个性化聚醚醚酮颅骨植入物多点柔性注塑工艺
Multi？？Point Flexible Molding for Personalized PEEK Skull Repair

针对目前增材制造聚醚醚酮(PEEK)个性化颅骨植入物强度远不如注塑工艺的问题,提出了增材制造与注塑工艺相结合的新方法――多点柔性注塑工艺。首先,将连续的平面离散化,采用增材制造靠模的方式,使用大量的活动方形钢针完成柔性模具形腔内表面的构建;其次,用注塑的方式制造PEEK个性化颅骨植入物;最后,研磨抛光去除台阶效应,获得高性能的PEEK个性化颅骨修复植入物。通过工艺分析、精度分析和体外细胞毒性实验进行研究评价,结果表明:采用该方法制作出的颅骨模型样品的平均偏差为0.475~-0.409 mm,所制作的拉伸样件的强度为72？？15～83？？26 MPa,可以满足颅骨修复植入物对于精度和力学性能的要求。在体外细胞毒性实验中,注塑原料组和试制样品组浸提液所培养的细胞存活率均达90％以上,证明了多点柔性注塑工艺所使用的材料无毒,在注塑成形过程中没有引入新的毒性物质,可以满足颅骨修复植入物对于生物相容性的要求。因此,该方法可制造出低成本、高性能、无细胞毒性的个性化颅骨修复植入物,在颅骨修复中具有重要的应用前景。
Since the strength of personalized poly？？ether？？ether？？ketone(PEEK) skull implants fabricated by material increasing manufacturing is lower than that by injection molding, a novel method of multi？？point flexible molding is proposed to solve this problem by combining injection molding with material increasing manufacturing. The continuous planes are discretized, and a large number of movable square needles are used to construct the flexible molding cavity surface by means of profiling. A personalized PEEK skull blank is then fabricated by injection molding, and the personalized PEEK skull implant is fabricated after the blank is polished. It is found that the average accuracy of the skull samples is in the range from 0.475 to -0.409 mm, and the tensile strength of the samples is within 72.15 MPa and 83.26 MPa, which can meet the requirement of implant for accuracy and mechanical property. In the cell toxicity experiment, the survival rates of the cells in the raw material leach liquor and the injection sample leach liquor are detected higher than 90％, which proves that the material used in multi？？point flexible molding is nontoxic, and no new toxic substances are introduced into the injection molding. So multi？？point flexible molding can meet the requirement of implant for biocompatibility. The method of multi？？point flexible molding can be chosen to fabricate personalized skull with lower cost and perfect performance, especially, without cytotoxicity