Breakage and deformation characteristics of japanese and U.S. manufactured hypodermic needles under static and dynamic loading

摘要

Physical hazards, such as broken hypodermic needles, are one of the concerns meat packers must address with their Hazard Analysis and Critical Control Points (HACCP) plans. Characterization of the strength of hypodermic needles and their strength limitations may reduce the risk of leaving broken needles in the flesh of animals. Needles and needle/hub assemblies were investigated for strength and breakage susceptibility. Stainless steel needles of various gauges combined with aluminum and plastic hubs were subjected to standard test-stand conditions to compare strength under various loading regimes. A device that simulated animal motion was also constructed to test breakage characteristics during animal movement. Results indicated that needles and needle/hub assemblies were very resilient to needle breakage, except when bent needles were straightened and a load reapplied. Needle gauge and needle length drastically affected needle strength. For 16 and 20 gauge needles, a 1.0 inch needle was 1.6 times stronger than a 1.5 inch needle. Adding animal movement for 20 gauge, 1.5 inch needles, resulted in a 40 percent increase in hub failures for plastic compared to aluminum hub needles. Japanese 1.8x30 mm needles were investigated for strength and breakage susceptibility. Stainless steel needles of 16 ga (1 1/2 inch length) from two US manufacturers combined with aluminum and plastic hubs were compared to the Japanese needles by subjecting each to standard teststand load conditions to compare strength in various loading regimes. A device that simulated pig motion was also used to test breakage characteristics assuming an animal moved during the injection process. There were significant differences in strength and breakage characteristics between the two country's needles. The Japanese needles were statistically significantly more resistant to bending or breaking