WOOD. Research papers. Reports. Announcements - No. 171 2004

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ISSN 1644-3985

 

Contents
 


RESEARCH PAPERS
Zofia KRZOSKA-ADAMCZAK, Magdalena NOWACZYK: 
Methodical investigation for evaluation of furniture surface resistance to scratching — Part I
(English language version)
5
Iwona FRACKOWIAK: 
From studies on the utilization of rape straw for the production of particleboards
(Polish language version)
31
Lelioara IANCU: 
Use of ultrasonic method in association with the imagistic method for detection of structural defects in gluing of the plywood
(English language version)
49
Vadim Grigorevich ULASOVEC: 
Determination of the rational plank thickness in sawing the central zone of pine logs
(English language version)
69
Ewa RATAJCZAK, Aleksandra SZOSTAK, Anna GALECKA, Gabriela BIDZINSKA: 
Analysis of the wooden small architecture market in Poland
(Polish language version)
81

REPORTS 
Jerzy WAZNY: 
Infection mechanism of wood construction by fungi
(Polish language version)
97
Stanislaw SPLAWA-NEYMAN, Witold PAZDROWSKI: 
Effect of site fertility upon formation of heartwood in timber of scots pine
(English language version)
105

ANNOUNCEMENTS
Ewa RATAJCZAK: 
International scientific cooperation in the area of used wood economy 
(Polish language version)
111

 

Summaries

 

RESEARCH PAPERS

Zofia KRZOSKA-ADAMCZAK, Magdalena NOWACZYK: 
Methodical investigation for evaluation of furniture surface resistance to scratching — Part I
(English language version)

This article presents a part of methodical investigations covering the determination of tip's geometry and its effect on furniture surface scratching traces (type of the surface damages). The aim of these investigations was to find the optimal parameters of the method useful to all possible furniture finishing materials. 
The next article (Part 2) will present the round robin test results performed by 5 European institutes. The aim of the test was to prove the usefulness of elaborated scratching test method, its parameters, repeatability and reproducibility of the results. Finally, the principles of the method will be presented.
The research has been done in cooperation with the Spanish partner - AIDIMA institute in Valencia and under the coordination of ihd Dresden.
Presented results are the part of European research development project FUNFACE realised within the 5th Framework Programme of the European Union, financially supported by the European Commission of EU and Polish Committee of Science.

Iwona FRACKOWIAK: 
From studies on the utilization of rape straw for the production of particleboards
(Polish language version)

The article presents, on the one hand, possibilities of the utilisation of rape straw in the production of particleboards and, on the other, the area of investigations essential to develop the technology for its processing. Trials were performed to shred straw and, in addition, straw fraction composition, geometry, bulk density, density and specific surface, pH and buffer capacity of straw particles obtained on the Condux shredder were determined. Three-layer boards were manufactured in which the proportion of straw in the inside layer was: 10, 25 and 50% as well as one-layer boards manufactured exclusively from sawdust. Properties of the experimental boards were compared with those specified for particleboards manufactured according to the same technological parameters and using identical chemical raw materials. Ureaformaldehyde resins were employed to achieve resination of straw particles. The applied technological parameters complied with the average, currently employed parameters in wood industry. The obtained research results indicate possibilities of the utilisation of rape straw to manufacture particleboards, either as the basic raw material or as an additive to traditional wood raw material. Properties of both one-layer boards from straw and tree-layer boards in which up to 25% rape straw was used only in the inside layer met the requirements of the PN-EN 312-3: 2000 standard required from boards intended for both inside constructions and furniture.

Lelioara IANCU: 
Use of ultrasonic method in association with the imagistic method for detection of structural defects in gluing of the plywood
(English language version)

This paper shows  the results obtained from the  samples of  plywood. The main purpose is  the detection of   defects by  nondestructive  method  using ultrasounds  in association with  the imagistic method for the form  reproduction by  direct  measurement of  flying times.Based  on  these  measurements, we  have  drawn up a  map of flying   times  which have  been   processed  through  the  numeric algorithms,  aiming   to  the maximization of  Baysian  posterior probabilities.
Presence of cellulose inside the  structure of  wood  gives it piezoelectric features. Position of cellulose  crystals  inside  the  mass structure  of wood  is very  complex. Wood  is thought as a system which  contains  numberless  crystals , having  an any  possible way  orientation-these are known and called by speciality literature, as a piezoelectric pattern.
The  equipment we  used consists of an ultrasonic apparatus,  with  60  kHz transducers  and a PC Pentium 250. Our  transducers  are equipped  with  wave   guides  to  make  sure  we  have  a pointlike  source  for  emission-reception.
The processing  of  the results  we  obtained   makes  possible  the realization  of  a map  of  the defects  zones. On the basis of the  matrix of  measured  flying times we are  able  to  express   graphically the  distribution of defects  in the  structure  of  wood  studied. The  results  demonstrate  o good  reproductibility of  defects

Vadim Grigorevich ULASOVEC: 
Determination of the rational plank thickness in sawing the central zone of pine logs
(English language version)

The influence  of the anatomic core of a tree with ring-type fractures in the annual ring around it , as well as the minimal plank thickness deflection gradient of the core from the geometric centre in the cross-section of a log , cut from the central zone of pine logs in the Urals, was investigated. It was established that the likely zone of arising of such fractures includes up to 5 annual rings.

Ewa RATAJCZAK, Aleksandra SZOSTAK, Anna GALECKA, Gabriela BIDZINSKA: 
Analysis of the wooden small architecture market in Poland
(Polish language version)

The objective of the research Project was to analyse the market of wooden small architecture In Poland. Bearing in mind the fact that articles of this branch are manufactured in different plants of the wood processing industry, the study covered such industries as: sawmill industry, construction joinery and furniture industry. The basic source of information about the industry, due to the lack of official data, were the results of a questionnaire carried out among manufacturers of small architecture products and, additionally, fragmentary data from the branch sources.
It is evident from the performed investigations that the market of small architecture manufacturers is very dispersed. These products arc manufactured primarily by small- and medium-sized companies. A majority of Polish manufacturers of small architecture articles export their products mainly to Germany and France. The offer of manufacturers of these products is very wide, and individual articles arc manufactured in a variety of different versions and types. The market of wooden small architecture in Poland is not fully developed yet and does not operate according to principles of free market competition. In the international market, Polish products of this branch can still compete with the assortment offered by foreign producers. The main advantages of Polish articles on this market comprise, primarily, lower labour costs affecting directly the relatively lower levels of prices.
Generally speaking, it can be concluded that articles of wooden small architecture constitute a developing and promising segment of wood articles market in Poland.

REPORTS

Jerzy WAZNY: 
Infection mechanism of wood construction by fungi
(Polish language version)

On the basis the literature on the subject as well as the autor's own investigations, this study discusses current opinions concerning the conditions and the mechanism of the infection of construction wood by fungi causing wood deterioratin and moulding. In addition, the role of the consecutive stages of infection: production, release, disseminates and germination of spores as well as the course of the proper infectin were reviewed. The opinion was confirmed that buildings are mainly infected by spores.

Stanislaw SPLAWA-NEYMAN, Witold PAZDROWSKI: 
Effect of site fertility upon formation of heartwood in timber of scots pine
(English language version)

Sectional dendrometry methods allow to obtain reliable results in determination of share of the heartwood and sapwood in tree stem. Appearing lately mathematical models  such as "Lignum" presented in Silva Fennica are giving quite   another results. In this paper presented are effects of the age and site fertility upon share of heartwood and sapwood in stems of Scots pine.