Name: preparation and testing of plant seed meal-based wood adhesives
Uploaded: 2015-03-05T15:00:00.000+00:00
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Description: Watch this Scientific Journal Video about Preparation and Testing of Plant Seed Meal-based Wood Adhesives at JoVE.com

Data reported in this work are part of the USDA-ARS National Program 306 Project 'Values-Added Products from Cottonseed' research supported by the Agency's in-house funding. Publication of this paper is supported in part by the Journal of Visualized Experiments. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer. We acknowledge the constructive comments from JoVE science editor and peer reviewers in the review and revision process.

1. Cottonseed and Soy Meal-based Products (Figure 1)
<ol>
	<li>Obtain the raw materials, defatted cottonseed and soy meals, from commercially available sources.</li>
	<li>Obtain the working meal by grinding the solid defatted meal in a cyclone sample mill to pass a 0.5 mm steel screen16.</li>
	<li>Prepare water washed meals from the working meals after water extraction (25 g meal:200 ml water) to separate water soluble components in the meals21.</li>
	<li>Prepare protein isolates from the working meals by alkali extraction and acid precipitation16.</li>
</ol>
2. Preparation of Wood Veneer Strips
<ol>
	<li>Cut wood veneers (1.59 mm thick) obtained from a commercially available source into strips 25.4 mm wide by 88.9 mm long.</li>
	<li>Pencil mark a line across the wood grain at 25.4 mm (1.0&#34;) length from one end of each strip. Label these strips appropriately with testing treatments or numbers. 5 - 10 wood pairs are prepared for each testing variable.</li>
</ol>
3. Preparation of Adhesive Slurries
<ol>
	<li>Calculate the amount of water washed meal needed per the wood specimens for testing, by application rate (e.g., 4 mg dry content cm-2) x total bonding area (e.g., 581 cm2 of 90 wood strips with 2.54 x 2.54 cm bonding area each) plus about 30% extra for enoughness (i.e., 4 x 581 x 130% 3 g of water washed meal for the example).</li>
	<li>Mix water washed meal with deionized water (3:25 w/w), and stir with a magnetic stir bar for 2 hr in a beaker sealed with Parafilm.</li>
</ol>
4. Preparation of Bonded Wood Specimens
<ol>
	<li>Brush adhesive slurry onto one end of 2 wood veneer strips covering 25.4 mm (1.0&#34;) length. Air-dry for 10 - 15 min or until tacky.</li>
	<li>Brush a second layer of adhesive slurry on top of the first layer and air-dry again. The amount of dry adhesive preparation applied is about 4.5 mg dry solid per cm2 of bonding are of each wood strip.</li>
	<li>Overlap the tacky adhesive coated area (25.4 x 25.4 mm or 1.0&#34; x 1.0&#34;) of 2 wood veneer strips. Hot-press using a Benchtop Heated Press at 100 &#176;C for 20 min at a pressure of 400 psi (2.8 MPa). Note the pressure is the force applied by the press divided by the overlapped area of the wood samples. These bonding parameters may be changed as needed for each testing variable.</li>
	<li>Cool and condition the bonded wood specimens for 48 hr in a conditioning room or an incubator with humidity control (temperature of 22 - 23 &#176;C and relative humidity of 50 - 60%;&#160;Figure 2).</li>
</ol>
5. Water Resistance Experiments
<ol>
	<li>Immerse the bonded wood specimens, after initial conditioning, in tap water for 48 hr in a plastic tray at RT (22 - 23 &#176;C). The wet specimens after soaking are tested immediately for the shear strength at break and reported as wet strength. Excess water on the veneer surface may be removed by gently patting with paper tissue prior to measurements.</li>
	<li>Immerse another set of bonded wood specimens, after initial conditioning, in a water bath at 63 &#186;C for 4 hr, then dry at room conditions (temperature of 22 - 23 &#176;C and relative humidity of 50 - 60%) O/N (18 - 20 hr). Repeat the immersion-drying cycle once with a 48 hr drying time. The dried specimens are then tested for the shear strength at break and reported as soaked adhesive strength.</li>
</ol>
6. Lap Shear Strength Measurements
<ol>
	<li>Fit a bonded wood specimen into the 32 x 40 mm fishscale gridded wedge grips on a Materials Tester with a gripping pressure of 7 MPa, and set the crosshead speed at 1 mm min-1.</li>
	<li>Measure and record the shear strength at break for each bonded wood specimen. The results of multiple measurements are averaged for each adhesive formulation and test variable.</li>
</ol>

