We previously reported on needle damage to needles sterilized 50 times. This time we increased the number of sterilizations to 100 times and investigated needle damage. damage.
Sterilization was performed using a small high pressure steam sterilizer at a temperature of 126°C for 25 minutes each time.
1. Non-gold or silver needles had a tendency to become finer but there was no remarkable weight change noted.
2. Resistance to bending tests showed that Chinese needles become more difficult to break.
3. Elasticity tests showed that non-gold needles become easier to restore to their original state.
4. Insertion tests showed that some needles, especially Chinese needles and stainless steel No. 3 needles, become more difficult to insert smoothly.
5. Hardness and sturdiness tests showed a general decrease in both factors with the exception of hard silver No. 3 needles and Chinese needles which become sturdier.