WOOD. Research papers. Reports. Announcements - No. 170 2003

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ISSN 1644-3985
 

Contents       
 


RESEARCH PAPERS
Jadwiga ZABIELSKA-MATEJUK: 
Application of copper-amine complexes, quaternary ammonium compounds and triazole derivatives in wood preservatives
(Polish language version)
5
Andrzej FOJUTOWSKI, Aleksandra KROPACZ: 
Anti blue stain chemical preservation of pine wood from different age classes
(Polish language version)
27
Iwona FRACKOWIAK: 
Investigations on the usefulness of the bottle method of formaldehyde emission assays in the industrial control of formaldehyde concentration in particleboards
(Polish language version)
41
Jaroslaw BANECKI: 
Synthesis and properties of diurea modified urea-formaldehyde resins used to manufacture paper foil
(Polish language version)
56
Juraj LADOMERSKY, Emilia HRONCOVA, Dagmar SAMEŚOVA:
Investigation of appropriate conditions for wood wastes combustion on basis of emission 
(English language version)
90
Hanna WROBLEWSKA, Magdalena CZAJKA: 
Chemical composition of wood of one-year old shoots of Salix viminalis and Salix purpurea willow trees growing on soils fortified with composts obtained from wastes of composite wood products
(Polish language version)
99
Mariusz JOZWIAK, Stanislaw PROSZYK, Witold JABLONSKI:
Alkylresorcinol modification of melamine-urea-formaldehyde (MUF) adhesive resins intended for the manufacture of exterior plywood 
(Polish language version)
116
Anna MENCEL: 
Value as an instrument for managing an enterprise
(Polish language version)
130

REPORTS 
Jerzy WAZNY: 
The proposal optimization of the agar-block method for wood preservatives fungitoxic evaluation
(English language version)
155

ANNOUNCEMENTS 
Wladyslaw STRYKOWSKI: 
Jubilee of Professor Ryszard Babicki 
(Polish language version)
163
Ewa TOMASZEWSKA: 
Wood Technology Institute — distinguished with Michal Oczapowski Medal 
(Polish language version)
165

 

Summaries

 

RESEARCH PAPERS

Jadwiga ZABIELSKA-MATEJUK: 
Application of copper-amine complexes, quaternary ammonium compounds and triazole derivatives in wood preservatives
(Polish language version)

Experimental antifungal preparations were developed which based on complexed copper compounds (II), quaternary ammonium compounds (QACs) and triazole derivatives. Tertiary amines were applied as complex-forming ligands. QAC-type compounds utilised in preparation formulations included: didecyldimethylammonium chloride or didecylmethylpoly(oxyethyl)ammonium propionate. The fungicidal value and leachability of the developed preparations from pine wood Pinus sylvestris L. were determined by agar-block methods. In order to assess leachability of QAC-type preparation components from wood in conditions of contact with soil, a soil-block test was carried out. Concentration changes of quaternary ammonium salts in wood were determined extracting them from wood by low frequency ultrasounds. The quantitative analysis of QACs in extracts was performed using a two-phase titration method. Threshold fungicidal values in relation to Coniophora puteana, BAM 15 strain ranged from >2.76 to 3.85 kg/m3, after a leaching cycle - from 4.32 to 8.6 kg/m3 depending on the substrate types of copper-amine complexes, the QAC type of compound in the experimental formulation of preparations as well as the applied test method. In the result of the performed soil test, biodegradation of one of the components of experimental preparations - quaternary ammonium salts was observed. It ranged from 16.14% to 28.59% depending on the type of the applied salt. Leaching of QAC type compounds from wood in contact with sterile soil amounted to 10.38%. Microscopic examinations confirmed the resistance of Gliocladium roseum species to QAC type of compounds however, the presence in the formulation of preparations of copper-amine comp lexes and triazole derivatives limited the access of mould fungi to the impregnated wood in conditions of its contact with soil.

