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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.

Understanding What the Vertical Contour Cutting Machine Can Do

Contour Cutting is an Excellent Capability for Custom Foam Fabrication

It's difficult to cut curved profiles in foam and get smooth edges. Reciprocating tools tend to tear and leave unsightly steps while methods like water jet and die cutting have limitations with thick materials. In these situations it makes sense to use a vertical contour cutting machine.

Operating principle

Like the band saw used in many industries, vertical contour cutting machines use a continuous steel blade held vertically under tension. The work material, (usually foam,) is placed on a flat table that moves it into the blade to make the cut. Looped over pulleys, the blade moves continuously in one direction, ensuring that it's always cutting, (unlike with a reciprocating saw where half the motion is wasted.) Computer control over both the blade and the table motion allows production of complex shapes.

The cutting blade

As with any sawing process, the teeth shape and pitch must suit the material being cut. For foam 12 to 14 teeth per inch usually gives the optimal combination of cutting speed and edge finish. Some materials cut better with a wave form rather than teeth while others need only a flat knife blade.

The blade itself is made from high quality steel and measures 3.6 mm (0.144") deep and just 0.6 mm (0.024") in thickness. This geometry has two benefits. First, being very thin, there's minimal cut waste, which also minimizes the amount of dust produced. Second, it makes the blade maneuverable.

Blade maneuverability is one area where the vertical contour cutting machine differs from a regular band saw. The contour machine can rotate the blade through 360 degrees. Combined with the shallow blade depth, this lets it turn to cut complex shapes without compressing the foam.

Motion control

The vertical contour cutting machine has three motion axes under computer control. The table moves in one direction, pushing the foam through the blade. Carried on a bridge over the table, the blade can move left and right. If the blade and table moved at the same speed a foam block on the table would be cut at a 45 degree direction.

Axis three is blade rotation. It's this which lets the machine cut circles, corners with tight radii and complex contoured shapes. Internal holes in foam shapes are possible with just a single entrance/exit slot, (which is usually needed for fitting around bars, pipes, extrusions, cable conduit and so on.)

Machine capabilities

Merryweather's vertical contour cutting machine handles blocks of material up to 55" by 94" by 25". Cutting speed is as high as 230' per minute, depending on material density and whether bonded or laminated. Materials appropriate for vertical contour cutting include:

  • Polyurethane
  • Convoluted foam
  • Polyethylene
  • Cross-Linked polyethylene (XLPE)
  • Expanded polyethylene (EPE)

Material with densities up to 9 pounds can be cut, as can bonded layers of foam and foam laminated with either foil or textile material.

Process characteristics

  • Straight, smooth sides produced on thick foam blocks.
  • Cuts complex 2D shapes.
  • Programmed directly from CAD files.
  • "Nesting" function in software maximizes material utilization.
  • No tooling, so no tooling costs or delays for tool manufacture.
  • Ideal for small quantity orders
  • Small "kerf" (cut width) means minimal waste and dust.

Quality results

A vertical contour cutting machine is the best way of producing smooth, straight-sided shapes in soft materials like foam. Merryweather's machine handles large blocks of material quickly and efficiently with minimal waste. As no tooling is needed this process is ideal for both small and large quantity orders.​ Not sure if vertical contour cutting is the right capability for your project? Get in touch with us and we will be happy to answer any questions you have about custom foam fabrication cutting capabilities. 

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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.

Advantages

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.

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Engaged And Efficient: Why Merryweather Foam Embraces Lean Manufacturing

Successful People vs Unsuccessful People

Corporate waste isn't just a poor business move; it's a betrayal of loyal customers. Every piece of the production process that does not contribute to the final product means delays and high prices for patrons. Merryweather is committed to minimizing these costs and constantly improving our products and prices, which is why we have adopted lean manufacturing.

A Look at Lean Manufacturing

Lean manufacturing is a broad set of methods used to eliminate waste in the production process. While the specifics vary by company, lean methods usually involve:

  • Simplifying Systems - The fewer parts a system has, the less likely it is that something will go wrong, and the less energy, resources, and oversight it takes to maintain it.

  • Measuring Methodically - The more specific information a company has on production rates and times, the easier it is to set goals for improvement and meet them.

  • Correcting Continuously - Lean manufacturing companies are always on the lookout for waste, making sure that every part of the production line works as well with the others as possible. They are thus able to deliver an ever-increasing level of efficiency.

Merryweather has long embraced lean methods for all stages of production and distribution. These methods have allowed us to improve profits while delivering lower costs and better services to all our customers.

​It's a Personal Journey That Begins with Me
We believe that lean manufacturing begins on a personal level with our entire team--from the receiving dock to the factory floor to our executive offices. We believe in setting goals to continuously improve on both a personal and professional level. Our company culture encourages our team members to ask thoughtful questions throughout the daily scope of their job and to seek out ways that we can learn and grow together. The result of this mindset is a collective group of determined people that seek to serve of our customers. 

Additional Advantages

Besides lower prices, lean manufacturing has allowed us to offer:

  • Safe Jobs - Complex, wasteful systems are harder to monitor, putting employees at risk. By eliminating waste, we reduce the likelihood that our workers will be injured.

  • On-Time Deliveries - Lean manufacturing systems have few delays, and when delays do occur, it is not as difficult to diagnose and fix them. This makes it easier for us to finish and deliver all orders on time.

  • Endless Options - By minimizing delays in the production process, lean manufacturing allows us to quickly modify our methods and adapt in order to fill unique foam orders. It also lowers the chance that unique orders will disrupt ordinary production in ways we don't anticipate.

