Question about the required minimum vacuum pressure (10mbar) of XPREG XC110

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cumberdale	c cumberdale posted 7 Years Ago HOT Topic Details
c Group: Forum Members Posts: 32, Visits: 594	It says in the technical datasheet of Easy Composistes out-of-autoclave Prepreg XPREG XC110, that for curing the "minimum vacuum pressure is 10mbar". This is a pretty low value. There are many vacuum pumps that can only achieve 50mbar, for example. So my question basically is: why so low? To reduce the probability for pinholes? Because the relative gain in pressure when going from a 50mbar vacuum pump to a 10mbar vacuum pump is very small when you compare it to the outside pressure of a thousand mbar (well: 960mbar where I live).
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Warren (Staff)	Warren (Staff) posted 7 Years Ago ANSWER Post Details
Group: Administrators Posts: 2.5K, Visits: 7.9K	The 10mbar figure is based on sea level and standard atmospheric pressure ie 1 bar/1000mbar, so the higher you go, the less force is applied against the bag, so realistically with a very high vacuum pump, for exmple 0.03mbar, then as you approach 900meters or 900mbar atmospheric (eg a lower altitude in a severe "low pressure" weather storm), then the level of force applied to the vacuum bag and hence the pre-preg may well not be enough to ensure a pin hole free finish without extra force being applied, such as in a press or an autoclave. However this is quite a rare scenario for most users. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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