Vacuum Bagging Leak Rate & Infusion Calculator
Model composite vacuum bagging drop test integrity (VARTM / prepreg), calculate decay rate in mbar/min, evaluate volumetric leak flow, and qualify part porosity risk.
Part Geometry & Bag Enclosure
Vacuum Drop Test Measurements
Drop Test Evaluation
Bag Internal Volume & Pressure Scale
Infusion Process Risk Guidance
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
Why is a vacuum drop test mandatory prior to composite resin infusion?
During Vacuum-Assisted Resin Transfer Molding (VARTM), resin flows under atmospheric pressure gradient into dry reinforcement fabric. If air leaks exist around the sealant tape or through puncture pinholes in the nylon bagging film, incoming air bubbles are drawn into the resin front, creating fatal structural voids and un-impregnated dry spots.
What is an acceptable leak rate in aerospace carbon fiber infusion?
Aerospace specifications typically mandate a vacuum drop rate of less than 1.0 mbar over a 5-minute test period (≤ 0.20 mbar/min or ≤ 0.006 inHg/min) after achieving initial vacuum below 25 mbar absolute.
How does air leakage cause resin outgassing and boiling?
Resin systems (epoxy, vinyl ester, polyester) contain dissolved styrene and air. In a low-pressure environment, continuous air infiltration provides nucleation sites that cause dissolved volatiles and styrene to boil off, creating permanent micro-porosity.
Where do most vacuum bag leaks occur in composite shops?
Over 80% of vacuum leaks occur at sealant tape corner pleats (dog-ears), where the film is folded to create slack over vertical mold flanges, around vacuum drop port gaskets, and at thermocouple/tube pass-through sealant bridges.