Parker Support Community
  • About the Community

    The Parker Community is a knowledge base for anyone using or interested in using the company's technologies, products, and systems. Read more...

  • Ask A Question

    If you have a specific question, you can ask it here or ask it within the appropriate technology group.

  • Community Terms of Use

    Parker encourages all users of its social media sites, pages, channels and community to communicate and engage in a constructive, meaningful and professional way. Read more...

Latest Blog Posts

Electromagnetic Compatibility in Next Gen Autonomous Vehicles, Parker Chomerics, POWERING THE FUTURE OF EVs For more than 100 years, the car has simply been used as a device for transporting a driver and passengers from point A to point B at speed with minimum effort.  

With the introduction of Advanced Driver Assistance Systems (ADAS) and other semi-autonomous driving technologies, a different concept of the vehicle is emerging. In the future, the car will be a media playback center, telephone, office and extension of the home’s living room which also happens to be able to convey passengers from A to B.

This is having a profound effect on the characteristics and on the sheer number of electronics systems in new vehicles and this in turn will dramatically extend the demands on the EMI shielding devices used to attenuate the radiated emissions that could affect circuits in the car. EMI shielding materials will need to perform over a wide range of frequencies, in more applications as electronic systems take over more and more aspects of the car’s driving operations, while adding as little as possible to the weight of the vehicle.   

The time for OEMs to consider the options for achieving EMC in new car designs is at the start of a new design project, before the electrical and mechanical features of the vehicle’s systems have been decided. This gives design engineers the opportunity to bring considerations of EMI and shielding devices into the design process and enable optimization of the size, cost and performance of EMI shielding in the final system. 

Top challenges of next generation 5G networks
  • The first challenge for automotive design engineers is the range of frequencies that need to be attenuated will be far greater in new cars than it was in the past. Until recently, the main frequencies of interest were the AM and FM bands used by radio and frequencies below 3GHz used by Bluetooth radio and mobile phone networks.

    With the future introduction of 5G mobile phone network coverage, frequency coverage of EMI shielding materials will need to be extended. A higher frequency range is not the only issue. Cars are also going to support a much greater number of wireless communications systems within the vehicle.

New strict measures to attenuate RF emissions in compliance with safety standards
  • The second challenge is that the effectiveness of EMI shielding is likely to be more tightly specified in the future as automotive manufacturers move towards a strict view of the functional safety of the electronics systems in cars, codified in the ISO 26262 functional safety standard.

    So, what does this mean for the specification of EMI shielding materials?

Continuous development of new elastomer fillers

Parker Chomerics maintains an intensive research and development program aimed at producing new filler materials for electrically conductive elastomer products. An important goal for this research program is to produce EMI gaskets that can cover the broader frequency range of interest in autonomous vehicles, while maintaining the desirable mechanical characteristics. Parker Chomerics CHO-SEAL conductive elastomers are widely used in automotive systems and offer useful properties, including resistance to high temperatures and contaminants, and the ability to provide environmental sealing to protect circuits from the ingress of liquids.

These elastomer gaskets resist compression set, accommodate low closure force, and help control air flow. They are available in standard sheet form, extruded or custom shapes. 

In addition, Parker Chomerics CHOFORM Form-In-Place automated EMI gasket material can be dispensed directly onto castings, machined metal and conductive plastic and is widely used in tightly packed electronic housings. This advanced technology allows dispensing of precise positioned gaskets in very small cross sections and can free up valuable packing space of up to 60%. CHOFORM offers excellent shielding effectiveness which exceeds 100dB between 200 MHz and 12GHz.

New opportunities for weight saving

The development of autonomous and semi-autonomous vehicles is leading to a huge increase in the number of electronics modules per vehicle. This increases the scope for car makers to reduce weight by replacing conventional metal housings with lighter conductive plastic housings. While the weight saving on each module might appear small, when multiplied across the 100 or more electronics modules, the total weight saving becomes invaluable.

