I was recently reading about Gluing theory and wood adhesives and it caught my attention that adhesives are the most widely used material for furniture and wood derivatives. Moreover, adhesives have made a major contribution to the development of the industry and the efficient use of wood. Just think of the advent of plywood, chipboard and MDF, laminated beams and CLT, laminated timber or solid wood panels and it is enough to see how correct the statement is. However, we are often tempted to downplay the importance of adhesives, to consider them as mere auxiliary products. But without a quality adhesive, correctly chosen and used as recommended, we can end up with a reject, even if the wood and other materials used are of very good quality.
There are different types of adhesives, but the one identified by many with the wood industry is the type aracite, i.e. PVA (polyvinyl acetate). Years ago, its range of use was restricted as it was not considered to be resistant to damp conditions, it was rigid and the bond line was very visible. In addition, the risk of damage at low temperatures made many reluctant to use it. But technologies have evolved and the product has been continually improved. We now find PVA adhesives that make joints elastic, with good resistance to wet or outdoor conditions and even resistant to very low temperatures. One such adhesive is Tiszabond D3D, distributed by the company Szolvegy from Târgu Mureș.
Features of Tiszabond D3D adhesive
The D3D adhesive is a D3 adhesive with improved characteristics. As a reminder, D3 adhesive is recommended for use in interior construction exposed to moisture or damp environments, but short term or for exterior construction in mild climates. The moisture resistance classification divides adhesives into 4 classes - D1, D2, D3 and D4. Find here restrictions of use in this respect.
The improvements are increased adhesion to the substrate, use on surfaces with high humidity, low film forming temperature, very good elasticity and, above all, retention of bonding characteristics even after 2-3 freeze-thaw cycles. The adhesive contains additives that increase flexibility and fixity on wet surfaces. Tiszabond D3D bonds wood, laminate flooring, laminate tiles, cork, paper, cardboard, felt and similar materials quickly and durably.
But why is it so important that the adhesive is elastic? If wood or derived panels are rigid, why do we need an elastic adhesive? To protect the chipping tools. For example, when a solid wood panel is made, the timber elements are glued together. To make sure that the glue is glued over the entire contact surface, the glue is always over-applied. By pressing the excess comes out and hardens like the glue. When the process is complete, the cured residue must be removed to achieve a beautiful surface. The elastic adhesive will deposit less resistance compared to a hard and rigid one, so the tools will be less stressed and have a longer life.
Tiszabond D3D meets the requirements of the European standard EN71, is non-toxic and non-flammable. Even if the bonding takes place much faster, the maximum waterproofing of the adhesive film is reached 7 days after bonding. Like any polymerisation reaction, the curing reaction of the adhesive film also sets over time. It is considered that one week is needed for the reaction to be completed and thus the bonding to reach the strength of the data sheet. If even better moisture resistance is desired, so that the bonded product can be used outdoors (D4), 3,5-5% of special additive D3D4 can be added to the adhesive.
A product well received by factories
The adhesive is recommended for joining furniture elements, gluing laminate flooring, fixing doors and windows, obtaining solid wood panels and wooden stairs. Although the idea of developing such a product came from a user in Miercurea Ciuc, an area with very low temperatures in winter, the adhesive has been well received by the factories, which also appreciated its other qualities.
For example, with Tiszabond D3D adhesive, Dippanels produces solid wood panels, steps and indoor wooden stairs. The elasticity of the adhesive helps to keep the splintering tools in good condition for a long time and allows for quality wooden stairs. Transparent glue lines contribute to the aesthetics of the products.
The consistent quality of the adhesive should also be mentioned. Szolvegy is constantly concerned with this aspect by regularly and randomly analysing the quality of the adhesives it produces. Analyses are carried out by a neutral entity - the Hungarian Wood Institute - and samples are taken at random from the factory, customer warehouses or shops.
Frost resistance also makes it suitable for the construction industry
Wood adhesives are also used in construction. The low temperature resistance makes Tiszabond D3D one of the preferred adhesives for this field. Better wetting, improved wet adhesion, low film forming temperature lead to safe and winter time bonding.
In construction it is used for:
- gluing of wooden interior structures in conditions of high humidity but of short duration or which may be exposed to water for a short time
- gluing of structures where at least one of the elements is wood or derived material (wooden steps on concrete stairs, fixing doors and windows in the wall structure)
- bonding of protected, weatherproof exterior structures.
As I said, acrylic adhesives are no longer those adhesives that are only used for interior work that is not subject to any aggression or for DIY activities. Modern technologies have made it possible to produce adhesives with much improved strengths that can be used in high-capacity factories. A very important characteristic, in addition to the technical ones presented, is the lack of toxicity, of organic solvents. It is a product that does not emit free formaldehyde, and products glued with it do not have the characteristic smell.
It's weak adhesive. Maybe for interior plywood and it works, but for glulam, it sure doesn't.