces shielding costs for enclosures
APPLICOAT EC225 provides an order of magnitude better electrical shielding than nickel paints. The thickness is under half that of nickel, so the applied coating cost is significantly reduced.
Conductive paints are widely used for EMI / RFI shielding of plastic enclosures. They offer many advantages over alternative methods of shielding. these include: relatively short manufacturing lead-times; ability to coat selectively; suitability for low as well as high volume production; moderate to high levels of shielding and excellent adhesion to most plastics.
Paints can be made conductive by adding nickel, copper or silver particles to the resin.
Traditionally nickel paints were specified for low cost / low performance applications.
For high levels of shielding, silver is normally specified.
However these coatings are considerably more expensive than copper or nickel paints.
Applied Coating Technologies (ACT) has recently introduced a new coating, APPLICOAT EC225, based on paint containing silver-plated copper particles.
This coating costs less than nickel paint yet provides shielding performance comparable to silver paint.
To compare the applied thickness and sheet resistance of nickel, APPLICOAT EC225, and silver coatings: a nickel coating of 50-70 microns provides a sheet resistance (ohms/cm2 of 0.2-0.5 and 10-15 microns of silver, a sheet resistance of 0.03-0.05 ohms/cm2.
APPLICOAT EC225 of thickness 20-25mm provides a sheet reistance of 0.05-0.08 ohms/cm2 APPLICOAT EC225 provides an order of magnitude better shielding than nickel paints.
However as the applied thickness is less than half that of nickel, processing and material costs are reduced and hence the applied cost of the coating is significantly reduced.
APPLICOAT EC225 also offers other benefits; it is formulated using alcohol based solvents and hence has minimum impact on the intrinsic properties of the substrate.
ACT specialises in the application of shielding and decorative coatings onto plastic substrates.
The company also offers vacuum deposited and electroplated coatings for EMI / RFI Shielding.
Versatile masking products are reusable
Samco Silicone Products has introduced a new range of high performance reusable silicone masking products which include bungs, caps and pull plugs, suitable for
Versatile masking products are reusable Samco Silicone Products has introduced a new range of high performance reusable silicone masking products which include bungs, caps and pull plugs, suitable for applications in painting, powder coating, metal finishing and enamelling. Standard operating temperatures are up to 250?degC, but higher specification is available by special order. Samco’s range offers a choice of silicone compounds and moulded, extruded, fabricated or hand-made components.
The products come pre-packed in sets and are colour coded to aid efficiency.
Full technical assistance is provided to overcome difficult masking problems.
The company also offers a custom service, low-cost tooling, and the ability to provide individual samples or high volume runs.
Trimite paint can promotes image
Over 300 years of expertise in the manufacture of industrial paint, powder and inks are behind the Trimite brand with the launch a new corporate brochure designed as a
Over 300 years of expertise in the manufacture of industrial paint, powder and inks are behind the Trimite brand with the launch a new corporate brochure designed as a 5 litre can of paint. Looking exactly like the distinctive product packaging, the brochure presents an overview of Trimite, its products and services. The Uxbridge-based company supplies the widest range of paints and powder coatings in the UK, as well as pre-treatment systems for industry and Shackell Edwards printing inks, varnishes and pressroom chemicals.
Products include coatings for ferrous and non-ferrous metals, plastics and wood, as well as the many new substrate materials such as sheet steels, composites and modern engineered plastic polymers.
Trimite’s team of technical experts regularly advise customers on the right type of coating and most effective method of application for their production by evaluating their needs, on site, under the customer’s own working conditions.
If nothing within the company’s extensive range of paint and powder coatings meets the criteria, products can be customised to match specific requirements.
Even colour matches between paints and powders, a difficult result to achieve, are possible with Trimite products.
The company, which is both British and privately owned, prides itself on its high standards of quality and customer service, offering a personal approach which is in great demand.
It offers daily deliveries throughout Britain with its own fleet of over 50 vans and lorries supported by 18 regional centres, as well as exporting to over 60 countries worldwide.
Their network of Regional Service Centres throughout the UK and Ireland is now easier to contact with the introduction of a new NationalCall number: 0870 605 1234.
