Investigating face veneer check development in decorative plywood panels: the impact of four common manufacturing factors

Abstract

An optical method based on digital image correlation was used to investigate the impact of four decorative plywood manufacturing factors (core type, veneer type, adhesive type and lathe check orientation) on face veneer checking. The four core types were: combination core, medium density fibreboard, particleboard, and veneer core. The four veneer types were: peeled 0.604 mm, peeled 0.706 mm, sliced 0.508 mm, and sliced 0.564 mm. Both loose-side out and tight-side out lathe check orientations were used. The adhesive systems were urea–formaldehyde, polyvinyl acetate, and soy-protein based. 96 treatment combinations with 8 replicates were tested. All specimens were exposed to harsh but realistic drying conditions (approximately 30°C and 26% relative humidity) for 4 h during inspection. Checks were detected on 428 out of a total of 765 specimens (56%). The estimated mean check densities (area of checking per unit area) indicated some unfavourable factor combinations. All factors had some degree of interaction with one another and check development could not be attributed to a single factor examined in this study. The data were fit to a generalized linear mixed model based on Tweedie’s compound Poisson distribution. Confidence intervals were calculated via bootstrapping. The check density estimates produced by this model can be used to cautiously guide manufacturers as they decide on panel components. The broader use of the model is to highlight the complexity of the problem and guide future research in this area.

Evaluation of Oak-Specific Consumption, Efficiency, and Losses from an Aesthetic Veneer Factory

“…The packages of 12 veneers were formatted in length and width, the remains resulting from the guillotine scissors being in the form of veneer strips. The reporting of the veneer residues [27,28] was done as in the previous cases to the initial volume of each log considered, with a similar relationship as Equation ( 4).…”

Effect of Veneer Initial Moisture Content on the Performance of Polyethylene Film Reinforced Decorative Veneer

“…There are many factors affecting the performance of decorative veneers as well as decorative veneer overlayed wood-based panels [21][22][23], among which the impact of initial moisture content (MC) is very complicated [24,25]. The decorative veneer is very easy to crack due to its small thickness.…”

An image processing algorithm for detection and analysis of slicing checks

“…Under constant relative humidity, slicing checks remain hidden under the coating layer. Checks migrate to the surface and become visible by cracking and deforming the coating layer when the material is subjected to drying conditions (Burnard et al 2019;Grubîi and Johansson 2019). This effect is present in cold climates where there is a considerable variation in indoor relative humidity between seasons.…”

“…Another method for automatic check detection, based on observing strains during rapid drying was proposed by Burnard et al (2018). The method was used to quantify slicing checks in the longitudinal-tangential surface plane based on their length and width (Burnard et al 2018(Burnard et al , 2019. Unfortunately, the method was not extended to characterise the slicing checks by depth.…”

“…Measurement output should be information about check properties, such as depth, length, width and thickness. The lack of check measurement methods might be the reason for a limited understanding of the influence of check properties on final surface checking (Burnard et al 2019).…”