It’s not a title. Not a number of years. It’s what you do when things get complicated.

At FAP, when we talk about experience, we don’t just mean our history - we mean everything we’ve learned by facing new challenges every day.
Experience is when you truly listen to a customer and understand what they need, even if they’re struggling to explain it.
It’s when, faced with a problem, you don’t stop - you change perspective. And you find a way forward.

Experience can’t be taught. It’s built, step by step.

We’ve designed and built hundreds and hundreds of machines. But what really matters isn’t the number - it’s the details.
Every customer has taught us something. Every project has made us better. Every mistake has made us stronger.

You won’t find that kind of knowledge in a manual.
It lives in the hands that weld, in the eyes that review a drawing, in the voice that advises a customer like a colleague.
It’s what makes our work faster, more effective - and more human.

Solution-oriented, not problem-focused

We can’t foresee everything. But we can face anything.
Our approach is simple: understand, analyze, solve.
We do it alongside our clients, in open dialogue.
And we do it internally, supporting one another, sharing knowledge, and offering our experience to those who have less.

Because for us, experience also means generosity - the ability to pass on what you’ve learned.

Tailor-made technology, real-world experience

Every FAP machine is different, because every need is different.
And often, behind a request, there’s something the customer can’t quite express: a new production need, a non-standard material, a space or time constraint.

That’s where experience comes in.

Not as a ready-made solution, but as a way of adapting.
Of creating something that works - really works.
Of turning a problem into an opportunity.

Here, our 'technical' icon of Experience transforms into a special work of art.

These values are not just principles - they are the way we work, every day.

Experience: The Ninth Pillar of FAP’s Identity

In previous months, we introduced other core values of our daily approach:
Flexibility, Our ability to adapt to the needs of each project and each client.
Listening, The attention we give to those who work with us and rely on us.
Integrity, The transparency and consistency that guide our words and actions.
Efficiency, Getting things done with clarity, speed, and purpose.
Reliability, How we build, how we respond, and how we follow through.
Collaboration, We believe in co-creating value.
Innovation, Only has value when it generates Real Impact.
Growth begins by looking inward.

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Experience is what remains when the manual ends

If you’re looking for a partner who doesn’t just give you an answer - but the answer that works - we’re here.
With experience you can see, feel, and rely on.

Discover Our Tailor-Made Technologies for Your Production

From October 8 to 15, we’ll be in Düsseldorf at K2025, the world’s leading plastics and rubber trade fair.
You’ll find us at Hall 16 / Booth 16D68 – and we’d love to meet you.

At K2025, FAP will present the best tailored solutions:

• Foam twin screw counter rotating extrusion lines for foam productions as EPE (expanded polyethylene), EPP (expanded polypropylene) and EPS (expanded polystyrene)
• Soft Winders for foam and bubble wrap film
• Hot laminating lines for industrial applications
• Cutting and bag-making machines for flexible materials

Each project reflects our way of working: listening first, designing custom solutions with care, and building long-term partnerships. Every machine is unique - and so is every conversation that shapes it.

But this year, there’s more than just technical solutions.

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✳ A Space for Values. A Space for People.

Inside our booth, we’re creating something unexpected and emotional.
It’s not about automation or technical features. It’s about what makes us human.

At FAP, we believe that our values are the real roots of everything we do. Each month of this year, we highlight one core value - Listening, Integrity, Efficiency, Innovation - and show how it drives our daily work, from engineering to after-sales service.

At K2025, we’ll celebrate these principles with a dedicated Values Corner – a space to pause, reflect, and reconnect with what matters most.

Because in today’s world, where automation, high-speed production, and streamlined processes dominate, we need to remember what keeps companies and people grounded.
Like the roots of a tree, values are invisible but essential: they support growth, give direction, and connect us to something meaningful - even as everything around us accelerates.

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✳ Stop by Our Booth...

With more than 3,000 exhibitors at K2025, it’s easy to get lost in the noise of machines and innovation.

That’s why we invite you to slow down and meet us.
Not just to explore high-performance foam extrusion technology for example, but to have a real, valuable conversation.

Let’s talk about your production challenges, your goals, and how we can support you create your next big success - with technology that fits your process, and a team that’s here for you.

Because your project deserves more than a standard solution.
It deserves our expertise - and our attention.

