Knowledge base

History of Phenolic Foam

Phenolic foam main raw material is a phenolic resin which is based on bakelite. The first Bakelite was developed by the Belgium chemist Leo Hendrik Baekeland (Gent, 14 November 1863 – 23 February 1944) at the end of the 19th century.

Over the years he emigrated from Belgium to the USA. Therefore most of the developments on bakelite have been initiated from the USA. Bakelite was a fairly low priced could be used in many commodity markets. In fact it is the first public plastic ever produced.

Bakelite is a thermoharder which gives specific properties to the product. The most important are; the end product is stable, does not melt or decomposes under heat and is a very efficient electrical and thermal insulator.Bakelite was first commonly used in products like electrical switches, phones, toilet seats, doorknobs, and not to forget the thin plastic layer which ‘glues’ the metal fitting to the glass of a light bulb.

Present Bakelite is not so regularly used in domestic applications. The use of the product moved to industrial applications. For example the glue on grinding paper and discs, binder in brake pads of cars and trains, as compound for tires, engine parts, coating on waterproof wood structure cladding up till the in the USA developed closed cell insulation foam.

This American technology is in the mid 80s introduced in Europe by the joint venture Marec Isolatie in Kesteren (The Netherlands). This company produced the first phenolic insulation foam in Europe.

This company developed the product to set the standard of the product, one of the best thermal insulators available today. From this company many others followed and developed their own technology which to some extend is still based on the original formulations developed many years ago.

Teqtix Phenolic Solutions, based on the know how of its founders, combined this technology and know how and developed an extensive range of block foam products based on phenolic foam. Today this range is covering a wide range of applications for thermal insulation in combination with excellent fire behavior, fire resistance and compressive strength.

The main advantage of the block production is the flexibility in the chemical formulation which allows us to tailor the product to the customer demand whilst the large dimensions of the block product allow us to tailor the product to any shape or dimension to the customers need.

Thermal Insulation

Over the last decade the preservation of the environment, the limited availability of fossil fuels, the reduction in emission of CO2 and global warming have become more present in the news than ever before.

More and more innovations are made to generate sustainable green energy and this should also be stimulated. However, at Teqtix Phenolic Solutions we believe that the cleanest energy is saved energy.

Not only provides thermal insulation a saving in energy, but also:

  • reduces energy costs;
  • increases comfort and quality of life;
  • avoids condensation or hotspots;
  • improves efficiency and lifetime of heating and cooling equipment.

Thermal Insulation is measured by its thermal conductivity which is in the metric system given as W/mK.  The thermal resistance of a construction is calculated by dividing the thickness (in meters) by the thermal conductivity. The lower the thermal conductivity at given thickness, the higher the thermal resistance of the construction.

Many of the longer existing insulation materials use still standing air as their main insulator. However, still standing air is limiting these insulation products to meet thermal conductivity better than 0,030 W/mK. To make the next step you need to use a blowing agent with a lower thermal conductivity or vacuum in a closed structure. This step is made by all the ‘high performance insulation foams’ like Polyurethane (PUR), Polyisocyanurate (PIR) and also Phenolic Foam.

To set an even further step in the development of the best insulator one has to minimize the cell size of the closed cell foam structure and optimisation of the percentage of closed cells. Manufacturers who master this technique with phenolic foam are to our opinion part of the elite group of the insulation manufacturing industry. This statement also indicates that there are many manufacturers who do not master this technique. If the cell structure is not closed the blowing agent will evaporate and the thermal insulation value after aging will be significantly lower.

Closed Cell structure

Many of phenolic insulation blocks are converted in pipe insulation and pipe supports for the Heating, Ventilation and Air Conditioning (HVAC) market. In warm climates with high humidity there is a need to protect cold media piping avoiding condensation and also avoiding rise of temperature over distance. To do so it is vital to protect the insulation materials with a vapour control layer. Most of the manufacturers of insulation, including ourselves, offer their product cut to shape and protected with an aluminium facing. Because the phenolic foam pipe insulation is CNC cut and has a factory applied facing tolerances and failures are minimized. Application is secured with an aluminium tape over the joints. Nevertheless, there is always risk of leaks and penetrations. Open structure insulation materials will remain vulnerable for penetrations in the facing which will degrade the thermal insulation and forming of condensation (water saturated insulation and leaks).


Teqtix Phenolic Solutions, through its worldwide network of selected fabricators, is able to offer you insulation solutions in all shapes and dimensions. From straight pipes to cones, bends, domes and other complex shapes.

Fire behavior and fire resistance

The biggest trend, apart from increased insulation standards, in today’s market for thermal insulation is fire behavior and fire resistance.

At Teqtix Phenolic Solutions we make a clear distinction between these two properties as one does not necessarily excludes the other. The most simple definition can be put forward as:

  • Fire behavior is the behavior of the product during the fire which is indication the rate in which the product contributes to the fire if directly exposed to the fire or its thermal radiation.
  • Fire resistance is the time required for fire or heat to penetrate a structure or material which is exposed with fire or its thermal radiation from one of the sides.

