Engineers and program managers who have been through a composite program that didn’t go as planned often describe the experience as a surprise that, in retrospect, shouldn’t have been. The tooling geometry that required redesign after the mold was built, the first article that failed dimensional inspection on features never explicitly discussed, the material used outside its qualified shelf life because no one had a documented tracking system—these are not random failures. They can be understood as predictable outcomes of gaps in program structure, supplier capability, or specification quality that may have been present from the outset and could have been identified through appropriate planning and review.
The practical value of understanding composite program failure modes is that most of them are preventable, and prevention happens at the supplier evaluation and program structure stage rather than at the point of failure. Contact our engineering team through our contact page or call 949-361-7580 to discuss how CMI structures programs to address these failure modes from the beginning.
Tooling design errors discovered after production begins are among the most costly events in a composite program. A mold that cannot produce the required geometry, dimensional accuracy, or surface quality requires redesign and refabrication — a process that consumes budget, delays the program, and can require re-evaluation of the design itself if the tooling problem traces back to a feature that is difficult or impossible to produce by the intended process. A common root cause is the same pattern: tooling was designed without adequate manufacturing input, or an organization separate from the team responsible for producing parts designed it. When tooling design and composite manufacturing are handled under the same roof, by the same engineering team, the feedback loop that catches tooling design problems operates before the mold is built rather than after. CMI handles tooling design in-house, with the engineers who designed the molds working alongside the fabricators, as confirmed on our composite solutions page. More detail on our in-house tooling capability is available on our in-house design and engineering page.
Fiber orientations and ply drop-off configurations that are theoretically correct from a structural analysis standpoint can create manufacturing problems — fiber bridging at corners, resin-rich zones at ply terminations, or void content in regions where the layup geometry does not allow adequate consolidation — that a structural analysis model does not capture. These problems do not appear in the design intent. They appear in the part, and they typically appear at first article, when the cost of addressing them is substantially higher than it would have been during the design review. A design-for-manufacturability review, conducted before engineers with direct composite production experience commit the tooling, identifies these problems at the stage where they cost the least to address. CMI describes its design-for-manufacturability review process on our DFM service page, and our engineering team is available through our contact page to discuss DFM review for your specific program.
Prepreg composite materials have defined shelf-life requirements under controlled storage conditions—typically frozen storage with specific temperature requirements and cumulative out-time limits at room temperature. Programs without documented material control processes can produce parts from prepreg that has exceeded its out-time, been stored outside its temperature range, or not been tracked against its accumulated exposure history. The problem is that parts produced from out-of-condition prepreg may not fail visually at inspection — the dimensional and surface quality may appear acceptable while the laminate’s mechanical properties and void content are outside the acceptable range. Documented material control systems — incoming material certification review, frozen storage with temperature monitoring, and out-time tracking tied to individual material lot records — are the controls that prevent this failure mode. For regulated programs, the quality management system requires these controls. For commercial programs, they are simply good manufacturing practice. CMI’s quality system, including material traceability and inspection controls, is described on our composite solutions page.
First article failures that trace back to specification ambiguity are among the most avoidable problems in composite programs, and among the most frustrating — because the manufacturer produced what they believed the specification required, and the buyer receives something that does not match what they intended. Blanket dimensional tolerances that do not distinguish between features with different functional requirements, surface finish requirements expressed qualitatively without measurable acceptance criteria, and mechanical property requirements that do not specify the test method or specimen geometry used to measure them are common sources of this failure mode. The resolution at first article typically involves negotiation about what the specification actually means, revision of the specification to reflect the original intent, and a re-fabrication cycle that the program budget and schedule did not account for. Engaging with an experienced manufacturer at the specification stage, before tooling is committed, is the most cost-effective way to close these gaps. Our engineering team is available through our contact page to review specifications before they are finalized. More on the specification process is available on our carbon fiber specification blog.
Programs that use separate organizations for design, tooling, and fabrication accumulate risk at each transition between those organizations. The design intent that an engineering team documents in a drawing is interpreted by a tooling vendor who may make assumptions that differ from the designer’s intent. The tooling that vendor produces is then interpreted by a fabricator who adapts their process to the tool they receive. Each transition is a point where information is lost, assumptions are made, and problems that could have been addressed through direct conversation are instead discovered at first article. A vertically integrated manufacturer who handles design review, tooling design and fabrication, and composite production under one roof eliminates those transition points. The feedback loop between what the design requires, what the tooling can produce, and what the production process delivers operates through direct communication rather than through documentation passed between separate organizations. CMI’s vertically integrated capability, which encompasses design, engineering, tooling, manufacturing, and delivery of complex composite systems, is described on our composite solutions page and our custom composite engineering page. Contact our engineering team through our contact page to discuss how our integrated model addresses the failure modes that affect programs sourced from multiple vendors.
The five failure modes described above account for a significant share of the schedule delays, budget overruns, and quality disputes that affect composite programs. Each is more prevalent in programs where design, tooling, and manufacturing are separated across organizations, where DFM review occurs after tooling commitment rather than before, and where specification quality is treated as the buyer’s responsibility rather than a shared engineering conversation. CMI’s vertically integrated model, in-house tooling design and fabrication, design-for-manufacturability review process, and documented material control systems are structured to address each of these failure modes from the earliest stage of the program. Contact our engineering team through our contact page or call 949-361-7580 to discuss how our integrated approach applies to your specific program, or review our manufacturing capabilities on our composite solutions page.