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The authors have nothing to disclose.

This paper presents a basic procedure to prepare and test plant seed-based products as wood adhesives. The adhesive slurries exampled in this protocol are simply the defatted seed meal product and water. Various adhesive formulations can be reached by addition of testing reagents (such as sodium dodecyl sulfate, sodium bisulfite or tung oil)5,6,23 and/or changes in mixing conditions (such as pH, ratio of solid and water)3,24,25. Adjustment of the adhesive formulation is also needed if the rheologica...

Adhesive bonding of wood plays an increasing role in the forest product industry and is a key factor for efficiently utilizing timber resources1. Interest in the use of natural product-based adhesives for wood increased steadily from the 1930s to reach a peak around 19602. After this period, the price of petroleum-based adhesives became so low that they displaced protein adhesives from several traditional markets. In the past two decades, this trend has reversed with renewed interest in the use of materials that are renewable, biodegradable, and more environmentally acceptable. These natural resources include, but are not limited to, soy protein3-5, cottonseed protein6, rice bran7, wheat gluten8, distillers grain protein9, canola protein and oil10-12, lignin from sorghum and sugar cane bagasse13,14, and polysaccharides derived from shrimp shells15.
Whereas seed protein isolates have been widely evaluated as potential wood adhesives, the isolation procedure involves corrosive alkaline and acidic reagents and it makes isolate-based adhesives relatively expensive and less environment-friendly16. Thus, some defatted seed meals (flours) with or without treatment have also been tested for the adhesive purpose, even though the adhesive properties of these meals do not perform as well as protein isolates17-19. We have sequentially fractionated cottonseed meal (CM) into different fractions, and examined their adhesive strength in bonding wood veneers20,21. The water-insoluble solid fraction (hereinafter washed cottonseed meal-WCM) could be used as wood adhesives, comparable to cottonseed protein isolate (CSPI), and would be less costly to prepare than CSPI.
Adhesive strength and water resistance are two critical parameters in evaluating the performance of a potential adhesive material. Here, the adhesive strength is reported as the shear strength at break of the lap bond of each wood specimen. Water resistance of the adhesive is measured by the change in lap shear strength of the bonded wood specimen at break due to water soaking. Using defatted cottonseed and soy meals as raw materials, this protocol provides a simple and straightforward way to prepare and test plant seed-based products as wood adhesives. This protocol would be helpful in facilitating the effort in seeking more economic and environment-friendly formulations of natural product-based wood adhesives.

<table><tbody><tr><td>Defatted cottonseed meal</td><td>Kentwood Co-op</td><td></td><td>Kentwood, LA, USA</td></tr><tr><td>Defatted soy meal</td><td>Kentwood Co-op</td><td></td><td>Kentwood, LA, USA</td></tr><tr><td>Wood veneers</td><td>Certainly Wood, Inc.</td><td></td><td>East Aurora, NY, USA</td></tr><tr><td>Cyclone sample mill (model 3010-014)</td><td>UDY Corporation</td><td></td><td>Fort Collins, CO, USA</td></tr><tr><td>Benchtop heated press (model 3856)</td><td>Carver, Inc.</td><td></td><td>Wabash, IN, USA</td></tr><tr><td>Materials tester</td><td>Zwick GmbH &amp;amp; Co.</td><td></td><td>Ulm, Germany</td></tr></tbody></table>

