Frequently Asked Questions

Battery Separators

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Valve Regulated Lead Acid (VRLA)

Motive Power: What are H&V’s requirements for minimum order quantity?

H&V’s typical MOQ is 5,000 lbs for commercial orders.

Motive Power: What is the lead time for H&V battery separator?

Service is a cornerstone of H&V’s battery separator business. Our goal is to ship finished product in fifteen business days to all customers.

Motive Power: Why use synthetic fibers in battery separator?

Synthetics, if incorporated correctly into the separator, will increase strength properties. The synthetic fibers protect against punctures caused by plate imperfections and reduce scrap in battery assembly. Over the length of the battery’s lifespan, the vibration resistance and compression recovery is improved.

Motive Power: Are synthetic fibers stable in acid?

Choosing the correct synthetic for acid environments is critical. H&V’s selection of synthetic fibers ensures both chemical stability and proper function during the separator manufacturing process.

Motive Power: Can H&V produce globally?

H&V produces AGM battery separators across Great Britain, China, and the United States—utilizing four plant locations and five manufacturing lines. Global customers can be assured of the same product and quality regardless of its origin.

Motive Power: What is the grammage range of H&V separators?

H&V designs custom separators across all applications. If you need a specific grammage (basis weight), we can supply it. At present, our most popular grades range from 130 gsm to 490 gsm. Other weights are available on request.

Motive Power: What is the thickness range of H&V separators?

H&V is committed to match product specifications to your needs. We can supply whatever thickness your design requires. Currently, our most popular grades fall within 0.9 mm to 3.4 mm (measured with 10 kPA in accordance with BCI 3a-T4 test standard).

Motive Power: How do you test thickness?

Thickness is measured using a precision electronic caliper gauge loaded at 10 kPa pressure. 20 kPA and Japanese Industrial Standard measurement methods also available on request.

Motive Power: What is EnergyGuard®?

EnergyGuard® is a specialty brand of H&V AGM separator. EnergyGuard® separators use a special furnish composed of microglass fibers and synthetic fibers. It exhibits the full functionality of traditional all-glass separator but with unparalleled tensile and burst strength. This feature reduces the reject rate in battery manufacturing, particularly cutting back pasting-lump punctures and unwinding-related tears. EnergyGuard® experienced growth over the last five years and, today, holds a strong share in the AGM separator market place.

SLI Stop-Start: What is Start-Stop technology?

Start-Stop is a new automotive platform that turns off the car’s engine off during idling. The emissions savings that accumulate during city driving (such as sitting at a red light) can reach upwards of 5-10 percent. But it is not without challenges; frequently restarting the motor puts extreme stress on the battery. Traditional lead acid batteries have not met the challenges of Start-Stop. Automakers today have chosen AGM sealed-lead acid batteries as the battery of choice for power Start-Stop vehicles. AGM batteries are better equipped to deal with the challenges of frequent restarts and Partial State of Charge(PSoC). Across our three continental manufacturing sites, H&V is making the world’s premiere Start-Stop separator.

SLI Stop-Start: What does “PSoC” mean?

“PSoC” is an acronym for “Partial State of Charge”, referring to the demands placed on a Start-Stop battery before it reaches its full recharged state. In flooded lead acid batteries, PSoC leads to a greatly diminished cycle life. AGM batteries have allowed the automotive industry to meet these challenges. AGM lead acid attack PSoC demands by means of increased rate of charge acceptance, reduced positive-active material plate shedding, and resistance to acid stratification.


Lithium Primary: What are lithium primary batteries?

In the energy storage industry, batteries labeled as “primary” are designed for one use only–discharge and no recharge–while “secondary” refers to rechargeable batteries. Primary cells designed with lithium active materials utilize special chemistries. H&V produces lithium primary separator targeted tailored to lithium thionyl chemistry.

Lithium Primary: Does H&V supply lithium ion battery separator?

At this time, H&V provides separators for the lithium primary market only, not the lithium ion market.


Why is Hi-Sep preferred for automotive applications?

Hi-Sep is preferred in automotive applications because of its low electrical resistance and high volume porosity ensure minimum voltage loss in cranking. Its flat separator designs help to protect from active material shedding that can occur due to vibration in heavy duty trucks. Hi-Sep’s higher electrochemical oxidation ensures longevity in under hood conditions.

Why is Hi-Sep the preferred separator in motive power applications?

Hi-Sep has lower electrical resistance in this segment along with higher volume porosity and electrochemical oxidation. Hi-Sep maximizes watt-hour efficiency thanks to its’ lower ohmic-loss. H&V can produce Hi-Sep separators with a combination of rib or glass mat to increase acid availability to the positive plate which increases capacity and charge acceptance. Another benefit of the rib and glass matt is that they ensure protection against deep cycle.

Why is Hi-Sep preferred in standby applications?

Hi-Sep’s higher electrochemical oxidation and lower electrical resistance help in float charge applications which minimizes ohmic loss. Our separator’s non leachant formula helps the battery management system (BMS) to function optimally throughout its life.

What is Hi-Sep?

