Visuo-tactile and topographic characterizations of finished wood surface quality by French consumers and industrials: acceptability thresholds for raised grain
Raised grain occurring on wood surfaces after the application of a waterborne varnish was felt by human touch because of protruding peaks and a certain amount of materials in the core of the roughness profile. This tactile sensation was correlated with specific roughness parameters. Characteristics of a finished surface quality that is acceptable to consumers were determined.
Raised grain occurs on wood surfaces after the application of a waterborne varnish and forces manufacturers to sand the surfaces between coats. Actually, little research has characterised this phenomenon and no techniques have been discovered to avoid its occurrence.
This study aims to identify the topographic parameters that explain the visuo-tactile sensation of raised grain and to define a finished surface quality acceptable to consumers and industry.
Oak (Quercus robur L.) and beech (Fagus sylvatica L.) wood surfaces were planed and sanded in order to have various levels of raised grain. Visuo-tactile analyses were carried out on surfaces having received one coat of varnish to characterise raised grain and having two coats to characterise the acceptable finished surface quality without sanding. Topographic parameters were measured on each type of varnished surface and correlated with the visuo-tactile scores.
Raised grain was characterised by the visuo-tactile sensation of protruding peaks and a certain amount of material in the core of the roughness profile for both wood species. Industrials overestimated the surface quality required by consumers. Thresholds of topographic parameters were determined to define acceptable finished surface quality.
These findings allowed objective criteria to be defined for describing raised grain and to help industries to optimise their wood machining and finishing processes.
KeywordsRaised grain Topographic parameters Waterborne varnish Visuo-tactile analysis Planing Sanding
The authors wish to thank Critt-Bois Occitanie in Rodez (Aveyron, France) and Rozière industry in Bozouls (Aveyron, France) for providing the oak wood samples used in this study, and for their collaboration that allowed us to perform the machining and finishing processes in industrial conditions and to carry out sensory analysis. We wish to thank Sanguinet industry for providing Pyrenees beech wood samples, and the test persons for their collaboration for the sensory analysis.
This study was funded by the Ex-Midi-Pyrénées Region, Hautes Pyrénées Department and IUT of Tarbes in France.
Compliance with ethical standards
Conflicts of interest
The authors declare that they have no conflict of interest.
Statement on ethical approval
The authors declare that they obtained the informed consent from all participants, industrials and all test persons who collaborated for the sensory analysis.
- Bosquet L (2006) Research Methodology. Statistics course on correlation (Méthodologie de la recherche. Cours de statistique sur la corrélation). Université Lille 2, FranceGoogle Scholar
- CIRAD (2015) TROPIX 7: The main technological characteristics of 245 tropical wood species. http://tropix.cirad.fr/. Accessed 22 July 2018
- Cool J, Hernandez R (2011) Performance of three alternative surfacing processes on black spruce wood and their effects on water-based coating adhesion. Wood Fiber Sci 43:365–378Google Scholar
- Danzl R, Helmli F, Rubert P, Prantl M (2008) Optical roughness measurements on specially designed roughness standards, Proc. SPIE 7102, Optical Fabrication, Testing, and Metrology III, 71020M. https://doi.org/10.1117/12.798729
- De Moura LE, Hernandez RE (2006) Characteristics of sugar maple wood surfaces produced by helical planing. Wood Fiber Sci 38:166–178Google Scholar
- Ghazil S (2010) Etude de la migration des fluides dans le bois. PhD Dissertation. Henri Poincaré University, Nancy-1. FranceGoogle Scholar
