| 摘要 |
A cylindrical sack having a paper casing 30 formed of several layers and an inner lining in the form of a plastic film cylinder 31 placed inside the paper casing, and having a transverse weld 31' at the bottom end of the sack. The paper casing and plastic film cylinder are connected to each other in a normal manner by transverse top pasting 32 and dotted bottom pasting 33. According to the invention an extra line of transverse paste 34 is used to join the paper casing and the plastic film cylinder approximately at the edge of the sealing section closest to the bottom seal. This extra paste line 34 relieves the tensile stresses in the plastic film cylinder 31 when the sack is filled and thereby reduces or eliminates the deformation of the sealing section of the sack and thus facilitates satisfactory sealing of the sack. The extra paste line 34 is usually located 15-20 cm down in the sack, calculated from the sack's open end. The extra paste line 34 can be provided by means of an extra paste piece in a pasting unit in a traditional sack machine. <IMAGE> |
