Special Producers of ecological adhesive

THE DIVERSE TYPES OF WOOD ADHESIVE OUTLINED

THE RIGHT CHOICE STARTS WITH A KNOWLEDGE OF THE MOST COMMON TYPES OF ADHESIVE

In a previous edition we explained how to recognise an ecological adhesive. The main thing to remember is that there are several ways for an adhesive to be considered ecological, but the general rule is that water-based adhesive is usually much better for the environment than an adhesive with synthetic materials. Moreover, an adhesive is ‘better’ if it contains no formaldehyde or VOCs. The biggest drawback of a water-based product is the potentially longer drying time.

In this article we consider the main types of adhesive and define each of them briefly. This shows clearly what the market offers and what the benefits and drawbacks are. Adhesive types

The list is not exhaustive, but these are the main types which we have found: phenolic resins and amino-resins, vinyl resins, polyurethane resins, epoxy resins, polychloroprene resins, melting adhesives, polyurethane hot melts, natural and casein adhesives, cyano-acrylic adhesives, and resins based on condensed tannins. - Phenolic resins and amino-resins: These are thermo-setting glues. They comprise a resin and a hardener which are mixed before use. Amino-resins are usually colourless. Industry uses phenolic and amino-resins in particular for structural compounds such as glued plywood and panels such as multiplex and chipboard. The adhesive joints are fairly waterproof. - Vinyl resins (PVAc): These adhesives are also sometimes called

‘white wood adhesives’. They are suitable for both indoor and outdoor joinery. The colourless adhesive joints remain flexible and liable to creep. Vinyl resins are slightly to reasonably waterproof, depending on the adhesive formula. - Polyurethane resins (PU): PU adhesive consists of mono or dual-component resins, the volume of which increases during setting. That swelling capacity makes it possible to join surfaces which do not connect perfectly. Polyurethane resins are reasonably waterproof. They are also being used increasingly for bearing connections. - Epoxy resins: These comprise two components. The cold glued joints have a changing thickness and are relatively stiff and temperature-resistant. Epoxy resins are suitable for restoring structures affected by fungi or insects. - Polychloroprene resins: These ‘contact adhesives’ are composed on the basis of regenerated rubber and give a highly flexible joint.

In particular, materials with various expansion coefficients (such as wood, metal, or wood-ceramics) are suitable for glueing with this type. - Melt adhesives (butyl, SBR, and polyamides): Glueing with melt adhesives or hot melt is done warm. It is done mainly in industry for glueing panel edges. Mechanical performances are limited.

That’s why melt adhesives are also used for holding elements temporarily in place during the production process. - Polyurethane hot melts: This type of melt adhesive is a relatively new development. Here, the hardener is covered with a layer of polymer and thereby mixed into the adhesive. When this compound is heated, the hardener comes freely into contact with the resin, and this speeds up the setting. The result is a high and flexible adhesion and strong resistance to fluctuations in climate.

The technique is safer, more ecological, and more profitable than many classic types of glueing. However, the installation requires a lot of initial investment. - Natural and casein adhesives: Adhesives based on animal proteins (think, for instance, of bones) are only still used for the restoration of artefacts and antique furniture items. Casein adhesives belong to the same family. Some countries still use them in industry to connect structural indoor elements to each other. - Cyano-acrylic adhesives: These adhesives are hardly used in industry any more at all. However, they do stick wood perfectly to other materials. The joints have to be thin and brief but intense pressure has to be exerted on the connection for the binding. - Resins based on condensed tannins: Condensed tannins are present in abundance in the wood and resins of some wood sorts (e.g. acacia, schinopsis, tsuga, rhus, or pine resin). Resins based on tannins reduce the pressing time of chipboards. They also make it possible to use damper wood sections than with phenolic and amino-resins.

Source: houtinfobois.be (technical information on wood adhesive).

Bona

With a long history of sustainability, Bona still leads the way in sustainable innovations and solutions. In the 1970s, Bona started with waterborne parquet lacquers and was then the first to introduce dust-free grinding and to develop parquet oil from renewable raw materials. Bona was also the first to replace solvent parquet adhesive with silane adhesive. Silane parquet adhesives yield a strong and flexible floor, are waterless and solventless, and are therefore completely safe to use and not hazardous to your health. With the Bona Quantum silane adhesive and the next generation of parquet adhesives, Bona is once again taking a pioneer step in the Bona Sustainability Journey by using sustainable packaging made from recycled plastic buckets. The new packaging has a modern and visual exterior and is made from 75% recycled plastic. This reduces CO² by up to 13%. It also lowers their CO² footprint by about 60%. Bona also uses IML technology (in mound labelling): Packages are produced and labelled during the process. The new packaging reflects their objectives and the results as given in the Bona sustainability report. Their business choices are geared to the 17 global targets of the UN. Bona adhesives are updated in line with the latest environmental standards. Certificates include EMICODE EC1, DiBt, and GREENGUARD, something which ensures ecological products and healthier work environments for professionals. Bona continues to surge ahead with its progressive and sustainable approach.

Emfi

An ecological adhesive is an adhesive with no isocyanates, solvents, or TIO² and with the lowest possible carbon impact. We’re not sure if there are any 100% ecological adhesives on the market. The aim is to give ecological adhesives mechanical properties which are as close as possible to those of traditional adhesives. At EMFI they’ve been selling floor adhesives for a long time which can be defined as ecological. They even endeavour to pack their products in cardboard rather than buckets.