Productivity in the woodworking industry boosted by cutting-edge adhesives technology

Neutral pH, lower veneer penetration, shorter compression time and minimal formaldehyde content – these are all features that significantly improve the user experience of adhesives in the woodworking industry.  In this text, we will explain how a state-of-the-art D3 PVAc adhesive increases safety, improves process efficiency and reduces waste.

Acidity of adhesives is a well-known problem in the woodworking industry. For example, acidic glue discolours oak to a dark colour, which can lead to rejection of products by quality control.

“Thanks to the neutral pH of Kiilto’s next-generation PVAc adhesive, users can avoid discolourations in the wood. So when using the adhesive on oak, for instance, you no longer have to worry about darkening where the adhesive touches the wood,” says Kiilto Solutions Manager Juha Rinne.

For one thing, a neutral pH value reduces waste in the furniture industry by eliminating the need to remove products discoloured by adhesives from production.

“Adhesive penetration – visible penetration of the adhesive into the surface of the veneer – is usually only visible at the end of the process, like when a table is being varnished. So, if the glue is not visible on the surface of the veneer, there is one reason less to reject products.”

The advanced PVAc adhesive also allows users to utilise thinner veneers, thereby saving materials and cutting costs. 

Shorter compression times for faster production

The properties of adhesives have a significant impact on manufacturing efficiency.

Kiilto’s advanced adhesive speeds up the adhesion process in hot plate pressing, as the compression time required is significantly shorter than with conventional adhesives. For example, the compression time for the application of veneer can be cut down to less than a minute.

“If the maximum number of table veneers that can be compressed in a working day is currently 500, this adhesive makes it possible for users to increase that number to 600. On average, this adhesive speeds up the adhesion phase by about 20 per cent,” says Rinne.

Common applications for D3 class PVAc adhesives in the wood products industry include doors and parquet flooring, and kitchen and bathroom worktops.

Minimum formaldehyde content

One common problem with adhesives is that they contain formaldehyde, a volatile compound that contaminates indoor air. Although the formaldehyde content in PVAc adhesives is already significantly lower than in urea-based formaldehyde adhesives, PVAc adhesives have been developed to even further reduce the formaldehyde content from an average of 200 parts per million (ppm) to less than 20 ppm.

“Consumers are also increasingly concerned about lowering the formaldehyde content of adhesives used in furniture and other products,” says RDI Manager Jukka Jokela from Kiilto’s product development department.

The formaldehyde content of Kiilto’s new adhesive has been tested by an independent accredited laboratory, and has been granted the M1 emission rating, the highest rating for indoor air quality.

Painstaking product development for cutting-edge technology

Developing adhesives with new properties requires years of experience and expertise – or even decades.

Kiilto managed to reduce the degree to which the adhesive can permeate the veneer by modifying the structure of the adhesive. Importantly, the product development succeeded in optimising the absorption and penetration of the adhesive without compromising on its other properties.

“It is also a significant step forward that we managed to increase the pH of the adhesive from acidic to neutral, from three to seven, while maintaining D3 class adhesive properties,” Jokela says.

Woodworking industry tests have proven that with its new properties, Kiilto Pro WX 3070 adhesive not only increases the efficiency of the production process, but also guarantees a higher-quality finish.

Video of Juha and Jukka discussing the product benefits: