Surface treatment method for objects

Abstract

A surface treatment method of an object, including the following steps immersion of the object in a solution containing an acid or a mixture of acids, and having a pH between 0 and 6, so as to impregnate the surface of the object, removal of the object from the acid solution, and heating of the object to a temperature between 50 C. and the melting temperature of the object, until the required gloss and roughness surface properties are obtained, the method is particularly but not exclusively applicable to objects derived from additive manufacturing techniques.

Claims

1. Surface treatment method for an object, characterized in that it comprises the following steps: immersion of said object in a solution containing an acid or a mixture of acids, and having a pH between 0 and 3, so as to impregnate the surface of said object and activate the surface so as to define a transition between the surface and a core of said object characterized in that the surface has a lower melting temperature than the core of the object; removal of said object from said solution; heating of said object, dependent on formation of the transition, to a temperature between 120 C. and the melting temperature of the surface of said object, effecting melting the activated surface until the required gloss and roughness surface properties are obtained.

2. Surface treatment method for an object according claim 1, characterised in that said solution comprises one of the following inorganic acids: sulphuric acid, nitric acid, phosphoric acid and hydrochloric acid.

3. Surface treatment method for an object according to claim 1, characterised in that the immersion step is improved by applying a heat treatment and/or a mechanical treatment.

4. Surface treatment method for an object according to claim 1, characterised in that it also comprises a step of eliminating surplus liquid in the presence of at least one organic or aqueous solvent.

5. Surface treatment method for an object according to claim 4, characterised in that the step of eliminating the surplus liquid follows a mechanical process.

6. Surface treatment method for an object according to claim 4, characterised in that the step of eliminating the surplus liquid is done by applying a centrifugal force to said object.

7. Surface treatment method for an object according to claim 4, characterised in that the step of eliminating the surplus liquid is done by applying a pressurised gas flow.

8. Surface treatment method for an object according to claim 1, characterised in that said heating step is performed using a forced convection heating system.

9. Surface treatment method for an object according to claim 1, characterised in that at least one washing step is done on said object in the presence of a solvent or a mixture of solvents.

10. Surface treatment method for an object according to claim 1, characterised in that said solution also comprises additives deposited on the surface of the object during said immersion step.

11. Surface treatment method for an object according to claim 1, characterised in that it is applied to an object derived from additive manufacturing techniques.

12. Surface treatment method for an object according to claim 1, characterised in that it is applied to an object including at least one polymer.

13. Surface treatment method for an object according to claim 12, characterised in that it is applied to an object made of polyamide.

14. Surface treatment method for an object according to claim 1, characterised in that said immersion step is accompanied by physicomechanical processes conducive to impregnation.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The disclosed embodiment will be better understood after reading the following purely explanatory description of one aspect of the disclosed embodiment with reference to the figures in which:

(2) FIG. 1 illustrates the different steps in the method according to this disclosed embodiment,

DETAILED DESCRIPTION

(3) This disclosed embodiment relates to a surface treatment method of an object, for example made of polyamide, particularly but non-exclusively derived from additive manufacturing techniques.

(4) The method according to this disclosed embodiment comprises the following steps: Immersion of the object in a solution containing an acid or a mixture of acids, and having a pH between 0 and 6, so as to impregnate the surface of said object; Removal of the object from said acid solution; Heating of the object to a temperature between 50 C. and the melting temperature of the object, until the required gloss and roughness surface properties are obtained.

(5) FIG. 1 illustrates the different steps in the method according to this disclosed embodiment: impregnation, drying, heating and cooling, these different steps relating to the object that, in one aspect of the disclosed embodiment, is derived from additive manufacturing techniques.

(6) In one aspect of the disclosed embodiment, said method is applied to an object made of polyamide.

(7) In one aspect of the disclosed embodiment, the acid solution has a pH of between 0 and 3.

(8) In one aspect of the disclosed embodiment, the acid is an inorganic acid, and in one embodiment the acid is chosen from among the group including sulphuric acid, nitric acid, phosphoric acid and hydrochloric acid.

(9) In one aspect of the disclosed embodiment, said object is heated to a temperature equal to between 120 C. and the melting temperature of said object.

(10) In one aspect of the disclosed embodiment, the method according to this disclosed embodiment also comprises a step in which surplus liquid is eliminated.

(11) In one aspect of the disclosed embodiment, the step of eliminating the surplus follows a mechanical process.

(12) In another aspect of the disclosed embodiment, the step of eliminating the surplus is done by applying a centrifugal force to said object.

(13) In another aspect of the disclosed embodiment, the step of eliminating the surplus is done by applying a pressurised gas flow.

(14) In one aspect of the disclosed embodiment, the heating step is implemented using a forced convection heating system, providing better uniformity of heating.

(15) In one aspect of the disclosed embodiment, the impregnation solution also comprises additives, and according to one embodiment, additives are deposited on the surface of the object during the immersion step, which confers additional properties on the surface of the object.

(16) In one aspect of the disclosed embodiment, at least one washing step is done on said object in the presence of a solvent or a mixture of solvents.

(17) One particular application of this disclosed embodiment lies in objects comprising a polyamide, but it is also applicable to objects comprising other polymers such as for example polyethylene, polyvinyl chloride, polyurethanes, polyesters, polypropylenes and polyethylenes.

(18) The disclosed embodiment is described above as an example. It will be understood that an expert in the subject will be capable of making different alternatives to the disclosed embodiment without going outside the framework of the patent.