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Merryweather Foam Blog

Since 1948, we have been industry leaders in fabricating unique, foam components for customers in the medical, sound absorption, automotive, and unique packaging industries. At Merryweather Foam, we pride ourselves on our ability to combine experience, innovation, and excellent customer service. We have the knowledge, manpower & equipment to help you get the job done. Visit our website to see our fabrication portfolio as well as our capabilities.

4 Reasons Why Our Membership with the GFA Benefits You

As proud members of the GFA, or Gasket Fabricators Association, Merryweather foam is committed to delivering the best cutting-edge solutions to their customers. Through our engagement in GFA resources and events, our company connects with the best suppliers and innovators in our industry to ensure we remain competitive, agile and powerful for our end customer - you. We aren't content to rest on our laurels, despite having some of the industry's most cutting-edge choices in cutting edges - Water Jet Cutting, Die Cutting, Contour Cutting and more - as well as customer-focused production techniques and a commitment to overall product quality. Partnering with the GFA as a member has allowed us to expand our expertise:

Annual Meetings
As with many fabrication-based industries, a single piece of technology or technique breakthrough can provide better products, pricing and efficiency virtually overnight. GFA membership gives Merryweather Foam access to twice a year membership meetings. These gatherings allow us to peruse new suppliers and lock in component and equipment deals that empower us to deliver a more valuable product to you, our customers. 

A Strong Network of Peers
The seminars, presentations and networking opportunities enjoyed by GFA members allow us to meet and stay in contact with peers that can offer guidance for unique challenges. We pride ourselves in staying up-to-date on the latest problem-solving techniques in the foam fabrication field, and GFA seminars give our team the knowledge and network contacts they need to serve you.

Technical Webinars
Important industry news travels fast, and if it happens between annual meetings, GFA webinars help us stay informed. By virtually connecting with and learning from the brightest minds in our field, we're always well ahead of changes and ready to take advantage of any potential opportunities on your behalf. 

The TechTeam™
The TechTeam™ is a valuable panel of experts assembled and serving in conjunction with the International Association of Die cutting and Die making. The team is a unique GFA membership benefit that extends the reach of our problem-solving skills by giving us access to sharp industry minds outside of our factory walls. If you have an unusual product or unusual fabrication needs, we are able to confer with the TechTeam™ for new ideas and a fresh outlook, giving you the benefit of efficiency.

At Merryweather Foam Inc, our membership in the GFA is only part of our commitment to our customers. We know that the needs and demands of the marketplace - whether they're for retail goods, equipment operation and protection, filtering or other applications - deserve to be met as affordably and quickly as possible, and with the highest degree of skill and quality available. We're proud to meet those demands every day, and invite you to contact us for all of your foam fabrication needs.

To learn more about the Gasket Fabricators Association, visit their website. Also, we would love to help you with your next project--please get in touch with us if you are in need of help. 


3M Select Converter Status - Why It Matters

Since 1948, the hardworking and passionate team at Merryweather Foam, Inc. has committed itself to becoming an industry leader in the world of manufacturing unique foam components for customers all over the world. We're incredibly appreciative of our dedicated customers, many of whom have been with us since the beginning. We're not a business that is willing to just rest on its laurels, however, which is why we're always taking steps to continually improve and eliminate waste in our manufacturing processes.

This is a large part of the reason why we're always working hard to achieve new quality certifications that allow us to prove that Merryweather Foam has earned its place as one of the most trusted manufacturers working today. One of those is 3M Select Converter Status, which means a number of important things for both our company and for our customers.

What is 3M Select Converter Status?
3M Select Converter status is a quality certification awarded by 3M Converter Solutions. 3M Converter Solutions is a global engagement platform targeting markets like electronics assembly, appliance assembly and beyond. They're a company that has pledged to act with uncompromising honesty and integrity in all of their interactions with customers, to always satisfy the needs of their users with innovative and superior solutions and to respect the social and physical environments around the world. Given that pedigree, it's easy to see why Select Converter status is both such a sought-after qualification and one that the company is very selective when it comes to awarding with their partners.

In order to achieve 3M Select Converter status, we completed a range of product-specific training sessions. That, coupled with the large volume of 3M produced materials that the company is responsible for handling each year, allowed us to become a trusted name in terms of our manufacturing processes, our engineering quality and the knowledge of our sales personnel.

