Abstract: The invention relates to a package of a plastics material and consisting of a container and a lid adapted to be engaged with each other by snap engagement, there being provided complementary engagement faces which engage each other for establishing said snap engagement. An annular resilient sealing member is arranged between the engagement portion (40) and the bottom wall (19). The invention is characterized in that an axial compression of the sealing member (23) is provided during application of the lid (10), said compression being partially relieved when said engagement faces (29, 42) engage each other.

Abstract: Gypsum as a byproduct in the manufacture of phosphoric acid is converted into potassium sulphate or sodium sulphate by subjecting an aqueous slurry to anion exchange under acidic conditions. Adding solid potassium chloride to the obtained solution of potassium sulphate causes the latter to crystallize in pure state, the potassium chloride solution recovered after filtering off the crystallized potassium sulphate being used for the regeneration of the anion exchanger.

Abstract: In a building element of the type in which an internal core member of a material of an open air-permeable structure is covered on both side faces with cover boards and on the edge faces with edge strips, an adhesive bond having improved strength characteristics is obtained between the core member and the cover boards by means of a moisture-curing adhesive applied to the major surfaces of the core member and the internal surfaces of the cover board after application of moisture to all of said surfaces prior to arrangement of said core plate in an open casing formed by one of said cover boards and said edge strips, closing said casing by securing the remaining cover board to the edge strips and establishing a contact pressure between said surfaces by applying suction to the interior of the closed casing.

Abstract: In the manufacture of a building element of the type in which an internal core member of a material of an open air-permeable structure is to be covered on both side faces with cover boards and on the edge faces with edge strips by gluing with a moisture-curing adhesive, contact pressure is established by applying suction directly through an opening in one of the edge strips to produce an underpressure in the core member. Thereby, and by applying the amount of moisture necessary to cure the adhesive to the cover boards prior to application of the adhesive, a considerable reduction of the processing time and, thereby, a simplification and cost reduction is obtained. Relative to usual mechanical pressure application technology, adhesive bonds having improved strength characteristics are obtained together with effective removal of poisonous fumes arising during the curing.