subject: Pp Woven Bag [print this page] A pp woven bag for free flowing powders or granules has a cylindrical body portion of a bag proper, top and bottom end portion which close top and bottom openings of the bag proper, and a cylindrical filling portion formed on the top end portion. Top edges of the cylindrical bag proper are sewn along a line passing through a point of a central axis of the cylindrical filling portion. The above-mentioned bag is made from a sheet-like cloth or a tube fabric.
The present invention relates to bags for use in storing and transporting bulk materials, such as free-flowing powders and granules, farms produce and such like and a process for manufacturing such bags. More particularly, the present invention relates to an improved bag having a material filling opening formed in the top portion thereof and a process for manufacturing this bag.
Description of the Prior Art
In known bags having an opening for filling, formed in the top portion thereof, the filling opening and a top end cover are separately formed and sewn together, and the top end cover is then sewn to a bag proper. Accordingly, known bags have the defect that the sewing operation thereof is very troublesome and the efficiency of the sewing operation is very low.
Furthermore, the top end cover of the known bag is sewn to the bag proper along the entire length thereof to form a seam. As a result, the known bags have an additional defect in that this seam can be broken or loosened by an impact or shock imposed during the operation of piling or loading the bags for storage or transportation. Accordingly, from the viewpoint of carrying out the piling and loading operations without encountering this defect, it has been desired to improve the quality of these bags.
In a bag for use in storing and transporting a bulk material, having a cylindrical body portion with an axis, a bottom end portion which closes the bottom opening of said cylindrical body, a top end portion having an opening for filling the bag in the central portion of said top end portion about the axis, a plurality of handling slings sewn to said bag body at predetermined positions adjacent to said top end portion the improvement which comprises; a top end portion formed integrally with said cylindrical body portion, having a cylindrical portion for filling the bag having an opening smaller than the cylindrical body portion and sutured by a seam formed along a plane of the axis of said cylindrical body portion wherein said cylindrical body portion is provided with a pair of selvages formed at both end portions of said seam for said top end portion, said selvages folded inwardly and sewn to said seam.
