Hemp Pulp Research Articles

Usability of Hemp Plant in Poultry Nutrition

Hemp (Cannabis sativa L.) is an annual plant with 2n=20 chromosomes, one-year, C3 group, cultivated for its long and strong fibers and seeds. It is a plant that should be cultivated in a controlled manner due to the presence of THC in its natural structure. Producers who avoid control and monitoring have turned to alternative products instead of hemp farming. Countries that cultivate cannabis in large areas; France, China, and Canada. Some countries are updating their cannabis-related laws and making efforts to increase hemp acreage. It is known that hemp farming has been practiced in Anatolia since 1500 BC. Various products such as hemp seeds, hemp pulp, hemp oil have been used in various studies in poultry feeding studies, while no negative results have been encountered, but various positive results have been suggested and their use is recommended. It is of great importance to investigate the effects of cannabidiols, which have strong antimicrobial, antioxidant and immunostimulant effects, as they are expected to support the immune system in poultry, especially broilers. Some of the studies in which hemp products are used in poultry nutrition are as follows; Addition of hemp meal to laying hen diets has been reported to make no significant difference in egg production, feed consumption, feed utilization, body weight gain or egg quality, but results in lower palmitic acid concentrations and higher Linoleic acid (LA) and alpha-linolenic acid (ALA) concentrations, which are healthier for human consumption. Hemp seeds and hemp oil used in chicken rations caused an increase in the omega-3 polyunsaturated fatty acid content and color intensity of egg yolks, but no adverse effects were observed on the sensory profiles of cooked eggs. Addition of cannabis meal to fast growing broiler diets did not affect performance or mortality, and no effect on the number of Clostridium perfringens in the cecum was reported. Hemp seeds have a remarkable effect on the growth of broiler chicks and can help reduce feed expenditures for broiler rearing. In this paper, the use and usability of the hemp plant, whose production areas are expanding rapidly, in poultry will be examined.

Near-infrared spectroscopy and multivariate analysis as real-time monitoring strategy of TEMPO-mediated oxidation of cellulose fibers from different feedstocks

The regioselective oxidation of the primary hydroxyl groups of cellulose, usually mediated by the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl radical (TEMPO), is highly popular in the scientific literature. However, the lack of efficient monitoring techniques imposes a severe limitation to its upscaling. This work involves a portable, user-friendly near-infrared spectroscopy device, optimized preprocessing techniques, and multivariate calibration to quickly estimate the carboxyl group content of modified cellulose (i.e., the extent of the oxidation). For that, bleached pulps from eucalyptus, pine, hemp, and sisal were submitted to TEMPO-mediated oxidation, varying the dosage of spent oxidizer (NaClO) and thus attaining samples of different values of carboxyl group content. These values were related to near-infrared spectra (908–1676 nm) by Partial Least Squares regression, yielding cross-validation coefficients (RCV2) above 0.97 for wood pulps, 0.95 for sisal pulp, and 0.91 for hemp pulp. Based on the residual prediction deviation, the model for each pulp was found to show good predictability. Nonetheless, the overall regression model, comprising the four different materials, was unreliable. In light of this, spectra were submitted to principal components analysis (PCA), hinting that pulps could be classified in terms of their hemicellulose to cellulose ratio. Considering all the statistical parameters, the overall proposal presented here begins with a PCA—Linear Discriminant Analysis model to classify the sample by its fiber type, subsequently selecting a specific regression model for that class. Overall, the presented models in this work allow the determination of the extent of oxidation of different cellulosic feedstocks, expressed as carboxyl content, in a fast and simple approach using a benchtop near-infrared equipment.

