scholarly journals Walnut and Hazelnut Shells: Untapped Industrial Resources and Their Suitability in Lignocellulosic Composites

2020 ◽  
Vol 10 (18) ◽  
pp. 6340 ◽  
Author(s):  
Marius Cătălin Barbu ◽  
Thomas Sepperer ◽  
Eugenia Mariana Tudor ◽  
Alexander Petutschnigg

Walnut and hazelnut shells are agricultural by-products, available in high quantities during the harvest season. The potential of using these two agricultural residues as raw materials in particleboard production has been evaluated in this study. Different panels with either walnut or hazelnut shells in combination with melamine-urea formaldehyde or polyurethane at the same level of 1000 kg/m3 density were produced in a laboratory hot press and mechanical properties (modulus of elasticity, bending strength, and Brinell hardness) and physical properties (thickness swelling and water absorption) were determined, together with formaldehyde content. Although Brinell hardness was 35% to 65% higher for the nutshell-based panels, bending strength and modulus of elasticity were 40% to 50% lower for the melamine-urea formaldehyde bonded nutshells compared to spruce particleboards, but was 65% higher in the case of using polyurethane. Water absorption and thickness swelling could be reduced significantly for the nutshell-based boards compared to the spruce boards (the values recorded ranged between 58% to 87% lower as for the particleboards). Using polyurethane as an adhesive has benefits for water uptake and thickness swelling and also for bending strength and modulus of elasticity. The free formaldehyde content of the lignocellulosic-based panels was included in the E0 category (≤2.5 mg/100 g) for both walnut and hazelnut shell raw materials and the use of polyurethane improved these values to super E0 category (≤1.5 mg/100 g).

2020 ◽  
Vol 10 (21) ◽  
pp. 7526 ◽  
Author(s):  
Petar Antov ◽  
Vassil Jivkov ◽  
Viktor Savov ◽  
Ralitsa Simeonova ◽  
Nikolay Yavorov

The pulp and paper industry generates substantial amounts of solid waste and wastewater, which contain waste fibres. The potential of using these recycled wood fibres for producing eco-friendly composites that were bonded with a formaldehyde-free adhesive (magnesium lignosulfonate) and their use in structural applications was evaluated in this study. Fibreboards were produced in the laboratory with a density of 720 kg·m−3 and 15% magnesium lignosulfonate gluing content, based on the dry fibres. The mechanical properties (bending strength, modulus of elasticity and internal bond strength), physical properties (thickness swelling and water absorption) and formaldehyde content were determined and compared with the European Standards requirements for wood-based panels. In general, the laboratory-produced panels demonstrated acceptable mechanical properties, such as bending strength (18.5 N·mm−2) and modulus of elasticity (2225 N·mm−2), which were higher than the minimum requirements for type P2 particleboards and equal to the requirements for MDF panels. The moisture properties, i.e., thickness swelling (24 h) and water absorption (24 h) significantly deteriorated. The free formaldehyde content of the laboratory-produced composites (1.1 mg/100 g) reached the super E0 grade (≤1.5 mg/100 g), which allowed for their classification as eco-friendly, low-emission wood-based composites. The L-type corner joints, made from the developed composites, demonstrated significantly lower bending capacity (from 2.5 to 6.5 times) compared to the same joints made from MDF panels. Nevertheless, the new eco-friendly composites can be efficiently utilised as a structural material in non-load-bearing applications.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4875 ◽  
Author(s):  
Pavlo Bekhta ◽  
Gregory Noshchenko ◽  
Roman Réh ◽  
Lubos Kristak ◽  
Ján Sedliačik ◽  
...  

The purpose of this study was to evaluate the feasibility of using magnesium and sodium lignosulfonates (LS) in the production of particleboards, used pure and in mixtures with urea-formaldehyde (UF) resin. Polymeric 4,4′-diphenylmethane diisocyanate (pMDI) was used as a crosslinker. In order to evaluate the effect of gradual replacement of UF by magnesium lignosulfonate (MgLS) or sodium lignosulfonate (NaLS) on the physical and mechanical properties, boards were manufactured in the laboratory with LS content varying from 0% to 100%. The effect of LS on the pH of lignosulfonate-urea-formaldehyde (LS-UF) adhesive compositions was also investigated. It was found that LS can be effectively used to adjust the pH of uncured and cured LS-UF formulations. Particleboards bonded with LS-UF adhesive formulations, comprising up to 30% LS, exhibited similar properties when compared to boards bonded with UF adhesive. The replacement of UF by both LS types substantially deteriorated the water absorption and thickness swelling of boards. In general, NaLS-UF-bonded boards had a lower formaldehyde content (FC) than MgLS-UF and UF-bonded boards as control. It was observed that in the process of manufacturing boards using LS adhesives, increasing the proportion of pMDI in the adhesive composition can significantly improve the mechanical properties of the boards. Overall, the boards fabricated using pure UF adhesives exhibited much better mechanical properties than boards bonded with LS adhesives. Markedly, the boards based on LS adhesives were characterised by a much lower FC than the UF-bonded boards. In the LS-bonded boards, the FC is lower by 91.1% and 56.9%, respectively, compared to the UF-bonded boards. The boards bonded with LS and pMDI had a close-to-zero FC and reached the super E0 emission class (≤1.5 mg/100 g) that allows for defining the laboratory-manufactured particleboards as eco-friendly composites.