preparation and testing of plant seed meal-based wood adhesives

Recently, the interest in plant seed meal-based products as wood adhesives has steadily increased, as these plant raw materials are considered renewable and environment-friendly. These natural products may serve as alternatives to petroleum-based adhesives to ease environmental and sustainability concerns. This work demonstrates the preparation and testing of the plant seed-based wood adhesives using cottonseed and soy meal as raw materials. In addition to untreated meals, water washed meals and protein isolates are prepared and tested. Adhesive slurries are prepared by mixing a freeze-dried meal product with deionized water (3:25 w/w) for 2 hr. Each adhesive preparation is applied to one end of 2 wood veneer strips using a brush. The tacky adhesive coated areas of the wood veneer strips are lapped and glued by hot-pressing. Adhesive strength is reported as the shear strength of the bonded wood specimen at break. Water resistance of the adhesives is measured by the change in shear strength of the bonded wood specimens at break after water soaking. This protocol allows one to assess plant seed-based agricultural products as suitable candidates for substitution of synthetic-based wood adhesives. Adjustments to the adhesive formulation with or without additives and bonding conditions could optimize their adhesive properties for various practical applications.

Each adhesive formulation&#8217;s performance is determined by the shear strength of the bonded wood specimen at break and the values vary depending on the dimensions of the wood veneer used. For example, in Table 1, the dry and soaked adhesive strength values of the bonded specimens are lower when thinner and narrower maple strips are used (see Cottonseed-1), as opposed to the thicker and wider strips of Cottonseed-2 recommended in the protocol, using the same cottonseed-based adhesive formulation. Also...

Watch this Scientific Journal Video about Preparation and Testing of Plant Seed Meal-based Wood Adhesives at JoVE.com

Preparation and Testing of Plant Seed Meal-based Wood Adhesives

To facilitate the effort in seeking more economic and environment-friendly formulations of natural product-based wood adhesives, this work demonstrates the preparation and testing of plant seed-based wood adhesives. This protocol allows one to assess plant seed-based agricultural products as suitable candidates for the substitution of synthetic-based wood adhesives.

Recently, the interest in plant seed meal-based products as wood adhesives has steadily increased, as these plant raw materials are considered renewable ...

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8.7K Views.  United States Department of Agriculture. To facilitate the effort in seeking more economic and environment-friendly formulations of natural product-based wood adhesives, this work demonstrates the preparation and testing of plant seed-based wood adhesives. This protocol allows one to assess plant seed-based agricultural products as suitable candidates for the substitution of synthetic-based wood adhesives.

Video: Preparation and Testing of Plant Seed Meal-based Wood Adhesives

High-throughput Screening of Recalcitrance Variations in Lignocellulosic Biomass: Total Lignin, Lignin Monomers, and Enzymatic Sugar Release

The conversion of lignocellulosic biomass to fuels, chemicals, and other commodities has been explored as one possible pathway toward reductions in the use of non-renewable energy sources. In order to identify which plants, out of a diverse pool, have the desired chemical traits for downstream applications, attributes, such as cellulose and lignin content, or monomeric sugar release following an enzymatic saccharification, must be compared. The experimental and data analysis protocols of the standard methods of analysis can be time-consuming, thereby limiting the number of samples that can be measured. High-throughput (HTP) methods alleviate the shortcomings of the standard methods, and permit the rapid screening of available samples to isolate those possessing the desired traits. This study illustrates the HTP sugar release and pyrolysis-molecular beam mass spectrometry pipelines employed at the National Renewable Energy Lab. These pipelines have enabled the efficient assessment of thousands of plants while decreasing experimental time and costs through reductions in labor and consumables.

Plant cell wall structure and chemistry traits are evaluated to identify ideal feedstocks for biofuels and bio-materials. Standard methods have limitations when applied to large data sets. These high-throughput pretreatment, enzyme saccharification, and pyrolysis-molecular beam mass spectrometry methods compare large numbers of biomass samples with decreased experimental time and cost.