📍 We’re already scheduling meetings for K2025.
If you’d like to reserve a time slot, get in touch with us.

We’ll be there.
Will you?

In a world that changes every day, staying still is not an option.

That’s why at FAP, we’ve chosen to grow – together.

Growth, for us, is not a destination. It’s a daily choice.
It’s what pushes us to ask better questions, embrace new challenges, and become better - as people, as professionals, and as a team.

Learning is the first step to delivering more value

At FAP, we believe that real growth happens when learning becomes part of your culture. That’s why we invest in training: from technical updates to language support, from safety to commercial skills.
Every course is a tool - not only to perform better, but to think differently.
And when our team evolves, the value we deliver to our clients evolves too.

Growth begins by looking inward

But growth isn’t just about acquiring knowledge. Sometimes it means stopping to look inward.
We’ve taken the time to question our processes, improve our workflow, and face inefficiencies head-on.
This requires courage and collaboration. And it’s through these internal reflections that we’ve built a stronger, more agile organization - one that works with clarity, shared vision, and trust.

A healthy environment allows people to grow

There’s also a more subtle kind of growth. The kind that doesn’t show up on spreadsheets but is felt in the everyday atmosphere.
At FAP, we take care of our environment - not only the physical one, but the emotional one too.
Respect, listening, space for ideas: these are the conditions where people can truly thrive.
Because no machine can do what people do when they feel valued and heard.

Challenges are where real growth happens

And then there’s the growth that challenges us. The unexpected project. The client request that seems impossible. The moment when time is short, specs are unclear, and the pressure is high.
We’ve learned to welcome those moments.
They’re the ones that push us to stretch, to create, and to build something that didn’t exist before.

Here, our 'technical' icon of Growth transforms into a special work of art.

Growth means staying true to who we are

Still, we never want to grow for the sake of it. Growth without meaning is just movement.
What we want is growth with purpose – rooted in our values, aligned with who we are.
We want to grow in competence, but also in relationships.
To grow in results, but never lose our human side.
To grow without losing the essence that has always made FAP… FAP.

These values are not just principles - they are the way we work, every day.

Growth: The Eighth Pillar of FAP’s Identity

In previous months, we introduced other core values of our daily approach:
Flexibility, Our ability to adapt to the needs of each project and each client.
Listening, The attention we give to those who work with us and rely on us.
Integrity, The transparency and consistency that guide our words and actions.
Efficiency, Getting things done with clarity, speed, and purpose.
Reliability, How we build, how we respond, and how we follow through.
Collaboration, We believe in co-creating value.
Innovation, Only has value when it generates Real Impact.

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Let’s grow together

We don’t have all the answers. But we’re not afraid to learn.
If you’re looking for a partner who sees every project as a chance to evolve -
we’re ready.

Let’s build the next solution, together.

Advantages and its areas of application

Physically foamed polypropylene (EPP) and cross-linked polyethylene foam (XLPE)

There is no point in comparing non-crosslinked physically foamed polyethylene (EPE) with physically foamed polypropylene (EPP), since these materials are completely different in performance characteristics.
But we will look at some comparative characteristics of EPP and physically cross-linked polyethylene foam (further on XLPE), since the last one is closer in performance characteristics to EPP.

It can be seen that in terms of the comparative characteristics of thermal conductivity, elastic modulus and application temperature, EPP is superior to XLPE. Does this mean that EPP can replace XLPE in all applications? Of course not.

XLPE has excellent shock-absorbing properties, are much more elastic materials, have the same low thermal conductivity and a number of other qualities that differ from non-cross-linked polypropylene foam, which are necessary in some industries.

Global Goal

One of the main tasks of the global community today is to create a closed-cycle industry and introduce easily recyclable materials into our daily lives.

Physically and chemically cross-linked foams (XLPE) are very difficult and expensive to recycle, and the process is poorly organized. As EPP can be recycled by a rather simple granulation process and can be reused a large number of times. This fact creates closed-cycle production or closed-loop manufacturing, where all waste generated during the production process does not end up in landfills, but is very easily recycled internally in companies and used more times in the same foam manufacturing with different persantages. In addition, the production process of EPP is simpler and more efficient compared to the production of XLPE.

