THE NEW SUBSTRATE

The story of Rectigro’s latest foam family Polygrow® begins

1st generation of Polygrow®: incipient tests under real conditions in Dutch greenhouses

2nd generation of Polygrow®: expanded tests in greenhouses in the Netherlands and other European countries

3rd generation of Polygrow®: 70 growers around the world agree that Polygrow is worth to be called “the foam of the new generation substrate”

Polygrow® is present at the market

Rectigro initiates a trial to adapt Polygrow® to green roofs and walls

2005 was the year when the story of Rectigro’s latest foam family began.

At this time, the intention was to create a product independent from the existing divisions of the group: Bedding, Insulation, Automotive and Flexible Foams. The idea for a completely new plant growing medium at the horticultural sector was brought into focus. But simultaneously the question raised if this market is ready for a substrate consisting of polyurethane foam? The market said “yes”. And thus, the way was cleared for a foam that has been especially designed based on the growers’ needs. After incipient researches and basic tests the 1st generation substrate could be introduced in 2007. Three greenhouses in the Netherlands were willing to grow their plants on Rectigro’s foam. From now on it could be tested under real conditions. Finally, in 2009 Recticel managed to design a substrate that matches its requirements: 70 growers around the globe agree that this product is worth to be called “the foam of the new generation substrate”.Today, the foam that took its first steps in 2005 and has been tailored to the needs of the horticultural sector step by step is named Polygrow®.

Polygrow® is a polyurethane (PU) foam especially designed for growing media (substrates). With its unique characteristic it provides professional growers to overcome the current challenges at the horticultural sector.

THE NEW SUBSTRATE

Polyurethane (PU) stands for a group of products within the family of polymers or plastics. It is the generic name for a wide range of foam types. The struc-ture of PU foam consists of a network of dodecahedron cells which behave as micro-springs.

The morphology and the chemical structure of the ribs characterize the final properties of the foam. That’s why the analysis of the cell is an important approach to develop and design new foam varieties for specific demands – as in the case of Polygrow.

In the production of polyurethane foam three basic raw materials play a key role: polyol, isocyanides and water. Agents, such as catalysts and stabilisers, are used to support the chemical process. Supplementary, further components can be added to obtain several product properties. For Polygrow®, a unique combination of the raw materials had been developed to guarantee optimal properties for its applicationas substrate, e.g. the possibility to absorb and buffer water.

The emulsion that is created while mixing the raw materials will be cast on a rolling conveyer with vertical variable boards. Some seconds later a crème-like emulsion is formed, the volume expands and the foam reaches its maximum height after one to three minutes.

What is Polyurethane (PU) foam?

What happens during the foaming process?

Polygrow® for greenhouse vegetablesIn 2007 the development of Polygrow was put an enormous step forward: A cooperation between Recticel and BVB Substrates has been negotiated.

Today, we hold a completely new substrate, present at the market as BVB Sublime.

For more information about BVB Substrates or BVB Sublime please look at www.bvb-substrates.nl or www.bvb-sublime.com

In these years, the horticultural sector is driven by fast changes. Consumers are asking for more health and safety in produce as well as for product variation. Governments are setting up stricter environmental requirements. Depending on several regions, the growers have to face increasing energy costs and a limited supply of high quality water…There are numerous factors putting growers around the world under pressure. They can’t get away with diseases or crop failures. They are forced to update their operation processes, permanently.

Polygrow® provides the growers to overcome these challenges. For instance, its property of a good re-saturation. Or that Polygrow® is completely safe for the plant: while a biological growth test, the issue of toxic substances and other undesirable elements could be excluded. The substrate is airy, loves water and is stable in shape. Additionally, practical tests in greenhouses showed very good yields.