Andrzej FOJUTOWSKI, Aleksandra KROPACZ: 
Anti blue stain chemical preservation of pine wood from different age classes
(Polish language version)

Wood, a major raw material and utility material in many branches of industry, is subject to biological corrosion caused by insects, bacteria and fungi. Considerable 
wood losses result from, among others, discoloration wood defects including blue 
stain, which is caused by numerous fungi belonging mainly to the species of Ascomycotinafungi. These fungi attack primarily sapwood of coniferous trees, especially pine. The increase of demand for raw wood more and more frequently determines using younger wood of lower age classes which contains more sapwood. With the age of wood, the degree of lignification of cell walls also changes. This can exert some influence on the dynamics of fungal development in wood, susceptibility of wood to blue stain as well as on the effectiveness of chemical preservation against this defect. Therefore, it is important to recognise dangers posed by blue stain fungi to this species of wood, in particular, methods of wood preservation against their activities.
The objective of this study was to recognise the effect of the age of Scots pine trees on the effectiveness of sapwood preservation against blue stain with chemical agents.
The performed experiments were carried out on pinewood 30, 41, 61 and 97 years old derived from the fresh coniferous forest site. The experimental wood was preserved using the following preparations: Fungosept (active ingredient: alkaline activated benzalconium chloride) of 2.5, 4.5, 6.5 and 8.5% concentrations (the 
recommended concentration is 6.5%) and LP 12 215 (active ingredient: propiconazol, 
boric acid) of 0.5, 1.0, 2.0 and 3.0% concentrations (the recommended concentration is 2.0%). The preservation effect of the applied preparations against blue stain was estimated by the test according to NWPC 1.4.1.3./79.
The following mixtures of pure fungal cultures were used in the performed experiments: Aureobasidium pullulans, Ceratocystis imperfecta, Cladosporium herbarum, Sclerophoma pityophila.
The above-mentioned preparations were applied by dipping in a cold bath in solutions deposed on the wood surface, on average in the amount of, 123 g/m2 of Fungosept and 120 g/m2 of the LP 12 215 agent. The initial moisture content of the examined wood was as follows: about 150% in the case of 30-year old wood, 120% - in 41-year old wood, 120% - in 61-year old and 115% - 97-year old wood, whereas the final moisture content differed from these values by ± 5%.
The preservation effectiveness of Scots pine wood at the age ranging from 31 to 97 years against blue stain by Fungosept at concentrations of 2.5 and 4.5% and the LP 12 215 preparation of 0.5 and 1.0% concentrations, i.e. concentrations lower than those recommended by the manufacturer (Fungosept - 6.5% and LP 12 215 preparation - 2%), turned out to be insufficient. A stronger preservation effect (less blue stain) could be expected in the case of younger wood - up to 61 years of age than the wood aged 97 years. 
In the case of concentrations equal or higher than those recommended for the commercial application, the preservation effectiveness turned out close to satisfactory or satisfactory, although in the case of action of the examined preparations on wood of various age, differences could occur. However, these variations were not associated, in a regular way, with wood age.
The performed experiments revealed that the effectiveness of preservation against blue stain of Scots pine wood from 30 to 97 years of age using Fungosept and the LP 12 215 preparations increased with the increase of solution concentration of the experimental preparations.
It was demonstrated that age differences of pine sapwood showed no clear influence on the preservation effectiveness of chemical anti-blue stain preparations. It is not necessary to apply different preparation concentrations to protect pine timber of lower age classes. Preparation concentrations recommended by manufacturers for commercial applications should be used to protect wood against blue stain.

Iwona FRACKOWIAK: 
Investigations on the usefulness of the bottle method of formaldehyde emission assays in the industrial control of formaldehyde concentration in particleboards
(Polish language version)

