Effect of veneer side wettability on bonding quality of Eucalyptus globulus plywoods prepared using a tannin?phenol?formaldehyde adhesive

The peeling of small-diameter rubberwood logs from the current short-rotation practices undoubtedly will produce lower grade veneers compared to the veneers from conventional planting rotation. Hence, this raises the question of the properties of the produced laminated veneer lumber (LVL) from veneers peeled from small-diameter rubberwood logs using the spindleless lathe technology. Different thicknesses of rubberwood veneers was peeled from rubberwood logs with diameter less than 20 cm using a spindleless lathe. Three-layer LVLs were prepared using phenol formaldehyde (PF) adhesive and hot pressed at different temperatures. During the peeling of veneer, lathe checks as deep as 30–60% of the veneer thickness are formed. Owing to deeper lathe check on 3 mm rubberwood veneer, higher pressing temperature significantly increased the gluebond shear strength of the PF-bonded LVL. In addition, lathe check frequency was also shown to influence the bond strength. The presence of higher lathe check frequency on 2 mm veneer increased the wettability, thus facilitating optimum penetration of adhesive for stronger bonding. These findings stress the importance of measuring and considering the lathe check depth and frequency during the lamination process to get a better understanding of bonding quality in veneer-based products.

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Effects of Selected Parameters on the Bonding Quality and Temperature Evolution Inside Plywood During Pressing

Polymers ◽

10.3390/polym12051035 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1035 ◽

Cited By ~ 2

Author(s):

Pavlo Bekhta ◽

Ján Sedliačik ◽

Nataliya Bekhta

Keyword(s):

Heating Rate ◽

Phenol Formaldehyde ◽

Temperature Evolution ◽

Efficient Production ◽

Pressing Pressure ◽

Bonding Quality ◽

Pressing Time ◽

Temperature Time ◽

Required Quality

This research optimizes the process of plywood production to determine its effectiveness in reducing energy and adhesive consumption for more efficient production with the required quality. The influence of selected parameters including veneer treatment (non-densified and densified), plywood structure, temperature, time and pressure of pressing, on the bonding quality and temperature evolution within the veneer stacks during hot pressing was investigated. Rotary-cut, non-densified and densified birch veneers and phenol formaldehyde (PF) adhesive were used to manufacture plywood samples. The effect of pressure and time of pressing on bonding quality of the plywood was determined. Bonding quality was evaluated by determining the shear strength of the plywood samples. The temperature evolution inside the veneer stacks was measured for birch veneers for different pressing temperatures and pressures for different numbers of veneer layers. The heating rate of the veneer stacks increased as the pressing temperature increased and decreased markedly with an increasing number of veneer layers. At a high pressing pressure, the heating rate of the densified veneer stacks was faster than that of non-densified veneers at the same pressure. The use of densified veneers for the production of plywood can lead to a shorter pressing time (17–50% reduction), lower glue consumption (33.3% reduction) and a lower pressing pressure (22.2% reduction) without negatively impacting the bonding strength of the plywood.

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Production of plywood panels from Pinus taeda using veneers of differing densities and phenol-formaldehyde resin with high and low molecular weights

CERNE ◽

10.1590/s0104-77602013000200016 ◽

2013 ◽

Vol 19 (2) ◽

pp. 315-321

Author(s):

Graciela Ines Bolzon de Muniz ◽

Setsuo Iwakiri ◽

Lívia Cássia Viana ◽

Mário Andrade ◽

Cristiane Weber ◽

...

Keyword(s):

Molecular Weight ◽

Pinus Taeda ◽

Cold Water ◽

Phenol Formaldehyde ◽

Water Immersion ◽

Line Strength ◽

Formaldehyde Resin ◽

Low Molecular Weight ◽

Bonding Quality

This study aimed to evaluate the bonding quality of plywood panels from Pinus taeda using low and high molecular weight phenol-formaldehyde resin and veneers from three different density classes. The experiment consisted of six treatments, each of which produced three panels (replicates). Tests were conducted to evaluate glue line strength to shear stress after two boiling cycles and after 24 hours of cold water immersion. Also determined was the percentage of defects in wood samples. Results indicated that the density classes being assessed differed statistically. However, no significant difference was found between panels produced with high and panels produced with low molecular weight resin as to the mean values of glue line strength, whether subjecting them to two boiling cycles or after 24 hours of cold water immersion. Interactions between different density classes and adhesive formulations were found not significant either. Low molecular weight resin (BPM) and panels produced with higher density veneers were found to have better behavior, regarding both bonding strength and percentage of defects. It was concluded that the bonding quality of plywood panels from Pinus taeda was satisfactory after using different densities of veneer and also high and low molecular weight phenolic resins. All treatments were found to comply with minimum requirements established in European standard EN 314-1/1993, which addresses bonding quality of plywood panels.

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Influence of film thickness of Ti coating on bonding quality of glass with PET

Surface Engineering ◽

10.1179/1743294412y.0000000030 ◽

2012 ◽

Vol 28 (9) ◽

pp. 705-709 ◽

Cited By ~ 7

Author(s):

H X Liu ◽

K Wang ◽

C Zhang ◽

P Li ◽

Y Y Gao ◽

...