Applications where Physically Polypropylene foam EPP will dominate

Due to its superior characteristics described above, physically foamed polypropylene (EPP) is set to become a leading material in the following areas:

Insulation in construction:

• Soundproofing of impact and airborne noise during the construction of multi-storey buildings;
• Thermal insulation of constructions with high operating temperatures (saunas, hot water boilers, hot pipes);
• Reflective thermal insulation in the “warm floors”;
• Thermal insulation and sound insulation of metal roofing of buildings.

Insulation in the car interior:

• Sound insulation of the car floor and roof structure.

Food industry:

• Production of single-use tableware instead of polystyrene foam (EPS).

We have already talked about the possibilities and advantages of using EPP in single-use tableware and the reflection of thermal insulation in the “warm floor” design in our articles and posts. In this article we will consider exclusively those qualities of physically foamed polypropylene (EPP) that are necessary for using insulation under high loads and in environments with high operating temperatures.

Sound and heat insulation of "floating floor" systems under concrete screed using EPP in the construction of multi-storey buildings

The issue of sound insulation always concerns the floor of the room in building. In the most countries there is a strictly established standard (the permissible number of decibels transmitted through floor structures). To meet this standard, when building or renovating constructions, it is important to ensure that the floor is insulated as much as possible from airborne and impact noise.

In the construction of the so-called “floating floor”, a variety of insulating materials are used from chemically and physically cross-linked polyethylene foam to polypropylene foam, foam rubber, stone wool, as well as non-cross-linked polyethylene foam.

Physically foamed polypropylene (EPP) is the best way to soundproof a floor under a cement screed.
Below are the results of the durability test "12 months under a load of 2000 N/m²", which shows the change in the thickness of sound insulation from foamed polypropylene (EPP) and cross-linked polyethylene (XLPE) over 12 months.

From the diagramm above we read that the stabilization of the thickness of physically foamed polypropylene (EPP) occurred at the end of the third month, and the loss of thickness at the end of 1 year was 10-11% of the original. Stabilization of the thickness of the crosslinked polyethylene foam (XLPE) occurred at the end of the fifth month, but the overall thickness loss was 20%.
Thus, after a year, the impact noise reduction rates for physically foamed polypropylene (EPP) decrease by approximately 4%, for cross-linked foamed polyethylene (XLPE) by 10%.
Decreasing impact noise reduction results in increased sound transmission through the floor in the room.

Thermal insulation of rooms and structures with high operating temperatures

Below are the shrinkage test results of physical polypropylene foam (EPP) and cross-linked polyethylene foam (XLPE) under various temperature conditions for 48 hours.

Please note that after the use temperature exceeds 105 °C for a long time of use, XLPE begins to deform quite severely.

As for physically foamed polypropylene (EPP), it can be used in conditions of constant high temperatures up to 125-130 °C, which gives this type of insulation additional advantages.

Physically foamed polypropylene (EPP) is an ideal solution in many industries

The production of this unique material is safe and environmentally friendly, which is one of the most important factors. Due to its molecular structure and a number of other qualities, EPP is quite easy to produce using carbon dioxide as a foaming agent, which creates additional value for this product.

We are confident that expanding the use of non-cross-linked Polypropylene Foam on the market replacing a number of difficult-to-recycle materials will allow to make our planet much better.

FAP’s Driving Force. Innovation and Research are the daily engine behind how we think, design, and evolve.

Innovation as Purposeful Progress

We believe that innovation only has value when it generates Real Impact.

Our Research and Development is driven by a clear goal: to make our Machines Smarter, more Efficient, and Ready to face the challenges of modern production.

From materials to mechanics, from automation to user experience, every improvement is the result of Listening, Analysis, and Creativity.

We innovate with our clients and partners - not just for them.

Innovation Through Collaboration

Together, we explore new possibilities, identify shifts in the market, and develop ideas that turn into solutions.

We are often invited to industry events to share how the power of collaboration leads to progress.

This shared vision turns technical challenges into opportunities, and every project into a path for learning and growth.

Suppliers, clients, collaborators, and partners - all contribute to driving us forward.

Here, our 'technical' icon of Innovation transforms into a special work of art.

Research as a Culture of Curiosity

At FAP, innovation is also a mindset.

We encourage every team member to question the status quo, experiment with new approaches, and keep learning.

From engineering to after-sales, every department is invited to bring ideas to the table.

