# Composite Layup Room Readiness Checklist > Source: https://netray.co/tools/composite-layup-room-readiness-checklist > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer A pre-shift and pre-layup checklist for clean rooms and layup areas covering environment, prepreg, tooling, bagging and documentation. ## Category quality ## Industry Aerospace ## Audience - Composites technician - Production supervisor - Quality engineer - Process engineer ## Tool **Kind:** checklist **Groups:** #### Environment and housekeeping **Items:** **Text:** Temperature and humidity in the layup room are within the process specification limits and recorded **Critical:** true **Text:** Positive pressure or filtered air confirmed where the specification requires a controlled area **Critical:** true Room particulate or contamination checks completed per schedule **Text:** No silicone, mold release aerosols or unapproved lubricants in the area **Critical:** true Floors, tables and cutting surfaces clean and free of fiber debris Personal protective equipment, gloves and garments available and in good condition #### Material and kitting **Items:** **Text:** Prepreg lot, certificate of conformance and shelf-life status verified before use **Critical:** true **Text:** Out-time tracked and remaining out-life covers layup, bagging and cure **Critical:** true **Text:** Material allowed to reach room temperature in the sealed bag before opening to prevent condensation **Critical:** true Ply kit matches the ply book: orientation, count and material code Cut plies labeled and stored on the backing paper in the correct sequence Core, inserts and adhesive films within shelf life and correctly identified #### Tooling and release **Items:** **Text:** Tool identified, calibrated or inspected as required and in current revision **Critical:** true Tool surface free of residue, scratches, dents and previous resin build-up **Text:** Tool vacuum integrity tested or leak checked per schedule **Critical:** true Release agent or film applied per specification and allowed to cure Locating features, dams and caul plates present and secure Tool thermocouple ports and vacuum ports are clear and labeled #### Layup, debulk and bagging **Items:** **Text:** Ply orientation checked against the laser projector or template for each ply **Critical:** true **Text:** Backing paper and any foreign material removed from each ply before the next is placed **Critical:** true Debulk performed at the frequency and vacuum level the traveler requires Bagging materials are the correct type and temperature rating for the cure Bag has sufficient pleats and no bridging at radii or corners **Text:** Vacuum ports and lines connected, and bag leak-down test is within the allowed rate **Critical:** true Thermocouples attached to coldest and hottest expected locations #### Records and handover **Items:** **Text:** Traveler complete, signed and includes material lot, tool and operator traceability **Critical:** true Out-time record updated and unused prepreg returned to cold storage correctly labeled Scrap and offcuts segregated and logged by lot **Text:** Deviations written up and routed to quality before the part goes to cure **Critical:** true Cure cycle record opened and linked to part serial number **Scoring Note:** Items marked critical should be satisfied before layup begins. Any failed critical item stops work until it is resolved or dispositioned by quality or engineering. Adapt the list to your controlled process specification. ## Content **Intro:** Most composite defects are introduced before the part reaches the autoclave: expired material, contaminated tools, a missed ply or a leaking bag. This checklist walks the layup team through the checks that prevent those problems and leaves a record that the area was ready. **Sections:** #### How to use the checklist **Body:** Use it at the start of a shift for the room and at the start of each job for the material, tool and bag. Work through each group in order and tick items as they are confirmed. Items marked critical block the job if they fail. Print the page or export it to PDF to file with the traveler. Many shops split the groups between the technician, the lead and quality; the grouping here makes that easy. Adjust wording and limits to match the controlled process specification that governs your parts. **Bullets:** - Treat the critical items as hold points, not reminders. - Record the actual temperature, humidity and leak rate, not just a tick. - Review failures weekly to find recurring causes such as tool wear or consumables. #### Why these checks matter **Body:** Contamination is a common root cause of bond failures and porosity, which is why silicone and uncontrolled release agents are banned from many composite areas. Temperature and humidity affect tack and moisture pick-up. Out-time and shelf-life limits protect resin flow and cure behavior. A leaking bag lets air into the laminate and creates voids that ultrasonic inspection will later reject. Ply orientation errors are among the costliest, because a part with the wrong angle can pass visual inspection but fail structurally. #### Standards and references **Body:** Aerospace composite work typically follows customer process specifications and industry practices for prepreg handling, such as those found in the SAE and CMH-17 guidance, plus the quality management requirements of AS9100. The thresholds for room conditions, leak rates and debulk frequency vary by material and program, so this list refers to your specification rather than quoting numbers. Where a customer requires a particular form, use that one and treat this as a supplementary shop-floor aid. #### Common mistakes **Body:** Teams often tick the room environment from memory instead of reading the instrument. Another common mistake is opening a cold prepreg bag early, which pulls moisture onto the tacky surface and shows up as porosity later. Vacuum checks are sometimes done on the bag but not on the lines and fittings, so a leak in a quick-disconnect goes unseen until the cure. Finally, skipping the debulk or doing it at the wrong vacuum level because of schedule pressure is a known driver of thickness and void problems on thick laminates. **Cta:** If you want pre-layup checks and holds enforced in the MES with the results stored against the work order, Netray can scope that integration with your ERP and quality system. **Faq:** #### What temperature and humidity should a layup room maintain? **Answer:** It depends on the material and specification. Many aerospace prepreg rooms hold roughly 18 to 24 C and 30% to 65% relative humidity, but you must use the limits in your controlled process specification and record actual readings. #### Why must prepreg thaw before the bag is opened? **Answer:** If the bag is opened while cold, moisture from the room air condenses on the material. That water becomes voids or porosity during cure. Let the sealed bag reach room temperature, often a number of hours depending on roll size, before opening. #### How often should the layup tool be leak checked? **Answer:** Frequency is set by the process specification and tool condition, often at tool acceptance and at defined intervals or after repairs. The bag is leak checked every cure. A tool with a failed leak test should not be used until repaired and retested. #### Who should sign the checklist? **Answer:** Typically the layup technician completes it and the lead or quality inspector verifies the critical items. Follow your quality system's rules for who may sign, and keep the form with the part traveler for traceability. ## Search terms composite layup checklist, clean room layup checklist, prepreg layup preparation checklist, composite shop audit checklist, vacuum bag checklist, layup room environmental controls, composite process readiness, pre-layup inspection form --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json