i'm using only polythene film over the laminate, no release no breather.
If you are not using a peel ply and breather, then how do you expect the bubbles to come out of the laminate?
Where do you expect the excess resin to go?
With excess resin in the laminate, how do you expect the pressure exerted by the vacuum to effectively compact the laminate?
When I was doing a lot of vacuum bagging with a clear resin finish, I found it was pretty easy to get dry spots in the laminate with too much vacuum. These dry spots would become obvious as a fairly uniform whitish haze after the laminate was fill coated with clear resin.
To eliminate the problem, I limited the vacuum to 15-18 in hg measured at the vacuum inlet to the bag. The amount of vacuum you need with your set-up need might vary however, depending on what you are using for your breather and peel ply, or if you are using a perforated film to reduce resin loss.