直立式聚丙烯输液袋壁厚度对输液性能影响的数值研究

目的研究直立式聚丙烯输液袋（简称直立式输液袋）壁厚度对袋体输液性能的影响，寻求输液袋各参数随壁厚度改变的变化规律。方法针对标示容量为100、250、500mL3种直立式输液袋，分别设置4种不同壁厚度（n2、n3、0．4、0．5mm），采用有限元方法模拟排液过程．研究直立式输液袋应力分布、实际加药空间及排空率等参数的变化规律。结果在标示容量一定的条件下．100mL的直立式输液袋应力随壁厚度变化不显著；250mL直立式输液袋随壁厚度的增加应力逐渐减小．最大应力降幅为65％：500mL直立式输液袋壁厚度为0-2～0．3mm时，应力变化不明显，而壁厚度由0．3mm到0．5mm，最大应力下降28％。3种直立式输液袋的实际加药空间、排空率和袋壁接触面积均随壁厚度的上升而降低，100mL直立式输液袋为27％、11％和67％，250mL直立式输液袋为54％、11％和38％，500mL直立式输液袋为49％、11％和43％。结论综合考虑应力分布、实际加药空间、排空率和袋壁接触面积等参数的变化规律，直立式输液袋壁厚度不宜过大。在所考虑的壁厚度参数中．最佳壁厚度为0．2mm，但最终的壁厚度确定还需要综合考虑直立式输液袋的透气、透湿性和抗穿刺能力等因素。

Numerical study on performance effect of wall thickness in upright polypropylene infusion bag

Objective To investigate the effect of wall thickness in upright polypropylene infusion bag on discharging process, and seek the change law of the parameters in infusion bag with the variation of wall thickness. Methods Four different wall thickness（0.2 mm, 0.3 ram, 0.4 mm and 0.5 mm） with the volume of 100 mL, 250 mL and 500 mL were performed, which based on finite element method to simulate the discharging process and analysis the variation of stress distribution, emptying rate and actual drugging space. Results Under the condition of same volume, the stress of 100 mL infusion bag showed no significant change. The 250 mL infusion bag decreased with the increasing of with wall thickness,the decreasing range of the maximum stress with wall thickness was 65 %. For 500 mL infusion bags, there was no obvious changed in stress with wall thickness of 0.2 - 0.3 ram, however,the maximum stress had decreased 28 % in wall thickness of 0.3 - 0.5 mm. Actual drugging volume, emptying rate and contact area decreased with the increasing of wall thickness, the respective decreasing amplitude were as follows： 100 mL 27 %,11% and 67 %; 250 mL, 54 %, 11% and 38 %; 500 mL, 49 %, 11% and 43 %. Conclusion It is demonstrated that for comprehensive consideration of stress distribution,actual drugging volume, emptying rate and contact area, lower wall thickness is recommended for upright polypropylene infusion bag. The best wall thickness is 0.2 ram. However, the ultimate wall thickness should be determined by further study on air permeability, moisture permeability, anti-puncture capacity and other factors of infusion bags.