Effect of veneer treatment with phenol formaldehyde on physical and wetting properties of oil palm stem (Ops) plywood

• Published in: Malaysian Construction Research Journal
• Main Author: Khalid H.; Ahmad Z.; Tahir P.Md.; Kasim J.
• Format: Article
• Language: English
• Published: Construction Research Institute of Malaysia 2021
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121211003&partnerID=40&md5=010e3ed2d2736318870772a941e5d318

Plywood is wood products frequently utilized by building as in concrete formwork systems. During concreting, the plywood formwork needs to be tough in order to withstand the pressure subjected by the wet concrete as well as the impact. To reduce the dependency on solid timber as plywood, oil palm stem offers the alternative materials. There are four main weaknesses of the oil palm stem (OPS) as a material for plywood manufacturing; high variations in density and moisture content (MC), high water absorption and high surface roughness. Therefore, this study modified the current process of drying and treatment process of OPS veneer. The veneer was pre-dried by using roller presser for removing a large amount of water and later treated with medium molecular weight phenol formaldehyde (MMwPF) in order to bond together parenchyma tissue, cell wall and lumen for much uniform density and better surface bonding. Then these veneers were used for manufactured plywood using 100% OPS and denoted as a PTA. In order to determine the performance of this plywood, a series of physical tests was conducted, namely moisture content, density, delamination and contact angle. These properties were compared with the properties of another two types of commercial OPS plywood denoted as PTB and PTC which were manufactured using OPS veneer with tropical hardwood veneer for face and back veneer and control plywood denoted as PTD which was manufactured using 100% tropical hardwood veneer. The results show that the pre-drying of the OPS veneer and the MMwPF treatment process has resulted in lower MC for PTA. All plywood passes the delamination requirement based on JAS 1751:2008. PTB exhibited highest density and contact angle value for PF resins. Whereas PTD has highest contact angle value for distilled water. © 2021, Construction Research Institute of Malaysia. All rights reserved.