The impressive growth of the medical device, biomedical and healthcare industries over the past 15 years continues unabated even as materials such as fluoropolymers are meeting the increasingly challenging demand for new products and procedures.
In general, fluoropolymers are progressively replacing other plastics in medical applications owing to their ability to meet the physical and biocompatibility requirements of the next generation drugs and devices. Fluoropolymers meet a unique set of performance criteria in such applications. These include biocompatibility, lubricity, sterilization, chemical inertness, a wide temperature use range, low binding to process equipment, high-purity with low extractables, dielectric properties, and USP Class VI certification.
The family of available fluoropolymers that meet the above needs include grades of PTFE, FEP, PFA and PVDF resin from various resin producers. PTFE(polymer) has a well-established implant history of soft tissue replacement due to its biocompatibility and inertness. Resin and downstream product manufacturers continue to respond to new performance requirements by making appropriate modifications to the chemistry of the resin and surface configuration of the products, respectively.
The biocompatibility of any polymer is a principal requirement in any medical device such as catheters, bio-containment vessels, syringes and sutures. PTFE, FEP and PVDF are well established biocompatible materials, and their lubricity and chemical resistance make them the material of choice for products such as multi lumen tubing and others that are used in minimally invasive procedures. Multi lumen fluoropolymer catheter tubing for example allows surgeons to perform multiple procedures using the same catheter.
Fluoropolymers, especially PTFE(polymer)and PVDF are widely used in microporous membranes. Membranes, containing billions of pores ranging in size from 0.01 to 10 microns act as filters for particles and bacteria in critical fluids. PTFE and PVDF are among the few polymers used for filter membranes. The surfaces of the polymers membranes can be modified to deliver specific filtration properties and can be hydrophobic (water repelling) and oleophobic (oil, solvent, low surface tension fluid repelling). PVDF membranes can be also be surface modified to be hydrophilic (water loving) for removal of viral particles in the manufacture of therapeutic proteins and monoclonal antibodies. PVDF blotting membranes are particularly well suited for low background immunoblotting (western blot analysis), as well as for amino acid analysis and protein sequencing.
Accessory equipment, such as pumps, tubing, fittings used in conjunction with medical devices must meet similar performance and specification parameters. Accessories in direct contact with fluids are constructed of fluoropolymers such as PTFE and PVDF. For example, metering pumps such as diaphragm pumps are required for precise and repeatable flow, sometimes for chemically aggressive fluids. Both PTFE and PVDF tubing are used in the construction of these pumps for this reason.
PVDF, although having a lower use temperature limit than PTFE(polymer), has a relatively high tensile strength and excellent permeation resistance to many fluids. It has a lower density (1.78 g/cc) than other fluoropolymers (approximately 2.18 g/cc). Due to a lower melting temperature than other fluoropolymers, it is more easily processible into products such as pipes, tubes, injection molded parts and films. It offers excellent dimensional and UV stability and is therefore finding new uses in aerospace, sensors, biotechnology and robotics markets.
Post time: Aug-06-2018