Hi-Sep battery separators are designed for flooded lead acid battery applications. Our non leachant formula is comprised of micro-glass fiber, synthetic fiber, fillters, and binders. Hi-Sep inherently exhibits low electrical resistance and has the highest porosity and highest electrochemical oxidation in its class. All these qualities make Hi-Sep extremely durable in a tropical environment.

Why is electrochemical resistance necessary for a lead acid separator?

Electrochemical oxidation resistance is beneficial in a separator because it means the battery is less suceptable to oxidative chemical attack from nascent oxygen and lead peroxide that occur as a result of the changing and overcharging process.

Do Hi-Sep battery separators have a shelf life?

Hi-Sep separators have no shelf life limitations.

Does Hi-Sep have any oil leachables?

No. Hi-Sep does not have oil leachables and is very stable even up to 1.80g/cc (98%) sulfuric acid.

How is the thickness of Hi-Sep measured?

Hi-Sep thickness is measured by using 25 mm pressure foot exerting 3.5 kPa.

What is the thickness range of Hi-Sep separators for automotive and SLI applications?

Hi-Sep separators are available in web thicknesses from 0.30mm – 0.50mm. Howerver, overall thickness can be as high as 2.0mm with a combinatio of rib and glass mat.

Is Hi-Sep suitable for automatic plate enveloping?

Yes, Hi-Sep battery separators can be run on high speed plate enveloping machines.

In what form is Hi-Sep available?

Hi-Sep is available in leaf (cut pieces), envelopes, or pouches for manual assembly, or rolls for automatic plate enveloping machines.

Industrial Products

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Embroidery Backing: What type of backing do I need?

Fabric stability, size of the design, stitch density, stitching speed and stability of the design are all factors to consider when selecting a backing. Backing, no matter what its type has to be stable enough to prevent movement during the stitching process.

Embroidery Backing: How many types of backing should I carry?

You need at least one medium weight cutaway, a lightweight tearaway and one cap backing.

Embroidery Backing: How do I decide whether to use a tearaway or a cutaway?

Tearaways are the backing of choice for most embroiderers. Designs can usually be finished more quickly, safely and cheaply with a tearaway vs. a cutaway. Cutaways are needed to provide a stable base for delicate and stretchy fabrics both during the stitching process and afterwards.

Embroidery Backing: Is there a special backing to be used for embroidering caps?

Yes. Cap backing is used to improve the crispness of the lettering. This is particularly important in low profile and unstructured caps. A clean tearing backing is very important to avoid pulling stitches.

Embroidery Backing: Do you have any backings that are safe for children’s clothing?

We do offer a grade that is a binder-free backing that meets the requirements for children’s wear due to fiber composition.

Embroidery Backing: Which backing should I use for a high stitch count design?

You would need a heavy cutaway (3.0 or 3.5 oz) or you can double-up on a medium weight. High stitch count is normally considered to be 10,000 stitches or more. For caps, the standard 3.0 oz cap backing is sufficient to high stitch count.

Garment Care Labels: How many types of labels do you produce?

Two cellulose based grades. One is designed to work well with dot matrix printers while the other is commonly used for laser, ink jet or flexographic printers.

Garment Care Labels: How many colors are your products available in?

We only offer white at this time. Most printers of labels use color printers to add aesthetic value. If the background needs to be something other than white, then the printer will do an all-over print color for the background and then do the printing of instructions on a second pass.

Garment Care Labels: What widths and put-ups do you sell in?

We sell large rolls in slit widths that are compatible with our distributor’s converting equipment. They do the perforated die-cutting (the finished label size) and cut the side pin-feed holes for continuous printers, or they simply sell perforated 8.5” X 11” sheets for sheet fed printers.

Waistband Interlinings: What kind of waistband interlinings do you produce?

We offer stable materials that prevent edge rollover or curling, and we produce stretch waistband materials that stretch with other elastomeric components that are used in comfort waistbands.

Waistband Interlinings: Are your waistband products washable or dry cleanable? How about shrinkage control?

All of our waistbands use raw materials that are designed to shrink less than the industry standard of 3% over the lifetime of the garment. All of our products are both washable and dry cleanable.

Waistband Interlinings: Do you offer different colors?

Our stable waistband grades are sold in both white and black. Black is available to be used with dark fabrics to prevent show through of the white.

Waistband Interlinings: Does H&V supply slit or slotted waistband canvas in rolls?

No. H&V is a large scale production mill. All of our nonwovens waistband products are sold through converter distributors. Contact us for the converter nearest to you.

Home Furnishings

Window Coverings: What is H&V's minimum order?

  1. Most commercial wet laid grades are available in master rolls of 2,000 to 3,000 linear yards.
  2. Most commercial dry laid nonwovens are available in minimum orders of 5,000 linear yards

Drapery Buckram: Does H&V make woven buckram?

No, we only make nonwoven buckram. H&V has sold this product under the Hovotex brand name for more than 40 years. It is proven to be the product of choice for custom as well as ready-made draperies and curtains.

Drapery Buckram: What is the minimum order per slit width?

10,000 linear yards.

