CCT Curing Processes & Autoclave Operations Flashcards
6 cards from real CCT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CCT Curing Processes & Autoclave Operations flashcards as text
What is 'out-time' for prepreg composite materials?
Answer: The total accumulated time a prepreg has been outside the freezer at room temperature
Out-time tracks cumulative room-temperature exposure of prepreg; exceeding the limit causes premature partial cure that degrades part quality and processability.
What is the purpose of a bleeder layer in an autoclave vacuum bag layup?
Answer: To absorb excess resin squeezed out from the laminate during cure
The bleeder layer absorbs excess resin expressed from the laminate during cure, controlling fiber volume fraction and preventing resin-rich areas.
What does a 'dwell' mean in the context of a composite cure cycle?
Answer: A period of constant temperature held for a specified time
A dwell is a hold period at a specified temperature, providing adequate time for resin flow, volatile removal, or crosslinking reactions to complete.
What is the gelation point in epoxy resin cure?
Answer: The point where resin transitions from liquid to gel and loses the ability to flow
Gelation is the critical transition where epoxy resin changes from a flowable liquid to an elastic gel due to crosslink network formation, after which resin can no longer flow.
What is post-cure in composite processing?
Answer: A secondary heat treatment after initial cure to achieve full glass transition temperature and mechanical properties
Post-cure is a free-standing oven heat treatment after demolding that advances the degree of cure to achieve the material's design Tg and full mechanical properties.
What is the significance of glass transition temperature (Tg) for a cured composite structure?
Answer: It defines the maximum service temperature above which the matrix softens and structural properties degrade
Tg is the temperature at which the polymer matrix transitions from rigid to rubbery, setting the maximum service temperature for structural composite applications.