Parker Chomerics PREMIER™ PBT-225 is a single-pellet conductive plastic for use in automotive housings. PREMIER PBT-225 offers excellent resistance to hydrolysis when exposed to extreme temperatures and provides for easy processing and uniform filler dispersion. As a result, EMI housings made from PBT-225 offer tightly controlled electrical and mechanical performance throughout complex geometries. A weight saving of 30% is also possible when replacing an equivalent metal or aluminium housing with PBT-225.

By collaborating early in development projects with Parker Chomerics, automotive system designers can ensure that their electronic and mechanical design is optimized for shielding purposes.

Learn more about Parker Chomerics EMI shielding and thermal solutions for the automotive Industry.








Mel French 


This blog post was contributed by Mel French, marketing communications manager, Chomerics Division Europe. 





Related content:

Five Ways to Maximize Performance of Electric Vehicle Batteries

Design Decisions Relating to EMC Shielding

Improved EMI Shielding Consistency of Single Pellet Conductive Plastics


Electromagnetic Compatibility in Next Gen Autonomous Vehicles

Read more

Honeycomb EMI Vent PanelsHoneycomb air ventilation panels are used in applications where superior electromagnetic interference (EMI) shielding must be incorporated with heat dissipation in the form of airflow. Every vent panel has a variety of design features, each providing benefits to end customers based on specific application needs. These design features can include framing, plating/painting, gasketing, and vent size control.

An often overlooked but highly important phenomenon to consider when designing EMI vent panels is that of polarity.

Polarity is the difference in EMI shielding of honeycomb in different X/Y directions.

What this means is that honeycomb vents can have differences in shielding effectiveness, sometimes as great at 50 dB, depending on the direction of the electromagnetic waves. 

For example, a basic aluminum honeycomb vent may provide shielding of 70 dB in the horizontal direction while only providing shielding of 25 dB in the vertical direction. This characteristic is due to the manufacturing process of standard aluminum honeycomb vent panels.

Basic aluminum honeycomb is created using thin ribbons of aluminum that are bonded using a non-conductive adhesive. Polarity is associated with seam leakage caused by the non-conductive bonds from cell to cell created during the manufacturing process of adhering aluminum ribbons together to make the honeycomb. While thin, this non-conductive gap is the cause of difference in shielding effectiveness (SE). It is important to note that polarity is only an issue for aluminum vents, not for steel, stainless steel, and brass honeycomb due to a different manufacturing process (steel and brass honeycomb use a welding process, eliminating the non-conductive gap). The below graph demonstrates the significant difference in shielding effectiveness in the horizontal and vertical directions.

Straight Cell Vent - No Plating














Fortunately, there are several solutions to combat this polarity issue:

Layered vents

With the addition of a second layer of honeycomb, offset at a 90-degree angle, the polarization effect can be dramatically reduced. The Chomerics term for these layered vents is Omni Cell. By rotating the second layer of honeycomb 90 degrees, RF wave interaction in both the X and Y axes are combated by the seam orientation of each layer of honeycomb. This means that while the electromagnetic waves may pass through one layer of the honeycomb, the offsetting layer will not allow them to pass through the entire vent assembly. Of note, airflow through the vent is not significantly impacted, allowing for enough heat dissipation. 

Omni Cell Vent Shielding Effectiveness














While the maximum shielding effectiveness of the Omni Cell vents is nearly identical compared to that of a single layer vent, the directional consistency is instantly noticeable. There is no longer a difference in the horizontal and vertical shielding effectiveness, with the offsetting layers eliminating the polarity effect.


Electroless nickel plating is an ideal plating option to combat polarity on aluminum vents. The nickel plating covers the non-conductive bonds and eliminates seam leakage between aluminum ribbons. The nickel plating electrically connects the aluminum ribbons which overcome the non-conductive adhesive.  Not only does nickel plating effectively eliminate the polarity effect, it increases the durability of the vents and improves their lifespan in harsh environments.