2021 ◽  
Vol 114 ◽  
pp. 70-75
Author(s):  
Radosław Auriga ◽  
Piotr Borysiuk ◽  
Alicja Auriga

An attempt to use „Tetra Pak” waste material in particleboard technology. The study investigates the effect of addition Tetra Pak waste material in the core layer on physical and mechanical properties of chipboard. Three-layer chipboards with a thickness of 16 mm and a density of 650 kg / m3 were manufactured. The share of Tetra Pak waste material in the boards was varied: 0%, 5%, 10% and 25%. The density profile was measured to determine the impact of Tetra Pak share on the density distribution. In addition, the manufactured boards were tested for strength (MOR, MOE, IB), thickness swelling and water absorption after immersion in water for 2 and 24 hours. The tests revealed that Tetra Pak share does not affect significantly the value of static bending strength and modulus of elasticity of the chipboard, but it significantly decreases IB. Also, it has been found that Tetra Pak insignificantly decreases the value of swelling and water absorption of the chipboards.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1750 ◽  
Author(s):  
Radosław Mirski ◽  
Pavlo Bekhta ◽  
Dorota Dziurka

This study examined the effects of selected types of thermoplastics on the physical and mechanical properties of polymer-triticale boards. The investigated thermoplastics differed in their type (polypropylene (PP), polyethylene (PE), polystyrene (PS)), form (granulate, agglomerate) and origin (native, recycled). The resulting five-ply boards contained layers made from different materials (straw or pine wood) and featured different moisture contents (2%, 25%, and 7% for the face, middle, and core layers, respectively). Thermoplastics were added only to two external layers, where they substituted 30% of straw particles. This study demonstrated that, irrespective of their type, thermoplastics added to the face layers most favorably reduced the hydrophobic properties of the boards, i.e., thickness, swelling, and V100, by nearly 20%. The bending strength and modulus of elasticity were about 10% lower in the experimental boards than in the reference ones, but still within the limits set out in standard for P7 boards (20 N/mm2 according to EN 312).


2015 ◽  
Vol 1134 ◽  
pp. 34-38 ◽  
Author(s):  
Nurul Atiqah Mohd Ayob ◽  
Mansur Ahmad ◽  
Nurul Nadia Mohd Khairuddin

In this paper, three type of natural-fibre reinforced polyethylene were produced. They are the coconut coir reinforced polyethylene (RPCC), kenaf reinforced polyethylene (RPKC) and bamboo reinforced polyethylene (RPBC). Water absorption test, thickness swelling test and tensile test of the different natural fibre composites were carried-out. The mass of HDPE and natural fibre were based on percentage of filler loading. Each board types were produced with two fibre ratios which are at fourty percent and thirty percent. The preparation of the test sample is according to ASTM D1037 and ASTM D638. The tensile modulus of elasticity, tensile stress, water absorption and thickness swelling of kenaf and bamboo reinforced polyethylene composites were found to increase with increasing fibre weight fraction. Kenaf and bamboo composites showed compatible result for tensile stress and tensile modulus of elasticity while coconut coir appears to be otherwise. However, coconut coir fibre composites displayed comparable results to kenaf and bamboo for both water and thickness swelling. There were significant differences in both tensile properties and the percentage of the water absorption among composites.


Holzforschung ◽  
2001 ◽  
Vol 55 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Edmone Roffael ◽  
Brigitte Dix ◽  
Thomas Schneider

Summary Thermomechanical (TMP) and chemo-thermomechanical pulps (CTMP) were prepared from spruce under different pulping conditions. The fibres were dried at 70 °C and medium density fibreboards (MDF) were made therefrom in pilot plant scale using urea-formaldehyde resins as a binder. The results of testing the physical-mechanical properties reveal that the pulping temperature has a significant influence on the thickness swelling and water absorption of the boards. MDF prepared from fibres produced at high pulping temperature (180 °C) generally show lower thickness swelling and water absorption than MDF made from fibres produced at low pulping temperature (140°C and 160 °C). However, high pulping temperature may have a negative effect on the internal bond strength of the boards. In general, CTMP leads to MDF with higher internal bonding strength compared to those derived from TMP. In addition, the influence of different drying conditions (150 °C and 170 °C) of TMP and CTMP on the physical-mechanical properties of MDF was assessed. MDF made from CTMP showed lower thickness swelling when dried under high temperature.


