Abstract: A method for increasing at least one of the following two parameters of a polyamide: (I) its melting point and (ii) its enthalpy of melting ?Hm, in which: this polyamide is brought into contact in the solid state with water or with steam at a temperature close to its crystallization temperature Tc for a time long enough to effect this increase; then, the water (or steam) is separated from the polyamide and the polyamide is dried.

Abstract: The present invention is a method for covering an object with a film resulting from the melting of a thin layer of powder, in which method comprises: (a) having a bed of electrified fluidized powder in a tank, this powder being charged by a forced-circulation tribocharging device; (b) dipping the object, connected to zero or sufficient potential, into the tank in order to cover it with powder; (c) placing the object, covered with the powder, in an oven at a temperature high enough to obtain the coating film by melting the powder. According to one advantageous embodiment of the invention, the oven includes electrodes raised to a high electrical potential so as to cause a corona effect which compensates for the relaxation of the charge on the powder particles while they are being heated. The charge on the particles is maintained and therefore they remain on the object and thus can form the film by melting. The present invention also relates to the apparatus for implementing the method.

Abstract: The present invention relates to a method for increasing at least one of the following two parameters of a polyamide: (i) its melting point and (ii) its enthalpy of melting &Dgr;Hm, in which: