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Friday, December 18, 2009
Inspection Connection: Radiographic and ultrasonic weld inspection
Inspection Connection: Radiographic and ultrasonic weld inspectionEstablishing weld integrity without destroying the component
This article outlines the differences in radiographic and ultrasonic weld inspection, the two most common methods if nondestructive testing. It gives an overview of both methods, including how they are used. Radiographic and ultrasonic weld inspection are the two most common nondestructive testing (NDT) methods used to detect discontinuities within the internal structure of welds. The obvious advantage of both of these testing methods is their ability to help establish the weld's internal integrity without destroying the welded component. Radiographic TestingRadiographic testing (RT) usually is suitable for testing welded joints that can be accessed from both sides, with the exception of double-wall signal image techniques used on some pipe. Although this is a slow and expensive NDT method, it is a dependable way to detect porosity, inclusions, cracks, and voids in weld interiors. RT makes use of X-rays or gamma rays. X-rays are produced by an X-ray tube, and gamma rays are produced by a radioactive isotope. The basic principle of radiographic weld inspection is the same as that of medical radiography. Penetrating radiation is passed through a solid object (in this case, a weld rather than part of the human body) onto photographic film, creating an image of the object's internal structure on the film. The amount of energy absorbed by the object depends on its thickness and density. Energy not absorbed by the object causes exposure of the radiographic film. These areas will be dark when the film is developed. Areas of the film exposed to less energy remain lighter. Therefore, areas of the object where the thickness has been changed by discontinuities, such as porosity or cracks, will appear as dark outlines on the film. Inclusions of low density, such as slag, will appear as dark areas on the film, while inclusions of high density, such as tungsten, will appear as light areas. All discontinuities are detected by viewing the weld shape and variations in the density of the processed film. This permanent film record of weld quality is relatively easy to interpret if personnel are properly trained. Only qualified personnel should conduct radiography and radiographic interpretation because false readings can be expensive and can interfere seriously with productivity, and because invisible X-ray and gamma radiation can be hazardous. Ultrasonic TestingUltrasonic testing (UT) can be used on ferrous and nonferrous materials and often is suited for testing thicker sections accessible from one side only. In general, it can detect finer linear or planar defects than can RT. UT makes use of mechanical vibrations similar to sound waves but of higher frequency. A beam of ultrasonic energy is directed into the object to be tested. This beam travels through the object with insignificant energy loss, except when it is intercepted and reflected by a discontinuity. The ultrasonic contact pulse reflection technique is used in UT. This system uses a transducer, which converts electrical energy into mechanical energy. The transducer is excited by a high-frequency voltage that causes a crystal to vibrate mechanically. The crystal probe becomes the source of ultrasonic mechanical vibration. These vibrations are transmitted into the test piece through a coupling fluid, usually a film of oil, called a couplant. When the ultrasonic waves pulse strikes a discontinuity in the test piece, it is reflected back to its point of origin. Thus, the energy returns to the transducer. The transducer now serves as a receiver for the reflected energy. The initial signal, or main bang; the returned echoes from the discontinuities; and the echo of the rear surface of the test piece all are displayed by a trace on the screen of a cathode-ray oscilloscope. The detection, location, and evaluation of discontinuities become possible because the velocity of sound through a material is nearly constant, making distance measurement possible, and the relative amplitude of a reflected pulse is more or less proportional to the size of the reflector. One of the most useful characteristics of UT is its ability to determine the exact position of a discontinuity in a weld. This testing method requires a high level of operator training and competence and depends on establishing and applying suitable testing procedures. Tony Anderson is a regular contributor to this section and technical services manager with AlcoTec Wire Corporation, 2750 Aero Park Drive, Traverse City, MI |
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RFID Drives Up Efficiencies at ABB
RFID Drives Up Efficiencies at ABBAt its factory in Helsinki, Finland, the manufacturer is using EPC Gen 2 tags to track the production and shipment of the motor drives it makes, resulting in a range of benefits. By Rhea Wessel Nov. 25, 2009—ABB a global manufacturer of power and automation equipment for utility and industrial companies, is employing radio frequency identification at its factory in Helsinki, Finland, to better track outbound shipments of approximately 200,000 drives per year. The drives are frequency converters that control the rotational speed of alternating current (AC) electric motors. ABB implemented the RFID system in order to reduce shipping errors, since such mistakes impact its invoicing process. Without a shipping receipt, the company cannot collect the funds it is owed. In addition, ABB faced a lack of floor space at its Helsinki facility, because production was rising at a rate of roughly 20 percent every year. ABB wanted to have a forwarding operator take over the task of logistics and warehousing, but was hesitant to do so because of its own unreliable, pen-and-paper- based method of manually tracking goods leaving the production area. The company believed that if it could improve its ability to track its goods shipments, it would then have reliable data to compare with that of a logistics partner—thereby reducing the risk involved in outsourcing some of its logistics and warehousing tasks.
