Special What are the major benefits of silane adhesives?

VARIOUS STRONG ASSETS

A MORE EXTENSIVE LOOK AT THE VARIOUS CATEGORIES

Viki Wouters and Jo Indesteege (Kaneka - B)

‘Silane adhesives are now a fully matured product.’

Silane adhesives have done well on the parquet market for many years now. Why are these adhesives so successful and what can they be used for best? Where’s the benefit for parquet floor fitters? We interviewed Viki Wouters and Jo Indesteege from polymer specialist Kaneka to find out more.

‘Silane adhesives aren’t really new anymore,’ Jo laughs. ‘Even though they weren’t available 15 to 20 years ago and everything revolved around hard adhesives, epoxy, and PU. If we go back 15 years in time, for instance, you note that in those days 75% of adhesives in Germany were still solvent-based. The fairly elastic silane modified glues yielded a relatively smooth transition, even though there were still two sides: On the one hand, you had those who advocated elasticity, whilst on the other hand there were those people who insisted that an adhesive had to be “hard” to keep the wood in place.’

Stricter regulations

Both interviewees point out that the increasingly strict Chemical/adhesive regulations are indirectly giving silane adhesives a boost. ‘Think here of the legislation on the use of isocyanates on the shop floor and how skin contact and air quality are very strictly regulated,’ Viki replies. ‘Silane adhesives have presented themselves to be an excellent alternative.’

Jo adds: ‘What we do at Kaneka is provide more added value. To sum up, you can say that we go back to somewhat more rigid adhesives, but these are adhesives which aren’t as “rock hard” as in the past. The position is: Either you fix the wood so that it can’t move, as you do with nailing, or you retain the movement of the wood by looking mainly to avoiding the use of harmful products.’

Here Jo Indesteege points out one problem with silane adhesives. The reaction releases methanol. Although, is this really a problem?

‘We certainly shouldn’t exaggerate here. Adhesive producers have carried out tests in Germany to determine how much methanol is actually released and you can say that this is fully under control and meets the various regulations. The products have also been adapted so that the emission is negligible. To make this a little clearer, give me a choice between a room where PU has been used and another room with silane, then I will opt for silane with no hesitation.’

The future?

If we consider the future, the question is where parquet adhesives should advance. The answers show amongst other things that hard no longer has to mean ‘rock hard’, but the chief aim is to withstand harmful components as much as possible.

‘Softeners are an absolute culprit,’ says Viki. ‘Softeners are added to make it easier to spread the adhesive, but if those softeners escape or migrate into the parquet floor, the consequences cannot be overlooked.’ ‘That’s why we provide softener-free solutions,’ Jo adds. ‘We advise clients to opt only for softener-free products in case substrates with quite high absorption are used.’ We return briefly to the development of the product and we learn here that there’s no real need to look for innovation in terms of performance, but the cost price does need attention.’

‘At Kaneka, quality is our top priority,’ Jo says. ‘It’s important to push down the cost price, but not at the expense of everything. Cheap parquet adhesives don’t guarantee quality. An example: MS polymer is also a sort of adhesive binder. If the concentration of the binder in the formulation is too low, the question in the end-product is what actually holds the “system” together. We don’t support that because we opt for quality as our priority.’

‘Actually, there are two main criteria for us. MS polymer is a highly stable and consistent product and this means that we always supply clients with products of the same quality. Clients know perfectly well what they’re getting, and that’s not always the case with some of our competitors. In addition, quality in the end product is absolutely essential because we don’t want to give silane technology a bad name.’

LVT adhesives

LVT adhesives are another innovation mentioned, apart from the established parquet adhesive market. With LVT, water-based acrylic adhesives have dominated the scene. The problem was that silane adhesives do have good adhesion on wood, but are usually not so good on PVC or vinyl floors. Since then, Kaneka has developed polymers which do exhibit great adhesion onto these substrates.’

‘This gives us an almost unique position on the market,’ Jo concludes. ‘The only problem is the difference in price with water-based adhesives, so we admit that this needs our attention for the future. We’re busy working on solutions to keep the cost as economical as possible. At the moment, our polymers appeal only to the premium market. The challenge for Kaneka now, is to develop our polymers at the same high quality at a better price that allows us to provide more material onto this market. That of tiles, for instance.’

The testimony with this article tells us how the management at Kaneka explain what makes silane adhesives so successful. Silane adhesives aren’t really new any more, but they haven’t been on the market all that long. However, it’s been clear for a few years that they have acquired a strong position on the parquet market.

Our interviewees also consider the various parts on which it is best to use silane adhesives. What we remember most of all is that these adhesives no longer strive for the age old ‘rock hard’ use and that there is a huge commitment to maximum environmental friendliness and care for both floor fitters and end clients.

Another producer (Lecol) gives us some insight here into the diverse categories in which their solvent-free adhesives come in the parquet industry. According to them, there are three different categories: elastic, hard elastic, and impact resistant. Below we clarify further exactly what that means.

Elastic silane adhesives

If we consider firstly elastic silane adhesives for parquet floors, these are defined as having a flexibility of 125% or more. Such flexibility is more than enough to absorb the movements of the wood (shrinking and swelling). At the same time, the adhesive isn’t hard enough to keep all sorts of parquet adequately in place without the formation of bothersome joints. And so, according to Lecol, you should limit the use of this type of adhesive, especially for the installation of multilayer parquet floors. These types of floors are highly stable due to the multilayer structure and wide joints between the parquet boards are limited. The two elastic adhesives which they offer are Wakol MS 228 parquet adhesive which is ready for use and Wakol MS 230 Parket Adhesive.