Straight Cell Vent Shielding Effectiveness















As with Omni Cell vents, the polarization effect is eliminated with the vent exhibiting nearly no difference in shielding between horizontal and vertical testing. A properly plated vent will also increase the SE of the entire honeycomb array, creating conductive contact between every individual aluminum ribbon in the assembly. The nickel plating also improves the electrical connection of the honeycomb to the frame if the plating process is done after assembly.

Based on the above graphs, a conclusion can be made about the techniques used in eliminating the polarity effect. Since the plating process can eliminate the polarization effect AND increase the SE, this approach is most common. Omni Cell construction is effective if it meets the desired shielding effectiveness level. It is rare to see a nickel plated Omni Cell vent.

Individual project specifications such as airflow requirements, shielding performance, environmental exposure, budget and a myriad of others will drive the design process of EMI shielding honeycomb ventilation panels, but it is important to know about principles such as polarity in making final considerations. 


Application and Design Guide to EMI Shielding Honeycomb Vents








Ben Nudelman Parker Chomerics



Article contributed by Ben Nudelman, market development engineer, Parker Chomerics Division.




  Related content:

Top Three Design Tips for Corrosion Resistant EMI Protection

Solving EMI Issues in Mobile Electronic Devices

What Are Electromagnetic Interference and Electromagnetic Compatibility Measurements, and Why Do We Care?


Honeycomb Air Ventilation Panels – The Polarity Principle

Read more

Pleated Filter Elements Improve Dust Collection for the Foundry Industry - Conversion to pleated filter elements - Parker HannifinBusiness growth creates new challenges. This is the case for plant engineers and maintenance managers responsible for the efficient operation of the most common form of dust collection equipment — pulse-jet baghouses — used in foundries across the globe. Many baghouses were designed and built to accommodate a certain amount of air flow that was sufficient for past demands. As foundries have increased production, these flow requirements have amplified and the original design of the baghouses are no longer suitable. Their obsolescence is perpetuated by raised scrutiny on emissions and the focus on the business community’s responsiveness as good corporate neighbors and stewards to a sustainable environment.

In this blog, we will explore pleated filter element (PFE) technology and examine how two foundries successfully upgraded their pulse-jet dust collectors by installing PFEs, resulting in: 

  • Increased air volume.
  • Improved filtration efficiency.
  • Reduced emissions.
  • Lower overall plant maintenance requirements. 


Pleated Filter Elements Improve Dust Collection for the Foundry Industry - Foundry Process - Parker Hannifin


Pleated Filter Elements Improve Dust Collection for the Foundry Industry - download the case study - Parker Hannifin



To read about more successful upgrades in a variety of foundry application processes, and for details on PFE performance testing, download the full case study.





The Environmental Protection Agency (EPA) and Occupational Safety & Health Administration (OSHA) regulations have become increasingly more stringent, requiring foundries to upgrade their current operational ventilation systems to comply with regulatory standards. Foundries have evaluated their furnaces, shakeout, pouring and cooling lines, sand handling systems, finishing areas and many other parts of their operations reliant on pulse-jet dust collectors for proper ventilation. Their evaluations have found a multitude of problems, including:

  • High air-to-cloth ratios.
  • Emissions caused by poor media filtration efficiency.
  • Inlet abrasion of filter bags.
  • Low air volumes at source due to excessive baghouse differential pressures.
  • Loss of production due to filter bag changeout downtimes.
  • High upward (interstitial) velocities between filter bags, resulting in ineffective cleaning. 
  • Pulse cleaning systems consume large volumes of compressed air.

As a result, foundries are looking for ways to upgrade their dust collection. The most economical and preferred option is to modify existing baghouses rather than installing completely new systems, which would require significant capital investment. PFEs provide an effective solution to this challenge.

PFE technology optimizes existing systems

Pleated filter elements, such as those manufactured by Parker Hannifin, are filters that use either a molded polyurethane or metal top and bottom that are used as direct replacement for standard felted filter bag and cage assemblies in pulse-jet baghouses, as well as in new equipment. Spun-bonded polyester fabric is the most common media used in PFEs because of its tight pore structure and rigid physical properties that allow it to hold a self-supported pleat —providing as much as 200 to 300% more filtration area at 99.992% efficiency than a filter bag in the same tubesheet hole.