"By implementing RFID into SAP, we have reduced our manual work and have a more reliable way of inputting transaction data," says an ABB spokesperson who requested not to be named, in compliance with his company's policy. "Input time for transactions is only seconds, and we generate multiple readings at the same time with RFID—something that is impossible with the bar code." The SAP implementation was a lengthy process, because ABB had to simultaneously perform a general update of its SAP system. Now, the firm is working to increase the number of fixed readers it uses at its dock doors from three to seven. The smallest drives that ABB manufactures weigh about 15 kilograms (33 pounds) and are shipped in boxes, while the largest drives weigh up to 400 kilograms (882 pounds) and are transported on pallets. As soon as a drive is manufactured, it is placed in a box or on a pallet, and a worker applies a printed adhesive label containing an EPC Gen 2 UHF inlay to that pallet or box. The drives are then loaded on trucks or trailers for short-term storage or immediate forwarding. RFID tags are interrogated as the goods are moved past fixed gate readers in the loading area near the dock doors. Information about specific goods is linked in the database to the ID number of the truck or trailer, which is entered manually so that ABB knows the loading progress of each vehicle, and has an exact description of the goods it contains. The system produces a warning error at the gate if a worker attempts to load the wrong products onto a vehicle, and it also notifies employees when a truck's consignment is incomplete. What's more, by outsourcing some of its logistics and warehousing to a partner, ABB was able to free up space at its factory to expand its production capacity. UPM Raflatac is supplying the tags for the implementation. Vilant Systems, which served as the systems integrator for ABB's RFID deployment, provided the readers, which have a range of 3 meters (10 feet). Later, ABB hopes its logistics partners will utilize the RFID tags on the pallets and boxes as well, in order to provide it with additional information regarding the status of goods, as well as improve its own services. The company plans to introduce item-level tracking for the components that make up the drives; a large drive may comprise thousands of parts. In a separate application, ABB has been using RFID in a kanban process involving reusable plywood boxes since December 2005. Both the supplier and ABB read the boxes' RFID tags. When a full box leaves the supplier, its tag is read and an electronic notice is created in SAP. Once an empty box leaves ABB's factory, it triggers a material order from the supplier. According to ABB, the system has decreased the manpower the company requires to process incoming packages. It has also reduced errors compared with the bar-code system previously used, the firm reports, and provided a return on investment within a few months. In December of this year, ABB plans to implement the same system at a factory in Estonia. Reference : http://www.rfidjour nal.com/logistic s A S Q |
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Monday, November 9, 2009
Fresh Graduates Vs Experienced Professionals
Fresh Graduates Vs Experienced Professionals
Young Vs Experienced Human Resources – An Overview Starting out as a young professional one is more flexible, eager to work for longer hours and more passionate about coming up with innovative ideas for the company. On the other hand, senior personnel tend to have a great deal of experience; they have explored different phases of their professional life and use their previously learnt experiences to come up with better solutions in different situations. Many employees with greater experience have a problem with relatively fresh individuals joining their departments because they take this as a threat. The reason is that the fresh graduates show much enthusiasm and eagerness to perform as compared to the employees in their middle ages. Thus, the elderly fellows see a clear potential that these young minds my surpass them and engulf their positions. Being connected with the developing trends in business and marketing, the fresh recruits bring new ideas to the table. Alternatively experienced workers have better networking in way to develop their career. Moreover, nowadays, companies are using Social Market Strategies in order to be more marketable. Businesses use techniques such as blogging and connecting with customers on sites like Facebook.com and Twitter.com. They are depending on the younger employees to lead the social marketing strategy initiatives; after all, they are more aware of the technology and are more internet-savvy. On the other hand, a great barrier that lies with the experienced employees is that they are relatively difficult to train, and not comfortable with new technology. 