Preparation of natural antibacterial regenerated cellulose fiber from seed-type hemp

Seed-type hemp fiber is hard to spinning and weaving because of its high lignin and hemicellulose content. In this work, the impurities in seed-type hemp fiber were removed by alkali degumming method, ammonium oxalate-complex enzyme method, ethylenediamainetetraacetic acid disodium -complex enzyme method, ammonium oxalate-complex enzyme-chemical method and ethylenediamainetetraacetic acid disodium -complex enzyme-chemical method, and the results were compared. The fibers were characterized by scanning electron microscopy (SEM) and fourier-transform infrared spectroscopy (FTIR). The fiber after impurity removal is prepared into pulp, and the structure of pulp was characterized by fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The hemp pulp was dissolved into ZnCl2 aqueous solution at a specific temperature to prepare a spinning solution and spun to produce antimicrobial seed-type hemp regenerated cellulose fibers by using a self-made spinning machine. The surface morphology, strength, moisture regain, and antibacterial properties were evaluated, the regenerated fibers had a superior performance.

Next-Generation Cellulosic Filaments from Hemp Pulp via Dry-Jet Wet Spinning Using HighPerCell® Technology

Fiber demand of cellulosic fibers is rapidly increasing; however, these fibers are mainly based on the use of wood pulp (WP), which often have long transport times and, consequently, a high CO2 footprint. So, alternative pulps based on non-wood, annual fast-growing plants are an option to cover the demand for raw materials and resources. Herein, we report on the use of a novel developed hemp pulp (HP) for man-made cellulosic fiber filament spinning. Commercial WP was used as a reference material. While HP could be used and directly spun as received without any further pretreatment, an additional step to adjust the degree of polymerization (DP) was needed to use the wood pulp. Continuous filaments were spun using a novel dry-jet wet spinning (HighPerCell® process) technique, which is based on the use of 1-ethyl-3-methylimidazolium octanoate ([C2C1im][Oc]) as a solvent. Via this approach, several thousand meters (12,000 m–15,000 m) of continuous multifilament filaments were spun. The HP pulps showed excellent spinning performance. The novel approach allows the preparation of cellulosic fibers for either technical—with high tensile strength—or textile—possessing a low fibrillation tendency—applications. Textile hemp-based filaments were used for first weaving trials, resulting in a flawless fabric.

Soda pulping of sunn hemp (Crotalaria juncea L.) and its usage in molded pulp packaging

Petroleum-based materials are often used in the packaging industry. However, the single use value of such products can be problematic with regard to proper waste disposal. As such, molded pulp packaging can be used as an alternative, given its ease of recycling, composting, and eventual biodegradation. In this work, we aims to study the pulp properties of sunn hemp and its usage as molded pulp products. For this purpose, unbleached beaten and unbeaten soda pulps derived from the whole stem of sunn hemp were examined for their fiber morphology, fibrillation, fiber classification, and physical properties. The sunn hemp pulp was subsequently molded using a batch molding machine. To determine the hydrophobicity of the molded pulp products, the molded samples were manufactured with and without additives. Finally, some properties of the molded pulp products were examined and compared with the commercially available bleached bagasse molded pulp products. It was observed that the molded products made from sunn hemp pulp with additives had a higher water contact angle than that of the commercial products. In terms of general usage, the molded products from sunn hemp pulp with additives were found to be capable of storing hot water, hot cooking oil, as well as microwaving water. We concluded that the sunn hemp pulp could be used as an alternative fibrous raw material in the production of molded pulp packaging.

Comparative Characteristics of Hemp Nanocellulose Extracted by Different Methods

Abstract: The study describes the extraction of nanocellulose from organosolv hemp pulp (OHP) by different methods: acid hydrolysis, oxidation in the medium of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and in deep eutectic solvent (DES). OHP was obtained from renewable plant material - hemp fibers by extraction with NaOH solution and cooking using a mixture of acetic acid and hydrogen peroxide. SEM and FTIR data confirmed the reduction of cellulosic fibers and the removal of non-cellulosic components from hemp samples during their sequential thermochemical treatment. The data of X-ray structural and thermogravimetric analyzes confirmed that with increasing crystallinity index and resistance of cellulose-containing hemp samples to the influence of temperature, the obtained nanocelluloses are arranged in the following order: OHP – NCD – NCT – NCH. The values of physical and mechanical parameters of hemp nanocelluloses obtained by different methods are compared. It was established that with approximately the same values of the transverse size of hemp nanoparticles, nanocellulose obtained in the process of acid hydrolysis (NСH) has higher values of physical and mechanical parameters than nanocellulose obtained in TEMPO-medium (NCT) and in the DES (NCD).