Drapery Buckram: What widths are available for purchase?

4” is the most popular but widths from 1.0” to 60” are available.

Drapery Buckram: What is the standard put-up?

We package Hovotex in cases of 25 rolls, 100 yards long on 1.5” ID cores.

Drapery Buckram: Is Hovotex washable and does it maintain stiffness after washing?

Yes, it is washable and dry cleanable, and yes, it will maintain stiffness after repeated washings.

Drapery Buckram: What is our lead time?

Two to three weeks.

Drapery Buckram: How do you activate the adhesive on 3130HS?

The heat-seal adhesive in 3130HS can be activated with a hand iron. It is a temporary tack to be used as a sewing aid to hold the buckram on the fabric while the pinch-pleats are being sewn onto the drapery.

Drapery Buckram: Where is Hovotex manufactured and ship from?

All Hovotex buckram is made in the USA and ships from our mill in Greenwich, NY.

Window Coverings: What type of nonwoven fabric does H&V offer for window coverings?

  1. Wet-laid made with cellulose and/or polyester.
  2. Dry-laid either latex bonded (made with polyester fiber and latex) or thermal bonded smooth roll, through air, or point bonded.  Most of our thermal bonds are made with 100% polyester.
  3. We also offer meltblown dry laid nonwovens.

Window Coverings: What converting processes does H&V offer?

Custom score cut slitting, laminating, and adhesive coating.

Window Coverings: What widths does H&V offer?

  1. Wet-laid nonwovens are available up to 115”.
  2. Most chembond and thermal bond dry laid nonwovens are available in widths up to 74”.
  3. Meltblown nonwovens are available up to 86” wide.
  4. Room darkening or light filtering composites up to 72” wide.

Window Coverings: What advantages do H&V nonwovens offer this market?

Uniformity in aesthetic appearance (when viewed in a window), thickness, and stiffness for reliable physical performance.

Window Coverings: What physical properties do H&V nonwovens offer that are marketable?

  1. Latex bonded nonwovens can be made inherently fire retardant or incorporate anti microbial, anti static, and other treatments.
  2. Thermal bonded nonwovens are available from 17 gsm to 240 gsm with bonding from 8% to 100% depending on the type.
  3. Room darkening composites that offer energy savings and light control.
  4. All H&V nonwovens for window applications are UV stable.

Window Coverings: Why should I purchase nonwovens from H&V?

We research the critical technical requirements (CTQs) you need for your end use and design our nonwovens to meet those requirements.

Window Coverings: What does H&V offer in market knowledge and direction?

H&V dedicates internal resources to research the market of interest and develop Product Road Maps to determine what direction the market is going in the next three to five years, what products we need to develop, and to present our research (Product Road Map) to our customers.

Advanced Fiber Nonwovens

Surfacing Veils: Will the AFN Group manufacture a nonwoven to my specification or use fibers or other materials that I supply?

AFN specializes in custom engineers webs for a variety of applications. We routinely work under Confidentiality Agreements and can utilize your raw materials as long as they meet our health and safety standards. AFN offers the unique ability to produce small “pilot line” size production on a fully capable 35.5” (90cm) wide production machine.

Surfacing Veils: Where are your veils produced?

Hawkinsville, GA.

Surfacing Veils: What weight and width are AFN surfacing veils produced in?

H&V can deliver materials 35.5” wide (90cm) in extremely light weight veils ranging from 4 gsm to 212 gsm.

Surfacing Veils: What is a surfacing veil and how are they used?

Surfacing veils are typically light weight nonwoven fabrics that provide protection against corrosion, abrasion, static discharge, to prevent micro cracks, or to cover up imperfections in a multi-layer buildup of fibrous materials. They are often used to produce a very smooth surface on both the interior and exterior of pipes and holding vessels. Other more exotic materials like holographic fiber and blends of a variety of fibers can be used in decorative applications like composite sporting goods, skis, snowboards, fishing rods, and bicycles helmets, where these fibers serve both as reinforcing components and the final decorative finish.

Surfacing Veils: What type of binders do your composite materials use?

We use a variety of binders that are designed to be compatible with most composite resins system including epoxy resins. Many of our binders are designed to break down following wets-out forming a very smooth surface.

Surfacing Veils: What type of material does H&V manufacture for FRP (fiber reinforced plastics) applications?

The Advanced Fiber Nonwoven Group at H&V custom engineers webs for a variety of applications requiring advances synthetic fibers. AFN scientists carefully select from materials like PAN carbon fibers, metal and metal-coated fibers, various types of fiberglass including ECR and C-glass, aramid and para-aramid fiber; in fact AFN can produce a “paper” using almost any material that can be produced in fiber form.

Shielding: Will the AFN Group manufacture a nonwoven to my specification or use fibers or other materials that I supply?

AFN specializes in custom engineers webs for a variety of applications. We routinely work under Confidentiality Agreements and can utilize your raw materials as long as they meet our health and safety standards. AFN offers the unique ability to produce small “pilot line” size production on a fully capable 35.5” (90cm) wide production machine.

Shielding: What products do you manufacture for Lightning Strike Protection (LSP)?

