WOOD. Research papers. Reports. Announcements - No. 173 2005

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ISSN 1644-3985

 

Contents
 


RESEARCH PAPERS
Ewa RATAJCZAK, Aleksandra SZOSTAK, Gabriela BIDZINSKA: 
The innovativeness of the Polish woodworking and furniture industries 
(Polish language version)
5
Jaroslaw BANECKI: 
The effect of acrylic modifier of urea resin on the properties of artificial veneer on paper foil 
(Polish language version)
35
Iwona FRACKOWIAK: 
The effect of changes taking place during storage of pine sawdust on the properties of boards made from the sawdust 
(Polish language version)
81
Vadim Grigorievich ULASOVEC: 
Estimating accuracy of methods for measuring the mean width of unedged boards 
(English language version)
95

REPORTS
Roger M. ROWELL: 
Chemical Modification: A Non-Toxic Approach to Wood Preservation
(English language version)
111
Przemyslaw GACA, Aleksandra DZIEWANOWSKA-PUDLISZAK: 
Volatile organic com-pounds emission of selected wood species and other materials applied in furniture manufacture
(English language version)
119

ANNOUNCEMENTS
Wladyslaw STRYKOWSKI: 
The Polish Technological Platform of the Forest-Timber Sector
(Polish language version)
127
Ewa RATAJCZAK: 
InnovaWood – European scientific network in the field of forest and timber industry 
(Polish language version)
131
Jaroslaw BANECKI: 
IV International Congress devoted to wood-coating „Woodcoatings” – Hague 2004
(Polish language version)
135

 

Summaries

 

RESEARCH PAPERS

Ewa RATAJCZAK, Aleksandra SZOSTAK, Gabriela BIDZINSKA: 
The innovativeness of the Polish woodworking and furniture industries 
(Polish language version)
 

Owing to a relatively brief tradition of economic research on innovation and various ways of understanding of the term, no generally accepted definition of innovation has yet been established. In the field of economics, innovation is increasingly seen as a process that incorporates progress in science as well as its technological applications in manufacturing. Innovation is commonly perceived to be based on novelty and change.
In the 1990s, developed countries underwent thorough changes which elevated innovation to the role of a key factor for economic growth and development. Essential feature of the new trends is rising importance of intangible production factors, particularly knowledge and skills (the knowledge-based economy). The business environment has adopted a new focus on networking, cooperation, knowledge development and international knowledge transfers.
Results of carried out studies suggest that despite improved performance in certain indicators observed in recent years, the level of innovation in the woodworking and furniture industries has been below the Polish industry average and much below that of the European Union. In 2003, the level of innovation in the woodworking and furniture industries, expressed as innovation layouts over product sales, was approximately 2.0%, compared to the total industry of 3.6% and the manufacturing industry of 3.8%. Much like in the industry as a whole, a distinctive feature of innovation in the Polish woodworking and furniture industries is that the bulk of financing goes to technical infrastructure. This stands in opposition to European Union trends where the majority of innovation projects focus on the product. Polish woodworking and furniture industry enterprises undertake little innovative activity in generating new knowledge (only a small proportion of expenditures goes into research and development); investments into innovation-related personnel training and marketing of technologically new and improved products are also small and still decreasing.
Yet, a number of signs indicate that the barriers to undertaking development activities are gradually being overcome as woodworking industry companies take to spending growing amounts on technical innovation. One positive sign is the renewal of machinery and equipment in industrial enterprises and the resulting reduction in the degree of its average wear and tear (which is 50% in the woodworking industry and 54% in the furniture industry, compared to 57% in total industry) and the growing rate of industrial process automation. Technological advances in the woodworking and furniture industries rely mainly on imitation, which is a common feature of all innovation processes in Poland. In the woodworking and furniture industries, the spread of technological progress has been mainly the result of foreign capital inflows to restructured companies.
The primary barriers to innovative activity in the woodworking and furniture industries are economic in nature (on the one hand - too high innovation costs and, on the other, the absence of a convenient financing system while the shortage of own resources occurs, in the form of low interest loans and tax breaks. Other significant barriers to innovation persist in the area of legislation which is either missing or inconsistent and provides no framework solutions to stimulate innovation. For the climate to improve, the state needs to reform its pro-innovation policies and, in particular, come up with efficient mechanisms for financing development, simplify administrative procedures for the adoption of innovation and establish a more friendly legislative environment. Some of the crucial internal conditions with a potential to foster innovation in the woodworking and furniture industries are: efforts to improve the financial status of companies, stimulation of innovativeness and creativity among management as well as production floor personnel, intensification of cooperation with R&D organizations and proper recognition market needs.

