Influence of Glue Line Thickness on the Strength of Joints Bonded with PVAc Adhesives

Bomba, Jan; Šedivka, Přemysl; Hýsek, Štěpán; Fáber, Jiří; Oberhofnerová, Eliška

doi:10.13073/fpj-d-17-00038

Cited by 7 publications

(7 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They are used mainly to bond solid wood, dowels and finish edges, and they are also used for veneering. Their advantages are in particular easy application, short hardening time, polymerization under normal pressure, and safety, because they do not contain formaldehyde (Bomba et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of parameters influencing the withdrawal strength of oak and beech dowels

Podlena

Böhm

Hýsek

et al. 2020

BioRes

Self Cite

View full text Add to dashboard Cite

The withdrawal strength of plain dowels with nominal diameter of 8 mm was compared with the spiral dowels manufactured from beech (Fagus sylvatica L.) and oak wood (Quercus robur L.). The test specimens were tested after conditioning at relative humidity (RH) 25%, 45%, 65%, and 85% at a constant temperature of 20 °C. Therefore, the influence of relative humidity (respective moisture content), dowel structure, and wood species of the dowels on the withdrawal strength was determined. The structure and low humidity (RH 25%) caused the highest strength (8.6 MPa) of spiral dowels. Compared to plain dowels, the higher withdrawal strength of spiral dowels was statistically significant. Adversely, the lowest withdrawal strength was found for plain beech dowels (3 MPa), which, in addition to higher relative humidity (RH 85%), was also caused by a combination of plain structure and greater diameter of the dowels, thereby decreasing the amount of adhesive in the bonded joint. The influence of the wood species of the dowels was not statistically significant overall.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of parameters influencing the withdrawal strength of oak and beech dowels

Podlena

Böhm

Hýsek

et al. 2020

BioRes

Self Cite

View full text Add to dashboard Cite

show abstract

“…When testing different bond line thicknesses (0.01 mm to 0.10 mm) in dowel joints, Ratnasingam and Ioras (2015) reported that the highest fatigue and static strength is achieved with the smallest bond line thicknesses (0.01 mm) using a PVAc adhesive. Bomba et al (2018) noted that the shear strength of joints with dowels, which were tested in accordance to EN 205 (2003), decreased as the bond line thickness of D4 grade adhesives was lowered from 0.5 mm to 0.1 mm. Therefore, the diameter of the single groove dowels in combination with a single groove as the primary influence on low withdrawal strength.…”

Section: Resultsmentioning

confidence: 99%

Axial loading of different single-pin dowels and effect on withdrawal strength

Podlena

Hýsek

Procházka

et al. 2018

BioRes

Self Cite

View full text Add to dashboard Cite

Withdrawal strengths of commercially available hardwood dowels were examined in this work. Multi-grooved dowels with a straight surface pattern and with pre-glued polyvinyl acetate (PVAc) were tested. Additionally, standard dowels with different single- and multi-grooved surface patterns were also tested, which were not pre-glued. Standard dowels were bonded with two types of PVAc and one type of polyurethane (PUR) adhesive. The influence of the type of dowel, the surface pattern, the dowel diameter, and the type of adhesive used on the dowel joint strength were investigated. Lower average strengths were observed for single-grooved dowels with a spiral pattern (4.9 MPa); failures generally occurred at the first or second thread of the spiral groove. For the pre-glued dowels, there were differences in the observed strengths, which depended upon how the PVAc adhesive was activated. Lower withdrawal strengths were noted for the pre-glued dowels when they were activated by dipping them in water (3.0 MPa) versus adding water directly to the pre-drilled holes (4.7 MPa to 5.4 MPa).

show abstract

“…After treatment A2, the addition of CNC to PVAc resulted in a slight shear strength increase, but in contrast, after wetting and re-conditioning (A3) much lower shear strength was observed. After A3 treatment, it becomes evident that PVAc hardens as a result of coagulation of dispersed adhesive particles after water is released into the surrounding material, giving a final shear strength which is comparable to the initial one [17]. The addition of CNC seems to introduce a disadvantage for this process because of a remarkable decrease in shear strength after treatment A3.…”

Section: Wetting (A2) and Wetting-reconditioning (A3)mentioning

confidence: 98%

“…PVAc adhesives showed advantages like polymerization under normal pressure, their safety and their great compatibility with wood. On the other hand PVAc is mechanically unstable and shows low resistance to moisture [17], which is restricting its utilization to indoor conditions.…”

Section: Introductionmentioning

confidence: 99%

Impact of Bio-Based (Tannins) and Nano-Scale (CNC) Additives on Bonding Properties of Synthetic Adhesives (PVAc and MUF) Using Chestnut Wood from Young Coppice Stands

Marini

Zikeli

Corona³

et al. 2020

Nanomaterials

View full text Add to dashboard Cite

Sustainability and ecotoxicity issues call for innovations regarding eco-friendly adhesives in the production of biocomposite wood materials, and solutions involving nano-scale and bio-based compounds represent a valid and promising target. One possible approach is to increase the performance of adhesives such as polyvinyl acetate (PVAc) or melamine-urea-formaldehyde (MUF) by means of nanoparticles in order to obtain a material with better mechanical and environmental resistance. When applying cellulose-based nanoparticles or tannin, the concept of a circular economy is successfully implemented into the forest/wood value chain, and chances are created to develop new value chains using byproducts of forestry operations. In this study, assortments coming from young sweet chestnut (Castanea sativa Mill.) coppice stands were utilized for the preparation of single lap joint assemblies using different commercial adhesives (PVAc, MUF) and cellulose nanocrystals (CNC) and tannin as additives. The results showed that addition of CNC and tannin to PVAc glue increased tensile shear strength in lap joint tests presenting a promising base for future tests regarding the addition of CNC and tannin in MUF or PVAc adhesive formulations. Unfortunately, the tested bio-based additives did not reveal the same encouraging results when tested in the wet state.

show abstract

Influence of Glue Line Thickness on the Strength of Joints Bonded with PVAc Adhesives

Cited by 7 publications

References 15 publications

Evaluation of parameters influencing the withdrawal strength of oak and beech dowels

Evaluation of parameters influencing the withdrawal strength of oak and beech dowels

Axial loading of different single-pin dowels and effect on withdrawal strength

Impact of Bio-Based (Tannins) and Nano-Scale (CNC) Additives on Bonding Properties of Synthetic Adhesives (PVAc and MUF) Using Chestnut Wood from Young Coppice Stands

Contact Info

Product

Resources

About