PEER-REVIEWED ARTICLE bioresources.com Khoo et al. (2020). “LVL veneers from small Hevea,” BioResources 15(3), 6735-6751. 6735 Laminated Veneer Lumber from Spindleless Rotary- peeled Veneers Produced from Short Rotation, Small Hevea Plantation Logs: Effects of Lamination Pressure Pui San Khoo, a Kit Ling Chin, a, * Paik San H’ng, a,b, * Chuan Li Lee, a Edi Suhaimi Bakar, b Zaidon Ashaari, b Luqman Chuah Abdullah, a and Seca Gandaseca b The invention of spindleless lathe technology has enabled veneers to be produced from small logs, such as logs from short rotation Hevea plantations, with low recovery loss. However, for structural laminated products, such as laminated veneer lumber (LVL), manufacturers are highly selective regarding the veneers for their conventional production. During the peeling process of small logs (< 18 cm), deeper and higher frequency of lathe checks were induced on veneer surface compared to the common log size used (> 30 cm). In this study, spindleless rotary- peeled veneers made from small rubber logs were processed into LVL using different lamination pressures: 7, 8, 9, and 10 kgf/cm 2 . The effects of lamination pressures on the physical and mechanical properties of the produced LVL were evaluated. Based on the findings, the specific gravity increased from 0.73 to 0.83 with increased lamination pressure. In terms of mechanical properties, all the values increased with lamination pressure, but with a sudden drop with 10 kgf/cm 2 . Understanding the effect of lamination pressure on the physical and mechanical properties can shed light on optimizing the usage of spindleless rotary-peeled veneers from small logs for the production LVL and other lamination products. Keywords: Laminated veneer lumber; Small Hevea log; Spindleless rotary-peeled veneers; Lamination pressure; Physical properties; Mechanical properties Contact information: a: Institute of Tropical Forestry and Forest Products, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; b: Faculty of Forestry and Environment, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; * Corresponding authors: kitling.chin419@gmail.com; ngpaiksan@gmail.com INTRODUCTION Rubber tree (Hevea brasiliensis) is a fast-growing hardwood species that is one of the most important agriculture crops in Malaysia (Teoh et al. 2011; Ratnasingam et al. 2012). Currently, Hevea plantations have been managed under intensive silviculture techniques to achieve a higher yield of latex production within a short-term period with less consideration for the wood yield (Teoh et al. 2011). Under such conditions, rubber trees are being felled after 15 years compared to the conventional 25 to 30 years; this practice produces rubber logs with small diameter (Khoo et al. 2018). Previous studies have confirmed that rubberwood harvested from a short rotation Hevea plantation (15 years old) contains wood properties that are different from rubberwood recovered from a plantation with a longer rotation of 25 to 30 years (Khoo et al. 2018). The tree age has a major effect on wood properties, with younger trees having lower wood density, shorter fibers length, smaller lumens, and thinner cell walls (Naji et al. 2012; Saffian et al. 2014).