As we have discussed before on this blog, design for manufacturing (DFM) is important for getting the most value out of your injection molding production. DFM is most successful when the contract manufacturer and OEM combine their design and engineering expertise in order to find the optimal choices of tooling material, thermoplastic resin, placement and size of core outs, number of cavities per tool, runner type (hot or cold), and the right gating structure. By focusing on key aspects like draft, wall thickness, coring, thin and fragile steel conditions, undercuts, and drawing tolerances, effective DFM can reap significant savings.
In this post, we’ll discuss the 8 most important reasons why DFM should not be skipped in your next injection molded project.
DFM Analysis Saves You Money
There is a difference between being cheap and being cost-effective. DFM provides many opportunities for the latter. In fact, these long-term savings result from our first 6 DFM benefits:1. By simulating and optimizing a mold in software during DFM, OEMs can avoid the expenses from scrapping, modifying, and repairing their prototype or production molds.
Your mold must not only make great quality parts for validations, but continue to do so after hundreds of thousands of cycles into approved production. This requires durable molds well-designed for the repeated stresses, temperatures, and material interactions that mold will encounter over its projected lifetime. When surface finish requirements are on the line, mold surface degradation must be kept to a minimum. A proper DFM that includes the mold as well as the plastic part, will take this into consideration.2. Scrapping parts due to an unreliable process is expensive. DFM can help prevent that.
This is especially true for expensive engineering resins, cold runner tooling, or scenarios where resin re-use by regrinding, isn’t an option. Advanced mold simulation software can alert mold design engineers to inadequate flow rates, pressures, or cooling times, saving cycle time and material from being wasted.3. DFM can minimize both the amount of resin used and the cycle time.
Optimal sizing and placement of core-outs as well as carefully chosen values for wall thicknesses can reduce the amount of molten resin that needs to be used, and cooled, per cycle. This is one area where DFM can have a direct impact on the final price per part.4. Improve the strength of the part via ribs and other features suggested during DFM
Minor design tweaks like adding reinforcing ribs and adjusting their location can have a big effect on the structural strength of the finished part, reducing failures in the field and improving customer satisfaction with the product’s performance. This in turn helps to reduce the OEM’s number of parts returned for replacement or refurbishment.5. Wisely combine separate parts into one.
What components of your product can be molded as one piece rather than mechanically fastened as individual parts later? An experienced contract manufacture can answer that question for you during DFM analysis. Reducing part count simplifies inventory and reduces the labor costs associated with assembly steps. Mold and part design DFM analysis can reduce costs well downstream of the injection molding process.6. Optimal mold design can minimize downtime through more reliable production.
We’ve mentioned the direct material costs of mold failure and degradation in #1, but as the old adage says, “time is money”. When a machine goes down, the price per part jumps because your fixed costs don’t take a timeout, and unexpected labor time & repair costs have just ruined the estimated profit margin. So, while it may seem tempting to bypass the DFM process, OEMs significantly increase their risk of both missing delivery requirements due to down time, and of facing unexpected costs to cover unplanned mold repair.
DFM Saves Time7. DFM helps OEMs get the design right the first time.
When the CM and the OEM both agree on a design that can actually be made as specified on the drawings, further design iterations can be avoided. This shortens the time to market, helping you outmaneuver your competitors.
DFM Can Save Your Product8. DFM can guide you towards the proper tolerances for your part.
By involving the contract manufacturer during the design phase, CMs can steer OEMs away from unrealistic tolerances while at the same time meeting required product functionality requirements, guaranteeing features that are critical to quality, and that achieve the desired CPKs. Avoiding that process could cause a debilitating bottleneck that jeopardizes delivery dates, hampers sales volume, and bites into your bottom line.
When you’re designing for manufacturing, you’re also designing for the whole product lifecycle, so make choices you’ll be proud to stand by. Crescent’s in-house mold engineering team has been helping our customers excel through simulation-assisted DFM analysis. Quality parts, reduced production costs, and time saved—that’s why DFM is a must.