Hard-elastic silane adhesives

With hard-elastic silane adhesives we learn that they have a flexibility of about 80%. This means that these adhesives are suitable for fitting just about all sorts of parquet, except for solid traditional parquet floors (old Flemish style), for instance, or crosscut. Their range in this category comprises Wakol MS 260 Parquet Adhesive.

Impact resistant parquet adhesives

Finally, this producer talks about the category of impact resistant parquet adhesives. This means that these parquet adhesives are relatively hard, although they need to have a certain flexibility so that they can absorb dimensional changes in wooden parquet floorboards (such as those caused by the weather). These adhesives have a flexibility of about 20% and this is sufficient to absorb the movements of wood (shrinking and swelling). The adhesive always stays more than hard enough to keep all sorts of parquet sufficiently in place so that hardly any joints can form between the parquet boards. In this category Wakol has launched MS 290 Parquet Adhesive on the market. This is a universal adhesive which can be used to glue all sorts of parquet.

Some other specialists have their say

Blanchon

The Blanchon range comprises four products: two spreadable adhesives, one adhesive in cordon, and one ‘ship deck’ seal. They all have an A+ rating: AB 2000: high-quality hybrid polymer adhesive for glueing solid parquet floors up to a width of 200mm and laminate floors up to a width of 400mm. Flexible and elastic. AB 1300: high-quality polymer hybrid adhesive for glueing solid wooden floors up to 130mm wide and laminate floors up to 260mm wide. Flexible and elastic, with good adhesion on most floors. AB 2000 and AB 1300 have an EC1R (GEV EMI CODE) and have been given optimised packing: 6kg aluminium bag. Adhesive for glueing in cordon: hybrid polymer adhesive, supplied in an aluminium tube, to be used with a special gun. Ideal for vertical

surfaces, even used a lot for all cordon installations on floors. Ship deck joint: black polymer hybrid putty, specially designed for the joint between parquet and skirting boards and for ‘ship deck’ joints.

Bona

By using high-quality raw materials and their own unique formulas, Bona silane adhesives guarantee strong adhesion for wooden floors. Bona Silane Parquet Adhesives are used on any type of subfloor. They ensure rapid initial adhesion and therefore the safe installation of the floor. Bona silane adhesives offer an ideal balance between strength and elasticity. FEATURES: 1-component – no primers necessary on solid dry subfloors – rapid initial adhesion – excellent adhesive back – adhesive splashes on the floor are easy to remove – ideal balance of strength and elasticity – long-term performance – low emissions – suitable for floor heating - EMICODE : EC1-R-Plus The all round silane adhesive in the Bona range is the new Bona QUANTUM. This adhesive represents the new generation of Silane Parquet Adhesive, with Bona’s revolutionary Titanium Crosslinking Technology. The brand-new formula yields excellent strength which hardens in the course of time and ultimately gives maximum strength. FEATURES: Parquet adhesive with integrated damp screen – Broad scope – Floor can be sanded after 12 hours – Improved tensile strength.

Emfi

There are various subgroups in the silane technology family: MS®, STPE, SMP, STPU, SPU, etc. There is no generally accepted definition of elasticity (or flexibility), but on the basis of standard NF EN 14293 Emfi uses the term elastic/flexible or rigid to show how far the connection stretches when it is pulled. To put it simply, the more elastic an adhesive is, the more it follows the floor movements and the less it strains the base. It’s important to find the right balance because if an adhesive is too elastic, this increases the risk of warps and splits. Adhesives are not designed specifically for one particular wood sort, so maker’s specifications are merely sales talk. Emfi offers EMFIPARQUET PRO PLUS and EMFIPARQUET PRO ECO as a spatula adhesive and EMFIMASTIC PS PARQUET for glueing in cordon. There is no such thing as a universal adhesive, so they prefer the term multifunctional to denote an adhesive which can be used to glue the most diverse sorts of parquet.

Stauf

20 years of competence in silane technology

20 YEARS COMPETENCE IN SILANE TECHNOLOGY

20 years ago, the German adhesive specialist, STAUF, launched a technology in the market that has fundamentally remained unchanged to this day: silane. Ever since they have been improving their silane products. Outstanding was the "pioneer" STAUF SPU 570, which changed the adhesive market altogether. Just recently they renewed STAUF S PRESS, a silane adhesive especially for ergonomic sticking of parquet. An ideal parquet adhesive balances useful elasticity with high strength. However, the individual mechanics of silane-based adhesives are very different. The parquet adhesive STAUF MULTILAYER for example has an elastic mechanism, preserves the subfloor and is suitable for all types of multi-layer parquet. STAUF SPU 460 and SPU 570 have well-balanced hard (elastic) mechanical properties. The subfloor is sensibly protected, the parquet does not tear off with the subfloor and the risk of dimensional changes is reduced – a perfect product characteristic for bonding solid wood. As a rule, no primer is needed. If the residual moisture is too high, STAUF SMP 950 or SPU 570 can also be used as a vapor barrier and adhesive in one.

Thomsit

Fitting parquet makes high demands of the performance of the floor fitter and the quality of the product used. For ready-for-fitting parquet Thomsit presents Thomsit P 675 Elast, with its strong quality and competitive price. By contrast, P 685 Elast Universal can be deployed more broadly and, amongst other things, is suitable for solid parquet. P 695 Elast Universal Strong is your master for all classes and is suitable for all sorts of parquet. These three glues all have the benefits of the FLEXTEC™ technology, which Thomsit itself has developed. These elastic glues absorb the movements of the parquet floor and that permanently reduces the tensile stress on the substrate. Moreover, they are strong and flexible and adhere to almost any substrate without the need for a primer. Apart from that, they also save you valuable drying time.