A Nickel coated carbon veil will dissipate the strike and not damage the structure; for more detailed information open the white paper on this subject found on this website.

Shielding: Do you supply materials that have a specific surface resistivity?

Yes, surface resistivity is express in Ohms per Square (Ω/sq). Consult the data sheets on this website for specific values by grade.

Shielding: What types of fibers are used for most shielding applications and why?

Nickel coated carbon for conductivity/reflectivity and carbon/glass blends for low observables for stealth.

Shielding: What are some of the applications you have developed conductive materials for?

X-Ray tabletops, Microwave absorbers, Avionics shielding, Locator strips, Fuel tank static dissipation, Aviation lightning strike protection, Wing deicing.

Shielding: What are some of the types of interference your products can shield against?

RFI (Radio Frequency Interference) shielding, EMI (Electromagnetic Interference) shielding, MRI (Magnetic Resonance Imaging) shielding, EMP (Electromagnetic Pulse) shielding, ESD (Electro-Static Discharge) electronics protection.

Shielding: What types of shielding are products does H&V manufacture?

The Advanced Fiber Nonwoven Group at H&V custom engineers conductive webs for a variety of applications requiring conductive fibers. AFN scientists carefully select carbon and metal-coated fibers as the key components in these wet-laid nonwovens, sold under the trade name Saf’N’Shielded.

Industrial Nonwovens

Stationery: In what applications are these materials used?

While they can be used in any application where a low strength material added toughness, they are designed as the reinforcing paper used on metal stationary clasps and the reinforced header on writing tablets.

Stationery: What is stationery fastener paper?

Although produced on a paper machine these high strength wet-laid nonwovens are a matrix of natural and synthetic fibers saturated with a polymeric resin to produce a product with extraordinary strength, stiffness, and tear resistance.

Stationery: Do you produce fastener paper in colors? What about printed product?

We produce a variety of colors that are customer formulated for each customer, but we do not print on any of these products. We can help you find a printer to achieve the finished product you desire.

Filtration Media

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Liquid Filtration

Fuel: How can I find out which type of resin treatments are available on your media?

Your account manager will be able to describe which type of resin treatments are applied to the media we recommend for your application. This will vary based on the type of application. We do treat our media in order to add strength, modify filter performance, and to improve water resistance/separation.

Hydraulic: What is the maximum temperature that H&V's media can operate in?

Our media are designed to withstand exposure to continuous oil temperatures of 180°C or 355F.

Hydraulic: What is the difference between single phase and dual phase media?

Dual phase media are produced using H&V’s proprietary manufacturing techniques to have a gradient density within one layer of paper. This is a single grade media that contains both pre-filter and final filter layers, which are formed simultaneously on the paper machine. This allows the dual phase media to have higher dust loading capacity than single phase media created by H&V or our competitors.

Hydraulic: How do I choose a laminated grade if I need more strength in my application?

First, you should select the correct base grade based on your filtration requirements (i.e. a 5 micron filter application), and then we can determine the correct products to laminate to the base to meet your strength requirements.

What is the difference between laminating and co-pleating?

Lamination is done at our mills, and the additional scrims or media are physically joined into a single media. In co-pleating the layers are not physically attached to each other. Using a laminated product can allow you to get more layers in your filter than is possible by co-pleating.

Coalescer: Why are glass fiber media preferred versus standard cellulose media for coalescing applications?

It is recognized that glass fiber media provides a better relationship between water elimination and differential pressure than other media. The reason for this improvement is that micro glass fibers are available down to 0,2µm diameter. We can tailored to specific application requirements by varying glass fiber size distribution in the media during our manufacturing process.

Coalescer: Are there industry standards on water removal?

H&V follows and is equipped to test according SAE J1488 and ISO16332 standards on water removal. Also we can test coalescing filter according to ISO 12500 for air compressor application.

Coalescer: Is a prefilter needed?

It depends on the application requirements but a prefilter will increase the life of a filter.

Process Fluids/Water: What polymers make up filtration media for water and process fluids?

H&V offers media in a wide range of polymers and fiber types which include, cellulose, microfiber glass, polypropylne, polyester, nylon and others upon request.

Process Fluids/Water: Why are these different polymers offered?

H&V offers media in a wide range of polymers for chemical resistance, heat resistance, or fiber size which directly affect the micron efficiency of a media . For example polypropylene is highly resistant to wide range of chemicals but would have lower temperature tolerance than polyester or glass. By offering many polymeric products, solutions can be identified to process a variety of liquid streams with different polarity, pH, and oxidizing properties.

Process Fluids/Water: Can H&V materials meet FDA, NSF and other regulatory expectations?

Yes, H&V produces wetlaid glass, polypropylene, polyester, and Nylon grades that support regulatory claims. Please check with an H&V representative for confirmation that a specific grades is FDA compliant.
• Polypropylene (21CFR177.1520)
• PBT polyester ( 21CFR177.1660)
• Fiberglass (21CFR 177.2410 and 177.2420)
• Acrylic Latex Binder in Fiberglass grades (21 CFR 175.105, 175.300, 176.170, 176.180, 177.1010, 177.2260)

Process Fluids/Water: Are H&V media NSF certified?

