The properties of the material(paraformaldehyde) for use in tissue ligating closure clips

The properties of the material(paraformaldehyde) for use in tissue closure clips 

Physical properties: POM is a thermoplastic crystalline polymer with a density of about 1.42g/cm³, with high steel and wear resistance. It has a small coefficient of friction, good self-lubrication, not easy to absorb moisture, water absorption rate of 0.22 to 0.25%, and good dimensional stability in a humid environment.

Processing characteristics: POM usually do not need to dry before processing, but in the process it is best to preheat (about 80 ℃), which helps to maintain the stability of product dimensions.POM's processing temperature range is narrow (0 ~ 215 ℃), in the cylinder stay time POM has a narrow processing temperature range (0～215℃), and it will decompose when it stays in the cylinder for too long or when the temperature exceeds 220℃, producing irritating formaldehyde gas. The holding pressure during injection moulding should be larger to reduce the pressure drop, the screw speed should not be too high, and the amount of residue should be less.

Application in tissue closure clips: Tissue closure clips made of POM material have good biocompatibility and stability, and are suitable for surgical clamping of blood vessels or closure of tubular tissues, including small and medium-sized arteries, bile ducts and so on. Its design includes elastic hinge, bowed nail leg, buckle lock, rondel and integrated non-slip teeth to ensure firmness of ligation and convenience of operation. In addition, the closure clip made of POM material is free of show and artefacts during MRI and CT examinations, ensuring the accuracy of the examination results.

In summary, the use of POM material in tissue closure clips has excellent physical properties, processing properties and biocompatibility, and is suitable for a wide range of surgical vascular and tissue ligation needs.