Polygrow® - its advantages in a nutshell:

good re-saturation no shape deformationhigher generative effect inert, clean % industrially producedmaximum yield unbreakable: flexible materialoptimal manageability low risk of root rotgood moisture control 100% thermally recyclable constant structure always adequate oxygen content

THE NEW SUBSTRATE

In 2009, a continuous crop of tomatoes grown on Polygrow® culminated in a 7% higher yield compared to stonewool. The yield figures from the cucumber crops showed the same picture: 1st crop +3.2%, 2nd crop +7.2% and 3rd crop +4.8%. In 2010 the cucumber test had been repeated and resulted in a 6.1% higher yield. Tomato researcher Lieve Wittemans from the Sint-Katalijne-Waver vegetable growing research station in Belgium explains: “Our conclusion is that the slab is more generative.”

Growth Test in Sint-Katalijne-Waver (B)

These advantages already provided a promising basis, but a foam usable as substrate needs more: Polygrow® stands out to its excellent ability of absorbing and buffering water. It also presents a good re-saturation while most other substrates have trouble to take up water again. Additionally, Polygrow® shows a good capillarity due to its cell structure and is able to increase its volume up to 5% after water absorption.

Polyurethane foam (PU) holds several characteristics that have been utilized to develop Polygrow®. Generally, these are its flexibility, inertness (i.e. no reaction with other chemicals like nutrients), cleanness (i.e. no harmful substances) and its shape stability.

Properties of Polygrow®

Jack Alblas: “The slab reacts instantly and resaturates very well.”

In the autumn of 2009 bell pepper grower Jack Alblas covered his entire growing area with Polygrow®. Because he had already been trialling the material for two years, he was willing to give this a go.

“What is so good about the slab? The crop is easy to control because the slab reacts so quickly. For example, a lower EC in irrigation water is quickly reflected to a lower EC in the drained water. There is almost no time lag. That is particularly beneficial in summer.

Rochus van der Meer: “I’m definitely keen to try out a new substrate.”

Rochus van der Meer, a vine tomato grower, tested Polygrow® between stonewool using the same watering regime. “After the longest day, it is more difficult to grow dry enough on stonewool. On rainy days the slab stays too wet, so the roots get too little oxygen and we lose root hairs. So I’m definitely keen to try out a new substrate. Another big advantage of Polygrow® I have found is that the structure of the slab is the same all year round. That does not happen with stonewool. What’s more, Polygrow® is made of flexible material. So it does not get damaged during handling

What do growers think about Polygrow®?

Polygrow® also seems to make it easier to increase irrigation in high temperatures. It is not so easy to drown the crop. On the other hand, growers don’t have to worry about the slab drying out. Even in an emergency you’re pretty safe with Polygrow®.”

THE NEW SUBSTRATE

Who is Rectigro? Under the motto The passion for comfort, Recticel, as a manufacturer of polyurethane foam products, strives to make a real difference to daily comfort for all.

Divisions: Flexible Foams, Bedding, Insulation, AutomotiveEmployees & sites: 8,400 in 120 establishments in 27 countriesTurnover 2009: EUR 1,276 million

Recticel aims to achieve sustainable, balanced added value and steady, profitable growth for the benefit of its customers and its shareholders. The company is quoted on NYSE EuronextTM in Brussels.

Environmental friendliness and sustainability play a key role in today’s business. Increasingly, consumers ask for products that guarantee safety, health and high quality. This requires a balanced interaction between the ecological use of materials, profitable economic growth, res-ponsible partnerships and the well-being of employees – Recitgro’s tack of living Corporate Social Responsibility (CSR).

Also in respect of Polygrow®, Rectigro takes care about the environment. For instance, by producing, a chemical reaction causes that the liquid raw materials are converted into foam. Due to this exothermic process that doesn’t require an additional heating source no extra CO2 will be emitted.

Because Polygrow® is a synthetic organic material it can be easily thermally recycled: After the substrate had been picked up at the grower by the waste processing company it will be used as fuel for waste incineration. Whether the released energy is supplied to the district heating or to the electricity network for usage in private households. Simultaneously we are testing possibilities to reuse Polygrow® after the cultivation period.

What are Rectigro’s efforts on environmental care?