Improving Seal Quality at Package Prototypes A project made at Tetra Pak R&D, Package Prototyping

Package Prototyping is a group within Tetra Pak R & D in Lund. Package Prototyping is producing different types package prototypes for different purposes. The sealing of the package prototypes is made with various sealing methods, in different sealing rigs, depending on package material. Package Prototyping has had problems with the quality of the package prototypes and have been searching for a way to enhance the knowledge about Package Prototyping has had problems with leaking packages. No seal evaluation method has systematically been used, neither has any quality improvement tool been used. The objective with this project was to obtain knowledge on how to produce high quality seals. I decided that a convenient way to reach the objective was to develop an evaluation method of the seal quality and to use factorial experiments to vary the different sealing rig parameters. A combination of the factorial experiments and the seal evaluation method is used as the quality improvement tool that generates knowledge to the performers, i.e. the package technicians. It is used when a new material enters the production. The transversal seal (TS) is sealed with the rig set as the factorial test schedule indicates, according to a 23-test schedule. The seals are made with the seal rig parameters set according to the factorial test schedule and are measured in the test rig. This test rig puts a pressure on the packages and a scale measures the force on the package. The force is increased until the package leaks and this measure is noted. The leaking force is the result variable in the factorial test. The best rig setting is statistically calculated in an Exel sheet made for the purpose. The effect each rig variable has on the seal quality is also indicated in this sheet. This method is applicable to all package material and sealing techniques. It is useful for Package Prototyping since the batches of prototypes produced are relatively small and new package material is often entered in the production.