Production of Particleboard Using Various Particle Size Hemp Shives as Filler

Particleboards with Recycled Material from Hemp-Based Panels

This research addresses the current need for sustainable solutions in the construction and furniture industries, with a focus on environmentally friendly particleboard. Particleboards were made from a mixture of virgin wood chips and hemp shives, which were then mechanically recycled and used to make new lightweight particleboards. Phenol-formaldehyde resin with 25% w/w phenol replacement by soybean flour (PFS) was used as the binder for the lignocellulosic materials. Laboratory analyses determined the resin properties, and FTIR confirmed the structure of the experimental PFS resin. The thermal properties of all the resins were evaluated using thermogravimetric analysis (TGA). The panels were manufactured using industrial simulation and tested for mechanical and physical properties in accordance with European standards. The FTIR study confirmed good adhesion, and the TGA showed improved thermal stability for the recycled biomass panels compared to virgin biomass panels. The study concludes that lightweight particleboards can be successfully produced from recycled hemp shive-based panels, providing a sustainable alternative to traditional materials in the construction industry.

Particleboard Creation from Agricultural Waste Residue of Seed Hemp

In this research, agricultural residue of seed hemp variety "Adzelvieši" was used to create hemp particleboard samples. Hemp was grown in three experimental fields where it was observed that after seed harvesting, 3.5 tonnes of hemp stems per hectare remained. The plants were processed with milling, cutting, and sieving equipment. Moisture content and particle size distribution were observed throughout raw material processing. Hemp boards were produced using the cold pressing method with 10% urea formaldehyde resin as the binder. The boards were made as 20 mm thick single-layer parts with a density range of 220 ± 30 kg/m3 and porosity of 86%. Board structural analysis was performed using optical microscopy and scanning electron microscopy methods. Mechanical strength was determined by performing bending strength, internal bond strength, and screw withdrawal tests. The thermal conductivity reached 0.047 ± 0.008 W/(mK). The results were compared with industrially produced hemp shive boards and materials in the developmental or production stage. The feasibility for the experimental production cycle proposed in the study is discussed.

Development of High Strength Particleboards from Hemp Shives and Corn Starch

In the current study, high-strength boards for the construction industry were developed from renewable natural resources, fibrous hemp shives, and corn starch. During the research, the influence of the composition of the mixture, the processing of raw materials, and technological parameters on the operational properties of the board were evaluated. The influence of the binding material and the water content on the properties of the molded boards was evaluated. It was established that the rational amount of starch is 15% of the mass of the shives, and the amount of water is 10%. It has been established that with the proper selection of the forming parameters of the board, it is possible to avoid internal disintegration of the structure due to the water vapor pressure, increase the bending strength, and ensure uniform sintering of the board throughout the entire volume. It was found that additional processing of hemp shives can increase bending strength by more than 40%. Furthermore, during the processing of shives by chemical means, soluble substances are washed out, which reduces the density and thermal conductivity of the shives. Selection of a rational level of compression allowed us to increase the bending strength of the boards by 40%. The assessment of all factors made it possible to obtain boards with a bending strength of 40 MPa. The additives used made it possible to reduce the water absorption of the boards up to 16 times and obtain non-flammable boards. The thermal conductivity of the resulting boards varied from 0.07 to 0.095 W/(m·K). The analysis of macrostructure and microstructure allowed us to evaluate the process of the formation of bonds between hemp shives.

Hemp: A Sustainable Plant with High Industrial Value in Food Processing

In the era of SDGs, useful plants which provide valuable industrial outputs and at the same time pose less impact on the environment should be explored. Hemp seems one of the most relevant gluten-free crop plants to meet such requirements. Its high nutritional value is comparable to soy. Moreover, almost the whole body of the hemp plant has a wide array of utility: industrial production of food, fiber, and construction materials. In view of environmental sustainability, hemp requires less pesticides or water in cultivation compared to cotton, a representative fiber plant. This short review investigates hemp's sustainability as a plant as well as its utility value as a highly nutritional material in the food industry. Recent application research of hemp protein in food processing includes plant milk, emulsifiers, fortification of gluten-free bread, plant-based meat production, as well as membrane formation. These studies have revealed distinctive properties of hemp protein, especially in relation to disulfide (S-S)/sulfhydryl (-SH)-mediated interactions with protein from other sources. While its cultivation area and industrial use were limited for a while over confusion with marijuana, the market for industrial hemp is growing rapidly because it has been highly reevaluated in multiple areas of industry. Conclusively, with its sustainability as a plant as well as its distinctive useful property of the seed protein, hemp has promising value in the development of new foods.

Hemp Shives as a Raw Material for the Production of Particleboards

Increased demand for wood affects its price and thus contributes to the growing interest in raw materials that can be used as a partial or total substitute for wood in the production of particleboard. One of the raw materials for the production of particleboard can be Cannabis sativa or, more precisely, hemp shives. In this work, 7 variants of panels with a density of 650 kg/m³ with 10 and 25% hemp shives substitution in different layers were produced. Particleboards containing hemp shives were characterized by lower density compared to conventional particleboards. The shares of hemp shives at the levels of 10% and 25% have a slight impact on the MOR and MOE; additional IB showed no statistically significant differences between the conventional particleboards and particleboards with a share of hemp shives. For particleboards with 25% hemp shives, a reduction in swelling was observed relative to particleboards made entirely of industrial wood particles.

Low-Density Particleboards Modified with Expanded and Unexpanded Fillers—Characteristics and Properties

Reducing the density of wood-based materials is a desirable research direction in the development of the wood-based materials sector. Even though lightweight wooden particleboards have been commercially available for many years, they still have a number of disadvantages, especially their low strength parameters. The aim of this paper was to determine the possibility of producing particleboards of reduced density for use in the furniture industry, as a result of using expanded polystyrene and two types of microspheres (expanded and unexpanded) to modify the core layer of three-layer particleboards. Analysis of the results of testing the particleboards’ properties when using various types of modifiers (expanded and unexpanded fillers), urea formaldehyde (UF) glue content (high: 10%/12% and low: 8%/10%), various glue-dosing methods, and different particle sizes, allows us to conclude that the most satisfactory effect was found when using EPS. One partly positive effect was observed when using the Expancel-type 031 DU 40 as a filler; therefore, it is recommended that research be continued in this area. Using microspheres that have not been used before as a filler in the production of wood-based panels is the novelty of the presented research. The proposed technology has potential for application in the industry.

Lignocellulosic Biomass from Grapevines as Raw Material for Particleboard Production

The study aimed to determine the suitability of agricultural lignocellulosic biomass in the form of vine pruning waste for particleboard production. Two variants of particleboards with densities of 650 kg/m³ and 550 kg/m³ containing a varied amount of vine pruning waste (0, 25, 50 and 100%) were evaluated. The strength (MOR, MOE and IB), thickness swelling and water absorption after immersion in water for 2 and 24 h were tested. The results revealed that vine pruning waste affected the board thickening and reduced strength properties. Boards with a 50% share of waste met the minimum requirements of strength properties specified in the EN 312 standard for boards with a density of 650 kg/m³. However, boards with a density of 550 kg/m³ entirely made with vine pruning waste met the minimum requirements of strength properties of the EN 16368 standard. Moreover, the pruned material reduced axial forces during drilling, swelling and water absorption.