The objective of the research project was to ascertain possibilities of applying the bottle method of determining formaldehyde emissions for the current control of particleboard production classified in accordance with European standards on the basis of formaldehyde concentration in boards and the scope of technological changes, which do not require the verification of correlations between results obtained by the bottle and extraction methods. The object of studies comprised particleboards manufactured in a laboratory, produced during industrial tests, collected within the framework of outside control from different producers and obtained from retail outlets. The period of board seasoning before their examination ranged from 2 hours to about a year. The examined boards were manufactured from pine shavings machined in the laboratory from cordwood, from chips obtained from industry, from waste chips and assortments - sawmill sawdust as well as shavings from planing and turning. The applied adhesives included: urea, urea-melamine and melamine resins modified by the phenol resin. The variable factors comprised: the degree of gluing, glue formulation - type and quantity of the applied hardener, urea supplementation as well as parameters applied for drying wood particles, pressing and board seasoning. Board density ranged from 640-740 kg/m3, their thickness - from 12 to 22 mm and moisture content at the moment of examination - from 4.0 to 8.7%. The formaldehyde concentration ranged from 2.5 to 20.0 mg/100 g of completely dry board (c.d.b), whereas formaldehyde emission fluctuated from 2.3 to 22.9 mg/g. Results of investigations and statistical calculations revealed that there was a close correlation between the formaldehyde emission determined using the bottle method and its concentration in boards even in the case of boards manufactured according to different recipes and parameters, seasoned in different conditions and stored for different periods of time. The correlation coefficient for the entire examined population amounted to 0.82; the limit emission value calculated from the regression equation was smaller than the acceptable formaldehyde concentration. The particleboard hygiene classification according to the formaldehyde concentration on the basis of studies of the formaldehyde emission based on the correlation determined on the basis of boards manufactured and seasoned in conditions characterised by such a considerable area of variability forced the author to adopt the limiting value of emissions at a very low, frequently unjustified level. Together with reduced factorial variability characterising individual particleboard sets, values of correlation coefficients calculated for the examined relationships as well as the limiting value of emission determining the acceptable formaldehyde concentration also increased. A change in glue formulations and basic parameters of particleboard production does not require a verification of interrelationships between the emission and concentration of the formaldehyde, provided that the type of resin is a constant factor.
The bottle method of determining formaldehyde emissions in accordance with the PN-EN 717-3 standard can be applied in on-line monitoring, which constitutes the basis of control of particleboard productionThe correlation coefficient for the correlation between the emission and concentration of the formaldehyde calculated on the basis of boards examined not later than 2 hours after their production was 0.97.
The variability of the wood raw material, in particular waste assortments stored for different periods of time, can result in the decline of the value of the correlation coefficient between results obtained using the perforator and bottle methods, even if the same chemical materials and board production parameters are applied for the particleboard manufacture.

Jaroslaw BANECKI: 
Synthesis and properties of diurea modified urea-formaldehyde resins used to manufacture paper foil
(Polish language version)

The paper presents results of piloting and main investigations concerning the modification of urea-formaldehyde (UF) impregnation resins in the course of their synthesis using, for this purpose, diureas.
The objective of this research project was:

  • to recognise the influence of a diurea introduced during the process of UF resin synthesis on properties of liquid and hardened modified UF resin,
  • to ascertain the effect of the quantity and method of tetramethylenediurea (TMDU) incorporation in the process of synthesis of the UF impregnation resin synthesis on its properties when in liquid form,
  • to manufacture a UF impregnation resin characterised by advantageous properties (reactivity, water tolerance) in liquid form and by reduced susceptibility to its hydrolytic decomposition in hardened form in paper.

