The present application relates to a protective leather case and a positioning device for protecting a smart terminal. The protective leather case includes a leather layer; an adhesive layer; and a positioning release film including a first release film and a second release film. The leather layer, the adhesive layer and the positioning release film are laminated sequentially. The first release film is provided in a first direction. At least two second release films are provided, and are arranged on both sides of the first release film in a second direction perpendicular to the first direction. The protective leather case can be used to facilitate accurate positioning and lamination between the protective leather case and the smart terminal.

The present application relates to a protective leather case and a positioning device for protecting a smart terminal. The protective leather case includes a leather layer; an adhesive layer; and a positioning release film including a first release film and a second release film. The leather layer, the adhesive layer and the positioning release film are laminated sequentially. The first release film is provided in a first direction. At least two second release films are provided, and are arranged on both sides of the first release film in a second direction perpendicular to the first direction. The protective leather case can be used to facilitate accurate positioning and lamination between the protective leather case and the smart terminal.

A process for preparing a powder of a material of natural origin, which includes a step of treating a substance containing at least 70% by weight of one or more leather wastes in particle form in a twin-screw extruder, wherein a temperature profile is applied that increases from an initial temperature of between 10 and 40 C. up to a maximum temperature of between 60 and 120 C., in the presence of water in an amount such that the weight ratio of water to substance is between 0.20 and 6.