Method of making thermoplastic bag and bag pack

A thermoplastic bag structure having, in its lay-flat condition, a front and rear bag wall, a two-film heat seal bottom; the outer side margins of the full length of said bag being folded toward but spaced from each other. The top most edge of each fold is heat sealed through the four films thereof along line corresponding to the width of the folds. An open mouth top portion being characterized by having double film handle loops at opposite ends of said mouth, said double film loops being extensions of the folded regions of said bags and the corresponding regions of said front and rear walls. The bag structures can be unitized by providing a detachable tab at the bag mouth opening and unitizing the bag structures through this tab. The method of forming said bags involves providing an end sealed collapsed thermoplastic film tube, folding the sides of the tube toward but spaced from each other, heat sealing one end of the tube through four layers thereof and removing plastic from this end of the structure to form a bag mouth and handles at one end thereof. The resulting bag is an ungusseted bag which can be unitized into a pack by providing a detachable, unitizing tab at the bag mouth opening.