5 Suggestions For The Experienced Professionals Following are the five suggestions for the senior employees (from the age of 29 onwards) that are either hunting or striving to sustain a job: Trim Your Appearance Improve your outfit and your outlook; but be careful not to do anything unnatural that makes you uncomfortable with your appearance. Market Yourself Although experienced professionals work hard, they do not know how to promote themselves to the world. Work on opportunities to speak at a conference or become quoted in an article that appears on the Internet, or update your biography on your company's website, if you are working at a higher post. Show Energy And Enthusiasm You have to keep your energy level up while talking to recruiters and interviewers. During an interview you should be proactive and lively. Experience counts a lot. Many companies staffed with younger employees still want a few gray heads around to call on the large corporate clients and to help the company avoid mistakes. Demand A Fair Financial Reward Find an employer who is willing to pay you according to your worth. Play on the fact that you are experienced and you should be remunerated accordingly. Get Yourself Wired To The New Technologies Keep yourself socially and technologically up-to-date. Things are changing more rapidly than you could ever imagine. If you want to work in the New Economy, you have to prove you belong there. Being computer proficient and Internet-savvy combined with much experience will make you a perfect choice of the employer. 5 Tips For The Fresh Graduates Here are five suggestions for the young employees (between the ages of 22 to 28) to help you win at the business world's game: Develop A Sellable Persona Think of yourself as an advertiser with the aim of promoting your own self. Learn to benefit from your skills, and briefly state your achievements. Your persona should be professional and decent. Establish Profitable Relationships Business networking is a valuable tool to gain career-related information, increase your recognition in your field and make connections that will help you move forward in your career. Make new contacts and set ideals, people who interest you the most. Master Goal Setting, Effective Communication And Time Management These skills will serve you well no matter what future path you decide to pursue. Make the most of your time. Work with your boss to set specific, reasonable, and attainable goals for your present position that will help you advance to the next stage. Stay Motivated There is no doubt that the business world is quite frustrating; however, remember that you can 'choose' your response to your environment. If you decide to begin each day with a positive attitude, negative conditions at work cannot take that motivation away from you. Respect Your Seniors Always respect your senior co-workers no matter how irritating they get. Keep in mind that other people don't care what you want; they rather want to know what's in it for them. If you show them respect and maintain an obedient attitude, they will automatically start cooperating with you. By approaching negotiations with an attitude that allows both parties to win, you'll be ultimately getting what you want. It is a fact that every organization definitely needs a combination of experienced employees as well as fresh recruits. Hiring fresh or experienced employees depends upon the pre-determined attitude of the employer. Moreover, in every organization there are non-productive workforce as well as fine and hardworking recruits and this can be applied to young and experienced alike. Well-experienced professionals or fresh employees, both should show the best performance for the sake of their team, their company and their boss. Holding back because one is afraid of working more than others and not be rewarded for it is an immature belief. Both, experienced and fresh employees, have an equal opportunity to develop their career with their own hard work and commitment towards their job. Salary or other fringe benefits should not be the ultimate goal. In order to acquire success one should concentrate on the performance, ability to cope with his responsibilities, and also the business needs of your company or organization. |
Many successful companies, both national and multi-national, pride themselves on recruiting the best employees, and tag their workforce as being the secret of their success. This set of employees consists of a combination of both experienced and fresh professionals. Two key points in this regard would be the role of employees in the attainment and success of company goals and their own career and personal growth.