Pleated Filter Elements Improve Dust Collection for the Foundry Industry - Pleated Filter Elements Materials of Construction - Parker Hannifin

Successful applications of PFE Induction furnaces

A major Midwest foundry used a three-compartment, 882-bag shaker baghouse to ventilate four induction furnaces, a scrap preheater system, and a magnesium inoculation station. The foundry struggled with the following problems in its dust collection system:

  • Twelve-month filter bag life.
  • High differential pressure due to media binding caused by particulate loading.
  • Loss of ventilation air in the furnace area.
  • Excessive emissions.
  • High labor costs associated with keeping the old system operational.

As a solution, the company converted the original shaker system to an engineered pulse-jet style cleaning system using BHA® PFEs manufactured by Parker Hannifin's Industrial Gas Filtration and Generation Division. The baghouse was retrofitted with a new tubesheet and a walk-in clean air plenum, to allow for a top-load design filter element. The baghouse has been operating consistently since the retrofit.

Since the retrofit, the baghouse has been operating consistently and the following results have been reported:

  • Upgraded air volume from 28,000 CFM to the required 55,000 CFM.
  • The amount of compressed air required for pulse-jet cleaning has been reduced from 60% to 40%.
  • Stack testing has confirmed that performance easily meets new environmental regulations.
Pleated Filter Elements Improve Dust Collection for the Foundry Industry - Shaker style dust collector with woven filter media vs. pleated filter elements - Parker Hannifin Finishing area

A large foundry that manufactures castings for the automotive industry had a top-load design pulse-jet baghouse that contained 650 felted filter bags and cages. The unit ventilated several shot blast cabinets, grinders, and other finishing equipment. The system was originally designed at an air-to-cloth ratio of 6.1:1. The filter bags measured 5.25 in. in diameter by 12 ft. in length, for a total cloth area of 16.5 ft2 per filter bag. The challenges the foundry was experiencing with the current design were:

  • Bottom-bag abrasion caused by the filter bags’ bottoms hanging directly above the parting line of the hopper. Abrasive metallic dust created small pinholes in the bottom of 9 inches of the filter bags. 
  • Unacceptable emissions at the discharge stack.
  • Significant production time reduction.

The foundry engineering team determined that installing Parker BHA PFEs in the dust collector was the most cost-effective solution.

Post installation results include:

  • Because of the PFEs' compact design, the filter bottoms were positioned five feet above the dirty-air plenum eliminating the bottom bag abrasion.
  • Reduction in the air-to-cloth ratio to 3.2:1.
  • Air consumption at the collector was reduced by 30% resulting in increased overall system efficiency. 
  • Unplanned maintenance and shutdowns were eliminated.
  • A reduction in average differential pressure across the filter elements to 3.0 to 3.5 inch water gauge.
Pleated Filter Elements Improve Dust Collection for the Foundry Industry - Pleated Filter Elements vs. felt filter bag compare cloth area available per element - Parker Hannifin

Pulse-jet dust collectors used in most foundry applications can be successfully upgraded with the installation of pleated filter elements. The case studies show that when aggressively designed to air-to-cloth ratios and demands for increased airflow capacity cause poor dust collector performance, the installation of PFEs can dramatically lower differential pressures, improve filtering efficiencies, reduce emissions and lower overall plant maintenance requirements.

Pleated Filter Elements Improve Dust Collection for the Foundry Industry - Download the white paper - Parker HannifinDownload the full case study to read more successful upgrades in a variety of foundry application processes and for details on PFE performance testing.


This blog was contributed by the Filtration technology team, Parker Industrial Gas Filtration and Generation Division.


Related content

Compressed Air Treatment Solutions for Today's Manufacturing Plants 

On-Site Nitrogen Generation for Aluminum Degassing

Why Are Coalescing Filters Installed in Pairs?


BHA Pleated Filter Elements Improve Dust Collection for the Foundry Industry

Read more

Latest Forum Posts