Purification & Filtration
Producing purification processing materials reliably and quickly with repeatable quality is critical. Diamond America provides extrusion solutions designed for maximum production while maintaining the highest quality. And our design approach is quality focused, as we pay close attention to the specific and unique requirements of each customer, and maximize performance through unique enhancements. For example, by changing the geometry of screws, barrel liners, and feeders, unwanted friction is reduced, dead spaces eliminated and stagnation prevented to provide peak performance with improved energy efficiencies.
Standard bulk feed extruders can be used to produce most carbon blocks, or even table top extruders for smaller diameter cylinders, however, Diamond America is happy to design custom extruders for various carbon filter applications.
Design & Manufacturing Process
Carbon blocks, or extruded activated carbon (EAC) filters can be manufactured cost-efficiently in quantity by continuous solid-state extrusion. They can be designed to satisfy the performance requirements for water purification and the level of chemical removal desired by varying:
- Source & Quantity of Carbon - carbon can be derived from coal, wood or coconut shell.
- Particle Filtration Size – e.g. 85% of particles at 0.5 micron.
- Additives - e.g. alumina-type compounds for heavy-metal removal.
- Kinetics & Flow Rates - liquid through the block.
Once block composition has been determined, thorough testing and approval must be conducted on all component materials, as well as evaluation of the block’s performance as a chemical filter. As with all extrusion processes, components must be thoroughly mixed to ensure a homogenous final product, however, this is vitally important when forming carbon block filters. There are several patented processes for carbon filter extrusion, but most of them use barrel heating to produce a uniform cylinder of carbon which is then cooled and cut to length before assembly into a filter cartridge. Finished filter cylinders are made in diameters ranging from 1″ to 4.25″ and lengths from 2.5″ to 40″.
Extruded Activated Carbon filters are used for:
- water purification at point-of-use (POU)
- filtration of residential water supplies
- commercial water treatment
- pre-filters for chlorine removal in reverse osmosis (RO) systems
- purification of petroleum materials
- glycerin purification
- air purification substrates for diesel trucks
Other extrusion applications include:
- membrane processes in separation and purification – bulk ceramic substrates formed by extrusion of a ceramic paste
- vaccine purification – two polymers are extruded together to make multicomponent/bicomponent fibers
- air & water purification – co-extruded tubing for air purification systems and water lines
- gas purification – extruded honeycomb-type catalyst blocks of Vanadia/Titania

Extrusion Test Facility
Diamond America’s test laboratory is equipped with several table top extruders, ideal for small batch scaled production, as well as full scale twin feed extruders. Capabilities include new product process and formulation testing for all applications.
Experienced engineers are always available to assist with extruder customization, die design, system controls and the selection of associated extrusion equipment.