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We, Thermaflex

Spanning generations

The story behind Thermaflex starts in the 50's as a small carpentry workshop. Nowadays we are an international and geographically spread company on an exceptional sustainability mission: taking care of energy and environment

450 mln.m.
It's in our nature...

In the Ordovician, around 450 mln years ago, the first land plants appear. These begin to diversify in the Late Silurian, around 430 mln years ago. The tree develops into one of the oldest and largest, yet most durable life forms found in nature. It's efficiency perfected over the ages.

Oak trees, for example, are found all over the world in different climates: hot or cold, dry or humid. We are inspired by nature in everything we do. It is always systemic, smart and efficient in its solutions. We truly believe there are ever-inspiring sources and solutions yet to be discovered. We just have to learn to take a good look around, often just to see what is right in front of us.

Harnessing the virtues of oak into crafts

Our relation with the oak tree all starts with a small carpentry shop, where Wilhelmus Baars learns to harness the virtues of wood into crafting staircases, furniture, tubs, and other workmanship. While business is going well in Rotterdam, he also teaches his skills to his son, Wilhelmus Petrus.

Mechanising craftmanship

Wilhelmus Petrus Baars moves to the Waalhaven industrial harbor zone in Rotterdam, as he upscales his business and becomes 100% owner. Professional and industrial applications become the main focus. To improve the quality and lead time of his products, he searches for ways to bring structure and mechanism in craftsmanship

He and his son Wilhelmus Baars (II) proudly show the workshop, although it had suffered severe damage from the British air raids...


As the Netherlands starts to rebuild its cities after the war, demand increases. So they continue to look for ways to further automatize processes by mechanical saws, drills and other equipment. They extend their assortment with the production of doors and frames. In 1951, father and son have to move again to a larger, 2000 m2 facility on pier 2 in the Port of Rotterdam. At this time, they also detect an increasing demand for thermal applications, such as pipe clamps and shielding

Innovating with cork, nature’s finest insulating technology

Here, in 1951, Wilhelmus (II) realizes that cork is an excellent insulator developed by nature to protect oaks against the cold, heat and raging forest fires. Inspired by nature’s ingenuity, Willem adapts early Portuguese technology to produce pipe and sheet insulation based on cork as the first in the Netherlands. The unique characteristics of the material, including its insulation performance, fire resistance, and non-toxicity proves cork to be an ideal solution.

It makes an enormous difference in energy savings and (condensation) protection for applications in shipbuilding, commercial buildings, petrochemical industry, cooling applications and the first district heating systems in the sixties. In the meantime, the 4th son in line joins the company: Leendert Baars

Innovation and entrepreneurship pushes business

Leendert complements cork with the first chemical-based foams such as polyurethane and polystyrene, further growing the business. These new materials would largely come to replace cork and other traditional products. In the early '70s, he moves the company to Tilburg, in the south of the Netherlands

The Netherlands suffers badly from the oil crisis during the OPEC oil embargo. To protect against future crises, the country invests heavily in district heating. When renovating today's district heating systems, we often come across old cork and polyurethane-insulated - and heavily corroded- steel pipes

Thermaflex founded by Leendert Baars

With the rise of polyolefins, a start-up is established in the small town of Waalwijk, based on a complete new technology to produce flexible foam insulation from (cross-linked) polyethylene sheets. After a few months of experimenting with the conversion and welding of the material, the first production line is developed and Leendert's mission accomplished. Thermaflex is born

The introduction of this first innovative range of flexible insulation tubes and sheets quickly proves to be an easy and efficient solution for installers of heating and sanitary water systems in regular home applications. The durable, lightweight, resilient and closed-cell material delivers outstanding performance results

Introduction of “Quick Zipper”

Innovation certainly did not stop there. The idea is born to apply a new type of clasp to make installation even easier, and even quicker. It would take months of trial and error, but finally the ingenuous 'Quick zipper' would take the market by storm.

We still produce this component today, as the slightly improved  'Ultra M'


The insulation of heating and sanitary water installations would no longer only be a job for dedicated insulators. It becomes a piece of cake for professional installers and plumbers, who are happy to integrate this in their pipe works. With the second oil crisis at hand, energy saving becomes lucrative and now possible for every building owner. 

Introduction of Flexalen 1000+

At this time, in Austria's rising district heating market, a company called 'Flexalen' made a real breakthrough with Flexalen 1000+, a polybutene pipe system with polyurethane insulation segments. 20 years later, the next generation for this product is co-developed with Thermaflex and would lead to the major development of the most sustainable pre-insulated piping systems

A co-development with STEWEA for district heating in Vienna

First lamination of sheet insulation

The laminated insulation covers a wider range of thicknesses and special layers for more protection. This breaks open the market for surface insulation of tanks, large pipes and ventilation ducts

Direct extrusion of polyolefines developed

Direct extrusion presents a better alternative for the production of our flexible insulation, and so the first foam extruder is built in Waalwijk, the Netherlands. It would take over a year to get results, but finally the polyethylene insulation tube as we know it, is successfully extruded. Capacity increases and export to Germany and Belgium is started. 

And that very first extruder still runs today! Unsurprisingly, as even now it is still highly esteemed; it allows full recycling and expels the need for toxic additives while securing an outstanding insulation performance. This production line was copied over 20 times before the technology was upgraded in this century

Start of international expansion

Founding of Thermaflex Germany as a sales office, and Thailand as a joint venture for both production and sales. In the same year the first indications arise that the use of ChloroFluoroCarbons (CFC’s) as blowing agents pose a serious threat to the ozone layer. Thermaflex starts co-development with TNO for CFC-free production

Successful fresh ideas from Germany


Thermaflex Asia becomes a full subsidiary. Projects quickly develop in the hospitality business of South-East Asia

Thermaflex Insulation Asia Ltd, the start of great things...

