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Cellulosic-based materials such as hemp fabric and paper have combined characteristics of renewability, biodegradability, flexibility, and recyclability. However, regular products are not suitable for use in unconventional applications due to inherent limitations, and accordingly, enabling new capabilities is a necessity. To this end, the conversion of regular hemp fabric and paper into high-strength products with hydrophobic function via surface engineering was explored. The fluorinated waterborne polyurethane (FWPU) emulsions were first synthesized as functional coatings by in-situ polymerization. The structure and properties of the FWPU emulsion and film were characterized by FTIR, XRD, SEM, TG, and XPS. The results showed that the grafting of perfluorooctanol imparts WPU film excellent hydrophobicity, and the water contact angle increases from 71.2° to 105.9°. After the FWPU coating, the water contact angles of the hemp fabric and paper increase from 0° to 117.1° and 112.8°, respectively. Quite encouragingly, the coating generation of waterborne polyurethane-derived functional additives led to the increase of mechanical strength by more than 23% and 82%, in the case of qualitative filter paper and hemp fabric. Meanwhile, the folding strength of filter paper is increased by 132 times. Overall, this functionalized waterborne polyurethane coating would direct paper and hemp fabric toward diversified applications. [ABSTRACT FROM AUTHOR]

Hemp hurd fiber, a low-value waste stream from the hemp industry, has potential downstream applications as an alternative to non-renewable plastics for single-use food service ware and packaging applications. Packaging paper substrates made from chemically pulped hemp hurd, mixed in varying ratios with bleached thermomechanical radiata pine pulp were developed and tested. Handsheets were characterized using several mechanical property tests including tensile strength, tearing resistance, burst strength, short-span compression, ring crush, together with Gurley air resistance, contact angle, and Cobb60 tests. Generally, addition of hemp hurd fibers significantly improved handsheet mechanical properties. Hot-pressing of the handsheets so as to approximate molded fiber thermoforming further enhanced their performance, with pure hemp hurd handsheets having the highest mechanical properties and barrier performance. A prototype was successfully thermoformed from hemp fiber, demonstrating overall feasibility of this fibre source for molded fibre objects. [ABSTRACT FROM AUTHOR]

A significant increase in the consumption of recycled fiber products has been observed worldwide, and the industry is forced to solve the challenges of recycled fiber quality and add strength agents and/or virgin fibers to reach sufficient properties. In order to investigate whether the mechanical and air permeability properties of waste fiber (WF) material can be significantly improved by adding wood kraft fibers (KF), hemp soda fibers (HF), and ammonium persulfate oxidated cellulose nanofibrils (CNF), different fiber blends were prepared and tested. Results revealed the excellence of hemp fibers over wood fibers regarding the improvement of WF products. The results of WF after the addition of 10% mixed fibers (KF + HF) were higher than the results of a 50% KF addition. The impact of CNF depended on fiber composition and properties. A formula for modeling the CNF impact on different fiber compositions was proposed. Obtained fiber material samples showed suitability for home composting, thus contributing to the goals of the European Green Deal regarding reducing landfill waste and the development of cleaner products. [ABSTRACT FROM AUTHOR]

The study describes the preparation of nanocellulose from organosolv hemp pulp and its application in the production of food packaging paper as an alternative to petroleum products. OHP was obtained from renewable plant materials hemp fibers by extraction with NaOH solution and cooking using a mixture of acetic acid and hydrogen peroxide. A stable transparent nanocellulose gel was extracted from OHP by acid hydrolysis followed by ultrasonic treatment. It was found that an increase in the consumption of sulfuric acid, temperature and duration of the OHP hydrolysis process improved the quality indicators of hemp nanocellulose. A linear dependence of the tensile strength and transparency of nanocellulose films on their density has been established. Morphological (SEM), structural (FTIR and XRD) and thermal analysis (TGA) of hemp fibers, OHP and nanocellulose were carried out. Nanocellulose films had a density of up to 1.56 g/cm3, a tensile strength of up to 66.7 MPa, a transparency of up to 87.3%. Atomic force microscopy method showed that the transverse dimension of nanocellulose particles is from 8 to 23 nm. Hemp nanocellulose had a higher crystallinity index (87.2%) than OHP (72.0%), but lower thermal stability. The positive effect of adding nanocellulose from hemp on improving all quality parameters of paper for food packaging has been shown. The addition of 2% hemp nanocellulose makes it possible to obtain paper that exceeds the breaking force requirements of premium grade paper by 40%, and the breaking length increases by 42% compared to paper without chemical additives. [ABSTRACT FROM AUTHOR]

