WOOD RESEARCH Volume 68, Number 1, 2023
Joanna Walkiewicz, Jakub Kawalerczyk, Radosław Mirski, and Zuzanna Szubert

Short notes: The tea leaves as a filler for UF resin plywood production

The addition of green tea leaves fractions < 0.315 mm as a filler to urea-formaldehyde resin to reduction of emission of formaldehyde from three-layer birch plywood was investigated. Moreover, other properties such as bonding quality and water resistance of plywood were investigated. It was found that green tea had an ability to absorb formaldehyde. This phenomenon was caused by phenolic compounds contained in green tea leaves. The addition of green tea in the amount of 20% and 25% resulted in a decrease in formaldehyde emission from plywood comparing to the reference sample. The bonding quality test showed that the addition of tea leaves as a filler did not affect the strength properties of the tested bond lines.

WOOD RESEARCH Volume 62, Number 1, 2017
Vladimír Ihnát, Henrich Lübke, Albert Russ, and Vlastimil Borůvka

Waste agglomerated wood materials as a secondary raw material for chipboards and fibreboards. Part i. preparation and characterization of wood chips in terms of their reuse

The article describes a method of preparing particles from waste particle boards (chipboards) and oriented strand boards (OSBs). Their reuse is the main target of recycling. Method of their destruction was determined in this work. Agglomerated materials disintegrated after an initial destruction were further processed under specified conditions with regard to the material humidity, type of materials, contained adhesives and given characteristics of final particles – wood chips. Wood particles obtained were characterized by a fractional composition and amount of residual formaldehyde as an important parameter for the reuse of waste materials in production of furniture boards. New chipboards and pulp for production of middle density fiberboards (MDFs) will be provided from such defined particles.

WOOD RESEARCH Volume 63, Number 3, 2018
Vladimír Ihnát, Henrich Lübke, Albert Russ, Pažitný Andrej, and Vlastimil Borůvka

Waste agglomerated wood materials as a secondary raw material for chipboards and f ibreboards Part II. Preparation and characterisation of wood f ibres in terms of their reuse

The paper describes a process for the preparation of fibre from waste wood particleboards (PB), oriented strand chipboard (OSB) and medium density fibreboard (MDF). The purpose of recycling of agglomerated wood materials is to reuse them for the production of fibrous materials. The agglomerated materials disintegrated after the initial destruction were further processed under the specified conditions with respect to the moisture content, their type, adhesive used, and properties of final particles – wood chips. The obtained wood particles were characterized by the fractional composition of chips. The resulting chips were mechanically defibred with subsequent characterization of fiber obtained for its reuse in the manufacture of MDF. A quantity of formaldehyde released into the water when cooking waste MDF and PB was set up depending on the cooking time. Residual level of formaldehyde is the main chemical load that determines the amount of waste material that can be reused for production of new panels based on ureaformaldehyde adhesives.

WOOD RESEARCH Volume 64, Number 2, 2019
Sergej Medved, Urška Gajšek, Eugenia Mariana Tudor, Marius Catalin Barbu, and Alan Antonović

Efficiency of bark for reduction of formaldehyde emission from particleboards

Bark is much underutilized material. Most of the bark is used as fuel and for landscaping but there are still significant amounts of unused bark, hence creating a problem when disposed. Due to the aspects like colour, shape/size and ratio, and mechanical properties, bark is not a desired constituent for particleboard production. One of the possible uses of bark is related to its chemical compositions, specifically due to the phenolic-like components, bark can be used as formaldehyde scavenger.The aim of the paper is to present the usability of bark as particleboard formaldehyde scavenger. Single-layer particleboard made from wood particles spruce (Picea abies) and pine (Pinus sp.) bark mixture using urea-formaldehyde and melamine-urea formaldehyde as resin were tested for formaldehyde release. The formaldehyde release was determined by the Perforator method (EN 12460-5), gas analysis (EN 12460-3) and Flask method (EN 717-3). The experiment showed that the presence of bark lowers the formaldehyde release.