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Sunday, November 8, 2009
Hand Tool Ergonomics
| How can one reduce the risk for work-related musculoskeletal disorders (WMSDs) resulting from the use of hand tools? What are the major ergonomic concerns of a hand tool design? What should one remember when selecting and using hand tools? How does hand tool maintenance reduce the risk for injuries? How can one reduce the risk for work-related musculoskeletal disorders (WMSDs) resulting from the use of hand tools? Tool design (weight, shape, fit to the user and the task), workstation design (size, shape and layout), and the way tasks are scheduled are all key factors in making hand tool use safe and risk-free. Since, none of those three areas is more important then the other, an effective prevention strategy must address all of them simultaneously. What are the major ergonomic concerns of a hand tool design? Weight of the tool Ideally, a worker should be able to operate a tool with one hand. Therefore the weight of the tool, especially for repetitive use, should not exceed 1 kg (2.2 lb.). It is also important that the centre of gravity be aligned with the centre of the gripping hand. In other words, tools should feel "easy" to hold either in an upright position or in the position it will be used (ie. pointing down). For example, drills that are "front-heavy" will require effort (especially in the wrist and forearm) to hold in a usable position and should be avoided. The exception to this principle is a power hand tool, such as a grinder, that has to be heavy in order to reduce the force that the worker has to exert while using it. Tools heavier than 1 kg or poorly balanced tools should be supported by counter-balancers. Power Where possible, power tools should replace hand tools which normally require the exertion of frequent and repetitive force to do the job, because the greater the force exerted with a hand tool, and the more the hand has to twist to use it, then the greater the risk for WMSDs. Handles With the exception of tools for precision work (e.g., watchmaking, microsurgery, carving), the handles and grips of hand tools should be designed for a power grip. The belief that smaller tools should have smaller handles while larger tools have larger ones is debatable. Handle shape Tools with "bent" or angled handles or tools with pistol-grips are beneficial where the force is exerted in a straight line in the same direction as the straightened forearm and wrist, especially when the force must be applied horizontally (see Figures 2, 3, 4). Figure 4 Tools with straight handles are for tasks where the force is exerted perpendicular to the straightened forearm and wrist, for instance, when the force must be applied vertically. Shaped tools such as bent-handle tools are effective where most of the tasks are done in the same plane and height as the arm and hand, and when only one or two other tools are used (see Figure 5). Knowing the tasks and the layout of the workplace where they will be used is vital for selecting the right tools for any given job. Select tools that do NOT require wrist flexion, extension or deviation. In other words, select tools that allow you to keep the wrist straight or in a neutral position. The crucial ergonomic principle in tool use and design -- bend the tool, not the wrists -- however correct and valuable does not always prevent discomfort and injuries when bent-handle tools are used indiscriminately, regardless of the layout of the work situation. Diameter Handles should be cylindrical or oval in cross section, with a diameter of between 30 mm and 45 mm. For precision work the recommended diameter for handles is between 5 mm and 12 mm. For a greater torque large screwdrivers should have a handle diameter up to 50-60 mm.Length A handle that is too short can cause unnecessary compression in the middle of the palm. It should extend across the entire breadth of the palm. Tool handles longer than 100 mm (preferably 115-120 mm) will reduce the negative effects of any compression exerted. Rounded handles will minimize palm compression on the palm still further. Keep in mind that the use of gloves requires longer tool handles. Separation between handles Crushing, gripping or cutting tools such as pliers or tongs are equipped with two handles. The recommended distance separating handle is between 50 mm and 65 mm. Such a range will fit both male and female users. Tools with larger or smaller spans will reduce one's maximum grip strength and may contribute to the onset of carpal tunnel syndrome. Power tool triggers Frequent movements of the index finger while operating the trigger of power tools (such as a power drill) poses a considerable risk for both "trigger finger" and "trigger thumb" (tendonitis in the index finger and/or thumb). A longer trigger which allows the use of two or three fingers to activate them reduces discomfort and minimizes the risk for injury. The recommended minimum length of the trigger is 50 mm. Materials and texture of handles To ensure a good grip on