On the Job: Consultant Helps Drive Success for Auto Parts Maker

14 Nov, 2005 Cadalyst

CAE Services provides mold-filling analysis for Intier Automotive to improve component quality.

Intier Automotive, the interiors company of Magna International, designs and manufactures automotive interior components for the global automotive industry. The company has staff throughout North America, Europe, Brazil, Japan and China in 74 production facilities; 15 product development, engineering and testing centers; and 21 sales/purchasing offices. At its Intertech facility in Nashville, Illinois, Intier manufactures door panels, quarter panels, lift (or swing) gates and instrument panels using injection molding and low-pressure molding processes, and performs full assembly operations.

Over several years, the Intertech operations have relied on CAE Services, based in Batavia, Illinois, to provide in-depth computer-aided engineering consulting services using Moldflow Plastics Insight software. Jim Betters, Intier's processing technology and tooling manager, says, "CAE Services has provided complete analysis for us on many applications on several vehicle platforms. They have performed mold filling, packing, cooling and warp analyses."

Accurate Understanding
Betters says that for any given part, Intier has to be very cognizant of proper gate locations, optimum number of gates and the ability to fill a complicated cavity within the capability of the molding system. "We look to CAE Services to help us with these challenges," Betters explains. "The design, processibility and long-term manufacturability of a tool starts with the basic understanding of how a mold will fill and how the stresses and temperature profile of the tool and material during processing will affect part appearance and dimensional characteristics. Working with CAE Services, we obtain an accurate understanding of the expectations of the parts to be produced for a new mold with the analysis.

"We decided to have the mold-filling analysis completed on large tools with multiple gates and complex geometry to incorporate greater efficiency," Betters continues, "as it helps to eliminate trial-and-error experimentation with gate locations and to determine in advance where we had shortcomings in our initial tool design scheme. We also wanted to examine relocation of water lines to address hot spots and awareness of unusual knit line locations and high pressure to fill situations."

Betters and his team expected the analysis to provide reasonable prediction of the filling patterns of the tool with the selection of various gating locations and gate designs and/or gate sizes. In addition, they expected the analysis to offer an opportunity to visualize the results of various filling and packing conditions on the end product with respect to warp and clamp tonnage, use the computer simulation to predict the optimum processing condition to create a more efficient tool start-up process, and therefore enhance confidence in end product quality.

Cooling simulation on an Intier part reveals excessive temperature differences in areas difficult to cool, which could lead to warpage in the part.

"We were very pleased with the results predicted from the mold-filling analysis, even on the most complicated tools," Betters says. "The predictions of knit line locations, filling pressure and clamp tonnage correlated extremely accurately."

Cost Justification
Betters says the cost of working with CAE Services is justified immediately by reducing the time and number of molding trials it takes to obtain first shots off a new tool and first shots of higher quality sooner in the process. In addition, Betters says that since his company has worked with CAE Services, he can't recall a single incident in which Intier had to move a gate or add additional gates to solve a processing issue or solve a cosmetic issue. "We were immediately at the processing window and it was up to us to make the minor adjustments to improve part appearance," Betters explains.

"A tool trial on a large 3,000 ton press operating at the minimum cost per day for the machine alone can be worth the price of employing up-front analysis. Add to that the cost of bringing people from the manufacturing site to the mold shop, material costs and shipping, and you're looking at some significant numbers for each testing trial. So the cost of the analysis will be justified with the elimination of just one trial," says Betters.