The Sweet Smell of Success - Wacker Chemie AG

The Sweet Smell of Success

Edel Group is a Dutch company that has now become the world’s first tufted-carpet manufacturer to coat the backs of its carpets with compounds based entirely on VINNAPAS® VAE dispersions. VAE binders offer a variety of advantages over traditional latex: they emit hardly any volatile organic compounds, provide greater flame-retardance, are easy to process – and are almost odorless.

This carpet does not smell. At least, not in the characteristic way of new carpets, even though it has come directly from the factory. This chocolate brown, super-cozy “Pamina” carpet made of polyamide fibers is so soft you have to feel it. This is being demonstrated by the Edel salesman to customers attending the Domotex Trade Fair for Floor Coverings in Hanover, Germany. This floor covering is just one example of Edel Group’s innovative line of carpets finished with a backing based entirely on vinyl acetate-ethylene dispersions (VAE). Edel Group markets these new carpet backings under the brand name “Ceneva®.” And it’s this binder that makes all the difference – including why the carpet smells the way it does.

Willem van der Meer (Edel Group purchasing manager, left) and Robert Tangelder (business development manager at WACKER), view the finished carpet’s quality in person.

“At first glance, our customers don’t notice anything different,” says Dr. Mike de Lange, operations manager at Edel Backing, a member of the Dutch Edel Group. The carpet backing looks the same as always. It holds the carpet together, stopping the fibers from coming away even after many years’ wear and tear. VAE dispersions from WACKER now enable Edel to produce a backing that can be processed with perfect results. The resulting backing is one which has excellent performance in everyday use and offers several additional benefits, of which the lack of an odor is only one.

The typical smell that pervades a room for several days after carpeting has been fitted is due to conventional styrene-butadiene latex (SBL) binders, explains Dr. Holger Künstle. He is in charge of WACKER POLYMERS’ carpet applications lab in Burghausen, Germany. Over the last few months, many square meters of carpet have passed through the hands of the chemist and his staff.

Furnace Chamber Test: Pictures from a furnace chamber test – in accordance with the DIN 4102-1 standard – at WACKER’s carpet laboratory in Burghausen. Films made with both VAE and SBL were tested, each time including 150% calcium carbonate as a filler. The images at the top show that the VAE-based films are self extinguishing (1A, 1B), whereas films made with SBL burn readily, issuing black smoke (2A, 2B). VAE-based binders therefore allow formulations that need fewer flame retardant additives.

Increased Flame Retardance

Since every carpet manufacturer has their own recipe adapted to existing equipment, Dr. Künstle and his team collaborated with Edel Group’s technical experts to create the optimal VAE carpet binder formulation for each carpet type. Künstle’s team also tested the ready-coated carpet specimens under practical conditions. He used machines that simulate shoes walking over the carpet thousands of times or the repeated rolling of office chair casters.

Dr. Künstle was particularly impressed by the tests carried out in his lab’s combustion chamber. During this test, he set fire to films of carpet backing compounds, some made with VAE, some with SBL. He observed that VAE films are less flammable than SBL films. In the case of certain f lame-retardant VAE grades, the fire was even self-extinguishing, whereas compounds formulated with SB latex burnt completely, releasing black smoke in the process. If the backings are bonded with VAE binders, much less flame retardant additive,such as aluminum trihydroxide, has to be added. On account of their relatively low flammability, carpets with a VAE backing are therefore ideal for commercial installations, such as in hotels and offices, or in aircraft construction and shipbuilding, where fire safety is a high priority.

“Our tests showed that in the case of a VAE carpet backing, the total emissions of volatile organic compounds are much lower than when SB latex is used”

Dr. Mike de Lange Operations Manager, Edel Backing
Successful Collaboration: Dr. Mike de Lange (Edel Backing operations manager), Feike van der Heide (business director for WACKER POLYMERS’ dispersions business in EMEA), Robert Tangelder (business development manager for WACKER POLYMERS’ dispersions business in EMEA) and Willem van der Meer (Edel Group purchasing manager)

Low VOC Emission Values

The benefits of VAE dispersions reveal themselves in emissions testing, too. Since their surface area is large, floor coverings have the potential to emit volatile organic compounds (VOCs) to the environment. The Association of Environmentally Friendly Carpets (GUT e.V.), an initiative launched by European carpet manufacturers, has established the “GUT” label. To receive this label, carpets must undergo extensive analysis for possible pollutants and must meet rigorous standards. These carpets are tested, among other things, for plasticizers, biocides, pesticides, aromatic compounds, hydrocarbons, aldehydes (e.g. formaldehydes) and ketones. Additionally, a sensory odor test is performed. “Our tests showed that in the case of a VAE carpet backing, the total emissions of volatile organic compounds are much lower than when SB latex is used,” says Dr. Mike de Lange.