  • Fast Prototyping- Lean manufacturing allows us to speed up prototype testing, minimizing the time it takes to adopt new methods or sell new products.

Adopting lean manufacturing isn't just a profitable move. It represents our commitment to treating our customers, employees, and community as well as we can. By improving efficiency, we are able to regularly make our work both better and safer, ensuring satisfaction for everyone involved.

For more information about our company or for help on your next custom flexible foam project, contact Merryweather today.

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Seven Surprising uses for Reticulated Foam

Ever unloaded the dishwasher and found the spoons or knives didn't come clean because they were stuck together? Well imagine that happening with surgical instruments. Placing instruments in bags made from open-cell foam is one way healthcare professionals avoid this. Steam reaches the surfaces but foam keeps them from touching.

Open-cell is another term for reticulated foam. One way of visualizing reticulated foam is to picture a mass of bubbles, then think how they'd look if the wall between each bubble was removed. Effectively, you'd have a three dimensional mesh where every cell is open to its neighbor. Cell size and density are controllable during manufacture. Density is specified in terms of pores per linear inch (ppi) and is controllable from 4 to 100 ppi. (A larger number means smaller pores.)

This results in some interesting and useful properties. Reticulated foam is compressible, yet springs back when the load is released. It's lint-free, porous, and at under two pounds per cubic foot, lightweight. As a result, it's used in a very wide range of applications. Here are some that may surprise you.

  1. Blood filtration and oxygenation. Heart-lung machines put oxygen back into blood, but tend to create bubbles. Passing the blood through a felted reticulated foam breaks these up, making it safe to return to the body.
  2. Air filtering. From automobile cabin air filters to nebulizers, there's a long list of air filtration applications. Even small lawnmower engines use reticulated foam to prevent dust and grit from being sucked in.
  3. Filtering molten metal. In casting, as metal is poured into a die it's important to remove impurities. Reticulated foam wouldn't withstand the heat; instead it's dipped into a ceramic slurry which dries to leave a more durable, heat-resistant mesh.
  4. Stabilizing fluid in tanks. Gasoline in an empty tank will slosh about, but fill that tank with reticulated foam and the gasoline moves slower. The foam can also help dissipate static, reducing the risk of fire if the tank ruptures. (Ink jet printer cartridges are a similar reservoir-type application.)
  5. EKG pads. Electrical conductivity between skin and electrode pads is improved with a specially formulated gel, but applying this adds a rather messy step. Reticulated foam EKG pads are pre-impregnated with the gel, saving time on prep and clean-up.
  6. Sound absorption. Reticulated foam makes an excellent windshield for microphones. Sound still penetrates but wind buffeting is absorbed, eliminating most background noise.
  7. Surgical instrument sterilization. Discussed before, reticulated foam: allows steam to penetrate, stops instruments touching, and avoids lint carryover.

Is your application next?

Reticulated foam is surprisingly versatile. With an open cellular structure it can filter or stabilize fluids, so finds application in areas ranging from motorsport to healthcare. If you're interested in learning how this lightweight material could benefit you, contact Merryweather today.

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Thick Material? No Problem! We can cut with Pressurized Water

Our water jet cutting machines leaves clean, straight edges in thick foam. Try it on your next custom foam fabrication job.

Cutting soft materials like foam is hard. Try pushing in the blade of a knife and the material compresses. The thicker and softer the foam is, the more it deflects. The only way is to use the point of the knife: once the surface is pierced the blade can go through.

That's why we have a waterjet cutting machine. Like an incredibly sharp knife, it lets us cut complex profiles from soft materials up to 6" thick. If you need pieces for a flexible foam fabrication, talk to Merryweather about waterjet cutting.

Process basics

In waterjet cutting a needle-thin jet of water moving at near supersonic speed slices through soft material. By moving the jet over a sheet of material it's possible to cut out intricate two-dimensional shapes. Recessed pockets can't be cut with a waterjet though, because it goes all the way through. Instead, the way to make those is from two separate pieces of foam. Combining waterjet-cut pieces that way allows creation of almost any custom foam fabrication.

Why cut with water?

It's a fast way of cutting out large, complicated shapes. It's a clean process with no chemicals or hazardous wastes, and has many other useful characteristics too.

  • Pierce straight through so there's no need to cut in from the outside. Essential for creating contiguous shapes with hollow centers (as you'd need for a pocket.)
  • Cuts very square, even on materials like thick reticulated polyurethane foam, and leaves smooth edges needing little to no finishing.
  • Very narrow cut width or "kerf" thanks to the thin beam. This allows cutting of very intricate shapes and lets us nest shapes to use a sheet efficiently.
  • No sideways forces, so there's no material distortion. This also lets us cut very thin wall sections.
  • No heat, unlike laser cutting, so there's no unsightly edge melting or heat affected zone.
  • There's no tooling or fixturing. All that's needed is a program for the waterjet's computer, and that comes from the CAD of the shape needed.

When is waterjet cutting appropriate?
With no need for tooling, waterjet cutting is ideal for one-offs such as for prototypes or for custom applications needing only a few identical shapes. As a single point-of-cut process, it's not the fastest method but does yield excellent results on thick, soft materials like reticulated polyurethane foam. Waterjet machines are also capable of cutting out very large shapes: ours handles sheets of material up to 60" by 132".

Small quantities that look good
Materials that are thick and soft, like those you might use in a custom foam fabrication, are difficult to cut cleanly. When appearance matters, tooling-free waterjet cutting is a cost-effective method of producing the shapes you need. If you're interested in learning more, contact us today.

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