Cure Cycle Records: What to Capture and How to Tie Them to Parts

What the Cure Record Must Contain

The record starts from the cure specification or the material data sheet and any customer process document. Typical parameters are heat-up rate in degrees per minute, one or more hold temperatures with tolerance bands, hold duration measured from the coolest thermocouple reaching the lower limit, applied pressure and its timing, vacuum level in the bag and the cool-down rate before pressure release. The record should hold the equipment ID, program or recipe number, operator, start and end time, and the identity of every part and tool in the load.

If you use pyrometry-controlled equipment, calibration and system accuracy test status for the oven or autoclave belongs with the record, as AMS 2750 requirements often apply to aerospace work.

• Recipe or program ID and revision actually run
• Air and part (or tool) thermocouple traces, with locations
• Vacuum and pressure traces, not only set points
• Pass or fail against each specified limit, with who reviewed it

Thermocouple Placement and Load Maps

Cure quality depends on the part, not the air. Thick sections and heavy tools lag the air temperature, so the dwell clock must run on the slowest thermocouple. Document where each thermocouple sits, typically on or near the part in the bag, on tool surfaces and at thin and thick regions, and keep a load map showing each part's position and its thermocouple channels.

Many nonconformances trace to a blocked vacuum port or a thermocouple lead that failed mid-cycle rather than to the recipe. Treat a lost channel as a recorded event with a documented disposition, not as something to ignore because other channels looked fine.

Linking One Chart to Many Work Orders

A load usually contains parts from several work orders, perhaps several customers. The data model should have one cure run record and a child list of parts, rather than copying the chart into each traveler. Each work order's cure operation then references the run ID, and any quality query on a part resolves to the same single record.

In ERP terms this means a batch or lot-like object for the cure run, with operation completion tied to it. Avoid retyping run data by hand: copy errors are the commonest cause of mismatched charts and parts in audits, and they are extremely time consuming to fix after shipment.

Review, Release and Retention

Before parts leave the cure operation, someone competent should review the chart against the specification and sign it off, and an exception should open a nonconformance rather than being passed forward. For aerospace and defense, customers often specify retention periods that run for the life of the program or many years, and some require records to be producible within days. Store the raw digital data, not just a PDF print, so the evidence can be re-plotted if challenged.

Make sure backups cover the data historian, and test that you can retrieve a cure from a year ago using only a part serial number.

Where Digital Capture Pays Off and Where It Does Not

If you run one oven, a handful of recipes and a few jobs per week, a good log, a scanned chart and a clear naming convention can be perfectly adequate. Automated capture from the controller into a historian linked to ERP lots makes sense once you run several autoclaves, multi-part loads or customers who audit cure records on every shipment. The main benefit is not speed but removing transcription steps, so a part's genealogy can be retrieved from one query.

Plan the interface early, because some older controllers export only to proprietary formats and need a gateway.