Ground Calcium Carbonate Research Articles

Study on the mechanism of waterborne polyurethane modified ultrafine ground calcium carbonate and its properties in polypropylene plastics

AbstractGround calcium carbonate (GCC) has the effect of reducing the incremental cost and improving the application performance as a plastic filler. In this study, waterborne polyurethane (WPU) was employed as a novel modifier for the wet modification of GCC. Polypropylene (PP)‐based composites incorporating GCC were then prepared for mechanical properties testing. The oil absorption value, wetting contact angle, and settling time in kerosene indicated that the modified GCC achieved an excellent modification effect with a WPU dosage of 2.0 wt%. The X‐ray Diffraction, Fourier Transform Infrared Spectroscopy, and X‐ray Photoelectron Spectroscopy results indicate that WPU was successfully coated on the surface of the GCC. SEM images revealed improved wettability and compatibility of GCC in the composites after modification. The mechanical tests showed that the GCC‐WPU/PP composites exhibited enhanced properties, including a flexural strength of 107 MPa, impact strength of 9.54 kJ/m2, tensile strength of 29.7 MPa, and an elongation at break of 30.9%.Highlights WPU was innovatively used as a modifier of GCC. An optimal modification effect was gained at the low dosage (2.0 wt%). GCC has excellent compatibility and wettability in PP composites. The obtained PP‐based composites have better mechanical properties. The study has the potential to apply GCC in plastics and other industries.

Valorization of food processing waste: Utilization of pistachio shell as a renewable papermaking filler for paperboard

Valorization of non-edible parts of food is an important method of reducing food processing waste. This study presents a potential application of nutshell wastes as a renewable and organic papermaking filler in paperboard packaging. Five pistachio shells particle (PSP) samples with different particle size distributions were prepared and their performance as a papermaking filler was examined relative to a conventional ground calcium carbonate (GCC) mineral filler. PSP fillers dispersed well in aqueous suspensions and showed better retention in handsheets compared to that of GCC, due to the improved retention by the larger particle sizes of PSPs. When PSP fillers had smaller particles than the pore sizes in the paper fiber network and their particle size distribution were narrow, they showed comparable mechanical properties in handsheets compared to that of GCC. Future research is suggested for successful applications of this organic and renewable filler in papermaking.

Effect of pressure and time on water absorption of coated paperboard based on a modified Cobb test method

This manuscript presents the study of water absorption by paperboard subjected to water at high hydrostatic pressure based on a modified Cobb tester. The new tester is based on TAPPI Standard Test Method T 441; however, the water column can reach up to 550 mm. The evaluation consisted of measurements of water absorption for coated and uncoated paperboard at different exposure times from 5 s to 45 s and water column heights from 10 mm to 500 mm (corresponding to hydrostatic pressures 98 Pa and 4.9 kPa, respectively). The coatings were formulated as a combination of styrene acrylate (SA; two binder levels) and two types of ground calcium carbonates (differing particle sizes) to form the two pre-coating structures: open and closed. The coating weight was 6 g/m2 applied on 210 g/m2 solid bleached board (SBB). In addition, 210 g/m2 uncoated boards were studied. Characterization of the coatings was performed with scanning electron microscopy (SEM), mercury intrusion, and roughness. It was found that the new device properly mimics the conditions of the current Cobb tester. The characterization of the coating also confirmed the presence of more open/larger pores of open coatings, confirming the desired coating structure. The absorption of boards was mainly driven by exposure pressure by comparing with exposure time. This was already evident after shorter periods of exposure time at 5 s and also 15 s exposure time. Paperboards with open coatings showed slightly higher absorption than other boards.

Mechanical and environmental evaluation of ground calcium carbonate (CaCO3) filled polypropylene composites as a sustainable alternative to virgin polypropylene