Several H&V meltblown grades have NFS certification. Please check with an H&V representative to confirm if a specific meltblown grade is NSF certified.

Process Fluids/Water: How do I evaluate media performance and its suitability for a filter?

There are three important properties to be considered relative to choosing the right filter media: Efficiency at a specified micron size, initial pressure restriction, and dirt holding capacity at a specified flow rate. When specifying media it is important to understand what efficiency the filter is designed to remove of a given micron particle size. To help in the selection process H&V can provide efficiency curves on some of our media which clearly indicates the efficiency of the media at different micron sizes at a specified flow rate. The initial pressure drop or flux of the media must be considered. In general there is a tradeoff between efficiency and flux or pressure drop. As the efficiency is increased the flux decreases. In choosing the correct media for your application you want a media with the desired efficiency for the micron rating at the lowest pressure drop as possible to get the maximum flow rate with the least amount of energy. Dirt holding capacity is also important in determining the life of the filter in use and should be taken into consideration when choosing the most suitable media.

Process Fluids/Water: What is BETA Ratio?

BETA ratio is used to measure the performance of a media at a specified micron size. It is the number of particles at a given micron size that the filter is challenged with divided by the particles at the same micron size that penetrate the filter.

Process Fluids/Water: Does H&V offer membrane media?

H&V’s Trupor® is a microfiltration media, available at grades down to 0.45 micron. Trupor® provides best-in-class flow rates with all the reliability customers demand from a membrane.

Process Fluids/Water: Does H&V produce a reverse osmosis, nanofiltration, or ultrafiltration membrane?

No, H&V does not produce these types of membranes. H&V’s Trupor® is a microfiltration membrane.

Process Fluids/Water: Can H&V offer media with a scrim or reinforcing media to enhance durability and pleating characteristics?

H&V offers media with scrims in both our glass and meltblown media product lines.

Fuel: Can your media be used with bio-fuels?

Yes, all of our media are compatible with exposure to bio-fuels. To get the best performance in bio-fuel filtration, you should consult with your account manager to find the best media for your application.

Fuel: Is the microglass used in your glass and some composite fuel media designs safe for common rail diesel systems?

When properly manufactured, H&V microglass media has proven to work effectively and safely in common rail diesel systems. In fact, the inclusion of microglass is responsible for the higher efficiency and higher permeability of our many of our fuel media.

Fuel: Does H&V make media with meltblown?

Yes, H&V provides a full suite of fuel media made with cellulose, microglass, synthetic, and meltblown fibers. We can supply 100% meltblown media or composite media of meltblown and cellulose which provide the optimum combination of efficiency and filter capacity.

Fuel/Water Separation: Why are glass fiber media preferred versus standard cellulose media for coalescing applications?

Glass fiber media are preferred because the smaller diameter fibers provide a better relationship between water elimination and differential pressure than other media.

Fuel/Water Separation: Are there industry standards on water removal?

A prefilter will increase the lifetime of a filter. Typically a wood pulp is used in this media type.

Fuel/Water Separation: Is a prefilter needed?

Water must be reduced to a maximum of 5 ppm in military applications and to a maximum of 15 ppm for civil applications. H&V coalescing media achieve these targets.

Air Filtration

Appliance: How can the right filter media influence the final performance of vacuum cleaner or room air cleaner?

The filtration efficiency and air flow resistance of the media at a given test face velocity are of primary importance. Both vacuum cleaners and room air cleaners operate at very high face velocities putting higher demands on the performance of the media. The size of the filter, the effective area, directly affects both the efficiency and the resistance of the filter. The larger the effective filter area, the lower the face velocity, which in turn lowers the resistance of the filter.

Appliance:  Why do appliances like vacuum cleaners and air purifiers require high performance filter media?

Both filtration applications are driven by consumers who demand higher levels of Indoor Air Quality (IAQ) in the home. Vacuum cleaners must collect dirt while not dispersing these fine particles back into the air. Room air purifiers filter and remove fine particles from the air. For these tasks high levels of filtration, even HEPA or sub HEPA efficiency, with low air resistance is required. Low air resistance allows maximum suction for vacuums while using the least amount of energy and the smallest size of motor. Similarly, room air cleaners benefit from low resistance media; air can pass through the filter as many times as possible. Both applications have limited space for the filter, so high performance media is needed to achieve the required efficiency and pressure drop.

Appliance:  What standards govern filter media for appliance applications?

Potable Room Air Cleaners ANSI/AHAM AC-1-2006: Vacuum Cleaners ASTM 141 ASTM 1411 F2608 ASTM F1977-04 (2010) Certified Asthma & Allergy friendly Certification Program

Appliance:  What types of media configurations deliver optimum results for appliances?

Our synthetic pleatable and microfiber glass media are designed for use in a pleated configuration. Technostat® media, with its very high efficiency and low air resistance, can be used in a flat sheet configuration as a prefilter or as a post/exhaust filter in vacuum cleaners. Technostat® is also available with a pleatable mesh for pleatable configurations. Our meltblown media is often used as a liner in vacuum cleaner bags to increase the efficiency of cellulose paper or synthetic media.