a handle, sufficient friction must exist between the hand and the handle. This is particularly important where a considerable force must be applied with a sweaty hand. Hand tools should be made of non-slip, non-conductive and compressible materials. For example, textured rubber handles provide a good grip, reduce the effort needed to use the tool effectively, and prevent the tool from slipping out of the hand. Glossy coatings and highly polished handles should be avoided. The electrical and heat insulation properties of the handles are important for power hand tools. Handles made of plastics or compound rubber are recommended. Sharp edges and contours can be covered with cushioned tape to minimize lacerations. Vibration The only effective way to reduce vibration in power tools is at the design stage. This fact makes tool selection most critical. The common practices of covering handles of vibrating tools with a layer of viscoelastic material or of using anti-vibration gloves made of similar material are of dubious value. These "anti-vibration" materials will dampen vibration above certain frequencies that are characteristic for the kind of material, but most of the vibration energy in a handle of a power tool is below those frequencies. What should one remember when selecting and using hand tools? When selecting and using a hand tool it is important:
How does hand tool maintenance reduce the risk for injuries? The condition of tools is an important factor. Blunt or dull tools such as scissors, cutters, saws, screwdriver tips, in fact any tools in a poor state of repair, not only compromise safety but also increase (sometimes by a factor of ten) the effort needed to use them. Tools in poor condition should be discarded (with the exception of those few that can be restored to optimum condition, for example, a wood chisel or wood saw) and replaced with new ones. |
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Saturday, October 24, 2009
The Benefits of Rapid Prototyping Technologies
The Benefits of Rapid Prototyping TechnologiesRapid prototyping is being used in just about all industrial sectors, although there are probably more applications in the automotive industry than any other. This is not surprising, however, given the intense global competitive pressures that are being experienced by automotive firms. A number of diverse application examples from different sectors are described in Chapter 2 of the Management Report. The application at Rockwell Automotive (see Chapter 2, page 38 of the Management Report) is a typical example of what many companies using this new technology are achieving. In Rockwell's case the technology was used to:
Rockwell claim that this allowed them to reduce by seven months the time taken to develop a prototype engine. They also claimed that cost savings were achieved on the development project. Time and cost savingsThe applications described in Chapter 2 of the Management Report show firms using rapid prototyping technologies to achieve both cost and time savings in the process of new product development. This is to be expected given the high emphasis that is being given in most industries to reducing both the cost of new product development and time to market. In most cases firms using rapid prototyping have gained time reductions in the production of prototype tooling and parts, which is mostly how these time savings have been specified. The figures for time reductions on prototyping vary greatly, ranging from 60 to 90%. On the whole this range is likely to be realistic given that the estimation of time savings, when compared to the conventional methods of prototyping, is a fairly straightforward matter. Little information is provided in the public domain about cost savings. Clearly there is a potential for cost reduction. For example, if mistakes can be identified before commitments are made to expensive tooling, then the costs associated with modifying such tools can be avoided. However, the information on cost reductions should be treated with some caution. The cases where cost reductions are claimed do not provide sufficient details of the basis for the calculations or the assumptions that have been made. InnovationWhilst pursuit of time and cost reductions are necessary business objectives, it is evident from studying the application examples in Chapter 2 of the Management Report, that some firms are using rapid prototyping in more innovative ways than others. Included in these innovative applications are:
Given the high capital costs of some rapid prototyping machines, especially the larger ones, these innovative applications are probably the key to the successful and cost-effective use of the technologies. It may be the case that rapid prototyping will only be seen as financially viable when these wider potential benefits are taken into account. http://www.cheshire henbury.com/ rapid/benefits. html |
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Global Supply Chain: Keys to Succeeding in China
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