Because innovation doesn’t only happen in the lab - it happens in every corner of a company that dares to evolve.

These values are not just principles - they are the way we work, every day.

Innovation: The Seventh Pillar of FAP’s Identity

In previous months, we introduced four other core values of our daily approach:
Flexibility, our ability to adapt to the needs of each project and each client.
Listening, the attention we give to those who work with us and rely on us.
Integrity, the transparency and consistency that guide our words and actions.
Efficiency, Getting things done with clarity, speed, and purpose.
Reliability, How we build, how we respond, and how we follow through.
Collaboration, We believe in co-creating value.

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Let’s Build Something Together

Looking for a partner who will understand your needs and turn your ideas into a high-performance solution?

Let’s Innovate.

Because when people work together, unique solutions - and lasting results - are born.

At FAP, we understand that the extrusion of gas-filled polymers is a critical process requiring precision and the right equipment. However, the lamination of physically foamed materials is equally important. This process involves bonding foamed polymers either to themselves (to increase thickness) or to other materials like reflective foil, PET, and HDPE, enhancing the final product's physical and mechanical properties. Our Laminator models has been specifically developed to ensure optimal lamination results, guaranteeing both flexibility and high performance in this delicate phase.

Though lamination might seem simple, it has many nuances that can affect the final product's quality, productivity, workplace safety, and production costs. What technical features of the equipment can be both an advantage and a significant drawback? Here’s what manufacturers and / or "converters" should consider when selecting equipment for laminating physically foamed polymers and bubble wrap:

1. Hot Roll Heating System: How was the Teflon applied? How is the "hot" Teflon roll heated? What is the longevity of the Teflon coating?
2. Air Blade Design: Is the airflow evenly distributed? What is the risk of material delamination?
3. Safety and Automation: What safety and automation systems are in place? How efficient is the operator’s time and energy in producing one unit of quality product?

Why Do Most Foamed Polymer Manufacturers in Europe and Beyond Choose FAP Hot Laminators?

For nearly four decades, FAP’s closed-cell foam polymer lamination technology has been trusted in Europe, North, and South America. Continuous improvement by our team of engineers and technologists, combined with a deep understanding of critical processes like "degassing" of physically foamed polymers and adhesion changes under complex esters and antistatic agents, allows us to create unique and high-quality lamination lines.

What sets FAP hot laminators apart to drive manufacturers to choose them?

• Advanced Heating System: FAP’s lamination lines feature a hot oil temperature regulation system for the Teflon roll, maintaining temperature within +/- 1 degree Celsius. This eliminates risks of deposits, heat loss, and uneven surface temperatures.
• Special design of Air Blade: Our unique air blade design evenly distributes hot air, ensuring consistent adhesion during lamination. Adjustable air blade positions further enhance the production process.
• Reliable Components: We use only the most reliable components from international brands like Siemens, ABB, and Leister.
• Efficient Winding Systems: Our lamination lines include winding devices with automatic rod rotation and a unique "soft winding" system.
• Non-Stop Production due to High Automation Levels: Accumulators allow for changing the foamed semi-finished product without stopping the line.
• Safety Systems: Our unwinding, cutting, and heating elements meet all certification requirements, ensuring a safe production process.

FAP hot laminators: The trusted choice for reliable, efficient, and high-quality production.

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The Value That Powers Every FAP Machine

At FAP, when you walk through our doors, you don’t just find machines - you find people working together. Engineers and technicians, sales teams, suppliers, and clients, partners. Because collaboration isn’t just a phase in our workflow - it is our workflow.

In a world of manufacturing, true innovation happens through collaboration. For us, it means building side by side - understanding every perspective, every expertise, and turning shared knowledge into cutting-edge, custom-built solutions.

Why Collaboration Matters in Industrial Machinery

The best machines aren’t born from a single idea. They are the result of open dialogue, technical exchange, and mutual trust. That’s why every FAP project starts - and evolves - through continuous communication with our clients.

Our machines are built for foam extrusion, lamination, and custom converting applications, but their foundation is always the same: a collaborative process that aligns technology with our clients’ real needs.

Real collaboration begins with listening, grows through flexibility, is anchored in integrity, and delivers results through reliability.

That’s why collaboration is the natural evolution of our values - and the force that connects them all.