The conversion of lignocellulosic biomass to fuels, chemicals, and other commodities has been explored as one possible pathway toward reductions in the ...

Method to Produce Durable Pellets at Lower Energy Consumption Using High Moisture Corn Stover and a Corn Starch Binder in a Flat Die Pellet Mill

A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National Laboratory, a high-moisture pelleting process was developed to reduce the drying cost. In this process the biomass pellets are produced at higher feedstock moisture contents than conventional methods, and the high moisture pellets produced are further dried in energy efficient dryers. This process helps to reduce the feedstock moisture content by about 5-10% during pelleting, which is mainly due to frictional heat developed in the die. The objective of this research was to explore how binder addition influences the pellet quality and energy consumption of the high-moisture pelleting process in a flat die pellet mill. In the present study, raw corn stover was pelleted at moistures of 33, 36, and 39% (w.b.) by addition of 0, 2, and 4% pure corn starch. The partially dried pellets produced were further dried in a laboratory oven at 70 &#176;C for 3-4 hr to lower the pellet moisture to less than 9% (w.b.). The high moisture and dried pellets were evaluated for their physical properties, such as bulk density and durability. The results indicated that increasing the binder percentage to 4% improved pellet durability and reduced the specific energy consumption by 20-40% compared to pellets with no binder. At higher binder addition (4%), the reduction in feedstock moisture during pelleting was &#60;4%, whereas the reduction was about 7-8% without the binder. With 4% binder and 33% (w.b.) feedstock moisture content, the bulk density and durability values observed of the dried pellets were &#62;510 kg/m3 and &#62;98%, respectively, and the percent fine particles generated was&#160;reduced to &#60;3%.

In this study, a protocol was developed to produce good quality pellets using a flat die pellet mill at reduced specific energy consumption testing high-moisture corn stover and a starch based binder. The results indicated that adding a corn starch binder improved the pellet durability, reduced percent fines and decreased specific energy consumption.

A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National ...

Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis

To facilitate the use of lignocellulosic biomass as an alternative bioenergy resource, during biological conversion processes, a pretreatment step is needed to open up the structure of the plant cell wall, increasing the accessibility of the cell wall carbohydrates. Lignin, a polyphenolic material present in many cell wall types, is known to be a significant hindrance to enzyme access. Reduction in lignin content to a level that does not interfere with the structural integrity and defense system of the plant might be a valuable step to reduce the costs of bioethanol production. In this study, we have genetically down-regulated one of the lignin biosynthesis-related genes, cinnamoyl-CoA reductase (ZmCCR1) via a double stranded RNA interference technique. The ZmCCR1_RNAi construct was integrated into the maize genome using the particle bombardment method. Transgenic maize plants grew normally as compared to the wild-type control plants without interfering with biomass growth or defense mechanisms, with the exception of displaying of brown-coloration in transgenic plants leaf mid-ribs, husks, and stems. The microscopic analyses, in conjunction with the histological assay, revealed that the leaf sclerenchyma fibers were thinned but the structure and size of other major vascular system components was not altered. The lignin content in the transgenic maize was reduced by 7-8.7%, the crystalline cellulose content was increased in response to lignin reduction, and hemicelluloses remained unchanged. The analyses may indicate that carbon flow might have been shifted from lignin biosynthesis to cellulose biosynthesis. This article delineates the procedures used to down-regulate the lignin content in maize via RNAi technology, and the cell wall compositional analyses used to verify the effect of the modifications on the cell wall structure.

Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis

A double stranded RNA interference (dsRNAi) technique is employed to down-regulate the maize cinnamoyl coenzyme A reductase (ZmCCR1) gene to lower plant lignin content. Lignin down-regulation from the cell wall is visualized by microscopic analyses and quantified by the Klason method. Compositional changes in hemicellulose and crystalline cellulose are analyzed.

To facilitate the use of lignocellulosic biomass as an alternative bioenergy resource, during biological conversion processes, a pretreatment step is ...