From the moment of production, paper as a printing substrate is exposed to the process of natural ageing regardless of the type of cellulose fibres in its composition. Accordingly, the prints produced by the various printing techniques are also exposed to several factors that impair the quality of the print i.e. its colour over time. Therefore, it is very important to properly select the printing substrate for achieving a high quality of graphic products. For that purpose, three types of papers with hemp fibres were used as printing substrates which were printed with laboratory hand-operated instrument Esiproof using flexographic cyan (C), magenta (M), yellow (Y) and black (K) water-based inks. Prints were artificially aged in SunTEST XLS+ test chamber according to standard ASTM D 6789-02 for 48 and 96 hours. Based on changes in the reflectance spectra of each printed ink after exposure to electromagnetic radiation it was noticed how composition of printing substrate strongly influence on colour stability of prints due time. An increase of exposure time to electromagnetic radiation leads to a decrease in the value of the reflectance of the printing substrate and cyan, magenta and yellow prints. It was confirmed how electromagnetic radiation have the greatest impact on the reflectance of yellow print, while the black one is the most stabile regardless of the substrate it was printed on.

The features of the primary preparation of hemp straw stalks suitable for obtaining cellulosecontaining materials and paper are considered in the article. The primary processes of the preparation of hemp raw materials for pulp production, which include harvesting, storage of straw stalks, transportation, and primary processing of raw materials suitable for obtaining cellulose-containing materials, are described. Methods of shortening stems and fibers applied in the pulping process are studied in detail. Technological methods of shortening straw stalks of technical hemp and cleaning raw materials from grains and garbage impurities are mentioned. The necessity of applying the processes of stalks crushing and wet purification of chopped straw stalks of technical hemp is proved. [ABSTRACT FROM AUTHOR]

El desarrollo y la investigación de nuevos productos que puedan sustituir parcial o completamente materias primas empleadas para la producción de energía, productos químicos de alto valor añadido e incluso la fabricación de papel, ha permitido que el cáñamo industrial (Cannabis sativa L.) se vuelva atractivo como principal materia prima en la reactivación de una economía de base biológica con altas condiciones y capacidades de producción. A partir de lo anterior, el objetivo de este trabajo investigativo es profundizar sobre el potencial del uso de fibra de cáñamo en la industria del papel, soportado por estudios realizados por el Estado Colombiano en lo referente a las disponibilidad de cultivos forestales con fines comercialesque inicialmente se destinan para la siembra y producción de recursos madereros como el pino y eucalipto. Se ha considerado de importancia demostrar que el cáñamo, como fuente de producción primaria, brinda ventajas competitivas económicas, ambientales y sociales frente a los cultivos tradicionales, incluso para las nuevas fuentes de investigación de base biológica.

From the moment of production, paper as a printing substrate is exposed to the process of natural ageing regardless of the type of cellulose fibres in its composition. Accordingly, the prints produced by the various printing techniques are also exposed to several factors that impair the quality of the print i.e. its colour over time. Therefore, it is very important to properly select the printing substrate for achieving a high quality of graphic products. For that purpose, three types of papers with hemp fibres were used as printing substrates which were printed with laboratory hand-operated instrument Esiproof using flexographic cyan (C), magenta (M), yellow (Y) and black (K) water-based inks. Prints were artificially aged in SunTEST XLS+ test chamber according to standard ASTM D 6789-02 for 48 and 96 hours. Based on changes in the reflectance spectra of each printed ink after exposure to electromagnetic radiation it was noticed how composition of printing substrate strongly influence on colour stability of prints due time. An increase of exposure time to electromagnetic radiation leads to a decrease in the value of the reflectance of the printing substrate and cyan, magenta and yellow prints. It was confirmed how electromagnetic radiation have the greatest impact on the reflectance of yellow print, while the black one is the most stabile regardless of the substrate it was printed on. [ABSTRACT FROM AUTHOR]

