Low temperatures can irreversibly damage wood adhesives. Use frost-resistant adhesives!

High temperatures in late autumn days can be deceptive. We become relaxed and forget to pay proper attention to cold-sensitive materials. Unlike summer, when the high temperature period lasts for a good part of the day, autumn is only 2-3 hours with high temperatures and nights can be really cold, especially in depressions. Left overnight in the transport car or in unheated warehouses, wood glue - spiders, as we have come to call them - can freeze and become unusable. But we can use cold-resistant adhesives that can still be used after repeated freeze-thaw cycles. Szolvegy Vegyipari Târgu Mureș, the distributor of the TISZABOND brand of adhesives, suggests three adhesives to use in the cold season and assures us that they already have these materials in stock from November.

Why a regular PVA adhesive that has gone through the freeze-thaw cycle can no longer be used

To understand what happens when the adhesive freezes, let's first see how bonding takes place. The phenomenon happens when PVA (polyvinyl acetate) molecules floating in water get close to each other and react with each other to form a new, solid and very strong product that binds the wooden elements together. The main cause of the approach is an increase in the concentration of molecules by removing a quantity of water. When the adhesive is applied to the wood to be glued, some of the water in the composition is absorbed into the wood and some evaporates during the open-joint period before the elements come into contact. The reaction does not take place instantaneously and therefore the pieces are held tightly in the press for a proper fit. In general, the bonding takes place within 2 hours and is complete within 24 hours (i.e. reaching near maximum bond strength). Temperature reduces the time, as hot soldering goes faster.

At 0°C the water starts to freeze. This also applies to the water in which the adhesive molecules float. The water in the packaged adhesive gradually starts to freeze and the adhesive molecules concentrate in the remaining liquid water. Their concentration creates the conditions for the reaction to start and so the adhesive starts to harden from the can. Gradual hardening has the effect of increasing the viscosity, making the adhesive thicker. When this happens, unless it is mentioned that it recovers after stirring, the adhesive should NOT be used. Adding water does not solve the problem but only dilutes a hardened adhesive that will not react after the water evaporates. Using it will result in poor quality glues that will fail at the first stronger mechanical shock.

Problems can also occur if the temperature in the work area is very low (unheated workshops in winter, in construction). A minimum temperature of 5°C is needed for the adhesive film to react and glue the wood to the surfaces to be glued. There are also adhesives specially formulated for working in winter conditions that also react at lower temperatures, but these are not the ones we are talking about. At temperatures below 5°C the film does not form and instead of a continuous film you will get a white powdery layer with no adhesion. The temperature at which this phenomenon occurs is called bleaching point andi is between 3 and 5°C.

It is obvious that the temperature level is very important in all 3 phases: transport, storage and working. For storage and transport the range 5-35°C is recommended, and for the working area the optimal temperature range is 18-20°C.

TISZABOND adhesives recommended for the cold season

In order to be able to work safely even when the temperature is very low, Szolvegy has developed 3 adhesives that can be used even when frozen or when the working temperature is very low. The development was made in collaboration with customers in the Miercurea Ciuc area, known for its very low temperatures in winter. At temperatures of -20°C, it was a problem even unloading the adhesive from the air-conditioned machine and transporting it to the heated warehouse.

TISZABOND 3000 is a D3 adhesive developed for users in the wood industry. To increase its water resistance, 3,5-5% crosslinking agent D3D4 can be added, making the adhesive D4. It can be used for gluing bathroom and kitchen furniture, for glued structures standing in high humidity or short water conditions, for gluing where at least one surface is wood or wood-derived (stair treads, door frames, windows). The adhesive resists without freezing to temperatures as low as -20°C, and if frozen can be used after thawing. It withstands 2-3 such cycles, after which it risks irreversible freezing. After the freeze-thaw cycle the viscosity of the adhesive may increase. Vigorous shaking in the drum is recommended for fluidisation. Adding water is not recommended as it decreases the properties. If the adhesive is thicker it is recommended to lower the pressure in the press.

TISZABOND 3010 is a D3 adhesive with enhanced characteristics developed for the wood industry. Moisture resistance is D3, and with the addition of cross-linking agent it can become D4. The adhesive has improved adhesion which contributes to a higher quality of bonding. After bonding, the adhesive film becomes more elastic, contributing to an increased average tool life. Does not freeze down to -20°C and withstands 2-3 freeze-thaw cycles. After thawing it should be mixed to decrease its viscosity.

TISZABOND 3011/D3D Winter is developed for the wood industry and the construction sector. It is an improved D3 adhesive with better wetting, improved wet adhesion, elastic film, no fillers. By adding 3,5-5% crosslinking agent the wet strength is increased to D4 adhesive. In addition to the low freezing temperature of -20°C and use after repeated freeze-thaw cycles, the adhesive has a film forming temperature of 0°C. This makes it very useful on construction sites, where winter temperatures can frequently fall below 5°C.

An adhesive that can be used under boundary conditions can make the difference between a continuous flow and one with fluctuations and delays in delivery times. Unlike in the past, when spackles could not be used in wet environments and if they froze they could not be used, a new, improved generation has now emerged. The important thing is to choose the right ones.