Top Cap for Residential Air Conditioner
Building & Construction Award
Molder: Mack Molding Company
Moldmaker: Delta Mold Inc.
Designer: Trane Advanced Innovative Design
Description
This is a protective cosmetic top cap for a residential air conditioner. This part WAS five separate parts that required a gluing operation and three molds to produce every part. Now this is one part made from one mold with no assembly required. The unique aspect of this part is how the part consolidating was successfully completed without detracting from the appearance of the part. The challenge of any consolidation opportunity is to achieve part function and appearance with respect to tool draw and geometric limitations. This is an excellent example of how tool design and part design can work together to effectively consolidate parts and still meet all product aesthetic and functional expectations.
Why is this Part Innovative?
Trane and Mack Molding Company established a developmental partnership early to improve an already successful critically important Cosmetic Cover for their top of the line residential air conditioner products. Mack Molding suggested Trane consider a complete consolidation of all louvers and the main housing which would streamline the number of molds required to supply each of these high volume Top Caps from six to two. In addition the cost of assembling louvers would no longer exist and field quality issues related to the adhesive assembly operation would be eliminated. Everyone recognized the financial benefits, but these changes would have to be done with respect to the unit performance and appearance so neither would be compromised. Mack Molding realized that the basic part geometry had to remain essentially the same, but minor changes would be required to accommodate the injection molding tooling. So Mack and Trane established a design team that included Advanced Innovative Design and Delta Mold. This team successfully reviewed a number of conceptual part design and tooling options specifically related to louver shape and form as well as core-side detail to improve process, yet still meet load and strength expectations. Trane and Mack realized early that this development team had to work very closely together so all product aspects and process improvements could be realized. Trane committed the resources to make decisions quickly and Mack and Delta represented the mold and process point of view on a real time basis so Advanced Innovative Design could complete the final design and 3-D Model to start the tool construction phase. The importance of this cooperative team can not be understated. By these four separate entities working together in a coordinated and collaborative manner, the number of design changes and the time to incorporate this new model was greatly reduced and cost controlled. The result is a successful next generation Top Cap. Issues related to assembly of louvers no longer exist and the logistics of two molds from six is a substantial productivity gain. The most impressive aspect technically is how the geometry changes worked with the tool design. Slide lines combine with style lines on the side of the part eliminating any unsightly tooling lines that would disrupt appearance of the texture. In addition, because the louvers are now integral, structural improvements and strength is improved which eliminated most of core side ribs required before which greatly improves molding process conditions because sink and flow disruptions associated with the ribs before are gone. In conclusion, these next generation Top Caps will be lower cost and better performing to benefit Trane for many years.
Process
Injection Molding: Why was this process chosen Injection Molding produces fast molding cycles for a high volume part like this and produces a part with the cosmetic appeal. Using External Gas helps with cavity texture replication, ejection of the part and lowers the injection pressure required to fill the part helping to reduce press size requirements.
Design
Design was done using CAD
Mold flow analysis
Finite element analysis
Tooling
Steel
Number of Cavities: 1
Molded in Texture: Yes
This is a large mold with four cavity-side mechanical slides to define the louver sections on all four sides. Note how the tool design works with the part design to hide the slide lines on the cavity side. In addition this mold was built with external gas incorporated in the tool.
Material
Polycarbonate
Finishing
Unfinished
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