Evaluation on layering effects and adhesive rates of laminated compressed composite panels made from oil palm (Elaeis guineensis) fronds Izyan Khalid a,b , Othman Sulaiman b,⇑ , Rokiah Hashim b , Wahab Razak a , Nadiah Jumhuri b , Mohd Sukhairi Mat Rasat a a Faculty of Earth Science, University Malaysia Kelantan, 88999 Jeli, Kelantan, Malaysia b Division of Bioresource, Paper and Coatings Technology, School Industrial Technology, Universiti Sains Malaysia,11800 Penang, Malaysia article info Article history: Received 23 September 2014 Accepted 3 December 2014 Available online 11 December 2014 Keywords: Oil palm fronds Laminated compressed boards Glue spread rate Frond layers Mechanical properties abstract The objective of this study was to evaluate layering effects and adhesive rates of laminated compressed panels manufactured from oil palm (Elaeis guineensis) fronds. Nine types of panels, namely 6-layer, 8-layer and 10-layer bonded with adhesive spread rates of 200 g/m 2 , 250 g/m 2 and 300 g/m 2 were manu- factured. The results showed that both bending and internal bonding strength properties all types of panels increased with increasing number of layers and adhesive amount with an exception of 10-layer panels bonded with 300 g/m 2 . Mechanical properties of such samples were slightly reduced due to their possible brittleness as a result of effect of densification, high resin content and temperature. Thickness swelling and water absorption of the samples enhanced with increasing number of layer and adhesive content. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Increasing demand for wood products in many countries is creating certain amount problem for raw material supply. Declining of timbers from the natural forests has also pressured the wood-based industry to find alternative sources for consis- tent raw material supply. In future, engineered wood products will play an important role in a way to protect the natural forest resources from being harvested. An alternative to solid wood products, various types of panel such as laminated veneer lum- ber, plywood, medium density fiberboard and particleboard have been developed in past. Most of these products come from the small size logs from the plantation and underutilized species [1]. Nowadays there are more biomass alternatives and non wood resources to replace solid wood in order to reduce our dependency on natural wood and transform the material into value-added wood products [2,3]. In Malaysia, oil palm (Elaeis guineensis) frond (OPF) is consid- ered as an agricultural waste from oil palm plantation and cur- rently, Malaysia is the second largest producer of palm oil in the world with the total planted area of 4.917 million hectares [4,5]. In 2011, there was 80 million tonnes of oil palm biomass produced by palm oil industry in Malaysia [6]. Pruning operations and replanting programmes have resulted in the abandoned of OPF in the field without being fully utilized. Generally, OPFs are left rot- ting on the ground as nutrient supplement to the soil. Therefore, the availability of fronds would be considered as an ideal potential raw material for manufacturing composite panels for non-struc- tural and structural purposes. Such panel products have various advantages compared to other structural products made from con- ventional solid wood including their renewability in short time span, low processing cost and low energy cost for their conversion into smaller elements [7]. Oil palm frond contains 70% of moisture content at green condi- tion at harvesting site [5]. Although its moisture content is not very high compared to that fresh felled oil palm trunk which can be as high as 300%, it is necessary to dry the oil palm frond in air drying way [8]. The moisture content of the material to manufacture com- posite product is very important because it can affect the quality and performance of the end product [9]. In order to improve drying behavior and increase dimensional stability of the frond, compres- sion technique was implemented in this study. This technique can remove large amount of water very quickly from the compressed material with the moisture content distributed evenly around the stem fiber [10]. It also prevents the fronds from being attacked by fungi and insects. Furthermore, the form of the compressed frond created continuous long fiber sheet along the grain which http://dx.doi.org/10.1016/j.matdes.2014.12.007 0261-3069/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +60 4 653 2929/2241; fax: +60 4 657 3678. E-mail address: othman@usm.my (O. Sulaiman). Materials and Design 68 (2015) 24–28 Contents lists available at ScienceDirect Materials and Design journal homepage: www.elsevier.com/locate/matdes