Non-covalently cationized nanocellulose from hemp: Kinetics, key properties, and paper strengthening

Cationic cellulose, despite its long history, has yet to find a place in the paper industry. However, recent research is evaluating the potential of its nanoscale forms. Likewise, the processes of Western manufacturers are optimized for wood pulps, relegating non-wood crops to specific products that, as also proposed by current research, could include nanocellulose. We combined these trends with the existing knowledge of the strong adsorption of poly(diallyldimethylammonium chloride) (polyDADMAC) on cellulosic fibers, which can be deemed a non-covalent kind of cationization. For that, polyDADMAC was first anchored to refined hemp pulps, under conditions that allowed the deprotonation of the primary hydroxyl groups of cellulose. The fiber surface remained positively-charged even after thoroughly washing the samples, owing not only to the small proportions of acidic hemicelluloses and lignin, but also to stable ion-dipole interactions. This non-covalent cationization was found to follow pseudo-second order kinetics, indicating that diffusion through the fiber was the rate-controlling step. PolyDADMAC-containing fibers were then fibrillated by high-pressure homogenization. The surface charge of cationic nanocellulose was greater than that of the starting fibers, as the specific surface area increased. Nonetheless, polyDADMAC caused agglomeration of fibrils to a certain extent. As a drawback, when applied in papermaking, cationic nanocellulose lowered air permeability to a lesser extent than non-cationized nanofibers. As an advantage, the tensile index increased by up to 57% in the absence of any retention agent. • Adsorption of polyDADMAC to hemp pulp fibers follows pseudo-second order kinetics. • Both refining and fibrillation increase the absolute value of the surface charge. • Strong binding of polyDADMAC: ionic in alkaline media, ion-dipole after neutralization. • The resulting nanofibers improve paper strength without the need of retention aids.

Preparation of hemp nanocellulose and its use to improve the properties of paper for food packaging

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.

Organosolv Pulping of Hemp Stem for a Potential Papermaking Pulp

Glycol ether-based organosolv pulping process was applied to hemp stem to identify a possible sustainable source for papermaking. The hemp organosolv pulps were produced by controlling the content of glycol ether with water, ranging from 30% to 90% at a fixed cooking temperature, time, and acid catalyst. Hardwood bleached kraft pulp (HwBKP) was used as a reference. In this study, the hemp stem including the bast and core consisted of 33.9% of α-cellulose and 36.7% of hemicellulose. The length-weighted length of the organosolv hemp pulp was 0.5-0.8 mm, which was similar to HwBKP. Morphology of organosolv hemp pulps was fibrillated higher than the HwBKP, resulting in a high tensile index in handsheets. In addition, the air permeability of handsheets of the organosolv hemp pulps increased with the increase of the glycol ether contents in pulping conditions.

Study on the application properties of high hydrophobic paper yarn base paper

As a new kind of paper-based textile materials and thanks to its healthiness and environmental protection, the paper yarn and its production will have a good future. This study mainly explores the papermaking process as follows: the beating degree of hemp pulp is 75°SR, the addition amount of PVA fiber, polyamide polyamine epichlorohydrin (PAE) and alkenone dimer (AKD) is 2.0%, 2.5% and, 0.2%, respectively. In addition, the pressure light pressure is 15 N/mm. The high hydrophobic paper yarn base paper has the wear resistance, water resistance, acid and alkali resistance. The analysis shows that the paper yarn base paper can be used as raw material in textile and weaving industries, thus reducing the use of viscose, polyester, plastic, etc.

