Structure, Mechanical Performance, and Dimensional Stability of Radiata Pine (Pinus radiata D. Don) Scrimbers

Jinguang Wei,Fei Rao,Yue Qi,Wenji Yu,Yahui Zhang,Chung-Yun Hse,Yuxiang Huang

doi:10.1155/2019/5209624

Jinguang Wei, Fei Rao + Show 5 more

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https://doi.org/10.1155/2019/5209624

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Abstract

Natural wood has certain advantages such as good processability and high specific strength and thus has been used for millennium as a structural material. But the mechanical performance and water resistance, particularly for fast-growing species, are unsatisfactory for high-end applications. In this study, the “new-type” scrimber technology was introduced to radiata pine (Pinus radiata D. Don) scrimbers. The structure, mechanical properties, and dimensional stability of the scrimber panels were investigated. Results showed that OWFMs as basic units of scrimber had been very even in size and superior permeability. The scrimbers exhibited a three-dimensional porous structure, and the porosity had a decrease with increasing density. Both OWFMs and densification contributed to the high performance in terms of mechanical properties and water resistance. The flexural, compressive, and short-beam shearing strength were significantly enhanced with increasing density. As the density was 0.80 g cm−3, the flexural strength (MOR) was approximately 120 MPa, much larger than many selected wood-based panels. Moreover, the water resistance and dimensional stability also were closely related to the density. At the density of 1.39 g cm−3, the water absorption rate and thinness swelling rate of the panels in boiled water were only 19% and 5.7%, respectively.

Highlights

Natural materials have advantages of sustainability, renewability, and low cost and are gradually overtaking synthetic materials, which suffer from high density, environmental problems, complex processes, and high cost [1]
The objective of this study is to explore the extensive applicability of the new-type scrimber technology and to develop high-performance wood materials using inexpensive and abundant pine wood
The pine log without barks was used as raw material to prepare the oriented wood fiber mats according to the reported method [20], and the scrimbers were obtained through laminating the mats impregnated with Phenol formaldehyde (PF) resin

Summary

Introduction

Natural materials have advantages of sustainability, renewability, and low cost and are gradually overtaking synthetic materials, which suffer from high density, environmental problems, complex processes, and high cost [1]. These woods have many advantages such as rapid growth, easy harvesting and processing, and acceptable tolerance to various site conditions They have inherent disadvantages including low density and natural defects and unsatisfactory mechanical properties [9, 10]. Since a series of uniform linearshaped cracks were formed on the surface, the mat had better permeability than the bundles prepared by the old method These improvements contributed to the achievement of excellent performance in terms of mechanical strength and water resistance. Radiata pine is a most widely planted fast-growing softwood in the Southern Hemisphere It has been a mainstay of the forest economy and reduced cutting pressure on native forests in Australia, New Zealand, Chile, Argentina, Uruguay, Kenya, and the Republic of South Africa [24]. The emergence of “new-type” scrimber technology has great possibility of improving pine wood performance and extending the application fields

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