Preparation and characterization of plywood panels using recycled HDPE as a formaldehyde-free adhesive: A comparative study

IF 1.7 4区农林科学 Q2 MATERIALS SCIENCE, PAPER & WOOD

Journal of Wood Chemistry and Technology Pub Date : 2023-08-27 DOI:10.1080/02773813.2023.2251463

A. Ashori, V. Heydari, N. Ayrilmiş

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引用次数: 0

Abstract

Abstract Formaldehyde-based resins such as urea-formaldehyde (UF) are the most widely used adhesives in the plywood industry. However, due to the concerns about formaldehyde toxicity, there is a need to develop formaldehyde-free adhesive materials. Therefore, the present study aimed to minimize or eliminate the harmful effects of UF resin by using recycled high-density polyethylene (HDPE) from post-consumed fruit packing boxes as a nontoxic adhesive. Three-layer plywood panels using poplar veneers and recycled HDPE films were prepared. UF was used as a control adhesive for the comparison. The influence of three variable parameters in terms of HDPE content (from 80 to 320 g/m2), hot-pressing temperature (from 140 to 180 °C), and pressing duration (from 3 to 8 min) on the properties of plywood panels were evaluated. For evaluation, physical properties, namely water absorption (WA), thickness swelling (TS), and mechanical properties, namely modulus of elasticity (MOE), modulus of rupture (MOR), and glue-line shear strength of the samples, were studied. The findings of this work confirmed that HDPE films gave the values of mechanical properties of plywood panels comparable to those obtained with UF adhesive, even though the adhesive content and pressing time were lower than when the UF adhesive was used. The obtained bonding strength values of HDPE-bonded plywood panels ranged from 0.82 to 1.60 MPa and met the requirement for the European Standard EN 314-2. According to FE-SEM micrographs, the fractured surface of plywood panels with 240 g/m2 of HDPE displayed a homogeneous cross-section area, and a large amount of HDPE was attached to the veneer surfaces. It was found that the average mechanical properties tended to increase with an increase in the pressing temperature and time. The type of adhesive had a significant effect on WA and TS. The smallest values of WA and TS were observed in plywood samples using high contents of HDPE films (240 and 320 g/m2). The optimum conditions were an HDPE loading of 240 g/m2, a hot-pressing temperature of 160 °C, and a hot-pressing time of 5 min. The overall results showed that recycled HDPE had enough potential to reuse as a promising adhesive for the environmentally-friendly plywood manufacturing.

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利用再生HDPE作为无醛胶粘剂制备胶合板及其性能的比较研究

摘要脲醛树脂是胶合板工业中应用最广泛的粘合剂。然而，由于对甲醛毒性的担忧，有必要开发无甲醛粘合剂材料。因此，本研究旨在通过使用食用后水果包装盒中回收的高密度聚乙烯（HDPE）作为无毒粘合剂，最大限度地减少或消除UF树脂的有害影响。采用杨木单板和再生HDPE膜制备了三层胶合板。使用UF作为对照粘合剂进行比较。三个可变参数对HDPE含量的影响（从80到320 g/m2），热压温度（从140到180 °C）和按压持续时间（从3到8 min）对胶合板性能的影响。为了评估，研究了样品的物理性能，即吸水性（WA）、厚度膨胀性（TS）和机械性能，即弹性模量（MOE）、断裂模量（MOR）和胶线剪切强度。这项工作的结果证实，HDPE膜的胶合板力学性能值与使用UF粘合剂获得的值相当，尽管粘合剂含量和压制时间低于使用UF胶粘剂时。获得的HDPE粘合胶合板面板的粘合强度值在0.82至1.60之间 MPa，并符合欧洲标准EN 314-2的要求。根据FE-SEM显微照片，240 g/m2的HDPE显示出均匀的横截面面积，并且大量的HDPE附着在单板表面上。研究发现，随着压制温度和压制时间的增加，平均力学性能有增加的趋势。粘合剂的类型对WA和TS有显著影响。在使用高含量HDPE膜（240和320）的胶合板样品中观察到WA和TS的最小值 g/m2）。最佳条件是HDPE负载量为240 g/m2，热压温度160 °C，热压时间为5 min.总体结果表明，再生HDPE具有足够的潜力，可作为一种有前途的粘合剂重新用于环保胶合板生产。

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来源期刊

Journal of Wood Chemistry and Technology 工程技术-材料科学：纸与木材

CiteScore

3.70

自引率

20.00%

发文量

审稿时长

3 months

期刊介绍： The Journal of Wood Chemistry and Technology (JWCT) is focused on the rapid publication of research advances in the chemistry of bio-based materials and products, including all aspects of wood-based polymers, chemicals, materials, and technology. JWCT provides an international forum for researchers and manufacturers working in wood-based biopolymers and chemicals, synthesis and characterization, as well as the chemistry of biomass conversion and utilization. JWCT primarily publishes original research papers and communications, and occasionally invited review articles and special issues. Special issues must summarize and analyze state-of-the-art developments within the field of biomass chemistry, or be in tribute to the career of a distinguished researcher. If you wish to suggest a special issue for the Journal, please email the Editor-in-Chief a detailed proposal that includes the topic, a list of potential contributors, and a time-line.