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January 1, 2003

7 Min Read
CAE for plastics, Part 2: An implementation primer

cae250.jpgMost, if not all, designs for IM plastic parts are now being created with a CAD package, whether 2-D or 3-D. Using CAE doesn’t end here, however. To take advantage of moldfilling analysis, the next logical step, designers must do one of two things: purchase analysis services from an outside firm, or add the necessary software and infrastructure.

In this second part of the series, we will concentrate on implementing CAE in-house. Doing so without prior planning can bring on a host of difficulties, according to implementation specialists at Moldflow Corp., supplier of various moldfilling analysis packages. But this need not be the case. Following some guidelines and answering a few questions before adding this CAE element can make the switch less chaotic and more immediately productive.

We asked the experts at Moldflow several questions aimed at this goal. Their answers provide details on taking the headaches out of this major change in the design process.

Which factors should molders and OEMs consider when changing to a CAE-based environment?

  • Study benefits. From a detailed return on investment (ROI) study, it should be determined what benefits a successful implementation of CAE technology would provide. Ask these questions: What CAE products will be used? By how many analysts? On how many projects per year? Which projects should and should not be subject to CAE analysis? Be aware that it is important to consider CAE products based on a broader ROI potential, not just on the cost of the software license.

  • Promote enthusiasm. Willingness to truly integrate CAE analysis into the workflow is necessary. To realize the most effective implementation, CAE analysis should be used proactively in the design cycle, where it can have the biggest impact on the bottom line. Be willing to implement results of the CAE analysis.

  • Added considerations. Before deciding to bring CAE analysis capabilities in-house, manufacturers also must consider:
    1. Who will be in charge of finding the right CAE products for this operation?
    2. Are there appropriate computer resources available?
    3. What are the computer hardware requirements for the CAE products being considered?
    4. Are there appropriate personnel resources available?
    5. Do information technology or systems administration staff members need to be involved?
    6. Who will run the software?
    7. Who will be responsible for implementing the results?

    What is the logical path to take to ensure that the CAE system selected is best suited to a particular manufacturing environment?
    First, it is important to identify shortcomings in the current design cycle (without CAE), and associate costs with those problems. The next step involves defining both requirements of the CAE product needed to resolve current problems, and the budget available.

    Moldflow suggests meeting with CAE providers to discuss these findings and developing a partnership to discover the solutions. Set up product demonstrations based on your toughest designs. This way you can verify that the candidate CAE product is able to address current problems.

    Evaluate potential providers, considering the future of each company and its products. Ask these questions:
    1. What customer support is available?
    2. What type of training is offered?
    3. Will the product continue to be developed to address industry changes?

    Implementation benefits abound

    Rochester, NY-based Jada Plastics is a custom injection molder running 28 machines ranging from 60 to 390 tons. Its 70 employees work around the clock five days a week. The company typically molds small to medium, tightly toleranced mechanical components for the automotive and office equipment markets. David Crispino, president and mechanical engineer, performs all flow analysis using Moldflow Fusion and Flow modules.

    Whenever Jada accepts a new job, the first thing Crispino and his team do is evaluate the work from a molder’s perspective. “We try to understand the features and components of the design that inhibit us from molding it successfully or explore what options we can change to make it more moldable,” says Crispino. He says they study issues such as tool design, gating, and cooling. 

    “In addition, we also look closely at elements that are involved in adhering to tight tolerances,” he explains. “We ask, ‘How are we going to measure the part after we mold it?’ When working with plastic parts, there are usually some challenges in this area. We are not measuring screw machine parts that have nice, true surfaces. Because of these issues, we believe in spending a lot of upfront time in these types of activities.”

    Crispino uses the software to evaluate and determine gate locations, for instance, to make sure weldlines do not appear in critical areas, to eliminate the possibilities of air traps, and to establish accurate pressures to fill. “Since installing the software, we’ve found that our intuitive choices are not always correct,” he says. 

    Jada also uses the software as a troubleshooting tool. “We might use Moldflow to iterate on a design and rerun an analysis,” Crispino notes. “Based on our findings, we can propose an alternate design to a part that will help in molding it. It definitely enhances our credibility when we can show our customer an analysis in a current design and then as a modified design with a flow analysis that confirms why a change is necessary.”

    Recently, an automotive supplier approached Jada Plastics with an existing part—a decorative component of a wiper system. The part had an inherent air trap that caused the scrap rate to climb to 35 percent, forcing a secondary sort. 

    “We analyzed the existing part and gate locations,” says Crispino, “and created the air trap within the existing model. Then, we made modifications to the wall thicknesses and the gate locations. Lastly, we performed a final flow analysis. In the end, we created a design that eliminates the air trap. We presented this new design to our customer, showing them the animation of the two models, before and after. The result was a very powerful and convincing tool to persuade the customer that the latter design change was meaningful and should be adopted. They agreed and today the parts are being generated at a near-zero scrap rate.”

    What objections must be overcome to get CAE technology implemented at a new customer site?

  • The technology is too expensive or not in the budget.   

  • There’s no appropriate user on staff.   

  • The CAE product doesn’t apply specifically to the process being used.   

  • Material suppliers provide analyses.   

  • The number of analyses run per year will not be sufficient to make up for the implementation cost.   

  • It will be too difficult to implement the CAE product effectively, i.e., early in the design process to realize maximum potential benefits.

    What kind of problems may be encountered in getting an installation up and running?
    Computer resources may be inadequate compared to CAE system requirements. CAE software that is not installed correctly can create glitches. Additionally, users must be trained properly and receive adequate support from internal group members.
    Implementing too slowly can introduce its own difficulties. When there is a long delay between the decision to buy a CAE product and installation, enthusiasm for the change in process can plummet.

    It is also important that there is a commitment from the company as a whole to using CAE.

    Watch also that CAE is implemented properly in the development process. If it is used reactively to solve problems rather than actively to prevent problems, resentment can surface.

    Implementation
    Finally, we asked Moldflow to provide an implementation checklist, one that lists each step mentioned above in chronological order:
    1. What are your immediate and long-term needs from a CAE system?
    2. Are products available to meet them?
    3. Do you have a budget, computer resources, and personnel that can be allocated for a CAE system?
    4. Have you received a product demo and are clear what it can deliver?
    5. Are you willing to make CAE analysis a constant part of your workflow?
    6. What kind of support structure is in place so that the analyst(s) can be part of a problem-solving team, with access to the CAE tools to simulate possible solution ideas coming from any number of people within the team?
    7. Are you open-minded about implementing suggestions from CAE?
    8. Have priorities been set to evaluate which projects will likely offer the biggest payback in terms of cost savings, quality improvement, and time-to-market savings?
    9. Have you completed an ROI study to ensure that the CAE system will be worthwhile?
    10. Who will be responsible for system installation, licensing, and updates?
    11. Who will be responsible for running the CAE system, and have they been properly trained?

    Contact information
    Moldflow Corp., Wayland, MA
    (508) 358-5848; www.moldflow.com

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