- Hendarto B, Shayan E, Ozarska B (2004) Characterisation of surface finishing processes in wood furniture manufacturing. https://pdfs.semanticscholar.org/6a6d/de2c2c28aaa20fb1376365071e58883be873.pdf. Accessed 12 March 2018
- Hernández R, Cool J (2008) Evaluation of three surfacing methods on paper birch wood in relation to water and solvent borne coating performance. Wood Fiber Sci 40:459–469Google Scholar
- INRS (2001) Design of capture devices on woodworking machines. INRS, ParisGoogle Scholar
- INSEE (2014) Estimation de la population française de la région Occitanie. http://wwwinseefr. Accessed 08 Jan 2016
- ISO 16610-21 (2011) Geometrical product specifications (GPS) - Filtration - Part 21: Linear profile filters: Gaussian filters. International Standards Organization. British Standards Institute, LondonGoogle Scholar
- ISO 16610-61 (2015) Geometrical product specification (GPS) - filtration - part 61: Linear areal filters - Gaussian filters. International Standards Organization. British Standards Institute, LondonGoogle Scholar
- ISO 25178-2 (2012) Geometrical product specifications (GPS) - Surface texture: Areal - Part 2: Terms, definitions and surface texture parameters. Https://www.iso.org/obp/ui/#iso:std:iso:25178:-2:ed-1:v1:en. Accessed 10 July 2018
- ISO/DIS 11136 (2013) Sensory analysis—methodology—general guidance for conducting hedonic tests with consumers in a controlled areaGoogle Scholar
- Jacquiot C, Trénard Y, Dirol D (1973) Atlas d’anatomie des bois des angiospermes (essences feuillues), Tome1, CTB, Paris. https://doi.org/10.1007/s13595-019-0807-1
- Khazaeian A (2006) Caracterisation 3D de l’état de surface du bois : stratégie de mesure - influence des paramètres liés à l’essence et à l’usinage. PhD Dissertation. Ecole Nationale du Génie Rural, des Eaux et des Forêts, Toulouse III. FranceGoogle Scholar
- Koehler A (1932) Some observations on raised grain. Department of agriculture forest service. Forest products laboratory, USAGoogle Scholar
- Lambillon J-M et al. (2013) Manuel de l'ingénierie bois. Chapitre I : Anatomie et identification des bois. Association des ingénieurs de l'école supérieure du bois. Editions Eyrolles. Paris, FranceGoogle Scholar
- Marra GG, Syracuse NY (1932) An analysis of the factors responsible for raised grain on the wood of oak (Quercus Ssp) following sanding and staining. College of Forestry at Syracuse University, New York StateGoogle Scholar
- NF EN ISO 2808 (2007) Peintures et vernis - Détermination de l'épaisseur du feuilGoogle Scholar
- Rajemison AH (2013) Proposition d’essences de substitution aux bois précieux en épuisement par la connaissance des propriétés du matériau bois: Cas du Palissandre de Madagascar - Application en ameublement. PhD Dissertation, Paul Sabatier University, Toulouse III, France and University of Antananarivo, MadagascarGoogle Scholar
- Ramanakoto MF (2017) Optimisation et qualification des surfaces usinées – Application au matériau bois. PhD Dissertation, Paul Sabatier University, Toulouse III, FranceGoogle Scholar
- Ramanakoto MF, Andrianantenaina AN, Ramananantoandro T, Eyma F (2017) Visual and visuo-tactile preferences of Malagasy consumers for machined wood surfaces for furniture: acceptability thresholds for surface parameters. Eur J Wood Wood Prod 75:825–837. https://doi.org/10.1007/s00107-016-1098-y CrossRefGoogle Scholar
- Ramanakoto MF, Ramananantoandro T, Eyma F, Castanié B (2018) Data about the visuo-tactile preferences of finished surface quality by French Consumers as regards raised grain on woods. V1. Zenodo. [Dataset]. https://doi.org/10.5281/zenodo.1318240
- Roux M-L, Delorme T (2012) Les finitions aqueuses pour les TPE et PME de l’ameublement et de l’agencement : des solutions pratiques. FCBA, FranceGoogle Scholar
- Stewart HA (1980) Some surfacing defects and problems related to wood moisture content. Wood Fiber Sci 12:175–182Google Scholar
- Taylor JM, Carrano AL, Lemaster RL (1999) Quantification of process parameters in a wood sanding operation. Forest Prod J 49:41–46Google Scholar