(H)CFC-free production

Thermaflex becomes the first company worldwide to completely switch over to (H)CFC-free production. After much research and experimentation, this could be realized without any loss of quality

This expertise is transferred to Thailand, and companies all over the world soon show interest in our know-how of (H)CFC-free production. Making the technology available for fellow insulation producers in e.g. Slovenia and Italy, Thermaflex stimulates the branch to strive for (H)CFC-free production. 


Establishment of Thermaflex sales and distribution in Worclaw, Poland. This paved the way to boost renovation and energy efficiency of buildings in Poland. In the same year, a co-extrusion development in the Netherlands takes form to cover insulation pipes with a protective layer

The Polish market proved to be fruitful. Just as in many states behind the former Iron Curtain, insulation had barely been applied in construction. The market develops at breakneck speed due to highly successful sales and marketing


Establishment of a joint venture with partner Form to switch their existing foam production to our technique. This leads to a production plant in Ankara. Thermaflex sees more and more projects in tropical climates because of the highly suitable properties and lifetime of our insulation.

It would turn out to be a real struggle in Turkey. With the move to a new plant in Hendek, an incident with draining flammable gas burns down the old plant. Then, the disastrous earthquake of 1999, killing 17,000 people and leaving approximately half a million people homeless, completely razes the new plant to the ground. As if our luck could not get any worse, a short circuit causes another fire a year later, destroying part of the production line. Thermaflex erected not 1, but 4 factories in Turkey!





The first process for pre-insulation of pipes developed in The Netherlands

Joint Venture with Flexalen

The search for new opportunities leads to several innovations for the pre-insulation of flexible pipes. And so we cross ways with Flexalen, an Austrian subsidiary of pipe manufacturer Pipelife, who itself is looking for a solution for the insulation of its Polybutene pipes. A joint venture sprouts, where Thermaflex will develop the production of the next-generation pre-insulated system

Pipelife and Thermaflex enthusiastically join forces for a unique product, and a unique future. Flexalen would eventually fully integrate within Thermaflex


Founding of Thermaflex Russia as a sales and support office. The positive development of the Russian market would lead to the establishment of a production site and 5 regional sales and support centers throughout Russia just a few years later

Flexalen 600

Flexalen becomes fully integrated in the Thermaflex group. This kick-starts the development of the production of Flexalen 600. This first flexible pre-insulated system worldwide is developed in cooperation with NUON, and a major breakthrough in - initially -  the market for district heating after a first, successful pilot project

F600: the next-gen pre-insulated system. The flexible PB medium pipe covered with high-grade PE foam and a robust, yet flexible outer casing proves ideal for district heating and cooling applications

Start of polybutene pipe production

Thermaflex takes over the production of polybutene pipes from Pipelife, starting in the Netherlands

Roll out of Flexalen in several European countries with trial projects in district and block heating proves succesful


Founding of Thermaflex Mexico as a sales and support office for the cooling market, mainly in the hospitality business


ACE France joins the Thermaflex group and becomes Thermaflex France. The roll-out of municipality and rural - often renewable - energy projects could now be better facilitated


Founding of Thermaflex Romania to support the national challenges of energy efficiency and network renovation


With the development of FlexaLink, the installation of district thermal water networks truly becomes child's play. Now, building connections could be pre-fabricated and easily assembled on site, allowing renovation or expansion to be realized in no time

The first renovation projects could be implemented in the Dutch cities of Den Haag and Purmerend, and proved to be highly successful


Founding of Thermaflex Panama as a sales and support office to advance efficient cooling and sanitary water networks in e.g. the hospitality market


2012 marked the development of FlexTools online software for network optimization. The flexibility and flow dynamics of Flexalen could be incorporated, and network designers and calculators supported anywhere in the world

Full-option network design...

Colombia, Italy, Denmark

Founding of Thermaflex Colombia, Italy and Denmark as offices for sales and support to better serve the needs the regional markets

Flexanet: Street in a Day

The introduction of Flexanet truly revolutionized district heating as we know it. In co-development with network engineers from Warmtenet Hengelo, a Dutch district heating company, the idea of completely pre-fabricated networks on coil becomes reality. The all-in-one concept of a main line with readily attached building connections marks a major breakthrough, reducing installation time by 80% in an efficient and sustainable solution.

Flexanet: a whole new ballgame...

The first pilot projects in the residential areas of Hengelo and Terborg put it to the test: 'Street in a Day' was a fact. Opening an entire street, trenching, laying, house connections and closing - all in just one single day! Read all about it here!

Proven sustainability

In line with our vision, brand and principles, Thermaflex achieves its Cradle-to-Cradle basic certification for Flexalen 600 and the first Environmental Product Declaration (EPD) for most insulation ranges (ThermaSmart PRO, ThermaSmart ENEV, ThermaEco FRZ and ThermaEco ZZ)

Thermaflex products, systems and solutions are modeled to nature's systemic processes. The materials we put it in the ground also become part of an ecosystem. We see our materials as nutrients circulating in a healthy, safe environment and so we act accordingly

2015 and beyond...

Sustainable by principle

Thermaflex increases its focus on products with a healthy environmental and social impact throughout their life cycle. This drives us to offer products that

  • are recyclable and / or consist of recycled content
  • are manufactured with environmentally friendly production methods (renewable energy)
  • are made by responsible suppliers
  • consist of safe materials
  • have an environmental product declaration (EPD)
  • minimize the waste of energy
  • maximize the use of renewable energy

That's why Thermaflex decides to discontinue the production of insulation made of synthetic rubber, rock wool or polyurethane


Thermaflex North West Europe (the Netherlands and Denmark) becomes a BCorp, using its business model to leverage social and environmental change

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