Polypropylene (PP) has raised environmental concerns particularly for its depletion of fossil-fuels and contribution to climate change. To lower environmental impacts, PP can be combined with biobased fillers such as calcium carbonate (CaCO3). The mechanical and environmental properties of CaCO3 filled PP have not yet been explored in depth. Therefore, this study examines the aesthetic, tensile, flexural, impact, and environmental (via life cycle assessment) properties of injection moulded CaCO3 filled PP with filler content ranging from 0% to 40% at 5% increments. As filler percentage increased, yield strength decreased (0% CaCO3: 17.68 MPa, 40% CaCO3: 12.73 MPa), but young's modulus, flexural modulus, and impact strength increased (respectively 69%, 51%, and 35% greater than pure PP). Flexural strength increased initially at 5% CaCO3 but then declined as more filler was added. A yellowish hue was observed within all blends which growed stronger with more filler. The addition of CaCO3 reduced the environmental impact for all 11 impact categories. For every 5% of CaCO3 added, the material's global warming potential (GWP) decreased by 100g CO2 eq. per functional unit (1000 cm3) of composite. Abiotic depletion of fossil fuels declined by 32% when 40% CaCO3 was added. In addition to this study, it would be beneficial to explore other factors that affect the properties of CaCO3 filled PP such as particle size, particle distribution, and binding additives.

Stearate-Coated Biogenic Calcium Carbonate from Waste Seashells: A Sustainable Plastic Filler.

Waste seashells from aquaculture are a massive source of biogenic calcium carbonate (bCC) that can be a potential substitute for ground calcium carbonate and precipitated calcium carbonate. These last materials find several applications in industry after a surface coating with hydrophobic molecules, with stearate as the most used. Here, we investigate for the first time the capability of aqueous stearate dispersions to coat bCC powders from seashells of market-relevant mollusc aquaculture species, namely the oyster Crassostrea gigas, the scallop Pecten jacobaeus, and the clam Chamelea gallina. The chemical-physical features of bCC were extensively characterized by different analytical techniques. The results of stearate adsorption experiments showed that the oyster shell powder, which is the bCC with a higher content of the organic matrix, showed the highest adsorption capability (about 23 wt % compared to 10 wt % of geogenic calcite). These results agree with the mechanism proposed in the literature in which stearate adsorption mainly involves the formation of calcium stearate micelles in the dispersion before the physical adsorption. The coated bCC from oyster shells was also tested as fillers in an ethylene vinyl acetate compound used for the preparation of shoe soles. The obtained compound showed better mechanical performance than the one prepared using ground calcium. In conclusion, we can state that bCC can replace ground and precipitated calcium carbonate and has a higher stearate adsorbing capability. Moreover, they represent an environmentally friendly and sustainable source of calcium carbonate that organisms produce by high biological control over composition, polymorphism, and crystal texture. These features can be exploited for applications in fields where calcium carbonate with selected features is required.

THE EFFECT OF SHRINKAGE CONTACT STRESSES ON THE ADHESION STRENGTH OF THE WATERPROOFING COMPOSITION AND THE «OLD» CONCRETE

The paper is devoted to the study of the effect of shrinkage contact stress on the bonding strength of the waterproofing composition of fine-grained cement concrete and «old" concrete. In order to obtain a strong contact when adhering old and new concrete, it is necessary to minimize the amount of internal stress in it. The cause of concrete shrinkage during the initial curing period is the reduction of the cement stone gel, the amount of free water that is consumed by evaporation and hydration of the cement. The semi-bound water (film water) surrounding the gel particles is then consumed. This causes the gel particles to come closer together and shrink further. In addition, the capillary pressure in the pores is very significant and increases with decreasing pore size. Since the micropores are scattered in the cement stone in different directions, the pressure, balancing each other, acts as a comprehensive compression, which also causes volumetric deformation. With further drying of the concrete, the moisture gradient decreases, the growing crystal growths provide more and more resistance to internal pressure and the shrinkage deformation gradually subsides. Thus, the more intensive the hydration processes in the waterproofing coating and the more crystalline hydrates are formed at earlier curing times, the earlier the resistance to comprehensive compression in the coating will be, and as a result, the crack resistance of the coating and the strength of its adhesion to the «old» concrete will increase. As a result of the research carried out in this work, it was found that the compaction of the waterproofing composition, which helps to reduce internal stresses during curing and thus increases the amount of its adhesion to old concrete, is achieved by introducing a finely ground calcium carbonate filler and a complex of chemical water-soluble additives of the second class. The mineral filler and chemical additives allow for the additional synthesis of etringite, calcium hydrocarbonate and calcium hydrochloraluminate, low-base calcium hydrosilicates, and calcite during cement hydration in its pores and capillaries. The developed permeable waterproofing composition in the form of a mortar has high adhesion strength to old concrete and can be used in repair, restoration and protection of building structures, buildings and structures from external influences related to the water environment.

