Paper Surface Research Articles

The Scarred Womb

Ruchika Wason Singh is a visual artist, art educator and independent researcher based in Delhi, India. In 2016, Ruchika founded A.M.M.A.A. -The Archive for Mapping Mother Artists in Asia, a project fostering the mapping, visibility and mobility of mothers/artists of Asian origin through documentation, workshops and artist residency programs. The Scarred Womb series, shared here, aims to create a visual resonance with the emotional value of the trauma of loss. Through forms created with pencil, ink and paint, followed by scraping, etching, and digging into the paper's surface, these works explore embodied experiences of the trauma of communal violence.

Preparation of double-effect water-proof and oil-proof paper based on carboxylated nanocellulose emulsified acrylate polymer

The materials utilized in paper packaging are derived from natural plant fibers, making them both environmentally friendly and biodegradable. However, traditional paper has been vulnerable to water and oil, which has limited its widespread use. In this research, a low-fluorine acrylate emulsion with a short carbon chain (CNF-C6FA) was created by employing carboxylated nanocellulose (TOCNF), dodecyl phenol ethoxylate, and sodium dodecyl sulfate as emulsifiers through semi-continuous seed emulsion polymerization. When combined with a specific amount of polyvinyl alcohol, this emulsion is applied to the paper surface to enhance the paper's hydrophobic and lipophobic properties. The findings revealed that paper coated with 5 g/m2 of CNF-C6FA achieved an oil-proof grade of 10 and a Cobb value of 13 g/m2, signifying a significant enhancement. It was discovered that TOCNF, acting as an emulsifier, not only maintained emulsion stability through steric hindrance, three-dimensional network structures, or vacancy effects but also conferred exceptional waterproof and oil-repellent properties to the paper. This can be attributed to TOCNF reinforcing the fluorocarbon groups in a directional arrangement, resulting in a dense and smooth coating layer on the paper's surface. The utilization of TOCNF as an emulsifier to produce environmentally friendly, waterproof, and oil-proof paper presents a promising approach for its high-value application.

Investigation of the effect of load weight on the discharge capacity of lithium–O2 batteries using carbon-paper–based electrodes

We prepared carbon electrodes with nearly uniform thickness and varying loading weights using carbon paper (CP) as a support material and current collector for single-walled carbon nanotubes (SWCNTs). These electrodes were used as the positive electrode in a lithium–O2 battery, tested at a lower voltage limit of 2.4 V with a fixed current of 0.26 mA/cm2 (0.5 mA). Results demonstrated that the discharge gravimetric capacity (capacity normalized per weight of SWCNTs) did not change significantly for loading weights ≥0.42 mg/cm2. However, for loading weights <0.42 mg/cm2, the discharge gravimetric capacity exhibited an inverse correlation with weight. Analysis of the prepared electrodes revealed that at very low SWCNT loading weights, the sheets of SWCNTs became extremely thin, leading to occasional tears. Nonetheless, these structural changes had no significant impact on the specific surface area or contact resistance. Further analysis of the post-test electrodes using scanning electron microscopy and X-ray diffraction, along with considerations of the carbon paper's surface area as a percentage of the total electrode surface, led to the conclusion that at low loading weights, CP actively contributes to the discharge process and serves as a deposition site for Li2O2. Consequently, when the weight of the active material falls below a certain threshold, there is a risk of misperception, potentially leading to an overestimation of the discharge capacity.

Analysing the impact of paper grammage and pulp blend on electrophotographic printing systems

AbstractThe effect of fibre length and grammage on the electrophotographic digital printing process was investigated in this study. While integral optical density values on handsheets have shown no significant change, unprinted handsheets have shown an increasing change as short fibre content has increased. Because of structural changes in the paper surface, the measured results for print chroma, brightness, contrast, and delta gloss differed between paper groups. This research confirmed that these changes have nothing to do with grammage or fibre length content. Regardless of the fibre length ratios, significant increases in tone values of ink, were accompanied by a decrease in the grammage of the handsheets among the grammage groups provided. The specimen grammage affected the universal colour diagrams, but not the fibre length. The discrepancies in all of these printing outcomes were thought to be caused by the random distribution of fibres and the distances between them on the paper's surface.

Determining special features in the topography of paper with water marks at the micro­ and nanolevels

We have studied the surface structure of tamper-proof paper with positive and negative watermarks at different scales ‒ from a micrometer to a nanometer level, by using the methods of contact profilometry and atomic force microscopy. Experimental research has confirmed that the structural parameters of the tamper-proof paper's surface differ at regions with and without watermarks.The results of measurements by a contact profilometer have made it possible to trace a correlation between values of the profile's mean arithmetic deviation and the presence of watermarks. It was determined that the value for the profile's largest height does not depend on a measurement region, which could be related to the chaotic arrangement of fibers and particles of the filler in the paper bulk that protrude above the profile's line.By analyzing the value of the profile's mean arithmetic deviation obtained by using a method of atomic-force microscopy, it was found that for regions with negative watermarks it is larger than that for regions with positive watermarks. The dependence of the profile's largest height on measurement region is not clearly observed. This may be due to that the size of the examined region (3,000×3,000 nm) covers only part of the pulp fibers.Thus, the results of our analysis allow us to argue that both methods are suitable for estimating the characteristics of paper's surface, and determine the character of interaction between a given type of paper and printing inks during printing process. In particular, it has been established that the method of profilometry makes it possible to determine parameters of the paper's surface profile, formed in a certain way, while the atomic force microscopy method allows analysis of the morphology of its components, located at the surface (fibers, filler's particles, etc.). The availability of information on the structural properties of paper makes it possible to predict the quality of printing reproduction, specifically clearness of reproduction of thin guilloche lines on watermarks, which is relevant because it prevents flaws in printing products for special purposes.

コーテッド紙のオフセット印刷品質に及ぼすゴムブランケットの圧縮性の影響

We examined the influence of the blanket's compressibility for sheet offset printing quality on coated papers by means of two commercial blanket's have its own compressibility on a practical printing press (ROLANDPALVA RZP-1) We got next results.1. The printing paper's surface roughness gives lesser influence to halftone reproduction than the blanket's compressibility.2. The hard blanket gives higher dot gain than the soft one ; higer P/B pressure gives poor halftone shapes.3. The high B/I pressure gives rich ink transference : We expect that the hard blanket has rich ink transference.

The Comparison of Equal-Value Gray Scales

Equal-value gray scales devised by cartographers and psychologists vary largely because of differing experimental designs and processes governing conversion of surface reflectances to inked-area percentages. Reflectance measurements for inked gray tones of a given area demonstrate a non-linear relationship. Mathematical models of printed paper's surface reflectance predict non-linearity of the same degree as that measured. This measured non-linearity is used to convert the Munsell and Stevens equal-value scales to inked-area percentages. Comparison of scales devised by cartographers over the years show that all except the Williams scale are similar to the Munsell value scale.