| Titre : |
Pinhole free smoother finishing on MDF : Controlled curing cycles prevent pinholes on MDF finishes |
| Type de document : |
texte imprimé |
| Auteurs : |
Hugo Renkema, Auteur ; Peter Amesz, Auteur ; Johan de Lange, Auteur ; Robert Vierhout, Auteur ; Peter Wellenberg, Auteur ; Vinayak Khatavkar, Auteur |
| Année de publication : |
2017 |
| Article en page(s) : |
p. 116-120 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Basses températures
Peinture poudre -- Défauts
Polymérisation
Revêtements -- Finition:Peinture -- Finition
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
The formation of pinholes on powder coatings caused by out-gassing of medium density fireboard (MDF) has been studies. A novel stoving method called asynchronous heat-curing has been developed to prevent pinhole formation when using a low-temperature curing powder coating. |
| Note de contenu : |
- MDF coating defects arise mainly with smooth finishes
- Why pinholes occur on MDF during curing cycles
- Modelling the temperature profile of MDF in the oven
- Pinhole formation and a limited prevention technique
- Asynchronous heat-curing allows gases to escape
- Concept is tested on a demonstration line
- FIGURES : 1. Pinholes visible on front surface and sides of 18 mm thick powder coated MDF and a panel without pinholes - 2. Underwater setup. A piece of MDF (100 x 100 x 18 mm) submerged in water and fed with air at 100 mbar. Bubbles escape through interconnected pores on all six sides - 3. (1) Unmolten powder on MDF, no overpressure pressure in pore. (2) Powder becomes molten, trapping expanding air and evaporating moisture inside the MDF, generating an overpressure. (3) Pressure in pore has become sufficiently high to deform the molten paint. (4) Pressure has increased high enough to burst the molten paint, forming to a pinhole - 4. Model of temperature evolution thorugh the cross-section of an 18 mm thick MDF board during healing up - 5. Model of pressure evolution through the cross-section of an 18 mm thick MDF board during heating up - 6. Asynchronous heat-curing concept : (1) All sides are heated (red arrow) except ghe back. (2) Paint is cured (red) on all sides and unmolten paint (blue on the back allows overpressure to escape. (3-4) Back is heated and cure. (5) Finished powder coated MDF - 7. Temperature profile of the front and back sides of a powder coated MDF panel heat-cured at 130°C for three minutes, using the asynchronous heat-curing method - 8. Pinhole free smooth powder coated MDF board (300 x 300 x 18 mm) |
| En ligne : |
https://drive.google.com/file/d/1--zrJXbWQC88SnlJuL-NCQwEIp_ZVhpd/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27957 |
in EUROPEAN COATINGS JOURNAL (ECJ) > N° 3 (03/2017) . - p. 116-120
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Pinhole free smoother finishing on MDF in EUROPEAN COATINGS JOURNAL (ECJ), N° 3 (03/2017)