Results of piloting experiments revealed that the reactivity of liquid, diurea modified UF resins observed in the process of their curing at the temperature of 100oC was lower in comparison with this attribute exhibited by a non-modified UF resin. This tendency occurred irrespective of the type of the applied hardener (20% solution of ammonium chloride or 20% solution of p-toluenesulfonic acid). The applied UF resin modification by diureas added during the process of synthesis further resulted in reduced water tolerance of modified resins and this reduction varied depending on the used quantities and type of diurea. Diurea modified UF resins cured in the paper carrier exhibited lower susceptibility to hydrolysis under the influence of short-term (5-minute) exposure to water vapour at the temperature of 100oC in comparison with cured, non-modified urea resin. The measure of UF resin susceptibility to hydrolysis was the formaldehyde emission expressed by the quantity of formaldehyde released by 1 g of resin cured in the paper, during 1 hour of experiment using the gas analysis method. The results of performed investigations showed that the susceptibility to hydrolysis of cured, modified UF resins decreased with the increase of the amount of diurea (hexamethylenediurea - HMDU or tetramethylenediurea - TMDU) in the condensed resin. It was found that TMDU modified resins (2.3 and 4.6% mol), in their cured form, were characterised by increased resistance to hydrolysis in comparison with cured resins containing the same quantities of hexamethylenediurea (HMDU).
Conclusions drawn from piloting investigations allowed selection of a modified UF resin with a distinctly reduced susceptibility to hydrolysis when exposed to short-term action of hot water vapour and, at the same time, maintaining favourable properties in liquid form (reactivity, water mixability, time of total paper penetration). The selected resin contained 2.3% mol TMDU and it was this modifier that was applied as an additive in subsequent syntheses of impregnation UF resins.
In the course of main investigations, a series of three impregnation UF resins were manufactured which were modified, to various degrees (1.1; 2.3; 3.5% mol), by tetramethylenediurea (TMDU) and non-modified resin. Basic properties of these liquid resins were examined and compared. It was found that increased TMDU content in the UF impregnation resin led to reduced water tolerance, lower concentrations of free formaldehyde and long gelation time of liquid resin at the temperature of 20oC. In the course of subsequent experiments, the author prepared and examined properties of impregnation moistures of selected UF resins with LBSK 55-45 latex used as a plasticising agent. The following important properties of the prepared mixtures were compared: reactivity at temperatures of 20oC and 100oC as well as the capacity for total paper penetration. Results of comparative analyses indicate that increasing quantities of TMDU in the UF impregnation resin caused deterioration of the paper penetration capabilities by the impregnation mixture containing modified UF resin and greater dependence of this penetration on the amount of the LBSK 55-45 latex in the mixture composition. Next, using the prepared impregnation mixtures, 6 types of paper foils without lacquer finish were manufactured. Using water-thinned, acid-hardened lacquer, 6 appropriate types of lacquered paper foils were produced. Gas analysis values of formaldehyde emissions determined for individual types of non-lacquered paper foils were small and ranged from 0.03÷0.10 mg/m2h. On the other hand, formaldehyde emissions from lacquered versions of paper foils as well as emission increases of this compound against gas analysis values determined for non-lacquered foils turned out to vary depending on the type of UF resin cured in the paper base. The greatest increase of the emission (12÷15-fold) was observed in the case of lacquered paper foils containing in paper base non-modified UF resin in the mixture with latex. An intermediate increase (6÷10-fold) of the emission was observed for lacquered foils containing a cured mixture of LBSK 55-45 with the UF resin of the highest  diurea content (3.5% mol TMDU). The smallest increments of formaldehyde emission (4÷5-fold) were found for lacquered foils containing in their paper base a cured mixture of LBSK 55-45 with UF resin of an intermediate degree of TMDU modification (2.3% mol). Non-lacquered and lacquered paper foils containing in their paper base selected UF resins cured in the mixture of the LBSK 55-45 latex applied at the amount of 30% by weight DM, were utilised for hot, double-sided veneering of particle boards. Results of the multiplication factor analysis of formaldehyde emission increments from the particle board finished with non-lacquered paper foil in relation to the emission from the paper foil alone showed that the foil containing cured UF resin with intermediate TMDU content (2.3% mol) turned out to be the least susceptible to the hydrolytic action of overheated water vapour liberated during the particle board veneering (temperature of veneering - 140oC). This TMDU modified UF resin turned out to be the impregnation material characterised by optimal properties in liquid form as well as by reduced susceptibility to hydrolytic action of hot water vapour in cured form. 

Juraj LADOMERSKY, Emilia HRONCOVA, Dagmar SAMEŚOVA:
Investigation of appropriate conditions for wood wastes combustion on basis of emission 
(English language version)

Degradation and oxidation of organic substances in a combustion chamber are carried out by complicated mechanisms that can be significantly influenced by different local burning-up conditions. This paper presents the experimental results of wood waste combustion. These results show that inappropriate combustion conditions in a combustion chamber can be effectively studied using hydrocarbon emissions expressed as total organic carbon (TOC), phenol and formaldehyde.

Hanna WROBLEWSKA, Magdalena CZAJKA: 
Chemical composition of wood of one-year old shoots of Salix viminalis and Salix purpurea willow trees growing on soils fortified with composts obtained from wastes of composite wood products
(Polish language version)