Jaroslaw BANECKI: 
The effect of acrylic modifier of urea resin on the properties of artificial veneer on paper foil 
(Polish language version)

This paper presents results of a range of experiments conducted within the scope of a doctoral thesis under the same title. The aim of the thesis was to study the effect of modification of impregnating urea-formaldehyde resin (UF resin) (by using acrylic resins with a side chain including such functional groups as carboxylic, amide, ester and cyano groups) on the properties of liquid and hardened impregnation mixtures, and on properties of paper foils made of those mixtures. The focus of the thesis was the following: (1) to study the properties of liquid impregnating mixtures of UF resin and different acrylic resins depending on the type and amount of the acrylic polymer used, (2) to study the properties of hardened impregnation mixtures of UF resin with some acrylic ones depending on the type of acrylic polymer, (3) to develop paper foils using selected impregnation mixtures, and (4) to study the properties of the obtained paper foils.
The results of the studies performed indicated that irrespective of the chemical composition of the applied acrylic resin, increasing its amount in the impregnation mixture from 10% m/m (type A mixture) to 40% m/m (type C mixture) led to an increase in the basic viscosity of the mixture and in the time of through penetration of decorative paper. It was also found out that the through penetration of paper with resin mixtures tends to extend in time with an increasing length of carbon chains of aliphatic substituents in ester groups of acrylic polymer. This tendency was reported especially for mixtures containing acrylic resins, which next to the ester group in the side chains of macromolecules also contain carboxyl groups or primary amide groups. Mixtures with acrylic resins containing carboxyl groups were found to better permeate the decorative paper than impregnation mixtures containing acrylic polymers whose macromolecules included primary amide groups.
Summing up the first part of the studies (cf. 1) concerning the properties of liquid impregnation mixtures, it was concluded that the type of acrylic resin used in the mixture with impregnating UF resin affected both the ability of the mixture of through penetration of paper and the values of gelation times at the temperature of 20°C and 100°C, knowing that the effect of chemical composition of acrylic polymer on the impregnating properties of liquid resin mixture was stronger than on its gelation time at the temperatures given. Moreover, it was claimed that the amount of acrylic polymer used in the mixture with impregnating UF resin, affected both the ability of the mixture of through penetration of paper regardless of the type of acrylic polymer used, and gelation times of the mixture at 20° and 100°C depending on the type of acrylic resin used.
It follows from the results of the examinations of homogeneity of hardened impregnation mixtures of UF resin with chosen acrylic resins (the study was conducted using nuclear magnetic resonance method 13C in a solid - 13C CP/DD/MAS/ NMR), and from the analysis of values of relaxation times of protons T1pH and T1H in hardened samples of the component resins and hardened mixture of these resins, as well as from the results of examination of the content of water-eluted substances (w.e.s) in hardened mixtures of resins, that:

  • Acrylic polymers containing primary amide groups along with other functional groups (e.g. ester groups, carboxyl groups) in a macromolecule, formed hardened mixtures with UF resin at the weight ratio of 1/1 (DM) of low w.e.s. content, which indicates a high degree of cross-linking with UF resin, which is also indicated by the homogeneity of hardened mixtures containing acrylic resins of a similar chemical composition.
  • Acrylic polymers whose macromolecules contain carboxyl groups next to ester groups, but do not contain amide groups or contain them at a very small amount, formed with UF resin at the weight ratio 1/1 (DM) hardened mixtures of a high content of water-eluted substances, which is indicative of a low degree of cross-linking with UF resin. This can be also concluded from the inhomogeneous structure of hardened impregnation mixtures containing acrylic resins of a similar general composition.

