Abstract: The present invention relates to a returnable package a comprises confining elements (2) that can be mutually assembled in a removable manner to define a holding volume, said confining elements having interfacing surfaces (2a) designed to be in mutual contact when two or more packages (1) are under piling-up and/or side-by-side relationship conditions; the package further comprises grip means (3) associated with the interfacing surfaces of the confining elements, the grip means being disposed in a matrix scheme defining directrices (4) intersecting at least two directions of possible relative sliding (5) that are mutually transverse and lie on the interfacing surfaces.

Abstract: A surface element (1) for friction increase comprises a lying portion (2) defining a reference surface, and engagement means (3) that can be extended and/or recessed relative to the reference surface and is suitable for interfacing with corresponding engagement means of a faced surface element for friction increase; the surface element further comprises a predetermined number of clusters (4) of the engagement means defined by respective confining edges (4a) and distributed on the lying portion, and in each of these clusters the engagement means is disposed along directrices (4b) having at least one predetermined curvature (4c) and one corresponding centre of curvature, centres of curvature of directrices belonging to clusters separated from each other not being coincident.

Abstract: The present invention relates to a returnable package a comprises confining elements (2) that can be mutually assembled in a removable manner to define a holding volume, said confining elements having interfacing surfaces (2a) designed to be in mutual contact when two or more packages (1) are under piling-up and/or side-by-side relationship conditions; the package further comprises grip means (3) associated with the interfacing surfaces of the confining elements, the grip means being disposed in a matrix scheme defining directrices (4) intersecting at least two directions of possible relative sliding (5) that are mutually transverse and lie on the interfacing surfaces.