Bioengineering

Rapid Testing of Resistance of Timber to Biodegradation by Marine Wood-Boring Crustaceans

Wood-boring invertebrates rapidly destroy marine timbers and wooden coastal infrastructure, causing billions of dollars of damage around the globe every year. As treatments of wood with broad spectrum biocides, such as creosote and chromated copper arsenate (CCA), are now restricted in marine use by legislation, naturally durable timber species and novel preservation methods of wood are required. These methods undergo testing in order to meet regulatory standards, such as the European standard for testing wood preservatives against marine borers, EN 275. Initial investigation of durable timbers species or wood preservative treatments can be achieved quickly and inexpensively through laboratory testing, which offers many advantages over marine field trials that are typically costly, long-term endeavours. Many species of Limnoria (gribble) are marine wood-boring crustaceans. Limnoria are ideal for use in laboratory testing of biodegradation of wood by marine wood-borers, due to the practicality of rearing them in aquaria and the ease of measuring their feeding rates on wood. Herein, we outline a standardizable laboratory test for assessing wood biodegradation using gribble.

This protocol presents a method for assessing the feeding rate of the wood-boring crustacean, Limnoria, by measuring faecal pellet production. This method is designed for use in non-specialist labs and has potential for incorporation into standard testing protocols, to evaluate enhanced wood durability under marine conditions.

Wood-boring invertebrates rapidly destroy marine timbers and wooden coastal infrastructure, causing billions of dollars of damage around the globe every ...

Extraction of Lignin with High &#946;-O-4 Content by Mild Ethanol Extraction and Its Effect on the Depolymerization Yield

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the emerging elegant procedures to obtain specific aromatic products rely on the lignin substrate having a high content of the readily cleavable &#946;-O-4 linkage as present in the native lignin structure. This provides a miss-match with typical technical lignins that are highly degraded and therefore are low in &#946;-O-4 linkages. Therefore, the extraction yields, and the quality of the obtained lignin are of utmost importance to access new lignin valorization pathways. In this manuscript, a simple protocol is presented to obtain lignins with high &#946;-O-4 content by relatively mild ethanol extraction that can be applied to different lignocellulose sources. Furthermore, analysis procedures to determine the quality of the lignins are presented together with a depolymerization protocol that yields specific phenolic 2-arylmethyl-1,3-dioxolanes, which can be used to evaluate the obtained lignins. The presented results demonstrate the link between lignin quality and potential for the lignins to be depolymerized into specific monomeric aromatic chemicals. Overall, the extraction and depolymerization demonstrates a trade-off between the lignin extraction yield and the retention of the native aryl-ether structure and thus the potential of the lignin to be used as the substrate for the production of chemicals for higher-value applications.

Here, we present a protocol to perform ethanol extraction of lignin from several biomass sources. The effect of the extraction conditions on the lignin yield and &#946;-O-4 content are presented. Selective depolymerization is performed on the obtained lignins to obtain high aromatic monomer products.

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the ...

Chemistry

Fabrication and Design of Wood-Based High-Performance Composites

Delignified densified wood is a new promising and sustainable material that possesses the potential to replace synthetic materials, such as glass fiber reinforced composites, due to its excellent mechanical properties. Delignified wood, however, is rather fragile in a wet state, which makes handling and shaping challenging. Here we present two fabrication processes, closed-mold densification and vacuum densification, to produce high-performance cellulose composites based on delignified wood, including an assessment of their advantages and limitations. Further, we suggest strategies for how the composites can be re-used or decomposed at the end-of-life cycle. Closed-mold densification has the advantage that no elaborate lab equipment is needed. Simple screw clamps or a press can be used for densification. We recommend this method for small parts with simple geometries and large radii of curvature. Vacuum densification in an open-mold process is suitable for larger objects and complex geometries, including small radii of curvature. Compared to the closed-mold process, the open-mold vacuum approach only needs the manufacture of a single mold cavity.