The hemp plant Cannabis sativa Linn, referring to industrial hemp, is a high-yielding annual industrial crop grown providing fibers from hemp stalk and oil from hemp seeds. Although hemp is a niche crop, hemp production is currently undergoing a renaissance. More than 30 countries grow hemp, with China being the largest hemp producing and exporting country. Europe and Canada are also important actors in the global hemp market. Traditionally, hemp as a fiber plant has been used for the production of apparels, fabrics, papers, cordages and building materials. The hurds, as waste by-product of fiber production, were used for bedding of animals, the seeds for human nutrition, e.g., as flour, and the oil for a wide range of purposes, from cooking to cosmetics. Hemp has also been an important crop throughout human history for medicine. Other more recent applications include materials for insulation and furniture, automotive composites for interior applications and motor vehicle parts, bioplastics, jewelry and fashion sectors, animal feed, animal bedding, and energy and fuel production. Foods containing hemp seed and oil are currently marketed worldwide for both animal and human nutrition. They also find applications in beverages and in neutraceutical products. Hemp oil is also used for cosmetics and personal care items, paints, printing inks, detergents and solvents. It is estimated that the global market for hemp consists of more than 25,000 products. Currently, the construction and insulation sector, paper and textile industries, and food and nutrition domains are the main markets while the cosmetics and automotive sector are growing markets. Innovative applications, e.g., in the medical and therapeutic domains, cosmeceuticals, phytoremediation, acoustic domain, wastewater treatment, biofuels, biopesticides and biotechnology, open new challenges. Hemp is also the object of numerous fundamental studies. This review presents and discusses the traditional and new uses of industrial hemp. [ABSTRACT FROM AUTHOR]

Hemp is a sustainable, recyclable, and high-yield annual crop that can be used to produce textiles, plastics, composites, concrete, fibers, biofuels, bionutrients, and paper. The integration of microfluidic paper-based analytical devices (µPADs) with hemp paper can improve the environmental friendliness and high-throughputness of µPADs. However, there is a lack of sufficient scientific studies exploring the functionality, pros, and cons of hemp as a substrate for µPADs. Herein, we used a desktop pen plotter and commercial markers to pattern hydrophobic barriers on hemp paper, in a single step, in order to characterize the ability of markers to form water-resistant patterns on hemp. In addition, since a higher resolution results in densely packed, cost-effective devices with a minimized need for costly reagents, we examined the smallest and thinnest water-resistant patterns plottable on hemp-based papers. Furthermore, the wicking speed and distance of fluids with different viscosities on Whatman No. 1 and hemp papers were compared. Additionally, the wettability of hemp and Whatman grade 1 paper was compared by measuring their contact angles. Besides, the effects of various channel sizes, as well as the number of branches, on the wicking distance of the channeled hemp paper was studied. The governing equations for the wicking distance on channels with laser-cut and hydrophobic side boundaries are presented and were evaluated with our experimental data, elucidating the applicability of the modified Washburn equation for modeling the wicking distance of fluids on hemp paper-based microfluidic devices. Finally, we validated hemp paper as a substrate for the detection and analysis of the potassium concentration in artificial urine.