Appliance:  Does H&V offer membrane media for vacuum cleaner exhaust filters?

While H&V does not manufacture membranes, we offer our patented Nanoweb® media made with nanofibers. These media have performance characteristics and pore structure similar to those of membranes and may be a significantly lower priced alternative to membranes in some applications in the micron range of 0.45 to 0.8 micron absolute. Nanoweb® is available in polypropylene and polyester, fiber size of 0.5 microns in both calendared and uncalendared versions.

Appliance:  Can H&V offer media with a scrim or reinforcing media to enhance durability and pleating characteristics?

H&V offers media with scrims in both our glass and meltblown media product lines.

Cleanroom:  What do HEPA and ULPA stand for?

HEPA = High Efficiency Particulate Air
ULPA = Ultra Low Penetration Air

Cleanroom: What standards govern HEPA / ULPA filtration?

The major standard used is the EN1822; an ISO standard has been approved, ISO 29463. Both standards use MPPS as the criteria for the filter classification.

Cleanroom: What is MPPS?

MPPS : Most Penetrating Particle Size
Looking at the fractional efficiency curve of a filter media (penetration as a function of particle size) a particle size exists that shows the lowest efficiency (highest penetration) under the given test conditions.
It is this minimum efficiency that is used in the classification under EN1822.

Cleanroom: What type of media can be used for HEPA and ULPA applications?

Media type depends on the filter configuration. There are two major product types used in HEPA and ULPA filters: deep pleat and mini-pleat filters. Both types of filters require thin and stiff media.

Cleanroom: Is electrostatically charged media required for HEPA and ULPA applications?

The small particle retention improves when charged is applied to a filter media. As a result, more open structured-media can be used without sacrificing efficiency level. Pressure drop of the filter will reduce.
However, this charge will naturally dissipate over time due to air contamination, temperature, and humidity. The efficiency will drop below the initial efficiency level and the filter will not perform as needed.
The EN1822 standard specifies that a filter with a medium containing more than 20 synthetics by weight should be discharged prior to testing.

HVAC: What standards govern HVAC filters and applications?

The major standards used are Ashrae 52.2 (US), EN779 (APAC) ) and ISO 16890 (Europe and APAC)

HVAC: Is there a correlation between the ratings assigned by Ashrae 52.2, EN779, and ISO 16890?

Although both standards work with similar equipment, the tests performed are different.
Nevertheless there it is possible to cross reference the standards:

EN779                ASHRAE 52.2
M6                      MERV 11
F7                       MERV 12
F8                       MERV 14
F9                       MERV 15

HVAC: What type of media can be used for HVAC applications?

Media requirements depend on the filter application. There are two major product types used in HVAC – pleated filters and pocket filters. For pleated filters a thin, stiff media or media composite is needed while pocket filters require a lofty product.

HVAC: What is the effect of electrostatic charge on media performance?

Electrostatic charge is a treatment given to synthetic media to enhance filtration performance on fine particles. Coarser fibers can be used to create a more open structure resulting in lower pressure drop. Typically, electrostatic charged synthetic material loses its charge over time which can lead to a reduction in performance over time. To achieve similar initial performance, mechanical media are made of finer fibers to guarantee a minimum filtration performance throughout the life of the filter. Mechanical filtration only medias will have increased air resistance compared to electrostatically charged medias of the same efficiency.

HVAC: Is charge decay considered in filter classification standards?

North American standards do not consider charge decay in filter classification, but refer to a standard test method. Ashrae 52.2 – Appendix J describes a method to discharge media using 0.03µm KCl particles. The discharged efficiency obtained this way has no impact on the filter classification.
In Europe there are a number of standards that take discharged efficiency into account in the filter classification:

  • P – Mark : a standard mainly used in Scandinavia
  • SWKI : a Swiss filtration guideline
  • EN779-2012 : the  revised EN779 standard
  • ISO 16890
  • Eurovent4/11 : an energy classification standard for filters

HVAC: How are H&V HVAC media rated?  What type of media would H&V recommend for pocket filter and pleated filter applications?

According to North American ASHRAE standard 52.2 H&V media performance is in the range of MERV 8 – 15. According to the old European standard EN779 H&V HVAC media is rated from F6 – F9.

The ISO 16890 standard evaluates the performance of the filter by its arrestance of 0.3 to 10 μm particles.

According to their efficiency, filters can be classified as PM 1 (particulate sizes ≤1 μm), PM 2.5 (sizes ≤2.5 μm) and PM 10 (particulate sizes ≤10 μm). To qualify for a group, the filter needs to have at least 50% efficiency at the respective PM size. If the filter does not achieve at least 50% in PM10 it is considered ISO Coarse.

We suggest charged meltblown media and mechanical meltblown media including NanoWave® for pocket filter applications. For pleated filters pleatable glass, pleatble synthetics are available.

Coalescer: Why does compressed air need to be purified?

