Strict standards govern aerospace composite manufacturing. Where do industrial oven providers fit in?

Industry and government each place much responsibility on the shoulders of aerospace composite manufacturers.

And rightly so: Some of these components are safety-critical. The well-being of anyone in flight depends on these parts performing as designed.

As such, the parts’ manufacturing processes must also meet rigorous benchmarks. And when equipment and processes are validated, the resulting paper trails must be thorough, organized and accessible.

CAD drawing of an aerospace composite oven.

But where does that leave the oven providers whose equipment is common in the forming, curing and drying of aerospace composites? How much of the burden do they bear?

As we discuss below, we have our lane and you have yours. But that doesn’t mean a solid wall should separate us. A window is more like it: Good oven providers use what they know about your responsibilities to make good on theirs.

A bright, solid line defines your accountability and ours

In aerospace manufacturing, the accountabilities are clear: Part manufacturers must meet any applicable standards because they develop the manufacturing processes that result in a part’s performance. An equipment provider is only beholden to the specifications handed to them by a manufacturer.

But this fact doesn’t make an industrial oven provider an irrelevant participant. In the case of honeycomb composite parts, the opposite is true. This emerging field of aerospace manufacturing requires equipment providers who can do more than merely follow detailed instructions.

How honeycomb composite oven providers fit into the QMS mix

Aerospace manufacturers are not the only ones who must implement a quality management system (QMS) under the ISO 9000 series, but they are among those that adopted their own sector-specific QMS frameworks — it’s AS 9000 in the case of aerospace manufacturers.

To meet aerospace QMS requirements, honeycomb composite manufacturers must be able to collect and store information on the process conditions for the parts they make. In the unfortunate event of a part failure, for example, the manufacturer must be able to show investigators whether their manufacturing equipment was operating according to its performance specifications at the time the failed part was processed.

Here’s where an oven provider comes in: A range of instruments inside aerospace composite forming or curing equipment are needed to provide this vital information.

Time and temperature trends will be mandatory across the board. For simpler processes, this may be the only data a manufacturer must collect.

More complex processes might require more, and more complex, instruments, such as:

  • Lower explosive limit (LEL) monitors that detect concentrations of combustible gases or solvents in air
  • Pressure monitors inside the oven chamber that balance air-in leakage instead of air-out leakage to ensure more energy-efficient operations
  • Differential pressure sensors throughout the system that alert operators to significant pressure drops, which indicate part maintenance or replacement is due
  • Flow sensors that show the direction and airflow rate inside a system

Because Davron only builds custom thermal processing equipment, our team has two distinct advantages that matter a great deal to honeycomb composite manufacturers:

First, we can engineer industrial ovens to do pretty much anything you can think of, including executing totally novel processes.

Second, we have a better understanding of — and more experience applying — a range of complex instruments within equipment to verify that specified process parameters are met.

We understand that, due to the safety-critical nature of many of the parts our aerospace customers manufacture, they confront more rigorous standards and requirements related to system instrumentation and data collection.

Of course our opinion is biased, but we believe this experience qualifies us as an ideal equipment provider to manufacturers in the rapidly advancing realm of aerospace composite thermal processing.

(Click the following links to see examples of thermoforming, curing and drying ovens we’ve engineered for past customers.)

An aerospace composite oven inside a factory.

Verifying performance via site acceptance testing

Once new honeycomb composite thermal processing equipment is installed in a manufacturer’s facility, the manufacturer’s QMS usually demands the completion of simulated production runs. These site acceptance tests (SATs) verify that, under normal operating conditions, the equipment achieves the processing conditions spelled out in the specification.

Here again is that bright, solid line of accountability.

On our end, we are responsible for building equipment that does what is stated in your specifications. If something we build does not meet spec, we must make it right. We are only off the hook once the data show that the oven does what we promised.

After that, the responsibility shifts to the customer.

It is quite common for manufacturers to make adjustments to equipment or process recipes once an industrial oven is delivered and site acceptance forms are signed to squeeze out a bit more speed or better part quality.

It’s your oven. Use it however you please. But we will only guarantee performance within the agreed design specifications. So to avoid the risk of unintended equipment damage or production errors, we recommend against making adjustments outside of the agreed specs.

Drawings, manuals and maintenance

Another important aspect of an aerospace manufacturer’s QMS is detailed documentation of everything related to part production, including information on production equipment.

Any oven provider will include manuals and drawings along with machinery as a matter of course, regardless of the customer, industry, product or process.

But providers should take special care to ensure that the maintenance manuals and drawings they provide to aerospace manufacturers are thorough, well-organized and easy to understand.

This has always been important because of the added complexity and higher stakes associated with aerospace manufacturing. But it is even more acute in the aftermath of the COVID-19 pandemic because turnover in facility maintenance crews is much, much higher than before. It’s better for everyone — but especially your maintenance personnel — if we make their reference materials as seamless and sensible as possible. It reduces the learning curve in an environment where it is when, not if, key maintenance staff turn over.

An aerospace composite oven.

Send us your napkin sketch

Aerospace composite manufacturing is advancing at a rapid clip. New designs and new materials mean new processing equipment will need to keep pace.

We know that engineers love to make napkin sketches, and it feels like a safe bet that you’ve got a drawer full of them.

We’d love to see them. And we’d love to help make the product of your happy hour daydreaming the real thing on your manufacturing floor.

Here’s how to start.