What 3M Select Converter Status Means for Our Customers
For our valued customers, working with a 3M Select Converter like Merryweather Foam brings with it a host of different benefits that can't be ignored. These include but are not limited to things like:

  • Access to 3M-certified Specialists and Support Services
  • Competitive Pricing
  • Access to the Latest Solutions that 3M has to Offer and More

The Dependable Solution You Can Trust
At Merryweather Foam, we understand that every application represents a unique circumstance that requires a unique material solution. As a 3M Select Converter, this puts our sales team in the perfect position to connect you with the right specialists and technical support operators, both in-house and directly at 3M. This level of support in turn is able to give you all of the specific answers that you need and who can recommend the perfect product and materials options out of the thousands that are released by 3M each year.

3M Pressure Sensitive Adhesive & Industrial Adhesive
As 3M Select Converters, our unique relationship with 3M puts us in a better position to provide our customers with the specific items they need for any application when they need them the most. Case in point: 3M currently makes some of the highest quality UL Certified Adhesive and pressure sensitive available on the market today.

Adhesives in general are routinely taking the place of traditional bonding techniques, due in large part to the significant advancements that companies like 3M are making. Pressure sensitive and industrial adhesives are so customizable to the application that not only can they be die cut, but they're also strong enough to remove the need for a weld of any type.

As 3M Select Converters, we're specialists in these types of pressure sensitive and industrial adhesives. You get the benefit of not only purchasing the highest quality solution from 3M, but also having it converted to fit your needs by Merryweather Foam. This is the type of versatility that you just won't find anywhere else.

Unbeatable Prices
This in turn allows us to pass the savings onto you, as a way to give back for all the support you've given us throughout our history. You get all of the materials and other items that you need when you need them the most and Merryweather gets the comfort that comes only with knowing that we were able to help you carry your project through to completion and to excel beyond your wildest dreams.

Let us Help
Please get in touch with us! We would love to help you on your next project--big or small. 


Open or Closed Cell Foam: How to Choose

When you are choosing the type of foam for your project, you will need to consider several properties. In addition to deciding the foam material, pore size and the density, you may also have to decide whether open cell or closed cell foam is better. Both Open Cell and Closed Cell foams can easily have adhesive applied on them. The right one to pick will depend on the application at hand.

Terminology: Open Cell and Closed Cell

Open celled foam is made up of porous, interconnecting cells or bubbles. These cells can be produced by the foaming operation along with having their membranes removed using a post-reticulation process. Closed cell foam has chambers that are completely closed off from the neighboring ones. No exchanges of gases can take place.

Which to Use When

Open cell foam is softer and more pliant. They are often used in cushioning and padding in furniture, boat cushions, car seats and other applications. They make a highly effective packing material. They are also a great choice for applications where airflow is a necessity, including speakers, small engines, compressors, air conditioning, vacuum cleaners, face masks and hair dryers. Open cell foam makes an excellent insulating material for reducing noise in everything from microwave covers to industrial machines. Poron® is also an open cell urethane used for gaskets, seals, spacers, cushion pads, vibration/motor mounts.

Open Cell foam functions & applications:

  • Holding or wicking a liquid
  • Filtering dust from the air
  • Low-pressure gasket for dust, light, vapor, and water
  • Acoustical absorption
  • Vibration dampening
  • Craft brushes
  • Make-up puffs
  • Whiteboard erasers
  • Floor scrubbers.

Closed Cell foam tends to be more dense and more rigid. Water and other liquids cannot enter the foam chambers. Closed cell foams come in a number of materials that include PVC, cross-linked polyethylene, sponge rubbers, and others. Softer closed cell foams like Polyethylene foam have great shock absorption and buoyancy, but over time will take a set and not rebound to its original thickness.These foams are highly flexible, and can be used in automotive, household insulation, and appliance applications.

Closed Cell Foam can be used in:

  • Gaskets
  • Seals
  • Automotive dunnage
  • Cervical collars
  • Floor underlayment
  • Joint & building filler strips
  • Boat decking
  • Insulation in hot tubs
  • Pool noodles
  • Flotation devices
  • Sporting equipment
  • Exercise mats.