If compressed air is not pure the entering oil will reduce the life time and can can cause leakages. Adsorptive media will lose their adsorptive properties when saturated with oil.

Coalescer: Why glass media?

The best results have been obtained with glass fiber media which are able to remove oil droplets in the range of less than 0,1µ up to more than 50µ: These are depth filters providing long life.

Cleanroom: How does coalescing work?

There are mainly 3 physical effects contributing: a) gravity, b) impaction, c) diffusion.

Coalescer: How important is the air velocity?

Surface area and fine fiber media, in combination with the air velocity will determine the efficiency of the element.

Engine Intake: Do I need to cure H&V Heavy Duty Air filter media?

  1. If your media uses acrylic based resins and is identified as “Low energy”, then the media is already cured sufficiently for the application it was designed for. Additional process warming, either through hot plates, IR heaters, or ovens may be used if desired to better optimize processing without harming the media.
  2. If your media uses phenolic resins and is off white / brown in color, then some curing is required. Please contact your account manager for more information.

Engine Intake: What is a Wire Side mark?

A wire side mark is a line that H&V puts on the downstream side of the media to indicate which side should be oriented to the ‘clean’ or downstream side of the air flow. The wire mark color and spacing is specific to an individual grade, but standard spacing is on 2 inch centers, and standard colors for the line mark are either black or blue ink.

Engine Intake: What is the usual test standard used to evaluate heavy Duty Air filter media?

ISO 5011 is a globally accepted test standard for either flat sheet or element evaluation of automotive or heavy duty air filter media or filters. Higher efficiency air filter media for newest emission legislation China VI diesel engine after treatment system protection, EN779:2012 and ISO16890 are recommended.

Gas Turbine/Dust Collector: Do I need to cure H&V Gas Turbine Air filter media?

If your media uses acrylic based resins and is identified as “Low energy”, then the media is already cured sufficiently for the application it was designed for. Additional process warming, either through hot plates, IR heaters, or ovens may be used if desired to better optimized processing without harming the media.

Gas Turbine/Dust Collector: What is the usual test standard used to evaluate Gas Turbine Air filter media?

ASHRAE 52.2, EN779 (2012), and EN1822 (2009) are the three globally accepted test standards for either flat sheet or element evaluation of HVAC Gas Turbine and Industrial Air air filter media or filters.

Gas Turbine/Dust Collector: Which grades are best for pulse cleaning gas turbine applications?

H&V has developed the Nanoweb® range of filter media that is expressly made for pulsing applications. The Nanoweb layer is positioned on the dirty or upstream side of the cartridge where it promotes dust cake formation. The rapid formation of the dust cake promotes a very complete pulse cleaning of the cake from the cartridge. This allows an optimized filter service interval and high MERV rating (13 to 15), F rating (8 to 9), or E rating (10-12)that cannot be obtained without use of fine fibers.

Medical Equipment: Are there any national or international standards that the media or the filter need to pass in order to be used?

There is an ISO standard test method for testing of medical filter devices – ISO 23328-1. This is a standard TSI 8130 NaCl aerosol efficiency test conducted on the device following its exposure to moisture in a breathing simulator, set up dependent on its intended application. The standard defines only the test method, not any required filtration efficiency levels.

Medical Equipment: What can affect the final performance of a medical filter?

Low breathing resistance is key for medical filtration applications. Technostat, with its low airflow resistance advantage, is widely used in filtration devices produced by leading medical filtration companies for various applications.

Medical Equipment: What is the advantage of Technostat Plus?

Technostat achieves the same penetration level as standard Technostat with basis weight reduced by 20-25%.

Medical Equipment: What is the storage shelf life of Technostat media?

Technostat is triboelectrically charged and is extremely stable when stored under normal storage conditions in the original package. We recommend storage at a minimum of -20 and a Maximum of 40 °C at less than 80% RH. Shelf life testing up to 5 years on the efficiency under normal conditions. Results can be provided upon request.

Molecular Filter Media: What is the difference between chemical filters and molecular filters?

Molecular filters and what are referred to as chemical filters are one and the same. These filters are also called carbon filters, gas-phase filters or adsorptive filters.

Molecular Filter Media: What is adsorption?

Adsorption is the process by which liquid or gaseous molecules adhere to the inner pore walls of an adsorbent, like activated carbon. This force is known as Van Der Waal force.

Molecular Filter Media:  What do molecular filters do?

Molecular filters remove and control odors, VOCs, irritants and toxic gases in indoor spaces, as well as vehicles.

Molecular Filter Media:  Can MFM remove odors and particulate in one system?

H&V’s Molecular filter media combines molecular and particulate filtration in one material.

Molecular Filter Media:  Can I use a filter media with standard activated carbon to handle all molecular contaminants?

MFM can be engineered to handle different molecular contaminants. The media choice will depend on if the molecular contaminant is odor, VOC, acid or base gas.

Molecular Filter Media:  What are VOCs?

