Artificial Heartwood: Functional modification of Scots pine sapwood for durable window applications

Purpose and goal:

The main objective of the project was to develop a 100% bio-based formula from tannin to improve the properties of wood products for window applications. The project specifically intended to test the following hypotheses: 1) Scots pine sapwood can be modified with the tannin-based formula to reach a high weight gain and fixation level

2) The natural durability and dimensional stability of the Scots pine sapwood modified with a tannin-based formula will be at the same level as the natural pine heartwood or meet the standard requirements of window components in Nordic Certified Scantlings Expected results and effects:

The performance of tannin-modified wood were evaluated in terms of water-related properties, resistance to accelerated weathering and mould growth. The experimental results showed that the retention value, water-related properties and resistance to accelerated weathering improved by increasing the concentration of the bio-based crosslinker. The durability against mould was only improved at high concentrations of the crosslinker, while there was no improvement effect observed on mould infestation compared to heartwood and control untreated sapwood.

Approach and implementation:

A reference group was formed at the beginning of the project, composed of researchers from universities, innovation engineers, and managers from industry, with the tasks of discussing the internal and external knowledge exchanges (including dissemination of the results), planning the detailed activities, and evaluating the results. In total, seven (7) meetings took place within six (6) months of the project´s life to monitor the project progress and ensure the project objectives were followed as planned.