Here, our 'technical' icon of Collaboration transforms into a special work of art.

Collaboration Across All Departments

Our machinery is custom. So is the way we work.

From design to delivery, every department at FAP contributes in synergy. Technical, commercial, production, and service teams share the same vision and work together to achieve it.

This internal synergy enables us to deliver smarter and more reliable machines - and that translates directly into better performance for our clients.

Collaboration With Clients: Co-Creating Solutions

We don’t just deliver equipment. We build partnerships.

Our most successful projects start with mutual understanding, grow through open feedback, and thrive on long-term collaboration. That’s how we go beyond meeting specifications - we exceed expectations.

When you choose FAP, you’re not just choosing a supplier. You’re choosing a technical partner who listens, supports, and co-creates with you.

These values are not just principles - they are the way we work, every day.

Collaboration: The Sixth Pillar of FAP’s Identity

In previous months, we introduced four other core values of our daily approach:
Flexibility, our ability to adapt to the needs of each project and each client.
Listening, the attention we give to those who work with us and rely on us.
Integrity, the transparency and consistency that guide our words and actions.
Efficiency, Getting things done with clarity, speed, and purpose.
Reliability, How we build, how we respond, and how we follow through.

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Let’s Build Something Together

Looking for a partner who will understand your needs and turn your ideas into a high-performance solution?

Let’s Collaborate.

Because when people work together, unique solutions - and lasting results - are born.

Why is it so important to choose the correct GMS dosing during the foaming/expansion process to produce high quality PE (polyethylene) or PP (polypropylene) foam material?

Simply because GMS, being an emulsifier and one of the most significant components, has a huge influence on many factors.

GMS is a crucial element in cell formation

During the foaming process, surface tension plays a crucial role. It refers to the physical effect that occurs when the blowing agent (such as butane, CO₂, or others) expands under heat inside the extruder. This phenomenon happens precisely when the blowing agent stops flowing and begins forming new foam cells at the point of critical expansion, stretching the walls of already existing cells.

The additive GMS (glycerol monostearate) helps reduce surface tension during this phase, facilitating smoother and more controlled cell formation. By lowering resistance on the cell walls, GMS improves the structural development of the foam, leading to more stable, uniform, and high-quality results.

GMS and Degassing: Controlling Gas Diffusion in Foam

Increasing the amount of GMS (glycerol monostearate) in the formulation can enhance the foam expansion process, but it also introduces several challenges. A high concentration of GMS tends to migrate from the lower layers of the foam to the upper layers, which creates a barrier to gas replacement with air. This results in:

• Longer conditioning times for rolls stored in the warehouse
• Foam structure rupture due to post-production gas expansion
• Formation of irregular or damaged cells
• Potential reduction in lamination quality caused by gas residues and surface GMS buildup

On the other hand, an insufficient GMS concentration can lead to the premature release of gas before the foam has properly stabilized, often resulting in foam collapse during or after production.

This is why it is essential to control GMS dosing accurately through production testing and technical experience. Avoiding both excess and deficiency ensures optimal foam structure, stability, and future lamination performance.

Foam Surface Quality: How GMS Reduces Friction and Static

Reduction of static charges on the surface of the foam during the production process - static charges accumulate on the surface of the foam as a result of friction - thus reducing the risk of fire

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The lower the density of the foam (kg/m³) and the saturation/gassing of it, the more the GMS will influence these factors.

Preventing Foam Shrinkage and Surface Defects in Low-Density Foams: The Role of GMS Dosing

One of the most common challenges faced by foam manufacturers working with ultra-light, low-density foams is the issue of shrinkage or rapid post-extrusion expansion during the conditioning phase in storage. This often leads to the appearance of surface bubbles, cracks, or breaks that compromise foam quality.

While some producers experiment with additional additives labeled as "Anticolaps", these products typically act in the same way as GMS (glycerol monostearate), offering no added benefit when used together. Thus, their use is generally redundant.

Best Practices for GMS Dosing in Foam Production

The optimal GMS concentration depends on multiple production parameters, including:

• Foam density
• Raw material feed rate (kg/h)
• Ambient temperature and humidity
• Day-night temperature fluctuations during storage and handling

Given these variables, accurate GMS dosing is essential for maintaining a stable foam structure and preventing post-production defects. A data-driven, experience-based approach to dosing ensures consistent quality and performance in PE and PP foam production.