Within the framework of investigations on the utilization of wastes derived from composite wood products employing the composting method, pot vegetation tests were carried out to estimate the suitability of the obtained composts for the cultivation of arborescent plants. The performed experiments employed two varieties of fast growing willow trees, namely Salix viminalis and Salix purpurea.
They were grown on substrates made of poor soil fortified with composts from wastes derived from chipboards (PW), medium density fibreboards (MDF) and wet-formed fibreboards (PP) at the following proportions by volume: 1:1, 1:3 and 1:9. Willow tree shoots obtained from respective experimental treatments, were subjected, without removing bark to wood chemical analysis. The following analyses were performed: cellulose concentration by Seifert method, Klason lignin by Tappi method, pentosans by Tollens method, mineral substances, substances soluble in 1% NaOH, cold and hot water as well as in ethanol-benzene mixture and pH.
The wood of the examined Salix viminalis and Salix purpurea trees derived from one-year old plants which were cultivated in the same atmospheric conditions but different trophic environments (substrate composition), which influenced the development of plants. This resulted in obtaining considerably varied yields (weight of shoots) per one plant (from 2.4 g to 18.7 g for Sałix viminalis and from 0.5 g to 16.7 g for Salix purpurea). It was found that the observed differences in the chemical composition of the examined wood samples could be associated with plant weight. Together with the increase of plant weight, characteristic trends were noticed in the increase of cellulose and decrease of lignin content as well as substances extracted by hot water and the ethanol-benzene mixture in the wood of both willow varieties.

Mariusz JOZWIAK, Stanislaw PROSZYK, Witold JABLONSKI:
Alkylresorcinol modification of melamine-urea-formaldehyde (MUF) adhesive resins intended for the manufacture of exterior plywood 
(Polish language version)

The article presents research results on the modification of glue materials manufactured using model melamine-urea-formaldehyde (MUF) resins and a mixture of natural alkylresorcinols in the form of a commercial product called "Alkyres". Resorcinol was used for comparative purposes and, additionally, urea was applied as the formaldehyde sorbent. The model MUF resins synthesised for the needs of this study were characterised by the concentration of dry matter at the level of at least 60% and a varying molar proportion of formaldehyde against melamine and urea.
The performed investigations involved the determination of selected properties of resins, reactivities of the modified glue substances as well as water resistances of adhesive bonds in three-layer beech plywoods following aging tests IF-20 and AW-100.
It was found that alkylresorcinols increased the water resistance of adhesive bonds. The observed fortifying effectiveness was particularly significant in the case of glue materials obtained from MUF resins with urea.
The experimental tree-layer beech plywoods bonded with MUF glues modified by alkylresorcinols fulfilled the requirements of the EN-3 14-2 standard with regards to IF-20 and AW- 100 tests. The expected impact of the molar formaldehyde share in MUF resins on the fortification efficiency using alkylresorcinols was not observed.
Alkylresorcinols can be applied as modifiers of adhesive materials from MUF resins used in production of exterior plywood.

Anna MENCEL: 
Value as an instrument for managing an enterprise
(Polish language version)

Management by value requires subordination of the entire strategy of functioning and development of an enterprise - in ail spheres of its operation - to generating income, which exceeds the cost of its capital. The condition of the company depends on the inflow of capital needed for restructuring, new investments and increase of effectiveness. Affecting the long-term development of a company by means of increasing its value requires the selection of an appropriate measuring instrument 
of its assessment. One of such instruments is the method of discounted cash flows (DCF).
This study presents an analysis of the DCF method performed on the basis of the value o cash flows in years of prognostication covering the period of 2002-2006, calculation of the residual value and determination of the discount rate. 
The paper also presents research results of factors influencing the increase of the company value, including major factors affecting the creation of this value, i.e. increased income from sales, cost reduction, more efficient management of the working capital, effective investments, the impact of the capital cost and long-term change rate of cash flows after the prognostication period on the company value. It was found that the DCF prediction applied to several different financing scenarios, yielded the most reliable basis for an objective assessment of the economical situation of the company and possibilities of affecting its development. The management concept, which assumes a long-term development of the company's value, was verified in practice in many different countries. Its implementation by Polish enterprises is crucial for the improvement of their competitiveness and value on the capital market.

REPORTS 

Jerzy WAZNY: 
The proposal optimization of the agar-block method for wood preservatives fungitoxic evaluation
(English language version)

On the base of own research and other scientists results the proposal for optimalization of agar-block method was presented by:

  • selection of test fungal species and strains and central distribution of their pure cultures,
  • change of the treatment and control samples exposure procedure,
  • application of mathematical estimation of toxic value results,

shortening the duration of fungitoxic test by miniaturization of wood samples.