Impact of different calendering strategies on barrier coating pickup

Paper was pre-calendered in a pilot scale configuration with a traditional soft nip calender and a metal belt calender. All calendering strategies reduced surface roughness and permeability of the samples, but different strategies affected the surface roughness and permeability differently. The metal belt calender seemed to have a larger effect on the large-scale variations compared to the soft nip calender. Six test points from the pilot calendered papers were chosen for laboratory coating studies. Uncalendered paper was included as reference samples. The calendered samples and the reference were pre-coated with a regular pigmented coating consisting of a ground calcium carbonate (GCC) pigment and a styrene acrylate (SA) latex. Both uncoated and pre-coated substrates were barrier coated with a polyvinyl alcohol (PVOH) in one and two layers. The coating pickup was determined gravimetrically, and the barrier properties were evaluated with TAPPI Standard Test Method T 454 grease resistance test. All samples needed two PVOH coating layers to form a grease barrier. The uncalendered sheets showed the best results with one coating layer, but this was at the expense of a higher coating pickup compared to the calendered sheets. The barrier coating pickup could be reduced by a combination of high temperature metal belt calendering and pre-coating. The high temperature and long residence time in the nip enabled plasticization of the fibers. This led to an irreversible deformation, even after water application. This meant that the smoothness obtained during calendering would be less affected by water-induced roughening during the coating operation.

Multifunctional barrier coating systems created by multilayer curtain coating

Functional coatings are applied to paper and paperboard substrates to provide resistance, or a barrier, against media such as oil and grease, water, water vapor, and oxygen, for applications such as food packaging, food service, and other non-food packaging. Today, there is increasing interest in developing recyclable and more sustainable approaches for producing these types of packages. This paper focuses on water-based barrier coatings (WBBC) for oil and grease resistance (OGR), water, moisture vapor transmission rate (MVTR), and oxygen barrier performance. The main goal is to create coated systems that can achieve more than one barrier property using multilayer curtain coating (MLCC) in a single application step. One advantage is in optimizing coating material cost with the use of functional chemistry in confined layers where performance is balanced within the coating layered structure. This allows simultaneous application of layers of different polymer types in one step to achieve the appropriate performance needs for a given barrier application. This paper provides working examples of using MLCC to create coating structures with multiple barrier properties in a single application pass. Barrier polymers studied include styrene butadiene, styrene acrylate, starch-containing emulsions, and polyvinyl alcohol. The paper also shows the effect of increasing the pigment volume concentration with platy clay or fine ground calcium carbonate on MVTR and OGR barrier properties.

Effect Of Increased Coating Weight on Print Characteristics of Various Paper Stocks

The research delved into the collective impact of calendaring and coat weight on the optical, surface, and printing characteristics of coated papers. K control bar coater was employed to apply coatings containing blends of paper coating pigments—Ground Calcium Carbonate (GCC), clay, and Precipitated Calcium Carbonate (PCC)—in ratios of 60:40:00 and 60:00:40, while maintaining a constant amount of additives. Various calendaring roll nips were utilized to examine how calendaring affected papers coated with different pigment blends. The findings revealed that coatings with PCC exhibited heightened bulk and opacity. Sheets with PCC displayed greater brightness compared to those with clay. While the gloss improvement effect was somewhat less pronounced in PCC coatings compared to clay, the impact of calendaring on ink holdout and paper surface strength was minor, yet more favorable for coatings containing PCC. Notably, a significant enhancement in print gloss was observed with higher proportions of PCC in the paper coating. Additionally, increasing coating weight contributed to the augmentation of desired properties.

The RSM-Based Optimization of Recycled Polypropylene Fiber Reinforced and Ground Calcium Carbonate Incorporated Roller Compacted Concrete for Pavement

The RSM-Based Optimization of Recycled Polypropylene Fiber Reinforced and Ground Calcium Carbonate Incorporated Roller Compacted Concrete for Pavement

Brazil, India & China: MTI – precipitated & ground calcium carbonate

Brazil, India & China: MTI – precipitated & ground calcium carbonate

Enhanced Water Absorbency and Water Retention Rate for Superabsorbent Polymer via Porous Calcium Carbonate Crosslinking.