Injection moulder installs painting robots
Plastic injection moulding experts Rosti (Scotland), based in Larkhall near Glasgow, installed its first ABB paint robots in 1994 to evaluate their merits against manual spraying.
Injection moulder installs six painting robots plastic injection moulding experts Rosti (Scotland), based in Larkhall near Glasgow, installed its first ABB paint robots in 1994 to evaluate their merits against hand spraying methods. Two IRB 510 robots - for which a purpose-built extension to the plant was built - were acquired as a measure to improve both productivity and quality on conductive surface finishes, which, at the time, were difficult to apply by hand spraying methods. The installation was an outstanding success, doubling productivity and improving quality to such an extent that seven years on, ABB paint robots are the standard by which Rosti measures all its automated paint processes.
The Rosti plant at Larkhall offers a total moulding process capability to its customers, as well as additional processes such as RFI/EMI Shielding, high volume cosmetic painting, printing, and assembly.
Technical Team Leader for the Paintshop and Assembly Areas, Scott Simpson, was one of the first to be trained in programming and operating the original robots: ‘In 1994, robot-equipped paintshops were quite ’state-of-the-art’ and it was a bold move by the company in investing in this technology.’ ‘With the new robots installed, however, we rapidly upped productivity and quality, which in turn made us more competitive, and this in itself brought in more work.
As our workload increased, this led to the purchase of a third IRB 510 paint robot to keep pace with demand.’ The unqualified success of the original unit led to the building of a new paint plant five years ago, for the application of special surface finishes to new products.
Rosti invested in new IRB 5002 paint robots that incorporated ABB’s unique Integrated Process System (IPS), enabling rapid selection of different spray gun control parameters.
Rosti’s engineers were able to modify the robots in other ways to make them even more efficient.
‘We were using a two-part paint mix for certain components,’ says Scott Simpson.
‘When the two elements were put together the paint was only viable for use within two to three hours or it would ‘go-off’.
There was, unfortunately, the odd occasion when large quantities of paint were pre-mixed; then unforeseen production hold-ups would mean that it couldn’t be used, thereby creating a lot of waste.’ ‘To alleviate this problem, we modified the robots by installing two gear-type metering pumps, separate lines for paint and hardener, and a mixing chamber within the body.
The only waste now is residual paint left in the line between the mixing chamber and the spray gun mounting - a matter of a few metres.
Using this method we have made savings of between 10 - 15 per cent in paint usage, in addition to the savings made over traditional hand spraying.’ Mr Simpson adds, ‘There is no overspray with the ABB paint robots, as with hand spraying, and on special coatings the IRB 5002 has to hold some very tight tolerances, usually two microns, which it does unfailingly.’ ‘The robots are also almost maintenance-free and work virtually non-stop for three or four years before any replacement parts are needed.
They are also extremely robust.
We have had incidents when the fixture conveyor (not part of the robot) has failed to move in co-ordination with the robot, and the two have collided.
Although the fixturing was badly damaged every time, the robot required little more than a lick of paint.’ ‘With the productivity, quality and paint saving gains we have achieved, coupled to an easy-to-learn programming language, robustness and reliability, I cannot praise ABB paint robots highly enough.
Paint pump evaluation will save car plant costs
Engineers are assessing potential energy savings on the knock-off spray pump in Longbridge’s No 2 paint plant, as part of MG Rover’s policy of continual improvement.
Engineers are assessing potential energy savings on the knock-off spray pump in Longbridge’s No 2 paint plant, as part of MG Rover’s policy of continual improvement. The spray is a powerful water shower that blasts oils, grease, dirt and debris off bodies in white prior to starting the multi-coat painting sequence. Car bodies are conveyed through the spray at a rate of one a minute, continually from Monday morning to Friday evening.
In the system as it currently stands a discharge isolating valve is permanently partially closed.
This has the effect of throttling the pump, and therefore also wasting energy, which led Rover’s in-house engineers to consider improving energy efficiency.
As is their usual practice they called in several expert teams to review the situation and submit proposals for improvement.
One such team included pump specialists from Cougar Pumps and control systems engineers Omron Electronics, whose combined expertise has been much in demand lately as British industry adapts to the Climate Change Levy.