Keyword(s):

Film Thickness ◽

Bonding Quality

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Numerical Investigation on Infrared Thermal Wave Detection Method Used for The Coated Bonding Quality of Different Materials in Solid Rocket Motors

2018 Joint Propulsion Conference ◽

10.2514/6.2018-4881 ◽

2018 ◽

Author(s):

Qi Chen

Keyword(s):

Numerical Investigation ◽

Thermal Wave ◽

Detection Method ◽

Solid Rocket Motors ◽

Bonding Quality ◽

Rocket Motors ◽

Wave Detection ◽

Solid Rocket

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The Investigation of the Effect Caused by Deposition Velocity on Bonding Degree within the Structure of FDM

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.764.142 ◽

2018 ◽

Vol 764 ◽

pp. 142-155 ◽

Cited By ~ 1

Author(s):

Jie Li ◽

Hong Bin Li ◽

Jing Chuan Dong ◽

Tai Yong Wang ◽

Hai Tao Zhang

Keyword(s):

Finite Element ◽

Deposition Velocity ◽

Quantitative Relationship ◽

Optimal Temperature ◽

Bonding Quality ◽

Building Process ◽

First Time ◽

Area Deposition ◽

Printing Method

In this paper, the effect of deposition velocity on bonding degree is studied in the aspects of experiment and theory. The experimental results show that the bonding quality of the adjacent filaments is weakened with increasing of deposition velocity. In addition, on the premise of guaranteeing every point in the building process to remain at the optimal temperature, the quantitative relationships between interval and filled area, deposition velocity are investigated by using the technique of deactivate and reactivate element of finite element. On the base of the quantitative relationships, the variable deposition velocity printing method is proposed for the first time. Namely, to reap the best bonding quality of filaments the time of completing one layer can be determined according to the filled area, and then, the optimal deposition velocity can be obtained according to the quantitative relationship between the interval and the deposition velocity. Printing the model at this speed can obtain the part with the best bonding quality between adjacent layers.

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Effect of curing condition on bonding quality of scarf-repaired composite laminates

Chinese Journal of Aeronautics ◽

10.1016/j.cja.2019.08.016 ◽

2020 ◽

Vol 33 (8) ◽

pp. 2257-2267 ◽

Cited By ~ 1

Author(s):

Jie ZHANG ◽

Xiaoquan CHENG ◽

Jikui ZHANG ◽

Xin GUO ◽

Wenjun HUANG

Keyword(s):

Composite Laminates ◽

Bonding Quality ◽

Curing Condition

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Investigation of different parameters on roll bonding quality of aluminium and steel sheets

International Journal of Material Forming ◽

10.1007/s12289-008-0136-7 ◽

2008 ◽

Vol 1 (S1) ◽

pp. 1279-1282 ◽

Cited By ~ 21

Author(s):

M. Buchner ◽

B. Buchner ◽

B. Buchmayr ◽

H. Kilian ◽

F. Riemelmoser

Keyword(s):

Bonding Quality ◽

Roll Bonding ◽

Steel Sheets

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Construction of a silicate-based epitaxial transition film on a zirconia ceramic surface to improve the bonding quality of zirconia restorations

RSC Advances ◽

10.1039/d0ra04735j ◽

2020 ◽

Vol 10 (54) ◽

pp. 32476-32484

Author(s):

Xiuju Liu ◽

Han Wang ◽

Shiyang Yu ◽

Qi Zhao ◽

Zuosen Shi ◽

...

Keyword(s):

Silicate Solution ◽

Zirconia Ceramic ◽

Ceramic Surface ◽

Bonding Quality ◽

Resin Bonding

The effect of a silicate-based epitaxial transition film on zirconia produced by a silicate solution during zirconia–resin bonding was investigated.

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A Multifunctional Mineral Binder for Plywood Production: The Effect of Manufacturing Parameters on Bonding Quality

Materials ◽

10.3390/ma13102360 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2360 ◽

Cited By ~ 1

Author(s):

Ali Shalbafan ◽

Amin Nadali ◽

Heiko Thoemen

Keyword(s):

Physical And Mechanical Properties ◽

Middle Layer ◽

Wood Products ◽

Surface Layers ◽

Bonding Quality ◽

High Roughness ◽

Mineral Binder ◽

Manufacturing Parameters ◽

Layer Position

Geopolymers show great potential for use as binders in developing and manufacturing multifunctional wood products. The objective of this study was to improve the bonding quality of a geopolymer binder, with wood veneers, using different manufacturing parameters. To this end, we produced five layered plywood panels treated with various lay-up times (1, 5, 10, 15 min), panel compressibility values during hot pressing (5%, 10%, 15%, and 30% compression), veneer roughness values (low, medium, and high roughness), press temperatures (120, 140, and 160 °C), and veneer layouts via changing the middle layer position of plywood relative to the surface layers. The results show that the shear strength and thickness swelling were negatively influenced by increasing the lay-up time of resinated veneers and panel compressibility. Increasing the veneer roughness significantly increased the panels’ properties. Furthermore, the panels produced with a pressing temperature of 140 °C showed the best performances. The veneer layouts also significantly changed the physical and mechanical properties of the plywood panels. Generally speaking, the results obtained in this study show that improving the bonding quality of geopolymer binders with wood can be done through the manipulation of plywood manufacturing parameters.

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