Volatile organic compounds (VOCs), natural or synthetic, are emitted as gases from certain solids or liquids. There are millions of different compounds that can be classified as VOCs, some may have short and long term negative effects on your health. VOCs can off-gas from many different products. Examples include: paints and lacquers, cleaning supplies, pesticides, building material and furnishings, office equipment such as copiers and printers, glues and adhesive.

Molecular Filter Media: What is the difference between molecular filtration and particulate filtration?

  Molecular Filters   Particulate Filters
  Designed to filter gases   Designed to filter particles
  Pressure drop remains the same, regardless of loading   Pressure drop gradually increases as filter loads
  Filter efficiency decreases over time   Filter efficiency increases over time
  Filtration is not visible   Filtration is visible
  Standards and test procedures to rate filters still being developed   Existing standards and test procedures to rate filters

Respiratory Protection: Does H&V have NIOSH or other government approvals on respirator media?

Finished facemasks and respirators are certified by NIOSH or government approvals such as EN 149 for disposable mask; the media is not approved. H&V can make recommendations on the best media to select for a specified facemask or respirator based on filtration efficiency and resistance of the media at a specified test velocity. However it is the responsibility of the facemask manufacturer to certify the performance of their mask and obtain all required government certifications.

Respiratory Protection: What characteristics can affect the final performance of the mask or respirator?

The efficiency and resistance of the media at a given test face velocity are of primary importance to the respirator media. Size, configuration and processing of the media can also affect the final performance in the respirator. The effective filter area directly influences the efficiency and resistance of the facemask. The larger the effective filter area, the lower the face velocity of the air flow through the mask. This consequently increases efficiency and lowers the resistance of the filter. The processing of the filter through molding, sealing or pleating operations can also affect the performance of the respirator.

Respiratory Protection: Can the media be molded, sealed, or pleated?

Both meltblown and Technostat can be molded. For molded mask production, H&V recommends 105 – 108 degrees centigrade for 6-8 seconds. These conditions tend not to affect the filtration characteristics of the meltblown or Technostat media, assuming an outer shell of protective nonwoven media is placed between the media and the heated die platens. Care should be taken not to stretch the media causing holes and breakage which will affect the efficiency of the media. Some final products require a sealing of the meltblown or Technostat media. This can be accomplished thermally or ultrasonically. Our microfiber glass media can be pleated and is recommended for these applications. Technostat and meltblown can also be pleated if the media is supported by a pleating backing layer.

Respiratory Protection: What is the storage shelf life of respirator media?

Both our meltblown and Technostat media are electrostatically charged. The electrostatic charge of both media is very stable when stored under normal storage conditions in their original packaging. The media should be stored in a protected environment of UV light, extreme temperatures and influence of moisture.

Respiratory Protection: What are normal storage conditions for polypropylene meltblown?

The media should be stored in its original packaging at temperatures less than or equal to 40 °C and protected from UV light. An already opened package should be repacked for storage to protect it from other environmental deterioration. The media, by itself, is stable against moisture and excessive humidity. Nevertheless, we recommend that during storage the relative humidity should not exceed 80 %.

Respiratory Protection: What affects the stability of respiratory media against environmental deterioration and chemical stability?

Mainly two factors determine the stability of a medium: – The mechanical/chemical stability, which is related to the stability of the polymer. – The stability of the filtration properties is based on the electrostatic charge.

Respiratory Protection: What temperatures are required to process polypropylene media?

Polypropylene has a melting temperature of 156-160 °C. The polymer can be processed without polymer degradation up to 120 °C for an extended period of time. Below 0°C, polypropylene will become slightly brittle. Polypropylene is stable against strong mineral acids and bases and many organic solvents. Non-polar solvents can cause swelling or dissolve the polymer. The stability of polypropylene against UV light is limited. This can cause yellowing of the fibers and a reduction in the mechanical properties.

Respiratory Protection: Do moisture and heat affect electrostatic charge?

Humidity does not affect the filtration characteristics of the media. Even when the media is submerged in water for 24 hours and allowed to dry, the filtration efficiency and pressured drop values are unchanged. Therefore, once the electrostatic charge is placed on the polymer, humidity has little or no effect. Alternatively, temperature does affect the filtration characteristics of the media. Heat will lower the efficiency of the media depending on the amount and the time of exposure. For short exposure times (3 days or less), H&V recommends not to exceed 55 degrees centigrade

Respiratory Protection: Do moisture and heat affect electrostatic charge?

Humidity does not affect the filtration characteristics of the media. Even when the media is submerged in water for 24 hours and allowed to dry, the filtration efficiency and pressured drop values are unchanged. Therefore, once the electrostatic charge is placed on the polymer, humidity has little or no effect. Alternatively, temperature does affect the filtration characteristics of the media. Heat will lower the efficiency of the media depending on the amount and the time of exposure. For short exposure times (3 days or less), H&V recommends not to exceed 55 degrees centigrade

Respiratory Protection: How should Technostat be stored?

Technostat is triboelectrically charged media and extremely stable when stored under normal storage conditions in the original package. We recommend storage at a minimum of -20 and a Maximum of 40 °C at less than 80% RH. Shelf life testing up to 5 years on the efficiency under normal conditions can be provided upon request.