Ecofriendly and innovative processing of hemp hurds fibers for tissue and towel paper

An innovative approach for preparing hemp fibers from hemp hurds for use in tissue and towel grades of paper is described. Hemp hurds are a low value by-product of industrial hemp processing that are generally used for animal bed litter. Tissue paper was fabricated from hemp hurd fibers by following three pulping processes: autohydrolysis (hydrothermal), sodium carbonate-based defibration, and high yield kraft pulping, and benchmarked against hardwood pulp. To meet industrial standards, hardwood and hemp pulp fibers were mixed at a dry mass ratio of 75:25, from which tissue paper sheets were prepared. Desirable tissue paper properties, such as water absorption, burst resistance, softness, and tensile strength (dry and wet), were measured and compared. Characterization of morphological and chemical properties of tissue handsheets was conducted with SEM and time-of-flight-secondary ion mass spectrometry (ToF-SIMS). The combined kraft pulped hardwood and autohydrolyzed hemp pulp fibers displayed improvements in tensile index, burst resistance, and softness of tissue handsheets compared to only kraft hardwood pulp handsheets without adversely impacting water absorption. Hardwood fibers showed a sparse distribution of surface lignin compared to hemp fibers using the same defibration. This technology can lead to a variety of eco-friendly tissue paper products that are not only highly energy efficient, but avoid harsh chemical processing.

A Method for Producing Microcrystalline Cellulose from Hemp Fibers

Background. Obtaining from annually renewable plant raw materials, in particular from hemp fiber, microcrystalline cellulose (MCC), which is suitable for use in the chemical industry. Objective. The was aim of the paper is to develop a technology for obtaining MCC from hemp fibers to reduce the number of the technological process stages and to determine the optimum values of the main technological parameters of the chelating and hydrolysis processes of peracetic hemp pulp, in which the quality indicators of the obtained MCC will meet the requirements of regulatory documents. Methods. Peracetic cooking of hemp fibers was carried out at liquor to solid ratio 10: 1 and temperature of 90 ± 1 °C, ranging from 60 to 240 min. The process of chelating pulp by Trilon B was investigated at consumption from 5 to 30 % in acidic and alkaline environments. At the final stage of MCC preparation, the hemp pulp hydrolysis process was carried out by sulfate acid at its concentration of 0.5 to 2.0 %, liquor to solid ratio 15:1 and a temperature of 90 ± 1 °C for 90 min. The quality indices of the obtained microcrystalline cellulose were determined by standard methods. Results. The high efficiency of the peracetic method of pulp production from hemp fiber is shown. It has been experimentally proved that the chelating process of hemp pulp is expediently carried out in acid environment at a Trilon B consumption of 20 % from the the bone dry process weight. It is shown that the MCC can be obtained by the hydrolysis of peracetic hemp pulp with a solution of 1.5 % sulfuric acid at a temperature of 90 °С during 90 min that satisfies the requirements of regulatory documents. Conclusions. The proposed technology for the MCC production from hemp fibers reduces the cost of finished products by eliminating the bleaching stage of pulp as well as due to the use of domestic renewable plant raw materials, in particular hemp fibers compared with imported cotton or softwood pulp. The obtained MCC meets the requirements of technical conditions and can be used in the chemical industry as a sorbent or filler in the production of plastics and a water stabilizer for paints and emulsions.

Conversion of various types of lignocellulosic biomass to fermentable sugars using kraft pulping and enzymatic hydrolysis

The aim of this work was to assess the utility of seven different kraft pulps produced from softwood (pine), hardwood (poplar, birch and beech), wheat straw and hemp (bast and harl) as potential sources of sugar feedstocks for fermentation processes. The pulps contained low amounts of hemicelluloses (1.9–8.2% d.w.) and lignin (1.7–15% d.w.). The crystallinity index values ranged from 55% (wheat straw pulp) to 79% (hemp bast pulp), while the average DP varied from around 230 (hemp bast pulp) to 1482 (poplar and birch pulps). The results of enzymatic hydrolysis showed that not only the residual lignin content but also the cellulose crystallinity index decided on the sugar yields while the average polymerization degree had a weak impact. More reducing sugars were obtained from the hardwood pulps and wheat straw pulp (100% d.w.) than from the pine pulp (around 89% d.w.) and two hemp pulps (40.5% d.w. and 44.7% d.w. from the bast and harl pulps, respectively). Glucose was the dominating (69–79% w/w) soluble sugar in enzymatic hydrolysates of the pulps. The sugar profiles of these hydrolysates make them suitable sugar feedstocks for fermentation processes.

