Office paper recyclability: first recycling

Recyclability is the ability of a material to reacquire the same properties it had originally. The aim of this work was to verify the recyclability of three printing and writing papers, from the characteristics of their fibers after two recycles. Three ECF bleached kraft eucalyptus bond commercial papers from Argentina and Brazil were studied (A, B, C). The papers were repulped and refined using different levels and intensities of energy (1st recycle). Laboratory sheets were produced, and they were repulped and refined again (2nd recycle). The microscopic characteristics of repulped papers were obtained by authomatic equipment based on image analysis. Differences found in the behavior of the different samples can be explained by fiber parameters. The fiber length was significantly different in the three papers (A> B> C) and globally decreased in the second recycle (about 6%). Sample A had the highest initial fiber length and length/width, but it largely decreased with refining...

Fibres and Textiles in Eastern Europe, 2012

The effectiveness of two regeneration methods (i.e. improvement of the papermaking potential) for five different grades of recycled fibres was investigated in present work. In the first method, only the refining operation was used, and in the second, removal of fines and subsequent refining were applied. The dewatering ability of every regenerated pulp (measured by the SR test) and basic strength properties of papers made from these pulps were tested. The results show that it was possible to increase the papermaking potential of all pulps tested; however, higher effectiveness was achieved when the removal of fines was followed by the refining operation. Further analysis of the results also indicates that recycled pulp grades based on kraft paper have sufficiently high papermaking potential, and in many cases they do not need additional regeneration. Pulp regeneration is strongly recommended in the case of pulps based on LWC, SC and Newsprint papers. Experiments have also proved that the selection of an optimal method for improved papermaking potential always has an individual character, and the method always has to be adjusted to a specific pulp grade and the paper grade made from it.

Cellulose Chemistry and Technology

Statistical data show that further increase of recovered paper (RP) supply to European paper mills could come mainly from increasing and improving household collection. However, it is generally accepted that an extended collection from household is always detrimental to RP quality. Low quality of recovered paper is due to the high content of unusable materials consisting of non-paper components and unwanted paper and board (paper and board not according with RP grade definition). In this paper, the effects of unwanted paper and board (p& b) on recycled pulp properties are analysed for RP grades 1.11 and 1.04, which are originated of household collection. In the case of deinking RP grade 1.11, it was shown that even a low content (3-5%) of brown packaging p& b affects strongly the optical properties of deinked pulp, by decreasing brightness and increasing the number and size of specks due to brown fibres flakes. In case of packaging RP grade 1.04, increasing content of graphic paper results in lower freeness, higher contents of ash and short fibres, and lower mechanical strength of recycled pulp.

Procedia Engineering, 2015

In accordance with environmental sustainability and in order to optimize the recycling process of prints from indirect electrophotography with liquid toner the results of investigating the effects of changes in printing conditions on the characteristics of recycled fibres is presented. Changing of printing machine conditions, respecting of voltage variations, comprises of the reverse rollers and intermediate cylinder. Based on the results it can be concluded that the change in the voltage of the reverse rollers more affect the recycling efficiency with respect to the voltage change of the intermediate cylinder. Brightness gain is higher when the print for recycling is made on uncoated paper compared to coated, and dependent on the voltage changes. Effective residual ink concentration decreases far more on handsheets obtained from recycled samples on uncoated paper in relation to both sides coated paper. Increasing the positive voltage of intermediate cylinder and increasing the negative charge of reverse rollers increases the 3 D gamut CIE L*a*b* color cubic units. Guidelines for the size of the voltage in order to obtain optimal print reproduction are provided. The further research will include the development in area of clean technologies, advanced materials, closed loop systems; therefore the significant terms in the area of environmental sustainability.

Cellulose

The degradation of paper-based materials involves several and complex mechanisms, such as hydrolysis and oxidation. The behaviour of different types of pulps can be very variable. In this study, the difference upon oxidation of contemporary non-recycled and recycled papers, which now constitute a considerable fibre source, is investigated. A 0.015 M potassium periodate solution is used to oxidise five types of paper, two non-recycled and three recycled, for 0.5, 1, 2 and 4 h. The effects of such oxidation treatments are evaluated in terms of carbonyl content and degree of polymerisation (DP). A modified procedure of the Szabolcs’s method and viscometry are used to measure the carbonyl content and DP, respectively. The carbonyl groups are found to increase more rapidly in the recycled papers than in the non-recycled ones. On the contrary, oxidation causes a larger decrease of the DP values in the non-recycled papers, the paper made of pure cellulose being the most sensitive in terms ...

