Purpose

The use of laser sintering (LS) in the medical sector has increased dramatically in recent years. With the move towards direct use of these parts in clinical applications, there is a greater need to understand the effects of standard processes on the part properties. The purpose of this study is to determine the effect that steam sterilisation has on the mechanical properties of LS polyamide 12 parts.

Design/methodology/approach

The research presented here focusses on the effect of a single steam sterilisation cycle on the mechanical properties of polyamide 12 parts manufactured using LS. The influence of water content on the properties was investigated, with additional drying steps trialled to establish the potential to reverse any changes observed and to determine their root cause.

Findings

The results show that steam sterilisation has a significant effect on the mechanical properties of LS polyamide 12 parts, with a 39% reduction in elastic modulus, a 13% decrease in ultimate tensile strength and a 64% increase in the elongation at break. These properties were also all found to correlate with the water content, suggesting that this was the cause of the difference. The original properties of the parts were able to be recovered after oven drying.

Practical implications

These results show that with an additional drying step, LS polyamide 12 parts can be steam sterilised with no effect on the mechanical properties.

Originality/value

This is believed to be the first investigation into the effects of steam sterilisation in isolation on LS polyamide 12 parts, the first instance of drying parts to recover mechanical properties and the first instance of multiple water content measurements being directly linked to the mechanical properties.

中文翻译：

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蒸汽高压灭菌对激光烧结聚酰胺12的影响

目的

近年来，激光烧结（LS）在医疗领域的使用急剧增加。随着这些零件在临床应用中的直接使用，越来越需要了解标准工艺对零件性能的影响。这项研究的目的是确定蒸汽灭菌对LS聚酰胺12零件的机械性能的影响。

设计/方法/方法

这里介绍的研究集中在单个蒸汽灭菌循环对使用LS制造的聚酰胺12零件的机械性能的影响上。研究了水含量对性能的影响，并尝试了其他干燥步骤，以建立逆转所观察到的任何变化并确定其根本原因的潜力。

发现

结果表明，蒸汽灭菌对LS聚酰胺12零件的机械性能有显着影响，弹性模量降低39％，极限拉伸强度降低13％，断裂伸长率提高64％。还发现这些性质均与含水量相关，表明这是差异的原因。烘箱干燥后，零件的原始性能得以恢复。

实际影响

这些结果表明，通过额外的干燥步骤，可以对LS聚酰胺12零件进行蒸汽灭菌，而不会影响机械性能。

创意/价值

据信，这是首次对隔离蒸汽灭菌对LS聚酰胺12零件的影响进行的研究，这是干燥零件以恢复机械性能的第一例，并且多次测量水分含量与机械性能直接相关的第一例。