We are not just an foam machinery designer & manufacturer, we are a developer of technological solutions.

Looking for a reliable partner in PE and PP foam extrusion?
Trust FAP’s experience in custom foam machinery and process optimization.

Contact us today to improve your production quality and reduce waste.

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May has already arrived, which means we are here to tell you about our fifth core value: Reliability.

You can’t fake reliability. It’s not about promises - it’s about showing up, doing the work, and doing it well, over and over again.

Reliability is a commitment we prove daily. It’s in every project delivered on time, every machine that runs for decades, and every time a client calls and knows we’ll pick up.

Here, our 'technical' icon of Reliability transforms into a small work of art.

Reliability as a Relationship

Trust is built over time, through consistency. We believe that being reliable means keeping our word when it’s easy - and especially when it’s not. That’s how long-term partnerships grow: with presence, responsibility, and results.

Reliability as a Product

A machine isn’t reliable just because it works today. It’s reliable when it performs just as well after years of use. That’s why we test, refine, and stand behind everything we design.

Our clients know: if it’s built by FAP, it’s built to last.

Reliability as a Mindset

Internally, we rely on each other. Every role matters, every handoff counts. We work in sync because we trust the people next to us. And that internal trust is what allows us to deliver externally - with confidence and continuity.

Reliability is the 5th value we’ve chosen to highlight as part of FAP’s identity.

We bring this mindset into every relationship - with clients, suppliers, and colleagues. We aim for results, not just actions. Furthermore, we know that true efficiency is built on preparation, organization, and mutual respect. Because being efficient means being reliable.

These values are not just principles - they are the way we work, every day.

In previous months, we introduced four other core values of our daily approach:
Flexibility, our ability to adapt to the needs of each project and each client.

Listening, the attention we give to those who work with us and rely on us.

Integrity, the transparency and consistency that guide our words and actions.

Efficiency. Getting things done with clarity, speed, and purpose.

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Let's figure it out together.

How to Produce Low-Density Physically Foamed Polyethylene Foam (EPE): Myths, Limits, and Real Solutions

Reduce Raw Material Costs Without Compromising Foam Quality

In today’s highly competitive foam polymer market, manufacturers are constantly looking for ways to reduce production costs. One of the most common strategies is to reduce the density of expanded polyethylene (EPE) foam. Why? Because raw material costs can account for up to 55% of the total cost per square meter. Even a 10% reduction in weight can lead to significant savings.

But how far can we go without sacrificing product quality, mechanical strength, or dimensional stability?

But at the same time, how can we avoid an increase in defects such as collapse, cell rupture, a decrease in the physical and mechanical properties of resistance to loads, etc. when reducing the density of physically polyethylene foam (EPE)? In addition, the question arises, what is the minimum density of the finished polyethylene foam product that we can obtain in the extrusion process so as not to have problems with quality later? Can we be sure that after a week of keeping the products in the warehouse we will not have to dispose of and granulate the entire batch or, even worse, pick up this defective batch of products from the customer's warehouse?

We often receive requests like:

"Can your extrusion line produce EPE foam with a density of 12 kg/m³ (0.75 lb/ft³) and still guarantee quality?" or again
"We bought a line recommended at a trade show, but we can’t achieve densities below 14 kg/m³ (0.87 lb/ft³). Can your engineers help us set it up properly?"

The purpose of this article is to clarify once and for all the TRUTH and the MYTH about the physical foaming of ultra-low-density polyethylene.

How to calculate the gas saturation coefficient of molten polymer and why it is impossible to cheat the laws of physics. Where is the limit of density reduction of physically foamed polyethylene and why most of the information on the market has nothing to do with REALITY.

Let’s be clear: producing physically foamed, closed-cell polyethylene with a density below 13–14 kg/m³ in a continuous extrusion process is a myth. Here’s why.

Let us remind you that we are talking exclusively about foaming polyethylene, polypropylene or polystyrene by extrusion and the solubility of liquefied hydrocarbon gases in them under pressure.

Yes, of course, various tests were carried out, such as obtaining physically foamed ultra-low density polypropylene in the range of 10 kg/m3 (0.62 lb/ft³) by one of the largest manufacturers of foamed polyethylene in the world, but these tests did not find industrial application, since the process is simply impossible to control on an industrial scale.

