Process for the surface treatment of polymeric three-dimensional objects

A process for surface treatment of a three-dimensional object which has been produced in an additive manufacturing processes from at least one polymer, the process comprising:

• a) immersing the three-dimensional object in a substance mixture A,
• b) leaving the three-dimensional object in the substance mixture A for a time,
• c) removing the three-dimensional object from the substance mixture A,
• d) immersing the three-dimensional object in a substance mixture B,
• e) leaving the three-dimensional object in the substance mixture B for a time, and
• f) removing the three-dimensional object from the substance mixture B,
• wherein the substance mixture A has a temperature (process temperature A) which is above a melting point of the at least one polymer and wherein a liquid component of mixture A is at least one substance selected from the group consisting of an alkane, an arene, an alcohol, a siloxane, a sulfoxide and an alkene, and wherein the substance mixture B has a temperature (process temperature B) which is below the melting point of the at least one polymer;
• a surface tension difference between a surface tension of a liquid component of substance mixture A and a surface tension of said at least one polymer of the three-dimensional object is at most 10 mN/m,
• the substance mixture A contains at least 50 mass %, based on a total mass of substance mixture A, of at least one substance which is liquid at process temperature A, and
• the at least one substance which is liquid at process temperature A is immiscible with further liquid components of the substance mixture A.