By starting with the right type of foam for your project, you can better assure your items functionality and durability. Talk to one of our consultants today about custom fabrication. We can get you started with the right materials for a successful and high-quality project.


All About Precision Foam Skiving

​Skiving is a manufacturing technique you don't see very often. Google it and you'll learn about thinning leather or shaping metal gears. What you won't see much of is how it's used for precision foam sheeting.

Skiving foam entails using a sharp knife to cut thin layers from a large block. That's the skiving process. It's different than sawing because that removes material whereas skiving splits it into two parts. It's an excellent way of cutting sheets of foam, which is why we use it here at Merryweather. To learn more about our precision foam skiving capabilities, keep reading.

Skiving basics

Skiving entails pushing a solid block of polyurethane foam through the blade of a knife. The blade is actually a steel belt around 1mm (0.040") thick with a very sharp edge, and is positioned horizontally above the machine table. To help the blade cut it's looped over two drums that pull it perpendicular to the direction the block is moving. These two motions help the blade slice through the material, shaving off the thickness required.

The skiving machine, sometimes called a continuous bandknife or a foam splitter, looks rather like a bandsaw laid down on it's side. Keeping the blade under tension ensures it doesn't sag, so we can cut a block of foam into thin sheets quickly and efficiently.


As skiving splits the foam rather than cutting pieces out it, there's no material removal. That gives it five big advantages over traditional sawing-type processes:

  • No waste - Sawing, and for that matter, processes like water jet cutting, have a 'kerf' or thickness of material that's lost. Skiving has no kerf so there's no waste. That helps keep costs down.
  • Dust free - Sawing is messy because the teeth carve away little chips of material. They stick to everything and can never be completely brushed off.
  • Smooth edges - Sawed edges are rough, which looks untidy and creates problems when sheets are put to use. Skiving polyurethane foam blocks avoids this problem, which means no secondary clean-up operations.
  • Close tolerances - A precision foam splitting machine, as we use at here Merryweather, keeps the blade tight and parallel to the machine bed. That ensures tight tolerances are maintained, which means customers receive sheets of consistent thickness.
  • Continuous resharpening - In material removal processes the cutting edge dulls with use, so the last piece cut has a different finish to the first piece. Skiving machines continuously resharpen the blade, so every sheet looks the same.

Merryweather for polyurethane & polyethylene foam skiving

The best way of producing thin foam sheets is by skiving. It's an efficient process that produces smooth, clean sheets of uniform thickness. If you need closed tolerance foam sheets, discuss it with us and we'll explain what skiving has to offer.


Glossary of Foam Related Terms

Our Engineering & Sales team has developed a helpful Glossary of Foam Related Terms to assist you in the selection and development process of your next project.  

DOWNLOAD: Glossary of Foam Related Terms (PDF)



The reduction of the intensity of a sound signal.


Anything that may be added to a foam mixture, not required to in order to produce the foam. Items such as plasticizers, colorants, colorants, antioxidants, and fillers.


One of the main divisions of organic compounds (those containing carbon) and particularly indicates those compounds having an open chain molecular structure.


The normal temperature of a room or environment in which the foam producing equipment or process is installed. It is often assumed to be 70 degrees "F".

A. S.T.M.:

The initials for the American Society of Testing and Materials.


Board Foot:

A standard of measurement in the foam industry which refers to a square foot of material (1) inch in thickness.


Synonym for gluing, adhering, laminating, or rebonding.


Cut-off segment of the continuously produced loaf of flexible or rigid foam being made by the slab technique. In some cases this block would have a top, bottom, and side skins intact and have cut surfaces only on the ends. In other cases, the top, bottom, and side skins may be removed by in-line trimmers leaving a smooth rectangular block.



The process of tying carbon and hydrogen molecules together to form polyethylene. Usually a chemical or radiation process.


A chemical that has the property of being able to change the speed of a chemical reaction without apparently taking part in the reaction


Known as a bubble or pore. It refers to the cavities left in the foam structure after the bubble walls have completely polymerized and solidified or curled back and fused into the boundary joints to form a skeletal structure.

Cell Count:

The number of cells per lineal inch or centimeter.

Cell Membrane:

The thin intact film that forms the bubble walls in closed cells, also know as windows.

