Plastic injection moulding of hypodermic needles

• Main Author: Ang, Poh Lin
• Other Authors: Ong Nan Shing
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Manufacturing::Polymers and plastics
• Online Access: http://hdl.handle.net/10356/16188
• Institution: Nanyang Technological University

Metal hypodermic needle is commonly used to perform in vivo drug delivery or blood extraction application. However, one of the most serious drawbacks such as the reuse of hypodermic needle becomes the major source of infections. Therefore, a concept of replacing the metal hypodermic needles with plastics is carried out in order to reduce the reuse of contaminated needles. This work presents the mold study, tooling design, fabrication and testing of plastic hypodermic needle by the mean of injection molding. Investigation and revising of existing mold design is a commonly used method for us to evaluate the prior deficiency. This can also stimulates our brainstorming process before proceeding to the conceptual design and finalized our embodiment layout if redesign of mold is necessary. Previous research has achieved on producing the surface configuration of plastic hypodermic needle but suffering from the problem of inconcentricity of its hollowed structure. Therefore, in this study, the approaches of achieving better efficiency of producing concentric plastic hypodermic needle are explored. Thus, the shearing effect as well as the penetration resistance on the interfaces of fluid and inner surface of needle is greatly reduced.