In Europe, there had been a long tradition of making carpet backings to similar formulations. After all, the carpet business is all about products that need to endure a great deal for many many years. So, it was an obvious step to turn to time-tested processes. Tradition is a cornerstone of Edel Group’s corporate philosophy, too. The family-run business, with its 120-strong workforce, has been making carpets at its base in Genemuiden, Netherlands, for almost 100 years. Not satisfied with standing still, Edel Group is always looking to improve. One example is the development of carpets made with recyclable raw materials.

Laboratory employee Kerstin Zeiler during the tuft bind test at WACKER’s carpet laboratory. This process tests how well the precoat bonds the fibers to the primary backing.

Polymeric binders are a traditional mainstay of the WACKER portfolio. Burghausen chemists were already producing vinyl acetate from acetic acid in 1928. By 1966, researchers had succeeded in combining vinyl acetate with ethylene to produce a copolymer. They created a binder that has now become an integral part of a wide range of applications. VAE dispersions are used in adhesives, low-odor interior paints, and nonwovens. VAE is the core technology at WACKER POLYMERS.

A Step Ahead

When Robert Tangelder, business development manager for WACKER POLYMERS’ dispersion team in Europe, introduced these VAE dispersions for carpet backing applications to Willem van der Meer, Edel Group’s purchasing manager, Willem realized this unique opportunity to start something new. Subsequently, he teamed up with his colleague Dr. Mike de Lange, a doctor in polymer chemistry, who brought in his technical perspective to explore the innovation based on VAE technology. Dr. Mike de Lange was immediately interested when Robert Tangelder showed him thenew VAE binders tailored to European carpet-industry needs. “At that time, Robert and myself had both just read the biography of Steve Jobs,” de Lange relates with a grin. “Sometimes, you just have to take the plunge without overanalyzing things. So, we thought: Why not give it a go?”

As far as de Lange was concerned, the arguments were obvious. For the first time, the VAE binders gave him an alternative to the previously unrivaled styrene-butadiene – an alternative that could be processed using existing equipment, too. “Customers from Scandinavia, a very environmentally conscious market, had often asked me why we couldn’t manage without SB,” explains de Lange. Now he finally saw an opportunity to do so and introduce a totally satisfactory substitute.

The delamination test inspects the adhesion between secondary backing and carpet.

This is also of crucial importance to Edel because the company not only manufactures carpet backings for its own carpets, but because they also toll-produce backings for other carpet manufacturers. The Edel facility conducts precoat and secondary coatings on residential and commercial carpets that use a broad variety of fibers, including polyamide, polyester, polypropylene and wool.

The Lisson test and Vettermann drum test (see below) are used to simulate the daily stress a carpet is submitted to, such as through footsteps and rolling office chairs.

When WACKER’s Robert Tangelder first approached the European carpet market, he’d had no prior contact with producers in this industry. Yet Tangelder found Edel extremely receptive right from the start. “Edel is a company that understands a great deal about chemistry and its work is very much based around finding solutions,” he says. “That is why they understood the special characteristics of VAE so fast and adapted them to their own processes.”

Initially, Dr. Mike de Lange certainly had his doubts. When he used SBL and VAE in parallel, the inherent differences in the flow propertiesof the two binders became apparent. So, the VAE formulation had to be customized. “Wow, we’re really charting unknown territory,” de Lange thought at times. Once the formulation had been optimized and following six months of intensive carpet testing, Edel was ready to change its technology. “From the moment we switched production entirely over to VAE, everything was fine,” he recalls, adding that, today, the in-factory processes were more stable and uniform with VAE than in the past, and didn’t have to be modified as often. “So, the production staff also see the positive effects of VAE during processing,” says de Lange.

Vettermann Drum Test

Successful Partnership

That’s something Feike van der Heide likes to hear. The Dutchman is responsible for VAE dispersions in WACKER’s EMEA region (Europe, Middle East and Africa). “The European carpet industry is quite a large, strategically important market for us,” he explains. “We have focused our efforts on penetrating this market by means of VINNAPAS® CA 55, our dispersion specifically designed for carpets. We’re now glad that we made the breakthrough.” What’s more, van der Heide was very proud of the close cooperation with a first mover such as Edel, which had been the first manufacturer to switch over its production entirely to VAE – both for the precoat and the secondary coat.

“That was a huge step for us, too,” adds Edel’s Willem van der Meer . “But we took it, because we trust WACKER as a reliable and major partner with a wealth of experience – and because we were given a great deal of support.”