scholarly journals Effects of the thickness of rotary-cut veneers on properties of plywood sheets. Part 1. Compressibility of plywood materials

2012 ◽  
Vol 51 (No. 9) ◽  
pp. 403-411
Author(s):  
J. Hrázský ◽  
P. Král
Keyword(s):  
Economic Evaluation ◽  
Urea Formaldehyde ◽  
Urea Formaldehyde Resin ◽  
Production Costs ◽  
Formaldehyde Resin ◽  
Institutional Research ◽  
Production Parameters ◽  
A Value

The paper summarizes results of the institutional research aimed at the determination of compressibility or values of the reduction of thickness of compressed plywood sheets. Assessing the effect of thickness and thickness tolerances of veneers to a value of compressibility in relation to production parameters was carried out on the collection of plywood whole-beech sheets of the nominal veneer thickness of 1.5 mm. The plywood sheets were manufactured as seven-ply ones and urea-formaldehyde resin DUKOL S was used for their manufacture. Following characteristics were assessed: thickness differences, size of shrinkage, compressibility of veneers. Sheets were pressed using a pressure of 1.5 and 1.7 MPa. Values of changes in the thickness of veneers in pressed veneer sheets and coefficients of compressibility of particular properties were then statistically analyzed. Basic economic evaluation was carried out of the effect of compressibility on the amount of production costs.

scholarly journals Effects of the thickness of rotary-cut veneers on properties of plywood sheets. Part 2. Physical and mechanical properties of plywood materials

2012 ◽  
Vol 52 (No. 3) ◽  
pp. 118-129
Author(s):  
J. Hrázský ◽  
P. Král
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Institutional Research ◽  
Nominal Thickness

The second part of the paper summarizes results of an institutional research aimed at the determination of physical and mechanical properties of different sets of plywood sheets pressed under different conditions. The first part dealt with the determination of compressibility or values of decreasing the thickness of pressed plywood sheets. In this second part, results are summarized of the analysis of physical and mechanical properties of the set of whole-beech plywood sheets of the nominal thickness of veneers amounting to 1.5 mm. The plywood sheets were manufactured as seven-ply and urea-formaldehyde resin DUKOL S was used for their production. The sheets were pressed using a pressure of 1.5 and 1.7 MPa. Following parameters were analyzed: moisture, density, bending strength, MOE in bending and shear strength.

Study on Modification of Urea Formaldehyde Resin with Keratin

2010 ◽  
Vol 113-116 ◽  
pp. 1787-1791 ◽  
Author(s):  
Jiu Yin Pang ◽  
Chuan Sun ◽  
Shi Cheng Zhang ◽  
Hai Xing Cui
Keyword(s):  
Low Cost ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Urea Formaldehyde Resin ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Formaldehyde Resin ◽  
Low Toxicity ◽  
Modified Urea

As the main adhesive types in wood-based panel industry，urea-formaldehyde has such shortcomings as high levels of free formaldehyde content and formaldehyde emission of its bonding product. In this experiment, we try to modify urea-formaldehyde resin with keratin through copolymerization reaction. Through the determination of such reaction technology as molar ratio, adding sequence of keratin and adding amount of keratin, we finally synthesized the low toxic urea resin. The results show that the optimum molar ratio is 1.3:1, the adding amount of keratin is 5% and adding keratin after the third feeding of urea is the best choice. By optimizing the synthesis process, we ultimately get the low toxicity modified urea-formaldehyde resin. At the same time, modified urea-formaldehyde resin cost has been reduced because extensive sources of keratin and low cost.

Activated carbon from co-pyrolysis of particle board and melamine (urea) formaldehyde resin: A techno-economic evaluation

2011 ◽  
Vol 172 (2-3) ◽  
pp. 835-846 ◽  
Author(s):  
K. Vanreppelen ◽  
T. Kuppens ◽  
T. Thewys ◽  
R. Carleer ◽  
J. Yperman ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Economic Evaluation ◽  
Urea Formaldehyde ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Particle Board

scholarly journals Effects of Three Biomass Fillers on the Properties of Melamine Modified Urea-Formaldehyde Resin

2020 ◽  
Vol 782 ◽  
pp. 022077
Author(s):  
Shanfeng Xu ◽  
Sanshan Xia ◽  
Yuzhu Chen ◽  
Hui Xiao ◽  
Maoyu Yi ◽  
...  
Keyword(s):  
Urea Formaldehyde ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Modified Urea

scholarly journals Calcium carbonate modified urea–formaldehyde resin adhesive for strength enhanced medium density fiberboard production

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 25010-25017
Author(s):  
Li Lu ◽  
Yan Wang ◽  
Tianhua Li ◽  
Supeng Wang ◽  
Shoulu Yang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Medium Density ◽  
Ionic Bond ◽  
Resin Adhesive ◽  
Uf Resin ◽  
Modified Urea

Reactions between CaCO3 and CH2O2 during polycondensation of UF resin produce Ca2+. Ionic bond complexation binds Ca2+ with UF resin. The UF resin crystalline percentage decreases from 26.86% to 22.71%. IB strength of resin bonded fiberboard increases from 0.75 to 0.94 MPa.

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