Cell Size:

The average diameter of the pores (bubbles) in the final foam product. Although often still referred to as fine, medium, or coarse, or by the diameter in microns, most people refer to the number of cells per lineal inch.

Clickable Foam:

Foam that recovers 100% form the pinching effects of die cutting or pinching. It is foam that is less likely to have a sealed edge after being cut.

Closed Cell:

The property of foam where each individual pore is sealed off completely

from its neighbor so that no exchange of gas can take place except by diffusion through the walls. With rigid foams, it is usual to try for 100% closed cells to achieve maximum thermal insulation ability and minimal water pick-up. With flexible foams, it is normal to try for 100% open cells for

Compression Load Deflection:

(C.L.D.) The determination of the resistance to compression of a foam sample when the entire area of the sample is compressed.

Compression Set:

The recovery of foam from static or fixed compression. Less than 10% compression set (which is greater than 90% recovery) is usually accepted as good. Also known as "Percent Set".

Compressive Strength:

The resistance of rigid foam to compression.



The weight of a specific volume of foam. Expressed as pounds per cubic foot.

Dielectric Constant:

That property of a dielectric which determines the electrostatic energy stored per unit volume for unit potential.


The measurement of hardness of a foam product. Expressed in terms of the scale in which it is measured, usually the Shore "o", 660-0" or "A" scales.


The gradual yellowing of urethane foam due to a photochemical reaction

occurring from the effect of certain wavelengths of light. It is faster in sunlight than artificial light.

Double Cells:

A synonym for the presence of a scattering of cells (2) to (4) times larger than the uniform background cell diameter.



The percent of its original length to which a specially shaped material will stretch before breaking.

Elastic Medium:

A substance with the ability to return to its original dimensions after the removal of stresses.


To make brittle.


Fine Cells:

A foam with a cell count of 80 or more per lineal inch.

Flame Retardant:

A flame retardant material imports a certain degree of flame retardancy to a foam, i.e. the foam will burn less rapidly.


The relative burnability of the material in a specified situation. Meanings vary according to test method.


A product (flexible or rigid) that has been produced by the internal generation or liberation of a gas in a fluid medium that is simultaneously polymerizing while expanding in a volume.



An affinity to water. Hydrophilic are more absorptive and generally make better sponges.


Water repellant properties or characteristics.


Indentation Force Deflection:

(I.F.D.) Formerly (I.L.D.). The amount of compressive force (stress) needed to cause an indentation deflection (strain) of given magnitude. A measure of the firmness of a foam.


The foaming and swelling of a plastic when exposed to high surface temperatures or flames.


An instrument used to measure the tensile properties of foam.


The chemical process of reticulation.


"K" factor:

A measure of the insulation ability or thermal conductivity of the foam or

material. In English the unit of measure is in BTUs/hour/square foot of area/degree F./inch of thickness. Since the measurement indicates positive heat flow, the relationship to insulating ability is inverse in that the higher the "K" Factor, the poorer is the insulation ability of the product and vice versa.



An ambiguous term applied to certain formulations of foam fulfilling conditions in test method ASTM D 1692. Some of the foams with this label may burn quite rapidly.


Open Cells:

A term applied to foam cell structures characterized by interconnecting cells or bubbles. A foam cell whose membranes have been removed through a post reticulation process.


A vacuum phenomenon wherein a substance spontaneously releases volatile constituents in the form of vapors or gases. In rubber compounds, these

constituents may include water vapor, plasticizers, air, inhibitors, etc.


Having a strong affinity for oil rather that water.

Ozone Resistance:

Ability to withstand the deteriorating effect of ozone (which generally causes cracking).



The rate at which a liquid or gas can penetrate into or through a material in this case foam.


One of many high polymeric substances, including both natural and synthetic products, but excluding the rubbers.


One of the families of compounds that can be prepared with reactive hydroxyl groups and thus can be used as a polyol in the preparation of urethane foam. These polyol are generally more expensive than polyether polyols.


One of the families of compounds that can be prepared with reactive hydroxyl groups and thus can be used a s a polyol in the preparation of urethane foam. These polyol are generally less expensive than polyether polyols.


A high molecular-weight organic compound, natural or synthetic, whose structure can be represented by a repeated small unit, the mer; Synthetic polymers are formed by addition or condensation polymerization of monomers. If two or more monomers are involved, a copolymer is formed. Some polymers are elastomers and some are plastics.