To improve the water absorbency and water-retention rate of superabsorbent materials, a porous calcium carbonate composite superabsorbent polymer (PCC/PAA) was prepared by copolymerization of acrylic acid and porous calcium carbonate prepared from ground calcium carbonate. The results showed that the binding energies of C-O and C=O in the O 1s profile of PCC/PAA had 0.2 eV and 0.1-0.7 eV redshifts, respectively, and the bonding of -COO- groups on the surface of the porous calcium carbonate led to an increase in the binding energy of O 1s. Furthermore, the porous calcium carbonate chelates with the -COO- group in acrylic acid through the surface Ca2+ site to form multidirectional crosslinking points, which would increase the flexibility of the crosslinking network and promote the formation of pores inside the PCC/PAA to improve the water storage space. The water absorbency of PCC/PAA with 2 wt% porous calcium carbonate in deionized water and 0.9 wt% NaCl water solution increased from 540 g/g and 60 g/g to 935 g/g and 80 g/g, respectively. In addition, since the chemical crosslinker N,N'-methylene bisacrylamide is used in the polymerization process of PCC/PAA, N,N'-methylene bisacrylamide and porous calcium carbonate enhance the stability of the PCC/PAA crosslinking network by double-crosslinking with a polyacrylic acid chain, resulting in the crosslinking network of PCC/PAA not being destroyed after water absorption saturation. Therefore, PCC/PAA with 2 wt% porous calcium carbonate improved the water-retention rate by 244% after 5 h at 60 °C, and the compressive strength was approximately five-times that of the superabsorbent without porous calcium carbonate.

Application of polysaccharide based modified ground calcium carbonate in wet‐end of papermaking

AbstractTo enhance the ash in paper without reducing its strength property, ground calcium carbonate (GCC) filler was modified using polysaccharide prior to its addition at wet‐end of papermaking. Till now, modification of GCC filler using chitosan acetate (CH.A) is not explored. The novelty lies in showing the effect of CH.A as GCC filler modifier and its application in papermaking. The results showed that ash of paper get increased by around 18%, 53% and 63% after adding GCC modified using cationic starch (C.S) @ 20 kg/t of GCC, CH.A @ 5 kg/t of GCC and CH.A @ 10 kg/t of GCC respectively, in comparison to that attained by paper using unmodified GCC at the same dose at wet‐end of papermaking. The breaking length, burst factor and tear factor of paper having 11% ash (made using unmodified GCC) was found to be 2485 m, 21.73 and 47.63, respectively. The paper having 18% ash (made using GCC modified by CH.A 10 kg/t of GCC) showed breaking length, burst factor and tear factor as 2364 m, 22.24 and 46.72, respectively. This approach of using CH.A in papermaking will help the papermaker to improve profit and quality of paper.

Physico‐chemical characterization and degradation analysis of mineral paper: Impact of accelerated weathering and aerobic biodegradation

AbstractMineral paper, a synthetic paper‐like material primarily composed of ground calcium carbonate (CaCO3) and a small amount of high‐density polyethylene (HDPE), has emerged as an important alternative to traditional paper and board due to the increasing demand for pulp and paper and the shortage of trees and fibrous material in many regions worldwide. This study aimed to investigate the impact of accelerated weathering and aerobic biodegradation on three different types of mineral papers. The specimens underwent 1000 h of accelerated weathering using a Gardner weathering device and were also buried in soil at a depth of 5 cm for 3 months with regular watering conditions for biodegradability testing. Physico‐chemical characterizations such as optical (whiteness), surface (roughness, contact angle, and paper topography), and chemical properties of the samples were studied before and after the artificial weathering and biodegradation tests. The results revealed a visible color change (darkening) in mineral papers, with an increase in HDPE content leading to a darker color after weathering and biological degradation. However, there were no significant differences in the color change between weathering and soil‐burial tests. The biodegradability test resulted in a decrease in ash content due to the demineralization process. All samples' surface roughness was reduced after weathering and biodegradation tests. The FT‐IR and EDS analyses confirmed the presence of calcium, carbon, and oxygen elements in all three samples, indicating a large amount of calcium carbonate in the mineral papers. The scanning electron microscopy (SEM) images showed the creation of micro holes and cracks on the surface of the samples after weathering and biodegradation. Overall, the soil‐burial test showed more degradation than the weathering test.Highlights The influence of weathering and biodegradation of mineral papers were studied After soil‐burial test, the ash content decreased due to the demineralization After weathering, micro cracks were created on the surface of the samples The degradation of the soil‐burial test was more than the weathering test Mineral papers most likely contain carbonate calcium and HDPE

Toward net zero carbon for concrete and mortar: Clinker substitution with ground calcium carbonate

