Re: [CAD_CAM_EDM_DRO] Vacuum Table

>
> If Bill will send me the mfg name and model # of nhis pumps I may be able
> to tell what they actualy are.
> I agree with Jon they probably are unsuitable for what you want and too
> good to destroy trying.
> I have a bit of experience with vacuum pumps and can hopefully tll you how
> they should be used.
> My suggestion to build a box beam for the table takes care of the
> deflection caused by the external pressure.
>
> for Doug:
> Simple vacuum baging can be done with a vacuun cleaner system. I have done
> it on boat composite parts with epoxy. The warning about motor cooling
> does apply. You don't need these high grade pumps. It s also not good to
> run the resign solvent vapours thru a high vacuum pump.For both these
> applications the atmosphere provides the pressure. the pump only provides a
> differential and handkes any leaks ( planned to be none).
>
> If you are thinking of aircraft composites-- these are a different beast
> altogether. These use special prepreg reforcements and various different
> polymer resins as the binder. These place the part in a bag to collect
> excess polymer . The part with its support tooling is placed in a high
> pressure autoclave that allows rapid pressurization , heat up to cure and
> cool down. The excess polymer is pulled out of the bag in the
> pressurization step into a low preessure sump system. The polymer resins
> are designed to cure or harden only under higher temeratures. The
> autoclaves are generaly can go to 150 psig. and can be heated with steam or
> electric heaters. The autoclaves are generally pressurized with nitrogen
> to prevent fires that result in part and tooling loss.
> William Scalione wrote:
>
> Jesse
>
> r, just a few liters a minute.
> Wild a substantial structure to resist the effort of the air to collapse
>
> it. You will probably get somewhere around 5 PSI differential, giving over
> 5 tons of force on that sheet.
>
> Jon
>
>
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