Their first task was a detailed examination of the pump system in-situ.
The fundamental information the team was after was exact pressure, flow and electrical power consumption, but they were also using their experience to consider wider issues, such as alternative systems, maintenance requirements, adaptability and long term effectiveness.
Although the motor had a theoretical output power of 75kW at 2900rpm, Omron used a power analyser to measure the power input over an extended period of time.
Meanwhile Cougar’s engineers were busy evaluating the mechanics of the pump system, including interviewing Rover’s own operatives on the system’s performance and shortcomings.
The results Omron/Cougar presented to Rover’s management team included the fact that nearly 12 percent of the energy used to drive the pump was being wasted across the throttling valve.
They rated the motor’s 92 percent efficiency as poor, and the pump’s performance at 56 percent efficient as very poor.
They were therefore confident that a significant improvement in overall energy consumption could be attained with relatively simple reengineering of the pump and its control and produced five suggested options for Rover to consider.
The first, simplest and cheapest was to remove the throttling valve and trim the pump’s impeller, which would save 12 percent.
They also suggested installing a 75kW inverter so that the speed of the pump could be trimmed to meet exact demand at any given moment in time; replacing the pump while retaining the motor; replacing the motor with a substantially smaller (45kW) energy efficient one; and finally fitting a 45kW inverter to the proposed new motor.
Each proposal was fully costed out, including details on capital outlay, total cost of ownership and energy savings.
This showed that cost of ownership over five years for the existing system was over GBP90,000.
The simplest improvement option, trimming the impeller would cut this by 10 percent, while the complete re-engineering proposal would save way over 50 percent! Rover’s stance is that excellence in energy efficiency is a requirement, not an option.
So it was able to advise Omron/Cougar that its preferred option was the final one - complete re-engineering.
Drives hold air temperature constant for painting
Three large chiller units, featuring FKI high power drives, ensure air temperature in Jaguar’s paint plant is kept constant.
Jaguar cars are impressive not only for their distinctive looks, but also for the standard of their paint finish. The company has invested large sums into its paint preparation plant to achieve this result. A major part of this investment has been directed into three large chiller units supplied by Carrier Engineering.
Employing high power FID 3000 drives from FKI, these units ensure that the air temperature in the paint plant is kept constant during the critical summer months.
High levels of production flexibility and environmental conformity are the order of the day at Jaguar Cars.
Cars are built to customer order in a highly automated process that enables the colour of the vehicle to be changed, at will, from one car to the next.
This is possible because the time interval between two cars is sufficient to clean the spray equipment of the water based paint, ready for another colour.
The colours of the cars may vary but the conditions under which they are prepared do not.
A general requirement is that air temperature must be held constant if perfect consistency of paint application, adhesion and curing is to be achieved.
Maintaining these parameters within the summer months is most difficult to achieve and requires special equipment.
This task was performed by large chiller units using refrigerant pumps with adjustable impellers, which altered the refrigerant flow to control the cooling rate of the system and, hence, the air temperature.
The system worked reliably, but was not efficient because the pump motors were always driven at a constant speed irrespective of the impeller position.
There were also environmental considerations for Jaguar, who were keen to change from non-ozone friendly gas (CFC) to ozone friendly refrigerants at this site.
However, as the refrigerant turns from liquid to gas, the ozone friendly mediums are not as efficient in ensuring the same levels of heat transfer.
As a result, the pumps would need to be driven faster to achieve the same level of refrigeration using the new ozone friendly medium.
Three large chiller units from Carrier, one of the largest suppliers of such systems in the world, were modified to incorporate FID 3000 drives from FKI, bringing the improved energy efficiency and enhanced levels of control required at Jaguar’s paint plant.
The drives are used to control the pumps in the chillers, matching pump speed to demand and eliminating the need for adjustable impellers.
The drive units are all rated at 600kW and will operate from April until the middle of October, each year, when they are turned off due to the seasonal drop in ambient temperature.
The drives were used to change the motor supply frequency, which was increased from 50Hz to 55Hz, increasing the motor performance and hence the refrigeration capacity.
This allowed the original system design to be used with the new refrigerant and yet still provide increased overall performance.