Manufacture of Specialty Paper with Hemp Bast Fiber Cultivated in Korea (Part 1)- Characteristics of Hemp-Wood Paper by Soda Pulping -

To conserve wood resources for papermaking, chemical compositions of the hemp (Cannabis sativa L.) bast fiber cultivated in Korea such as holocellulose, <TEX>${\alpha}$</TEX>-cellulose, lignin, alcohol-benzene extractives, hot and cold water extractives, and ash contents were investigated to manufacture the specialty packaging paper effectively. Significantly very low klason lignin content of 3.3% was accomplished by removing of the outer shell of bark. Laboratory soda pulping method which is very useful for the nonwood fiber was adapted, and it was found that there was no significant difference in both kappa number and H-factor between 25% and 30% NaOH charge. Hemp pulp cooked with the laboratory digester in 25% NaOH at <TEX>$170^{\circ}C$</TEX> were mixed together with the wood pulp(NBKP:LBKP=1:1) in order to find the optimum mixture ratio which exhibited acceptable paper strength properties such as tensile index, burst index, and tear strength. When 10% of hemp soda pulps was mixed with 90% of wood pulps comprised of SwBKP and HwBKP (1:1), all physical strength increased significantly. The physical strength decreased as the amount of hemp pulp increased because the cell wall of bast fiber is very thick which causes low conformability and low fiber-fiber bonding. These results showed that paper made of hemp-wood pulp can be used for the specialty packaging paper which requires both the characteristic surface properties and the high physical strength of hemp fiber.

The influence of exogenous fiber on the generation of carbonyl compounds in reconstituted tobacco sheet

In recent years, many efforts have been devoted to assessing the influence of saccharides on the toxicity of cigarette mainstream smoke. The primary goal of this paper was to investigate the influence of exogenous saccharides of hemp pulp (HP) and softwood pulp (SP) on the generation of carbonyl compounds (i.e., formaldehyde, acetaldehyde, acetone, acrolein, propanal, butenal, 2-butanone and butyraldehyde) in comparison with tobacco pulp (TP). The yields of carbonyl compounds in cigarette mainstream smoke of three reconstituted tobacco sheets (RTS) (TP-RTS, HP-RTS and SP-RTS) were studied under ISO standard smoking conditions. Thermogravimetric (TG) analysis and isothermal oxidative pyrolysis experiment in combination with high performance liquid chromatography (IOPy-HPLC) have been employed to indirectly investigate the influence of exogenous fiber on the generation of carbonyl compounds. The compositions of three fibers were analyzed by Ion chromatography (IC) and the monosaccharide was studied by IOPy-HPLC. Cigarette smoking results illustrated that, compared with TP-RTS, HP-RTS and SP-RTS generated significantly higher amounts of carbonyl compounds in cigarette mainstream smoke. TG results showed that the differences of thermal behavior between three RTS were mainly caused by the differences of three fibers. IOPy-HPLC results demonstrated that xylose (17.47mgg−1) generated significantly higher amount of carbonyl compounds than fructose (15.22mgg−1) and mannose (15.54mgg−1), and particularly than glucose (14.27mgg−1). Due to higher contents of xylose and lower contents of glucose, the exogenous fibers of HP and SP indeed generated higher amounts of carbonyl compounds than TP.