The industry is responsible for 65% of greenhouse emissions, contributing to dramatic and irreversible climate changes. Among all the industries, construction is the most carbon and material demanding. Therefore, short- and long-term solutions should be quickly found to reduce both materials needed and their carbon footprint. With more than 20 GT produced per year, concrete and mortar are the most used construction materials. Even if they have a low carbon footprint compared to steel, glass, or wood, their massive volume consumption generates more than 3 GT of carbon dioxide annually. This paper exposes how to reduce the carbon-intensive clinker by up to 75% by substituting two different grades of Ground Calcium Carbonate (GCC), reaching the 50% carbon emission reduction target of the Paris climate agreement. As an alternative to the still limited resources of conventional Supplementary Cementitious Materials (SCMs), using different grades of GCC reduces the water needed and, therefore, the clinker required for a specific strength. We demonstrate that this reduces the carbon footprint by up to 50% for concrete and mortar with similar mechanical properties. A theory is proposed, linking materials' strength and relative porosity, giving an excellent relation and explaining the impact of the clinker substitution with GCC. Ecological concretes and mortars with improved performances could then be obtained, demonstrating a possibility of reducing in the short term 50% of the carbon emission of concrete and mortar by using broadly available grades of low carbon footprint Ground Calcium Carbonate.

Biodegradable Cellulose/Polycaprolactone/Keratin/Calcium Carbonate Mulch Films Prepared in Imidazolium-Based Ionic Liquid.

Ionic liquid 1-butyl-3-methylimidazolium chloride [BMIM][Cl] was used to prepare cellulose (CELL), cellulose/polycaprolactone (CELL/PCL), cellulose/polycaprolactone/keratin (CELL/PCL/KER), and cellulose/polycaprolactone/keratin/ground calcium carbonate (CELL/PCL/KER/GCC) biodegradable mulch films. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy, optical microscopy, and Field-Emission Scanning Electron Microscopy (FE-SEM) were used to verify the films' surface chemistry and morphology. Mulch film made of only cellulose regenerated from ionic liquid solution exhibited the highest tensile strength (75.3 ± 2.1 MPa) and modulus of elasticity of 944.4 ± 2.0 MPa. Among samples containing PCL, CELL/PCL/KER/GCC is characterized by the highest tensile strength (15.8 ± 0.4 MPa) and modulus of elasticity (687.5 ± 16.6 MPa). The film's breaking strain decreased for all samples containing PCL upon the addition of KER and KER/GCC. The melting temperature of pure PCL is 62.3 °C, whereas that of CELL/PCL film has a slight tendency for melting point depression (61.0 °C), which is a characteristic of partially miscible polymer blends. Furthermore, Differential Scanning Calorimetry (DSC) analysis revealed that the addition of KER or KER/GCC to CELL/PCL films resulted in an increment in melting temperature from 61.0 to 62.6 and 68.9 °C and an improvement in sample crystallinity by 2.2 and 3.0 times, respectively. The light transmittance of all studied samples was greater than 60%. The reported method for mulch film preparation is green and recyclable ([BMIM][Cl] can be recovered), and the inclusion of KER derived by extraction from waste chicken feathers enables conversion to organic biofertilizer. The findings of this study contribute to sustainable agriculture by providing nutrients that enhance the growth rate of plants, and hence food production, while reducing environmental pressure. The addition of GCC furthermore provides a source of Ca2+ for plant micronutrition and a supplementary control of soil pH.

Improving the Optical Properties and Filler Content of White Top Testliners by Using a Size Press.

This study aims to investigate the impact of coating with ground calcium carbonate (GCC) on the optical properties and filler content of white top testliner (WTT) papers. The paper properties investigated include brightness, whiteness, opacity, color coordinates, and yellowness. The results showed that the amount of filler mineral used in the coating process significantly affected the optical properties of the paper. The use of 15% total solids of GCC in the coating suspension resulted in the highest level of whiteness and improved the brightness value by 6.8%. The use of 7% total solids of starch and 15% total solids of GCC reduced the yellowness index by 85%. However, the use of only 7 and 10% total solids of starch had an adverse effect on the yellowness values. The surface treatment led to a significant increase in the filler content of the papers, with a maximum of 23.8% achieved using a coating suspension with 10% total solids of starch solution, 15% total solids of GCC suspension, and 1% dispersant. The starch and GCC in the coating suspension were found to have a direct impact on the filler content of the WTT papers. The addition of a dispersant improved the uniform distribution of the filler minerals and increased the filler content of the WTT. The water resistance of WTT papers increases due to the use of GCC, while their surface strength remains at an acceptable level. The study demonstrates the potential benefits of the surface treatment in terms of cost savings and provides valuable information on the impact of the treatment on the properties of WTT papers.