Carrier chose the FID 3000 drives not only for their dynamic performance, but also because of FKI’s background knowledge of applying their drives and interfacing with sophisticated Carrier control units.
FKI also provides twelve pulse drives that are very low in current harmonics, making them supply friendly.
The ’supply friendly’ aspect of the drives was of particular importance due to the large amounts of power required by the pumps in the chiller plants.
This meant that their demand interference on the mains supply had to be considered carefully.
FKI also carried out a full harmonic survey as part of its overall service package to Carrier/Jaguar.
Plant optimises robotic paint spraying
ABB has invested over GBP250,000 in a purpose-built Surface Coating development plant at its Milton Keynes Business Centre.
ABB, the global technology company and leader in robot-based automation, has invested over GBP250,000 in a purpose-built surface coating development plant at its Milton Keynes Business Centre. The plant, the only one of its kind in the United Kingdom, will be used primarily to optimise paint spraying systems before delivery to customers, while complementing the existing ABB Milton Keynes customer training centre by integrating practical training on coating and painting processes. The facility incorporates a 4.5m wide spray booth enclosure with temperature controlled air supply, air exhaust system and ‘dry’ extract filters.
Built to stringent industrial safety standards, it can accommodate up to two ABB six-axis paint robots, such as the ground-breaking IRB 540, IRB 580 and IRB 5400 S4P robots.
The spray booth incorporates a 10m long floor-mounted, twin-chain conveyor with platen, rated at 500kg; air replacement system with direct-fired gas burner and class F5 and F7 filters; paint mix room; personnel entry vestibule; box oven to cure painted parts, and fully-equipped lecture room.
The incorporation of a lecture room allows robot theory to be instantly reinforced with practical demonstrations.
New customer systems can be installed in the paint booth and the specific application environment created.
Under realistic working conditions, paint spray robots can be fine-tuned by adjusting parameters such as brush settings, paint flow, atomizing air and fan air - without the economic pressures of the production line.
Using ABB’s IndustrialIT Software package, ShopFloor Editor, an advanced program editor designed for process optimisation and improving product finish quality without interrupting production, events can be adjusted directly by ‘dragging’ them on the Editor’s screen.
Robot path, speed and acceleration can therefore be adjusted so that when installation and commissioning is finally complete at customer premises, robots can be immediately productive.
By optimising robot and paint parameters to meet customer application requirements before installation, significant benefits are accrued for the customer - such as a shorter time to production, reduced costs in both time, labour and paint materials, improved process parameter control and a much higher level of product training.
About the facility, Senior Applications Engineer and manager of the project, Marcus Rock said: ‘ABB’s investment in the new paint plant ensures that our customers receive a surface coating system already tuned to the precise requirements of the application and which is productive from day one.
By delivering an optimum performing system, backed by unrivalled service, process and technical back-up, ABB is securing maximum competitive advantage for its customers in a very demanding market sector.
Lightweight couplings simplify colour changes
A range of lightweight couplings is ideal for use in low-pressure paint spraying applications making changing colours quicker and easier.
Staubli, the specialists in quick release connectors, have a range of lightweight couplings that are ideal for use in low-pressure paint spraying applications making changing colours quicker and easier. The LAK range of connectors has been specifically designed for direct connection on electrostatic or non-electrostatic, low-pressure spray guns and are suitable for both water and solvent based paint and adhesives. They can be used on both circulating and non-circulating paint systems, accommodating paint pots where fitted.
Typical applications are in automotive body shops (both OEM and end user) as well as in general industry painting applications.
The use of a LAK connector alongside a St„ubli RBE or RCS safety coupling for the compressed air line eliminates any chance of cross connection.
The LAK coupling is easy to connect and disconnect, the raised push button used for disconnection can be operated even when wearing protective gloves which is a particularly useful feature.
The plug is drip proof, 4 x 1.5mm oval capillary openings at the end of the plug prevent the paint from dripping when disconnected.
The highly polished, smooth plug profile prevents damage to the seals, even with frequent connection and disconnection.
The LAK has a nominal flow diameter of 4mm and can be specified with a range of thread forms and seal types.