The effects of traditional hand-crumpling on the performance of Manila hemp paper

Hemp paper made from Manila hemp pulp was processed by a traditional Japanese hand-crumpling technique. The applicability of the hemp paper to clothing was examined. Hand-crumpling decreased the dry tensile index of the hemp paper but increased the seam strength index of the sewn hemp paper. A scanning electron microscope was used to observe a piece of hemp paper; the results showed that pulp fibers that were not hand-crumpled suffered brittle fracture without being elongated, while pulp fibers of hand-crumpled hemp paper were elongated and broken by ductile fracture. This implies that hand-crumpling inhibits cracks generated in the stitch from propagating and produces a high stitch strength index. The air permeability and water absorbency of the hemp paper were considerably increased by hand-crumpling. Hand-crumpling considerably improves the softness of Manila hemp paper and enhances its applicability as clothing material.

Study on Mainstream Smoke Characteristics and their Risks of Low Ignite Propensity Cigarettes

To learn differences and mainstream smoke (MSS) risks of between Low ignite propensity (LIP) cigarettes and the common, their MSS and 7 main harmful compounds in MSS are analyzed, and their MSS risks are also evaluated. The results indicate that: (1) It will improve yields of tar, nicotine, HCN and other main harmful compounds in MSS of the cigarette rolled with LIP cigarette paper replaced of common cigarette paper, and lead risks of their MSS to increase; (2) It is a way to reduce yields of some main harmful compounds and lower risks of their MSS risks of LIP cigarette paper with higher diffusion rate of flame retardant bar or higher original porosity; (3) The LIP cigarette paper produced by hemp pulp rather than wood pulp can also reduce appropriately yields of NH3, CO and other harmful compounds and lower their MSS risks of the LIP cigarettes.

Impact of xylanase pretreatment on peroxide bleaching stage of hemp pulp

Pretreatment of hemp pulp with xylanase was investigated. Unbleached hemp pulp was treated with commercial xylanase, and then bleached with hydrogen peroxide. Control pulp bleached with out xylanase was compared with xylanase bleached pulp. Application of xylanase was found to have a positive effect on followed peroxide stage in terms of low kappa number and high brightness of pulp.

Combination treatment of kenaf bast fiber for high viscosity pulp

The viscosity of kenaf bast fiber has been found to be highly sensitive and variable with different pulping methods; therefore, it is important to choose proper chemicals and conditions for pulping and bleaching of kenaf bast fiber. From several pulping experiments, a nonconventional pulping method with a combination of ammonium oxalate pretreatment followed by soda pulping at normal pressure and then acidic chlorite delignification was developed to obtain high-viscosity pulp (162 centipoise). The optimum level of alkali dosage of soda pulping for high-viscosity pulp was found to be 15% (on pulp as NaOH). Pulps showed linear relations between viscosity and xylose or glucose contents, but the combination pulping method gave extremely high pulp viscosity, beyond the relations. The highest viscosity pulp from kenaf bast fiber demonstrated a tear index about twofold and a folding endurance 6.2-fold higher than those of Manila hemp pulp with comparable tensile and burst indexes. The high-viscosity pulp could be used in the production of high-quality currency paper or longevity paper for special uses.

Load-Elongation Behavior of Fiber-Oriented Manila Hemp Sheets.

Fully restrained fiber-oriented sheets, machine-made paper, and handmade sheet by the standard method were prepared from Manila hemp pulp. Strain-to-failure of the fiber-oriented sheets was almost the same in both the machine (MD) and the cross machine (CD) directions, while a distinct direction-dependence was observed in the machine-made paper. This indicates that a degree of fiber orientation of paper is not a dominant factor controlling strain at break. Furthermore, dried-in shrinkage in CD of the machine-made paper can be simply estimated by comparison of strain-to-failure of this paper with that of the fully restrained fiber-oriented sheet or the handmade sheet prepared. Uneven profile of strain-to-failure in CD of the machine-made paper is observed over the width direction. This profile may possibly be explained by analogy of the geometrical and mechanical conditions of the wet web at the dryer pocket with those of the short span thin body. Notable acoustic emission (AE) from the specimens sampled from both edge and center of the dried web in the elongation test was not observed except at the final stage of plastic region. The result indicates that difference of strain-to-failure between them is attributed to a different degree of dried-in shrinkage since structural breakage like bond failure or fiber breakage which may happen in plastic deformation causes emission of elastic wave.