The results of the studies also indicated that the type of aliphatic substituent in ester groups, which were next to amide groups in macromolecules of acrylic polymers, did not have a significant effect on the content of w.e.s. in their hardened mixtures with UF resin.
The infrared absorption spectrophotometry was used to investigate the chemical structures of hardened mixtures of UF resins with chosen acrylic ones, and then the structures were compared with the chemical structures determined separately for the hardened UF resin and for a given dried acrylic polymer. It follows from the spectral analysis of the hardened impregnating resins that the hardened mixtures containing acrylic polymers composed of mers of acrylamide and ethyl or butyl acrylate, are made of structures whose presence seems to suggest that during the hardening of liquid mixture of UF resin with such an acrylic polymer, chemical interactions between primary amide groups of the acrylic polymer and hydroxymethyl groups of UF resin, occur. These interactions are probably fostered by hydrated formaldehyde molecules which are present in UF resin solution.
Non-lacquered paper foils were produced on a laboratory scale by saturating decorative papers with impregnation mixtures of type A, B, and D containing respectively 10, 25 and 50% m/m of acrylic modifier. The impregnation mixtures were selected according to criteria described in the paper. Small batches of paper foils were obtained, and they differed in the composition of impregnation mixture hardened in the paper core. Paper foil made with use of impregnation mixture containing unmodified UF resin and a specific amount of hardener was used as the reference material.
For paper foils containing 10% m/m of acrylic modifier, it was reported that an increase in the amount of amide groups in the acrylic modifier does not bring about considerable differences in such properties of paper foils as formaldehyde emission, paper saturation with resin mixture, the content of volatiles, elasticity and air permeability, while an increase in the fraction of carboxyl groups in the acrylic modifier results in a clear decrease of elasticity and increase in the content of volatiles as well as in a lower formaldehyde emission and air permeability through a paper foil. When the amount of the acrylic modifier was raised to 25% m/m in the impregnation mixtures with UF resin, the paper foils composed of those mixtures were characterized by a lower degree of paper saturation, higher formaldehyde emission, higher content of volatiles as well as by lower air permeability, in comparison to the properties of paper foils made of impregnating mixtures containing only 10% m/m of the acrylic modifier. The greatest decrease in formaldehyde emission from paper foil, in relation to reference material, was reported for impregnating UF resin modified by acrylic polymers whose macromolecules contained amide groups next to carboxyl groups, or ester groups significantly outnumbering amide and carboxyl groups. On the other hand, the greatest growth of formaldehyde emission from paper foil, was stated when acrylic polymers whose macromolecules contained only ester groups or ester groups combined with carboxyl or cyanide groups, were used as modifiers of UF resin. Paper foil showing the optimum utility properties and acceptable formaldehyde emission (E1 class), was obtained by modification of UF resin at the weight ratio 1/1 with acrylic polymer composed predominantly of mers of acrylate, methyl metacrylate as well as n-hexyl and of small amounts of mers of acrylamide and acrylic acid.

Iwona FRACKOWIAK: 
The effect of changes taking place during storage of pine sawdust on the properties of boards made from the sawdust 
(Polish language version)