Hop (Humulus lupulusL.) is an ancient perennial crop plant, native to the Northern Hemisphere. The archaeological evidence dates back to at least the sixth century ad in Europe. Hop has been used for beer brewing, in sleeping draughts, as bedding and for antibacterial purposes. Less known is that hop fibres have also been used for textiles and paper. However, it is difficult to distinguish hop from other bast fibres. Here, we present a set of fibre features, which, when found together in an archaeological/historical material within a European context, provide a strong indication that the fibres are hop. [ABSTRACT FROM AUTHOR]

The goal of this study was to prove the feasibility of fiber and paper production from hemp. Experimental tests of the properties of paper obtained from hemp woody core fibers were performed. Fibers from hemp woody core were isolated by a chemical-thermo-mechanical procedure. Sheets of paper were made from thus isolated fibers. The mechanical and optical properties of the paper sheets were also examined. The properties of paper sheets obtained from spruce and beach fibers were examined in the same way for comparison. The obtained results showed that paper produced from fiber isolated from hemp woody core by a chemical-thermo-mechanical procedure had poorer properties than the properties of paper produced from beech and spruce fibers, but it still satisfied conditions for producing low quality newspaper.

Lignocellulosic crops like kenaf, flax and hemp have been extensively studied the last years with the help of new technology and many new products fabricated with them are ready for the market or have already been marketed. Both the core material and the bast fibers of these crops are ideal feedstocks for the production of yarns and paper of high quality, for rendering flame retardant properties to composites reinforced with them, for the production of energy via a sustainable way without polluting the environment and for use as alternative materials to wood for the manufacturing of panels like particleboards and fiber boards (MDF, HDF, etc.). The investigation of lignocellulosic feedstock as potential source for the sustainable production of materials, products and energy has resulted in promising solutions for the successful replacement of their counterparts made from fossil raw materials. However, the related industries still have some challenges to face, like the cost of materials from lignocellulosic plants in comparison with those derived from fossil sources and the availability of the feedstock throughout the year. [ABSTRACT FROM AUTHOR]

Abstract: Natural continuous bast fibres (hemp, flax, etc.) are gaining popularity in composite materials because they can advantageously replace glass fibres. It is found that intrinsic properties of unidirectional (UD) composites are almost equivalent to those of unidirectional glass fibre composites. Unfortunately it is difficult to get repeatable results because of the inherent variability in the properties of bast fibres compared to glass fibres. Their quality is largely affected by the weather conditions, the extraction location along the plant and the techniques used to extract them (retting, bleaching, etc.). In this work, unidirectional hemp/paper/epoxy and flax/paper/epoxy composites are manufactured by adding one or two sheets of paper at the surface of a unidirectional layer of hemp or flax fibres before molding. The composites are tested under tensile loads and the results compared with those obtained for UD composites made without paper. The results show a significant increase in strength and modulus repeatability when the paper layer is present. A significant increase in strength and modulus was also obtained compared to the base epoxy properties. The resin permeability of the flax–paper reinforcement has also been evaluated and compared to that of a standard glass fabric. Globally, the results suggest that adding thin sheets of paper at the surface of reinforcement layers stabilizes and increases the composite strength but slightly reduces the Young’s modulus. However the permeability of the flax–paper reinforcement was much lower than that of the glass fabric. Modifications to the paper architecture will be required to improve this aspect. [Copyright &y& Elsevier]

Hemp is a primary substance for papermaking, having been used for 2,000 years in this capacity. In the 20th century wood pulp came to replace hemp and other long fibres, and this has been an environmental disaster. Recent efforts to re-introduce hemp fibres into paper pulp are under way, with a number of writing papers having been manufactured in Europe and North America. However, most of these were done in small batches. Most papermills in southeast Asia produce 500,000 tons or more annually, whilst mills in the West tend to be small, specialty paper mills. Hemp is used rather consistently for fine papers, including cigarette paper and cosmetic tissue paper, but writing paper may continue to be made from trees until we run out and are forced to use other material. One large papermill in Germany, Gmund (which is distributed in the UK by The Hemp Shop) is starting to catch up, with a number of different papers including writing paper now being made in increasingly larger batches. A number of other companies are also offering hemp papers, ranging from writing paper to wallpaper. Part of the issue is the fact that the hurd, which is lower in cellulose content that the bast, can be used for paper, as demonstrated by the US government in the early 20th century. doi:10.1300/J237v12n02_08 [ABSTRACT FROM PUBLISHER]