Delignified densified wood represents a new promising lightweight, high-performance and bio-based material with great potential to partially substitute natural fiber reinforced- or glass fiber reinforced composites in the future. We here present two versatile fabrication routes and demonstrate the possibility to create complex composite parts.

Delignified densified wood is a new promising and sustainable material that possesses the potential to replace synthetic materials, such as glass fiber ...

Engineering

Evaluation of the Curing of Adhesive Systems by Rheological and Thermal Testing

The analysis of thermal processes associated to the curing of adhesives and the study of mechanical behavior once cured, provide key information to choose the best option for any specific application. The proposed methodology for the curing characterization, based on thermal analysis and rheology, is described through the comparison of three commercial adhesives. The experimental techniques used here are Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Rheology. TGA provides information about the thermal stability and filler content, DSC allows the evaluation of some thermal events associated to the cure reaction and to thermal changes of the cured material when subjected to temperature changes. Rheology complements the information of the thermal transformations from a mechanical point of view. Thus, the curing reaction can be tracked through the elastic modulus (mainly the storage modulus), the phase angle and the gap. In addition, it is also shown that although DSC is of no use to study the curing of moisture curable adhesives, it is a very convenient method to evaluate the low temperature glass transition of amorphous systems.

An experimental methodology based on thermal and rheological measurements is proposed to characterize the curing process of adhesives with to obtain useful information for industrial adhesive selection.

The analysis of thermal processes associated to the curing of adhesives and the study of mechanical behavior once cured, provide key information to choose ...

Comprehensive Compositional Analysis of Plant Cell Walls (Lignocellulosic biomass) Part I: Lignin

The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st century. This has rekindled interest in the use of plant products as industrial raw materials for the production of liquid fuels for transportation1 and other products such as biocomposite materials7. Plant biomass remains one of the greatest untapped reserves on the planet4. It is mostly comprised of cell walls that are composed of energy rich polymers including cellulose, various hemicelluloses (matrix polysaccharides, and the polyphenol lignin6 and thus sometimes termed lignocellulosics. However, plant cell walls have evolved to be recalcitrant to degradation as walls provide tensile strength to cells and the entire plants, ward off pathogens, and allow water to be transported throughout the plant; in the case of trees up to more the 100 m above ground level. Due to the various functions of walls, there is an immense structural diversity within the walls of different plant species and cell types within a single plant4. Hence, depending of what crop species, crop variety, or plant tissue is used for a biorefinery, the processing steps for depolymerization by chemical/enzymatic processes and subsequent fermentation of the various sugars to liquid biofuels need to be adjusted and optimized. This fact underpins the need for a thorough characterization of plant biomass feedstocks. Here we describe a comprehensive analytical methodology that enables the determination of the composition of lignocellulosics and is amenable to a medium to high-throughput analysis. In this first part we focus on the analysis of the polyphenol lignin (Figure 1). The method starts of with preparing destarched cell wall material. The resulting lignocellulosics are then split up to determine its lignin content by acetylbromide solubilization3, and its lignin composition in terms of its syringyl, guaiacyl- and p-hydroxyphenyl units5. The protocol for analyzing the carbohydrates in lignocellulosic biomass including cellulose content and matrix polysaccharide composition is discussed in Part II2.

Comprehensive Compositional Analysis of Plant Cell Walls Lignocellulosic biomass Part I: Lignin

Plant biomass is a major carbon-neutral renewable resource that could be used for the production of biofuels. Plant biomass consists mainly of cell walls, a structurally complex composite material termed lignocellulosics. Here we describe a protocol for a comprehensive analysis of the content and composition of the polyphenolic lignin.

The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st ...

