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world’s leading technology for cutting thinnest high-quality hard foam sheet.

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the world's thinnest high-quality hard foam sheet.

Ground-breaking thin foam technology for pioneering lightweight innovations

MILLIFOAM® is a fine selection of foamed polymers that are skived into thin sheets. These thin sheets find their way into various lightweight composite technologies in different market segments. As individually selected and tailored to specific customer’s requirements MILLIFOAM® core decrease the weight and increases the stiffness of components at the same time. With the foam core thickness range of 0.5mm up to 7mm MILLIFOAM® is used for thin structures as well as for high performance composites. In all cases it is the goal to exploit the entire lightweight potential.

The foam grades used to produce MILLIFOAM® sheets range from Evonik PMI over DIAB PESU, 3A Core Materials PPSU, Gurit PET and many others. Depending on the foam grade MILLIFOAM® sheets have different thickness ranges and specific properties. A good overview can be found in the datasheet collection we provide for MILLIFOAM®.

A special property of our method of skiving foam block is, that the polymeric foam structure is retained and there are hardly any ruptures of the cell structure after the skiving progress. This is especially advantageous if MILLIFOAM® is used in combination with resin systems, where the resin ingress is an important parameter. This leads also to the production method for the composite where MILLIFOAM® is planned to be used as a core.

MILLIFOAM® can be used for all common production methods like resin transfer molding method (RTM), autoclave processing or prepreg production. It is a matter of process duration, temperature and pressure – also in relation to the thickness of the foam sheet.

Millifoam MYcell

We have an extensive database  for all grades and thickness ranges of MILLIFOAM® available. It enables us to select the right foam grade and to adjust the production parameters in coordination with our customers.

A unique property of MILLIFOAM® is its drapability – although the original material may be stiff or brittle, the sliced foam sheets show outstanding mechanical properties. Depending on the radii, MILLIFOAM® can normally be draped on without any additional treatment. That reduced the efforts in the manual lay-up process and ensures component consistency.

MILLIFOAM® thin sheet can be produced with very high thickness accuracy, taking into account that the base materials are usually closed cell foams of rather low density. This is a unique advantage for selected applications, whether the goal is to create ultra-thin sandwiches for acoustic applications, or a precise composite with a surface coming close or reaching highest surface quality (class A). The accurate adjustability of the foam core thickness therefore provides a highly reproducible starting product for further processing.

MILLIFOAM® is a universal foam core solution for many different various applications that need stable core material for thin composites. In addition, we offer our customers our outstanding know-how on foam sheets and composites. 


MILLIFOAM® is made of well-known foam grades using a unique skiving process. We provide our customers a wide range of thin hard foam sheets suitable for different application in high performance laminates. Additional, the superior surface finish of MILLIFOAM® sheet offers our customers an advantage in the further processing.

Millifoam sortiment

When thinking about using a thin foam sheet for the first time in a laminate there are several aspects to consider like the production method, the process temperature and used pressure, the compatibility to the resin system and the availability of foam dimensions. Due to our years of experience we can easily find the right solution with our customized MILLIFOAM® foam sheet. Soon after definition of the requirements, a preliminary foam selection is made, and samples can be provided for first lamination trials.

MILLIFOAM® is also applicable for 3D shaped laminates. Even rigid foam types gain on drapability when they are cut very thin. Therefore foam sheets can be deformed and laid up to a certain extend. This is an additional advantage of MILLIFOAM® that is mainly know from conventional core materials.

Due to our broad customer maarkets and product deversity, we can provide various MILLIFOAM® sheets very quickly. A large varienty of foams in our stock enables us to provide foam sheets for first trials rapidly, which is affordable in the prototype phase of a product or first trails, before going to the first production stage.

MILLIFOAM® is the best choice when it is planned to enhance a composite part, because the stiffness can be increased, the weight reduced, acoustic behavior optimized and costs reduced.

MILLIFOAM® is defining a new standard of foam sheet quality. It is setting itself apart in regards of surface quality, tightest thickness tolerances and selectable foam grades.

Certifications and Standards


The foundation for the ultrathin MILLIFOAM® hard foam sheet products have been implemented almost 20 years ago. These were the days when cell phones were on the verge to become what they are today: A device that we have always on our side, that we use for communication, for internet banking, for social media, to watch videos and much more. Twenty years ago only a few 100 million cell phones per year were delivered, this figure has grown to over a billion per year today.

How does this link to MILLIFOAM®? MILLIFOAM® is widely used in smartphone acoustics especially for the speakers. The more the phones minimized their size and got thinner to become handier, the more our quality expectations went up. It increased the need to get the speakers thinner and to raise the sound quality at the same time. 

One excellent way to improve the sound quality is to use very thin, stiff and light sandwich structures made from thin aluminum and thin foams. They are placed on the top of the speaker membrane and help to adjust the speaker regarding its frequency response and its sound pressure level. Reinhard Hafellner, founder and CEO received a request for such sandwiches out of his professional network. He recognized the potential of sandwich material with foam core and started with the lamination of specific dome sandwiches. Based on this knowledge the MILLIFOAM® technology has been developed. To achieve a perfect sandwich, a precise and light foam core was needed, which was hardly available at that time. So, Reinhard Hafellner started the development of a unique foam skiving systems in 2004 and founded 4a manufacturing at the same time. It started with a few different foam types and a cutting machine in a prototype stage. Since the first customers were already there, the production increased and the team of the 4a manufacturing also grew. Soon it was possible to establish tight relationships with foam core suppliers to be able to establish a wide range of speaker domes. Throughout many thousand cutting trials and continuous improvement of the skiving process, MILLIFOAM® has established a new worldwide standard for thin foam sheets.

Over the last years the annual production of smartphones has risen to around 1.4 billion devices per year. To meet the increasing demands, 4a manufacturing decided to install a second, more versatile skiving machine. As a result, the product range could be widened and the selection of processable foam cores was further expanded.

Today MILLIFOAM® is the core material for several hundred million of smartphones that are produced every year. The precise thickness and the ultrathin sheets that can be a thin as 0.5mm make MILLIFOAM® an unexchangeable foam core with top notch technical properties.

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