Method for modifying 3D printed object

A method of modifying an article comprises the steps of: I) providing an article constructed at least in part from a build material comprising a thermoplastic polyurethane. The method further comprises the steps of: II) contacting the build material at least in part with a first liquid comprising > = 80% by weight, based on the total weight of the first liquid, of a polar aprotic solvent for a first predetermined duration; iII) contacting the region of build material in contact with the liquid in step II) with a second liquid comprising > = 80% by weight, based on the total weight of the second liquid, of a polar protic solvent for a second predetermined duration. Preferably, the first liquid is DMSO or acetone, and the second liquid is water. 对物件进行改性的方法包括步骤：I)提供至少部分由包含热塑性聚氨酯的构建材料构建的物件。所述方法还包括步骤：II)使构建材料至少部分与包含基于第一液体的总重量计≥80重量%的极性非质子溶剂的第一液体接触第一预定持续时间；III)使在步骤II)中与液体接触的构建材料区域与包含基于第二液体的总重量计≥80重量%的极性质子溶剂的第二液体接触第二预定持续时间。优选地，第一液体是DMSO或丙酮，且第二液体是水。