The process of storing sawdust in the industrial scale was examined in experimental heaps of the following size: height 15 m, width 25 m, and length 45 m. The method of forming the heaps and placing in them study samples stored for different periods of time were described. Throughout the whole storage period,, temperature in the heaps was controlled by means of probes inserted in the heaps when they were formed.  Fraction composition and buffer capacity of fresh sawdust (prior to the storage period and when stored already for 4 and 6 month) were examined throughout the whole width of the heaps at different distances from the ground. Fraction composition and buffer capacity of sawdust were determined. 
Then the sawdust stored for four and six months, taken from different places of the heaps, was used to manufacture three-layer particleboards. The technological parameters and chemical substances used to make the boards were in agreement with those currently applied in manufacturing particleboards; they were unmodified in our tests. 
It follows from the results of the tests that the fraction composition of sawdust does not change during the 4-month storage. In contrast, after six months, the amount of fine fractions clearly increases. The chemical changes observed and expressed by means of buffer capacity of sawdust are related to the time of storage and storage place in the heap. A manifold increase of acid buffer capacity of sawdust stored for six months was observed. 
The properties of particleboards made from pine sawdust according to the unmodified parameters from the same chemical substances are determined by the value of acid buffer capacity. In the tested time interval, increase in acid buffer capacity resulted in a decrease in strength of the boards and an increase in the content of formaldehyde.
The parameters of static bending and perpendicular tensile strength of boards and the content of formaldehyde are interrelated thought a linear function. The values of the parameters associated with acid buffer capacity of sawdust are equal to 87%, 82% and 91%. 
In the studied range an increase in acid buffer acidity brings about a decrease in the thickness of swelling after 2 hours of soaking the boards in water. The value of determination coefficient for power function defined for this interrelation is equal to 0.84.

Vadim Grigorievich ULASOVEC: 
Estimating accuracy of methods for measuring the mean width of unedged boards 
(English language version)

The present standards for calculating the volume of unedged boards recommend to determine their mean width as the half-sum of widths of two sawn sides, measured in the middle of the board length. In this paper it is shown, that such recommendation leads to underestimating the real volume of unedged  boards.

REPORTS

Roger M. ROWELL: 
Chemical Modification: A Non-Toxic Approach to Wood Preservation
(English language version)

Reaction of wood with anhydrides, isocyanates, and epoxides reduces the moisture content of the cell wall and increases the resistance of the modified wood to attack by fungi.  As the level of bonded chemical increases, the cell wall equilibrium moisture content decreases and the resistance to attack by white- and brown-rot fungi increases.  There is a direct relationship between the decrease in cell wall moisture content and resistance to fungal attack. The mechanism of the effecti-veness of chemical modification to provide decay resistance seems to be due to the reduction of moisture content in the modified wood.

Przemyslaw GACA, Aleksandra DZIEWANOWSKA-PUDLISZAK: 
Volatile organic com-pounds emission of selected wood species and other materials applied in furniture manufacture
(English language version)

The emissions of volatile organic compounds from particleboards, plywood, finish foil, furniture elements and polyvinyl acetate (PVA) adhesive have been measured. Samples emission properties in small chamber was given both qualitative and quantitative characterisation with the use of TD-GC/MS system. Very high volatile organic compounds (VOC) emission for veneered particleboard was observed. Relatively high emission was observed also in the case of solid pine wood and lacquered sample of pine wood (child bed sample) where aromatic derivatives were detected. For plywood, PVA adhesive and finish foil VOC emission was found low and met the IKEA requirements. Significant differences, both qualitative and quantitative, between unfinished and finished samples were observed.

ANNOUNCEMENTS

Wladyslaw STRYKOWSKI: 
The Polish Technological Platform of the Forest-Timber Sector
(Polish language version)

The goal of the Polish Technological Platform of the Forest-Timber Sector is to closely cooperate with the European Technological Platform in the field of balanced development of the forest-timber sector, introduction of new technologies, rational use of resources, encouragement of innovations and research, as well as scientific and technological development.  

Ewa RATAJCZAK: 
InnovaWood – European scientific network in the field of forest and timber industry 
(Polish language version)

In is both desirable and imperative to set up scientific networks in modern economy de-manding high innovation and competition. Innovawood  includes almost 80 European scientific, research and development, as well as educational centers specializing in fore-stry and timber industry. Is main aims are consolidation of research studies and exchange of experience.

Jaroslaw BANECKI: 
IV International Congress devoted to wood-coating „Woodcoatings” – Hague 2004
(Polish language version)

The subjects discussed during this Congress concerned new methods of wood modifica-tion, develipment of methods for testing of properties of woodcoatings, technologies of producing coatings, and innovative coating materials characterized by a low emission of organic volatile compounds.