2014 ◽  
Vol 599-601 ◽  
pp. 140-143 ◽  
Author(s):  
Xiang Fei Fu ◽  
Cheng Yong ◽  
Ming Jie Guan

In this paper, the bamboo-poplar composite oriented strand board (OSB) with different hybrid ratios were aged under the standard of ASTM D1037 to evaluate its weathering performances. The thickness swelling (TS), water absorption, modulus of rapture in perpendicular direction (MOR⊥), modulus of elasticity in perpendicular direction (MOE⊥) and internal bonding (IB) of specimens were tested. The results showed that the reduction rate of TS ranged from 21% to 69%, which increased with the poplar ratio increasing; the growth multiple of 24h water absorption of bamboo-poplar composite OSB were at the similar level, the values of which were much smaller than that of the pure bamboo or poplar OSB; the maximum and minimum retention rate of MOR⊥ and MOE⊥ belonged to pure bamboo and poplar OSB respectively, retention rate of MOR⊥ of the bamboo-poplar composite OSB rose with the increment of poplar ratio, while retention rate of MOE⊥ and IB of bamboo-poplar composite OSB were similar and the hybrid ratio 2.5:7.5(bamboo: poplar) obtained the maximum IB retention rate of 16%. Through detailed comparison, the bamboo-poplar composite OSB with the hybrid ratio 2.5:7.5 performed the best after aging.


2007 ◽  
Vol 18-19 ◽  
pp. 43-48 ◽  
Author(s):  
J.O. Osarenmwinda ◽  
J.C. Nwachukwu

The purpose of this study was to determine the effect of particle size on the mechanical properties (Modulus of Elasticity, Modulus of Rupture, and Internal Bond) and physical properties (thickness swelling and water absorption) of rice husk particleboard. The particle sizes used were 1.0mm, 1.18mm, 2mm, 2.36mm and 2.80mm. Each was mixed with a constant resin (urea formaldehyde) concentration of 20% of oven dry weight of rice husk particles. The results showed that as the particle size increased, the particleboard’s mechanical and physical properties decreased. For example, the modulus of elasticity, modulus of rupture, internal bond, thickness swelling and water absorption for 1.0mm particle size particleboard were 1590N/mm2, 11.11N/mm2, 0.28N/mm2,10.90% and 38.53% respectively, while for 2.8mm particle size they were 1958N/mm2,14.2N/mm2, 0.44N/mm2, 11.51% and 47.21% respectively. Overall results showed that particleboard made from rice husk exceed the EN standard for modulus of elasticity, modulus of rupture, internal bond. However, thickness swelling values were poor. Hence, the smaller the particle size the better the properties of the particleboard.


2019 ◽  
Vol 8 (4) ◽  
pp. 11016-11019

Particleboard has been widely used in producing products such as cabinets, furniture and various home use products. In this study, epoxy resin has been used as a binder for replacing urea-formaldehyde (UF) resin which is widely used in the production of existing particleboards. Epoxy resin has strong binding properties in composing composite materials. Epoxy resin also does not release any gas as carcinogenic formaldehyde released by UF resin. The basic materials used in the production of this particleboard are palm oil fiber obtained from the Charuk Putting Palm Plant, Temerloh and dust wood obtained from the timber factory around Kuantan. The main purpose of the research scientifically known is to reduce the forest logging activities in addition to utilizing waste materials. There are 2 different size of particle material used in this study which are < 2.36mm (particle A) and 2.36mm < x < 4.75mm (particle B). The particleboard that has been produced was tested ith Universal Tensile Machine (UTM) for looking to the Modulus of Elasticity (MOE) and thickness swelling (TS). From the result, it shown that the value of Modulus of Elasticity (MOE) for particle A was 16,364 MPa while particle B was 35,578 MPa. The value of thickness swelling (TS) for particle A was 0% when it immersed for 2 hours compared o particle B which was 1.7% in the same duration. As a result of experiments, all tests have passed the minimum level of particleboard based on the Japanese Industrial Standard (JIS), 2003. Therefore, particleboard of a mixture of palm oil fiber and dust wood with epoxy as a resin can be used as a new alternative in the production particleboard for furniture industry in the future.


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