Biology

Twin-Screw Extrusion Process to Produce Renewable Fiberboards

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pre-treatment on lignocellulosic biomass before using it as source of mechanical reinforcement in fully bio-based fiberboards was developed. Various lignocellulosic crop by-products have already been successfully pre-treated through this process, e.g., cereal straws (especially rice), coriander straw, shives from oleaginous flax straw, and bark of both amaranth and sunflower stems.
The extrusion process results in a marked increase in the average fiber aspect ratio, leading to improved mechanical properties of fiberboards. The twin-screw extruder can also be fitted with a filtration module at the end of the barrel. The continuous extraction of various chemicals (e.g., free sugars, hemicelluloses, volatiles from essential oil fractions, etc.) from the lignocellulosic substrate, and the fiber refining can, therefore, be performed simultaneously.
The extruder can also be used for its mixing ability: a natural binder (e.g., Organosolv lignins, protein-based oilcakes, starch, etc.) can be added to the refined fibers at the end of the screw profile. The obtained premix is ready to be molded through hot pressing, with the natural binder contributing to fiberboard cohesion. Such a combined process in a single extruder pass improves the production time, production cost, and may lead to reduction in plant production size. Because all the operations are performed in a single step, fiber morphology is better preserved, thanks to a reduced residence time of the material inside the extruder, resulting in enhanced material performances. Such one-step extrusion operation may be at the origin of a valuable industrial process intensification.
Compared to commercial wood-based materials, these fully bio-based fiberboards do not emit any formaldehyde, and they could find various applications, e.g., intermediate containers, furniture, domestic flooring, shelving, general construction, etc.

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pretreatment on lignocellulosic biomass was developed, which leads to an increased average fiber aspect ratio. A natural binder can also be added continuously after fiber refining, leading to bio-based fiberboards with improved mechanical properties after hot pressing of the obtained extruded material.

A versatile twin-screw extrusion process to provide an efficient thermo-mechano-chemical pre-treatment on lignocellulosic biomass before using it as ...

Standard Test Method ASTM D 7998-19 for the Cohesive Strength Development of Wood Adhesives

The properties of cured wood adhesives are difficult to study because of the loss of water and other components to the wood, the influence of wood on the adhesive cure, and the effect of adhesive penetration on the wood interphase; thus, normal testing of a neat adhesive film is generally not useful. Most tests of wood adhesive bond strength are slow, laborious, can be strongly influenced by the wood and do not provide information on the kinetics of cure. Test method ASTM D 7998-19, however, can be used for fast evaluation of the strength of wood bonds. The use of a smooth, uniform, and strong wood surface, like maple face-veneer, and sufficient bonding pressure reduces the adhesion and wood strength effects on bond strength. This method has three main applications. The first is to provide consistent data on bond strength development. The second is to measure the dry and wet strengths of bonded lap shear samples. The third is to better understand the adhesive heat resistance by quickly evaluating thermal sensitivity and distinguishing between thermal softening and thermal degradation.

We present a procedure, ASTM D7998-19, for a rapid and more consistent evaluation of both dry and wet strength of adhesive bonds on wood. The method can also be used to provide information on strength development as a function of temperature and time or strength retention up to 250 &#176;C.

The properties of cured wood adhesives are difficult to study because of the loss of water and other components to the wood, the influence of wood on the ...

Preparation and Testing of Plant Seed Meal-based Wood Adhesives

Summary

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Chapters in this video

High-throughput Screening of Recalcitrance Variations in Lignocellulosic Biomass: Total Lignin, Lignin Monomers, and Enzymatic Sugar Release

Method to Produce Durable Pellets at Lower Energy Consumption Using High Moisture Corn Stover and a Corn Starch Binder in a Flat Die Pellet Mill

Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis

Rapid Testing of Resistance of Timber to Biodegradation by Marine Wood-Boring Crustaceans

Extraction of Lignin with High β-O-4 Content by Mild Ethanol Extraction and Its Effect on the Depolymerization Yield

Fabrication and Design of Wood-Based High-Performance Composites

Evaluation of the Curing of Adhesive Systems by Rheological and Thermal Testing

Comprehensive Compositional Analysis of Plant Cell Walls (Lignocellulosic biomass) Part I: Lignin

Twin-Screw Extrusion Process to Produce Renewable Fiberboards

Standard Test Method ASTM D 7998-19 for the Cohesive Strength Development of Wood Adhesives