Is a chemical compound with more than one reactive hydroxyl group attached the molecule.


These are families of chemical compounds that can be prepared by reaction

of isocyanate containing material with a hydroxyl containing material.


Resilient Foam:

A foam that has a very rapid recovery from extreme compression and a

fairly linear increase in resistance to compression per inch.


A term describing the unsaturated polymers or monomers used in the paint industry. In particular, those that apply to the polyester family. It is sometimes applied to the polyols in the urethane foam industry.


The normal or natural mode of vibration of a volume of air, panel of material

rod, etc.


The process of removing residual membranes or cell windows from the foam structure so that only a skeletal web like network remains.

Reticulated Urethane Foams:

Very low density urethane foams characterized by three-dimensional

skeletal structure of strands with few or no membranes between the strands, containing up to 97% or more void space..


The amount of rebound when a steel ball is dropped on the foam. It is a measure of how bouncy a foam is. It is expressed as a percentage of the dropped height.



Self Extinguishing:

The ability of a foam to stop burning after it has been started burning in a controlled manner. One test used to determine this is ASTM D1692.

Support Factor:

Also called the comfort factor. It is a function of IFD ratios and is an indication of how much "body" a foam has.


A disturbance in an elastic medium creating a "hearing" sensation to a receiver.

Sound Absorption Coefficient:

The ration of the sound energy absorbed by a surface to the sound energy incident on that surface. Also expressed in percent of absorption.

Sound Pressure Level:

A value 20 times the log10 of the ratio of the pressure of a sound to a reference pressure.

Sound Transmission Loss:

The ration of sound energy incident upon a panel to the sound energy radiated from the opposite side; expressed in dB.


The higher density outer surface of a foam article. It is the result of surface cooling.

Slab Foam:

Foam made by the continuous pouring of mixed liquids on a conveyor generating a continuous loaf of foam as long as the machine is operating.


Classified as free rise foam. A blown elastomer, particularly those with high load bearing and higher densities (8 pounds per cubic foot and higher). It is sometimes used to describe an open cell product and sometimes to refer to a closed cell product.


Tear Resistance:

The ability of a piece of flexible foam to resist deepening a cut already made in the foam sample. Expressed in pounds/inch.

Tensile Strength:

Normally expressed as the pounds per square inch of force required to stretch a foam sample to the breaking point.

Thermal Conductivity:

The ability of a material to conduct heat; the physical constant for quantity of heat that passes through unit cube of a substance in unit of time when the difference in temperature of two faces is 1 degree.


Materials that may not be reheated and softened again. Once the structural framework is set, these plastics cannot be reformed.


Materials that become soft when heated and solid when cooled to room temperature. This softening and setting may be repeated many times.


"U" value:

The overall coefficient of heat transfer. This value incorporates all the factors involved in the transfer of heat from one area to another, including boundary layer transfer of any or all "K" factors. "U" values are generally used in calculating heat transfer of a structure in a particular environment; whereas "K" factors are generally used for single components of a structure.


Zone of invisible radiations beyond the violet end of the spectrum of invisible radiations. Since ultraviolet wavelengths are shorter than the visible, their photons have more energy, enough to initiate some chemical reactions and to degrade most plastics.


A term used for years as the common name for a chemical more property called "Ethyl Carbonate". The term is now used to refer to the product of a reaction between a chemical containing reactive hydroxyl groups on its molecule. These compounds are, for the most part, biologically inert. The compounds are called polyurethanes. Since the name refers to the molecular joint between the monomers, many different chemicals can be used as building blocks or monomers with the final product still being known as a urethane compound or polymer.

UV Stabilizer:

Any compound which, when mixed with a resin, selectively absorbs ultraviolet rays.


Water Absorption:

With rigid foam, percent by weight of water pickup on submergence of a specified sample under a specified depth of water.


Cell membranes of walls in flexible foam that are broken or ruptured (but intact) which interfere with free air movement through the foam. Generally a high proportion of windows, as indicated by the shiny reflection of light through a cut surface, indicates a foam tending towards closed cells, which results in poorer physical properties.

Wave Length:


The wavelength of sound is the distance between analogues points on two successive waves.