As the demand for materials continues to grow and the supply of natural resources continues to dwindle, recycling of materials has become more important in order to ensure sustainability. However, many materials can only be recycled a limited number of times due to physical degradation (paper and board), chemical degradation (plastics), or the presence of impurities (metals). This paper presents a review of solid recycling, focusing on the technology for paper recycling. It describes studies on pulp and paper recycling in five problem areas: paper and fiber sorting technologies, deinking and contaminant removal, pulp bleaching technologies, restoration of papermaking properties of recycled fibers, and performance characteristics of recycled paper. During the past two decades, numerous studies have been conducted on the potential of papermaking from recycled fibers. Most studies have shown that the strength properties of fibers and paper are reduced upon recycling. Recycled pulp is an important component of many paper products. Over 50 grades of waste paper have been identified. As a result, most waste paper has to be sorted, graded and baled before going to paper mills. The quality of the waste determines the end quality of the recycled paper. Mixing all these different type of quality paper will reduce the purity of the highest quality fibre. The recovered paper may contain fibers which may have been recycled once, twice, or perhaps several times. Wood fibers can only be recycled five to seven times before they become too short and brittle to be made into new paper. Previous studies showed two basic approaches to improve the properties of recycled pulp. In summary, the effect of recycling on pulp strength properties is a complicated process.

Journal of Oleo Science, 2021

system. USA and Japan are recycling several tens of million tons of recovered papers (generally refers to the used paper re-covered for use as raw material) to manufacture the new paper and paperboard 4) . Recycling involves collecting and separating waste materials and remanufacturing or converting them into new reusable materials. Almost everything around us can be recycled or necessary functional materials can be prepared from waste. For example, nanoporous activated carbon materials have been successfully fabricated from agricultural lignocellulosic wastes and explored in high energystorage supercapacitor as well as water purification applications . Cellulose, which is mostly used in the paper industry, is one of the essential components of the lignocellulosic agro-wastes suggesting that used or waste papers would be the valuable reusable source that can be recycled Abstract: Recycling technology contributes to sustainability and has received considerable interest in fulfilling consumable products' social demands, including papers. Recycled fibers are the primary source of the papermaking industry. Papers, valuable daily used materials, can be further recycled for further implementation. Here, we report a simple method for recycling waste papers for further use. Our method includes re-pulping, deinking, bleaching, and papermaking. The sample and the recycled papers were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). XRD data shows the presence of cellulose and filler minerals in the sample and the recycled papers. FTIR analysis confirmed the presence of hydroxyl, carbonyl, and methyl functional groups in the recycled papers suggesting that the deinking and bleaching did not cause any structural changes. The fibrous structures were also sustained after recycling, as confirmed by SEM studies demonstrating that the recycling was successful and the papers can be further used and recycled. EDS analysis further confirmed the filler minerals in the sample paper with a trace amount of lead, which decreased upon bleaching the paper. The structure and properties of the sample and the recycled papers were quite similar, inferring that waste papers can be recycled again and different products from low to higher grade papers can be fabricated.

Paper recycling is the process of turning waste paper into new paper products such as newspaper, corrugated boxes, tissue products and egg boxes. Thermomechanical pulp (TMP) and chemi-thermomechanical pulp (CTMP) were also used in the manufacture of newspaper, lightweight coated and sanitary papers. The aim of this study is to produce newspapers from waste papers. For this reason, waste papers were bleached in 3 stages which were oxygen, hydrogen peroxide and sodium dithionite bleaching. Optical and physical properties of bleached waste papers were determined and compare with CTMP newspaper. So that in an increase of brightness of bleached pulps with three-stage from 31.32 (%) to 50.14% elrepho and in a decrease of yellowness from 34.89% to 33.50% elrepho. Brightness, yellowness and opacity of bleached waste papers' pulps were found higher than those of unbleached waste papers' pulps. Waste papers' pulps bleached by hydrogen peroxide can be used in the production of newspapers.

Journal of Oil Palm Research, 2003

The effects of blending oil palm empty fruit bunch (EFB) pulp with recycled papers on the paper properties were studied. The EFB was pulped by the soda-anthraquinone process. Laboratory papers were made by blending the unbleached EFB pulp with old carton board (OCB), copier paper (OCP) and newspaper (ONP) at ratios of 25%, 50% and 75%. The structural, mechanical and optical properties of these papers were measured and compared to unblended recycled papers. The paper properties were considerably affected by incorporation of the EFB pulp. The changes on the properties varied, depending on the particular property, level of pulp incorporation and the type of recycled paper used. ONP has the highest degree of change and OCB has the lowest degree of change. OCB, OCP and ONP have the highest tensile index when incorporated 25%, 75% and 75% of EFB pulp respectively. OCB, OCP and ONP have the highest burst index when incorporated 75% of EFB pulp. OCB, OCP and ONP have the highest tear index when incorporated 25%, 75% and 25% of EFB pulp respectively. OCB, OCP and ONP have the highest folding endurance when incorporated 75% of EFB pulp respectively. The best blend for OCB is 25% of EFB pulp and for OCP and ONP is 75% of EFB pulp. The EFB soda-AQ pulp can be used to enhance the structural and mechanical properties of recycled paper.

2014

Waste materials of environmental risks, costly landfill disposal can be utilized in cement and concrete applications. Partial replacement of cement in engineering projects reduces the cost of construction with ecological benefits. The type and mix ratio affects the strength and workability of cement-concrete matrices. This research deals with the replacement of Class F fly ash and kaolin with cement used in concrete. Replacement of 10% fly ash with cement improves the comprehensive strength of concrete in 28 days period, and the workability is increased by 53.8%. The kaolin replacement reduced both the strength and workability of concrete.