The Czech Hemp Association (CHA) was founded to re- introduce industrial hemp to Czech fields as well as to processing plants, bringing it to various industries. The CHA aims for every region to establish small hemp industrial centers able to process 7400 to 10000 tons of hemp fiber annually. The basic prerequisite for a successful regional development is a sufficient growing area within a distance of 70 to 100 km from the functional scutching line, together with mechanisms for harvesting. In several Czech regions pilot projects of this type have been started. [ABSTRACT FROM AUTHOR]

Much of the hemp plant is a carbohydrate known as cellulose, found mostly in the outer bark of the stem, which is about 75% cellulose, while the core is about half that or more. This is in fact typical of plants, making cellulose the most common compound in the vegetable kingdom. It is a simple compound, utilising the three common elements of carbon, hydrogen and oxygen, and is a structure of many glucose molecules compounded together. There are slight differences in the arrangement of the glucose from plant to plant, making for different qualities in the cellulose yielded. Hemp if one of the best plants for cellulose production for the reasons that the cellulose it produces is well suited for paper manufacture and textiles, and further, it grows quickly without any great need of pesticides. Hemp use has been suppressed in recent times, but due to its usefulness and the ecological advantages in harvesting hemp over cotton and trees, there has been a call for hemp use which is growing worldwide. Businesses such as Minawear in California and Ecofibres in Australia have been working for the last several years with hemp and both have seen an increase in demand. At present most hemp is grown in China, Canada and Eastern Europe, but has in history been grown in almost every country of the world, due to the ease with which it is cultivated and the need for the cellulose fibres that it yields. [ABSTRACT FROM PUBLISHER]

Hip Hemp Happenings highlights some of the companies and products that are successfully marketing hemp in creative and innovative ways. Ranging from colorful and practical hemp clothing to nutritious hemp nut based desserts, this article illustrates different approaches to the same problem: how to make hemp hip. It also shows how some companies are using the star power of celebrities and athletes to promote their hemp products. [ABSTRACT FROM PUBLISHER]

In this column, John E. Dvorak provides insight into some of the best industrial hemp websites on the Internet. Areas covered in detail include news portals, hemp associations, new products and research sites. Reviews relating to specific topics such as hemp food, textiles, paper and other industrial uses will also be periodically touched upon. The ever-changing nature of the world wide web will be reflected in the many different types of websites reviewed. While the focus of this column is on North America, a concerted effort is being made to incorporate as many sites from as many countries as possible. [ABSTRACT FROM PUBLISHER]

Hemp is a sustainable, recyclable, and high-yield annual crop that can be used to produce textiles, plastics, composites, concrete, fibers, biofuels, bionutrients, and paper. The integration of microfluidic paper-based analytical devices (µPADs) with hemp paper can improve the environmental friendliness and high-throughputness of µPADs. However, there is a lack of sufficient scientific studies exploring the functionality, pros, and cons of hemp as a substrate for µPADs. Herein, we used a desktop pen plotter and commercial markers to pattern hydrophobic barriers on hemp paper, in a single step, in order to characterize the ability of markers to form water-resistant patterns on hemp. In addition, since a higher resolution results in densely packed, cost-effective devices with a minimized need for costly reagents, we examined the smallest and thinnest water-resistant patterns plottable on hemp-based papers. Furthermore, the wicking speed and distance of fluids with different viscosities on Whatman No. 1 and hemp papers were compared. Additionally, the wettability of hemp and Whatman grade 1 paper was compared by measuring their contact angles. Besides, the effects of various channel sizes, as well as the number of branches, on the wicking distance of the channeled hemp paper was studied. The governing equations for the wicking distance on channels with laser-cut and hydrophobic side boundaries are presented and were evaluated with our experimental data, elucidating the applicability of the modified Washburn equation for modeling the wicking distance of fluids on hemp paper-based microfluidic devices. Finally, we validated hemp paper as a substrate for the detection and analysis of the potassium concentration in artificial urine. [ABSTRACT FROM AUTHOR]