Fire behavior is tested and classified in accordance with many National, European, American and International standards. What most of these standards have in common is that these tests are concentration on the following properties:

  • Release of energy during the fire exposure;
  • Spread of flames or surface ignition;
  • Deformation and melting of the product;
  • Smoke production and in some cases toxicity of released smoke;
  • Burning droplets and burning particles.

In some standards also product composition, like the percentage (weight%) of inorganic fillers or raw materials, is essential to achieve higher ratings of fire behavior.

Why is fire behavior relevant for a insulation material?’ is a question asked many times. The answer is simple; The fire behavior gives an indication of the rate the fire can develop using the insulation as part of its fuel. Not only that; most casualties in a fire are caused by the smoke in the room. This is due to the toxicity of the smoke, but also the fact that trapped people can no long see emergency exits.

Insulphen does not have a melting temperature like most of the thermoplastic insulation materials and inorganic insulation materials like glass- and mineral wool. In case of fire material is transformed in a carbonized layer which are protecting deeper layers of the material minimizing the contribution of energy to the fire. It does not melt nor create any burning droplets and maintains it integrity.

The smoke emission in firebehavior testing is extremely low which is much different to most other ‘high performance plastic foams’ like polyurethane (PUR) and polyisocyanurate (PIR) foam. The combination of these characteristics makes the product nearly incombustible.

The Teqtix Phenolic Solutions Productrange is tested and classified on firebehaviour in accordance with the EN13501-1 and ASTM C84.

Fire resistance tests give a more clear picture of the total performance of a construction or material during a fire. Fire resistance tests are concentrating on more distinct parameter of the construction which would lead to:

  • maintaining the loadbearing capacity of the construction preventing collapsing of the supported floors or roof.
  • compartmentation of the fire, leading to faster control of the fire by the fire departments;
  • prevention of spontaneous ignition of flammable materials stored at the non exposed side;
  • managing the skin temperature of the non exposed side of the construction in case somebody would be in direct contact;

Due to its low weight it is selected by many 3th party customers as core material for doors, composite panels and lightweight internal and external walls and facades.

The experienced technical team of Teqtix Phenolic Solutions is available to support the development of your product using phenolic foam to meet the fire resistance requirements of your construction, door or composite panel.

Compressive strength

Phenolic foam is known to be more fragile than other types of high performance insulation foam. This is due to a lower reversible flexibility (E-modulus) of the foam structure which is related to the nature of bakelite. Simplified; Under stress the cell structure will have less ability to bend, extent or contract leading to collapse of the individual cell wall.

If you would look with more detail to the foam you could see that the cell structure is existing out of the cell walls and the ‘struts’. The ‘struts’ are the intersection of the individual cells and the finer the cell structure of the foam the smaller these ‘struts’ become.

Percentage wise lower density phenolic foam has more of the weight is linked to these ‘struts’ which have a lower contribution to the strength of the product than the cell walls. At higher density automatically the product has a higher compressive strength as the cell wall becomes thicker. However, it is crucial that the cell structure of the foam does not become much courser. At Teqtix Phenolic Solutions we strive to manufacture a very fine foam structure which will benefit compressive strength even at low densities.

In combination with a thin laminate, which is used in composite panels and doors, the laminate will protect the product from a concentrated load which would be above the reverse flexibility capacity. The load capacity and strength of a combined panel of phenolic foam, even at low density like 40 kg/m3 and 60 kg/m3 combined with a thin laminate is extremely high and rigid. (See application..)

At high density like 80 kg/m3 and higher the material is a favourable product compared to other high performance insulation foams for applications like pipe supports due to the minimum creep under load. In this case the lower reversible flexibility (E-modulus) which is making sure that the material over time maintains shape and function. (See application..)

The highest densities could even be used as thermal insulating replacement for wood in construction and can be used as carrier for mechanically fixed  systems with coarse thread screws. (Read more..)

Product manufacturing

Teqtix Phenolic Solutions is manufacturing to the latest standards and technology. Based on customer specification we also have the ability to make tailor made products utilizing special additives.

To give a basic introduction to the production steps and capabilities:

In the mix of the carefully selected raw materials we use the phenolic resin and add special additives which are mixed together with the blowing agent and inserted in the mould. This semi liquid mix will start to rise and create its foam structure.

In the manufacturing process of block foam we are using moulds to shape our product. The internal dimensions of these moulds are 2500x1000x1200 mm and 2400x1200x1200 mm. The top of the moulds are flexible to allow rise of the foam structure. This will allow us to form blocks from 300 mm to 1000 mm high, but standard we produce products from 600 mm to 900 mm height.

After filling of the mould with the raw materials the product is transferred to the curing oven. In this process we utilize the elevated temperature to control the rise of the foaming process to maximize quality control.

After production and curing the foam is unmoulded and shipped to the cutting facility where material is trimmed to customer specification. This process can be trimming of the top side, long sides and ends.