It is no secret that the low density of physically foamed polyethylene is achieved by solubility in the melt of the largest amount of foaming agent, in our case, a gas such as Butane. The higher the viscosity of the gas and the greater its volume retained in the liquid state inside the extruder, the better the gas is dispersed into the melt and a smaller volume of it evaporates when the polymer exits the foam extrusion head (foam extrusion die).

During the extrusion of low-density polyethylene, the melt temperature in the extruder reaches 160-180 °C (320-356 °F) degrees and at this temperature it is necessary to maintain a minimum melt pressure (> 50 bar) so that butane has sufficient viscosity in the "borderline" state in order to mix with the polymer melt.

The technology of twin-screw extrusion with counter-rotation from FAP is capable of maintaining such a high melt pressure regardless of the pressure in the foam extruder head (foam extrusion die) and that is why this technology, unlike the most common single-screw extrusion on the market, is capable of producing both very thin foams with a thickness of 0.3-0.5 mm (1/64-1/50'') and foams with a thickness of 25-30 (1-1,2'') mm on the single line.

But even the counter-rotating twin-screw extrusion technology from FAP, which is the best technology for physically foamed polymers today, has a limit in the volume of gas dissolved in the polymer and, accordingly, the weight and density of the finished foam product.

The Physical Limits: Why You Can’t Cheat the Laws of Physics

Let’s break it down with an example:

Producing physically foamed polyethylene (EPE foam) with:

• Thickness: 2 mm (1/12'')
• Width: 2 meters (6,6 ft)
• Density: 15 kg/m³ (0.94 lb/ft³)
  
  Means dissolving about 4–4.5% gas into the melt. That’s already near the physical maximum for industrial processes. If you increase the gas content beyond this, you get:
• Foam collapse
• Cell rupture
• Shrinkage during degassing

That is, if we take the volume of the polymer mass of 250 kg / hour in the extrusion process, we can dissolve in it only 10-11 kg of liquefied butane, taking into account the polymer processing temperature and the melt pressure both in the extruder and in the extrusion head. The rest of the introduced volume will evaporate during the foaming of the polymer with a sharp drop in pressure. Increasing the solubility of gas in the melt is complicated by the fact that it is necessary to both reduce the melt temperature to increase the viscosity of the gas and significantly increase the melt pressure.

The second limitation is that with such a low density of foam plastic, the walls and edges of the cells are very thin and, accordingly, the risk of shrinkage, collapse of the foam plastic, or rupture of the cells during gas expansion is very high and is almost 100%. Such a low density is not a problem for open-cell foam plastics such as polyurethane, since there is not such a high pressure difference in the cells as in closed-cell foams. If we consider foamed polyethylene with a density of 12 kg/m³ (0.75 lb/ft³) during production, we will see that the foaming coefficient is 77.08, and the volume of the polymer itself per 1 m³ of foam (finished product) will be only 1.297%. As you understand, these figures are on the verge of fantasy.

To take wishful thinking as reality

Why Trade Show Samples Can Be Misleading

But how do we come across such light samples of physically closed-cell polyethylene foam at exhibitions? Today, more and more manufacturers declare such figures, misleading manufacturers. In fact, there is nothing unusual. As manufacturers, we measure the density during the production process, at the moment when the material is produced on the production extrusion line. But how does the density of foamed polyethylene change after the full degassing period, that is, when the butane inside each cell is replaced by air.

For visual calculations, let's take the same material of polyethylene foam with a thickness of 2 mm (1/12'') x a width of 2 m (6,6 ft) x a density of 15 kg / m³ (0.94 lb/ft³):

Thus, it is important to distinguish the time of measurements of the finished foam product and understand when these measurements were made.

At FAP, we believe in truth over marketing hype. Our goal is to help you find the most efficient and realistic production parameters for your application.

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Why FAP Technology Makes the Difference

✔ Counter-rotating twin-screw extruders
✔ Higher melt pressure and gas solubility
✔ Reliable low-density production
✔ Technical support and process optimization
✔ Full control over foam thickness and quality

Need to reduce your EPE production costs safely?
Talk to our team. We’ll help you reach the lowest density possible - without sacrificing performance or quality.