Welcome Trish.

That only works if your sealer has an adjustible heat controller. Zipper bags are made of a different plastic, and require lower heat to work. At high heat you just burn through them.

BTW, to achieve a vacumn seal in a zipper bag that's even better than the machines, close all but about a half inch of the zipper. Then submerge the bag in water right up to the zipper line. Seal the last half inch. You will have forced _all_ the air out by doing that.