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Moldflow : McKechnie Plastic Components
McKechnie Plastic Components is a division of McKechnie plc, an international engineering group headquartered in the UK. McKechnie plc designs, develops, and manufactures specialist engineering components and engineered plastics for markets as diverse as medical, consumer, electronics, aerospace and telecommunications. The groups' strengths lie in the design and engineering expertise that have resulted in the development of long term global partnerships with blue chip customers.
Mal Hare, the Moldflow Engineer at McKechnie Plastic Components, is responsible for running Moldflow analysis on all new products and on any existing designs that may be problematic during production. Since product quality is a number one issue, McKechnie also use Moldflow software to study product designs that may affect part quality.
Hare says, "Our customers typically want to keep production costs at a minimum. We give them a choice - scrimp on costs and risk quality or take advantage of our technology and expertise to obtain the highest quality products possible. The second most important element associated with our work is time to market. When a customer approaches us with a new concept that they need delivered as soon as possible, we have all the services on-site to make that happen. Our expertise is second to none when it comes to professional resources including feasibility engineers, design engineers, analysts, project management, and full production. We can deliver a product based on a concept, which is why more companies are approaching McKechnie."
McKechnie invests in highly talented resources and the best CAD/CAM, plastic simulation, and rapid prototyping software. Once the CAD geometry is imported into Moldflow, Hare analyzes the data to determine how the part will fill, where potential weaknesses may occur, and other issues such as wall thickness and gating.
"This process is always a compromise," notes Hare. "Typically, the customer wants thin walls to save material costs while we're always looking for more efficient methods to mold parts. However, over the last couple of years, customers have come to realize the benefits of using Moldflow as part of the design process. The technology is accepted as a necessary step to eliminate guesswork and problems that historically cropped up downstream during the manufacturing process. Customers today have a much greater understanding for the technology and recognize the benefits of using it early in the design stage especially on a new project."
Hare says the biggest benefit to using Moldflow is the confidence that it brings to the department. "While the software will never provide 100% assurance that the part will mold perfectly, it offers more reliability than sheer guess work which is the way it was always done in the past. Using the technology, we can do multiple iterations of different molding scenarios for the customer to show that several options were investigated. From this our customers gain a higher understanding of both their product and our production methods."
Case in point
A recent new product introduction caused Hare to improve the processing capabilities of a suite of Black & Decker tools. The parts were for a new range of lawnmower were problematic during their first years' production run. Hare was tasked to improve the filling pattern and reduce the pressure to fill that in turn, would improve part quality and the main problem of short shot moldings. The analysis using the CAD model seemed to show no real problems, but when Hare cut up the actual parts, it was noted that the wall sections varied. The next job was to re-input the actual wall sections on the Moldflow model and re-run the analyses. The results were amazing - now showing exactly where the short shots were occurring. They also showed a dramatic increase in pressure to fill the part. Now that the existing process was replicated, Hare thickened the relevant areas to give a balanced fill and reduced pressure. The tools were modified and the parts now have much wider process window.
McKechnie is a long time Moldflow user. The software was first installed approximately 10 years ago. Hare has been using it for about six years. "I've evaluated all the other packages and I think Moldflow is the best. Plus, the software and the company have a global presence," adds Hare.
He says that just five years ago, using analysis software was incredibly difficult because of the lack of technology to accurately import CAD geometry. As a result, using the software was frustrating and time consuming. "The learning curve is a lot different today," notes Hare. "It's easier to import models. I used to spend 90% of my time getting the CAD model correct and 10% actually analyzing it. That was a huge waste of time. Today many organizations use mid range CAD systems to produce solid models. However, that wasn't the case five years ago. Sometimes we had to create solid models from scratch. We could easily spend two to three weeks just reading the model in.
"Today, to actually learn how to use an analysis package such as Moldflow, it takes just four to six weeks to become productive. The challenge is what to do with the part once we obtain the results. It takes expertise to determine what modifications are necessary when problems arise. So, really, the learning curve is an ongoing process. We are always learning because every part is different and every job is different."
Hare adds that once users obtain analysis results, they should discuss possible modifications and remedies with a group of multidisciplined colleagues including designers, mechanical engineers, feasibility engineers, project managers, and others. "You should look at the situation from a number of different angles as part of a team effort. The use of Moldflow initiates additional discussion about making parts better."
Hare's ideal world
Hare says that in a perfect world, engineers should achieve success using as few pieces of technology as possible. "The more software you implement, the more training and staff are needed which incur additional costs to the overall organization. At McKechnie, we have tried hard to find a balance - deploy the right software necessary for the right job. Several of our competitors used to rely on the materials suppliers to do design, analysis, and Moldflow analysis work but today this service isn't so readily available. That's where McKechnie come into the equation.
"By investing in the best CAD/CAM and flow analysis systems, we can tackle tough jobs and get them done quickly. McKechnie are one of the few companies in the UK to offer this type of service and strategic approach to solving molding issues using Moldflow. I can't imagine going back to the old days when guesswork and fire fighting were part of a day's work. As a result of using products such as Moldflow, we have the confidence to take on any job and be successful."
For more information about McKechnie, visit www.mckechnie.com. / www.mckechnie-plastics.co.uk Visit www.moldflow.com for more information about Moldflow, its products, and services.
Author: Laura Carrabine