Modified ground calcium carbonate mineral powder using in asphalt concrete: modification mechanism characterization at macro and micro levels

The study investigated the modification mechanism of modified ground calcium carbonate (GCC) mineral powder using in asphalt concrete. Two types of Titanate coupling agents, namely, K38S (TCA-K38S) and 201 (TCA-201), as well as sodium stearate coupling agent, were adopted to prepare modified GCC. The optimized preparation process was obtained through the orthogonal test. Two kinds of modified GCC were preferably selected to prepare asphalt concrete according to modification mechanism characterization, their performance was analyzed and evaluated at macro and micro levels. The study results show that, the optimal scheme of sodium stearate modified GCC is modification temperature of 80°C, modification time of 50 min, modifying agent dosage of 2.0%. The crystal structure of GCC remains unchanged after modification, with the original lattice structure being maintained. TCA-201 and sodium stearate exhibit better coating properties than that of TCA-K38S. The contact angles of TCA-201 and sodium stearate modified GCC are larger than that of TCA-K38S modified GCC. The in-service performance of AC-13C asphalt concrete modified with sodium stearate is found to be superior to that of TCA-201 modified AC-13C asphalt concrete. Compared with the unmodified AC-13C asphalt concrete, the Marshall modulus, residual stability, freeze-thaw splitting strength ratio, and maximum flexural tensile strain of sodium stearate modified AC-13C asphalt concrete are increased by 54.55%, 2.73%, 10.47%, and 26.41% respectively. This paper provides theoretical guidance for the application of GCC mineral powder in asphalt concrete.

Preparation of Flexible Calcium Carbonate by In Situ Carbonation of the Chitin Fibrils and Its Use for Producing High Loaded Paper.

Flexible calcium carbonate (FCC) was developed as a functional papermaking filler for high loaded paper, which was a fiber-like shaped calcium carbonate produced from the in situ carbonation process on the cellulose micro-or nanofibril surface. Chitin is the second most abundant renewable material after cellulose. In this study, a chitin microfibril was utilized as the fibril core for making the FCC. Cellulose fibrils for the preparation of FCC were obtained by fibrillation of the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) treated wood fibers. The chitin fibril was obtained from the β-chitin from the born of squid fibrillated in water by grinding. Both fibrils were mixed with calcium oxide and underwent a carbonation process by the addition of carbon dioxide, thus the calcium carbonate attached on the fibrils to make FCC. When used in papermaking, both the FCC from chitin and cellulose gave a much higher bulk and tensile strength simultaneously than the conventional papermaking filler of ground calcium carbonate, while maintaining the other essential properties of paper. The FCC from chitin caused an even higher bulk and higher tensile strength than those of the FCC from cellulose in paper materials. Furthermore, the simple preparation method of the chitin FCC in comparison with the cellulose FCC may enable a reduction in the use of wood fibers, process energy, and the production cost of paper materials.

Producing flexible calcium carbonate from waste paper and their use as fillers for high bulk paper

Microfibrillated cellulose (MFC) was prepared from post-consumer old corrugated container (OCC) material, which was first disintegrated in water, cleaned to remove impurities, and then fibrillated by grinding. Those processed MFCs were treated with in-situ formation of calcium carbonate by adding calcium oxide and injecting carbon dioxide into the mixture up to the ratio of 1:40 (MFC : calcium carbonate) by weight. The MFCs had a dark brown color initially but turned into high brightness materials similar to commercial ground calcium carbonate (GCC) after the in-situ formation process. The MFCs that had calcium carbonate attached on their surfaces, which were lengthy and flexible, were called flexible calcium carbonate from OCC (FCCO). Paper containing FCCO gave higher bulk, higher stiffness, and higher tensile index without lowering smoothness when compared to the paper containing commercial GCC. However, brightness was slightly lowered because of initial low brightness of the OCC. This study also demonstrated the feasibility to substitute wood fibers up to 5% with FCCO without lowering essential properties for printing paper. Benefits of the waste paper are savings of both wood resources and production cost.