Consider the cartridge for an ink jet printer, a plug-in air freshener, a water purifier on your sink, or your dentist providing you with a teeth whitener procedure. What do these have in common? They all require custom porous plastic components. In fact, each of these products would fail to operate without their porous plastic components.

Sintered porous plastics are a semi-rigid, open-cell porous material whereby heat sinters together porous polymers such as polytetrafluoroethylene (PTFE), polyethylene (PE) and polypropylene (PP). The resulting part, which appears to be solid, is actually made up of thousands of tiny connecting pores.  These inter-connecting pores mean that the material is permeable to fluids. Permeability is adjusted, as needed, by controlling the pore size which enables the part to be used as a filtering, wicking, venting, or diffusing mechanism, depending on the need. Typically, the proportion of the open material, called the void volume, is 30-50% although materials may be produced with void volumes as high as 70% for special applications. The ability to produce plastics with a well-defined pore size distribution, combined with a material exhibiting excellent robustness and chemical resistance, has meant that sintered porous plastics may be widely adopted for a diverse range of applications.

Some of the specific applications include:

  • Vents and self-sealing valves for medical devices, caps and closures, and vehicle batteries
  • Liquid filters for clarification of drugs, blood separation, and chemicals
  • Hydrophobic barrier vents for lab instrumentation
  • Hydrophilic media for fluid delivery applications
  • Wicks and absorbent media for diagnostic testing
  • Fluid delivery components for printers, marking systems, applicators, copiers, and more
  • Wicks for fragrance delivery products and systems
  • Filters for air and water purification
  • Air, dust, liquid, and fuel filters for power tools and appliances
  • Barrier vents for gas, pressure and humidity sensors

Advantages of Sintered Porous Plastic

Porous plastics have excellent resiliency, high physical strength and are light-weight, providing a rugged easily-handled part. They retain most of the physical properties of solid equivalents yet offer a set of unique properties. The nature of the material’s filtration path produces high filtration efficiency that combines properties of surface and depth filters whereby filtration efficiencies of 99.8% can be achieved.

  • Lower Cost
  • Inexpensive Tooling
  • Repeatable Performance - controlled porosity
  • Sterilizable
  • Chemically Resistant - to most acids, bases, solvents and hydrocarbons
  • Excellent Corrosion Resistance
  • High Purity - FDA/USDA approved resins
  • High Strength, Light Weight - friendly to assembly requirements
  • Dual Filtration Capabilities - acts as both a surface and depth filter
  • Hydrophilic, Hydrophobic, or Self-Sealing Properties

Our Research & Development

Polystar Technologies' Research and Development team has developed novel, active polymer structures that are:

  • ion selective
  • anti-microbial
  • chemically reactive
  • protein adsorptive
  • hydrophilic, hydrophobic, or oleophobic
  • self-sealing
  • activated with C18

By partnering with Polystar Technologies and using our unique PolySmart™ technology, we will help you to create components to fit every shape, size, and function that will precisely perform for your products needs.