Glass & Ceramics Technology

El presente artículo analiza el desarrollo de la industria vidriera valenciana entre los siglos XIII y XV. Para ello se recurre a un centenar de documentos de carácter notarial, normativo, judicial y fiscal, procedentes de distintos archivos valencianos. Estos permiten estudiar la localización de los hornos de vidrio en el reino de Valencia y las formas de trabajo de los vidrieros, así como los procesos de distribución y los sistemas de venta del vidrio doméstico. Finalmente, se aborda la demanda y el consumo de estos bienes y sus usos en las viviendas de
diferentes sectores sociales de la época. Todo ello invita a reconsiderar la relevancia de esta industria en el reino de Valencia, mucho menos estudiada que sus homólogas catalanas y mallorquinas, en el contexto de la Corona de Aragón y del Mediterráneo noroccidental durante la Baja Edad Media.

This essay analyses the development of the Valencian glass industry over the 13th–15th centuries, by looking at around one hundred documents from notarial, normative, legal and tax records, held in various Valencian archives. These reveal the location of glass furnaces in the kingdom of Valencia and the glass-makers’ activities, as well as the sale and distribution systems of domestic glass. Finally, it addresses the demand and consumption of these goods and their usage within the dwellings of various social strata for the period. This all leads to a reconsideration of the relevance of this industry in the kingdom of Valencia, far less studied than its counterparts from Catalonia and Majorca, in the context of the Crown of Aragon and the North-Western Mediterranean during the Late Middle Ages.

Main purpose of this study is to know the current raw materials avaliable in our
country to be used for ceramic industry and to improve artistic glazing works using such
raw materials.
There is almost no collective study on chromate glazes found in both national and
international literature. Therefore, it is intended that the results of the study made on this
subject will constitute a reference for the ceramists and inorganic chemists who would like
to work on this subject in the future.
Chromate glazes are member of the group of artistic salt glazes. Chromate is called
as chromium salt. In this study, chromium salt is put under reaction with various
carbonates and colorant other salts and their under-glaze and in-glaze effects at high
temperatures have been scientifically observed and documented.
Chromium salts are rather variable and unstable salts. Using chromic acid, earth
alkali elements have been transformed into chromate to the extent it is practicable. Such
chromates have been scientifically observed by making additions of different percentages
within ready frit, easily soluble at low temperatures, and transparent glaze structure. In
summary, with this study we obtained positive results at 750ºC – 1020ºC, while
experiments for chromium slats which do not yield any results , further to various
chromate glaze structure. Additionally, the study handles, to great extent, general
specifications of raw materials used for ceramic technology, where and how these are used
and the areas of use for artistic ceramic glazes.
At the conclusion of the study, the effects of chromium salts at high temperatures
and in diluted vitreous bodies are scientifically studied and documented together with the
risks and solutions they bring along.

Ogata Kenzan (1663-1743) was born and raised in Kyoto and built his illustrious career as a ceramic designer in that city. However in his final years he chose to move to Edo, where he worked until his death. Although there is a paucity of evidence for this period, this article considers Kenzan’s motivations, his interactions with elite patrons and local ceramics workshops in Edo, and finally how that legacy resonated for later professionals and amateurs who variously evoked his name and techniques in handwritten and printed manuals.

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Finds from a 1st century BCE workshop making glass inlays at Denderah are presented.
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Unworked glass is discussed according to the results of morphological observations.
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Coloured glass cakes show morphological similarities to LBA Egyptian glass cakes.
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Glass lumps and trails suggest that glass-colouring was practiced at Denderah.
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A connection between Egyptian temples and Ptolemaic glass industry is hypothesized.

The study of the ancient black ceramic coating that decorates the surface of Classical and Hellenistic pottery from Attica and other main production centres in the Mediterranean has been the subject of more than three centuries of research. The physicochemical characterisation and analysis of the black glaze/gloss (BG) with the use of a broad spectrum of analytical techniques has gradually revealed its nature as an iron-based glass-ceramic material. At its best, it is coloured by polycrystalline nanoparticles of magnetite or mixed magnetite/hercynite spinels, dispersed in the amorphous K-aluminosilicate phase doped by Fe2+/Fe3+. We discuss the technique to produce the BGc (black glass-ceramic, hereafter), known as the “iron reduction technique”, with emphasis on the 3-stage firing under oxidising-reducing-oxidising (ORO) conditions as well as the latest analytical results through XPS, high-resolution TEM, SR-micro XRD and XANES. The discussion is based on data and research experience accumulated over the years from the application of conventional techniques (such as SEM-EDS and hhXRF) on ancient samples, laboratory reproductions and contemporary full-scale reproduction of similar artefacts. We show that the parameters affecting the quality of the BGc (sheen, colour, micromorphology) depend on the nature of the clay-slip, the application process, the ORO firing scheme and weathering mechanisms due to burial in humid terrestrial or marine environment. The proposed analytical protocol for the routine characterisation of the micromorphology and the analysis of the BGc and the ceramic body involves the use of non-destructive or minutely destructive techniques with special emphasis on the pottery sample classification and documentation.

Complete and accurate chemical characterisation was performed on a repertoire of glass tableware and lightingware from San Lorenzo in Carmignano (Apulia, Italy). Twenty-three samples were investigated by scanning electron microscopy, electron microprobe analysis for major and minor elements, laser ablation inductively coupled plasma mass spectrometry for trace elements and thermal ionization mass spectrometry for Sr and Nd isotopic analyses. The research was aimed at improving the state-of-the-art knowledge on Apulian glass, especially on prunted beakers. Main results were: (a) two goblets were characterised as natron-based glass (one likely recycled, one of Egyptian provenance) and backdated to Late Antiquity; (b) the other twenty-one samples were made of plant ash-based glass, likely "fresh". Seventeen specimens were divided into three chemical groups based on their elemental and isotopic composition: 1) Prunted 1, compatible with Mediterranean glass (in particular, Syrian or Adriatic); 2) Prunted 2, compatible with either Mediterranean or Mesopotamian glass and 3) Prunted 3, using of a much purer silica source and compatible with Slovenian and North Adriatic prunted beakers, "blanchum" Venetian glass and some Levantine or Syrian glass. The hypothesis of Apulian workshops recycling preexisting materials was also put forward.

Distinctions between the concepts of ‘invention’ and ‘innovation’ are often confusing and ambiguous. Rarely, if ever, is invention the result of a lightening-strike ‘aha’ moment. Rather, invention tends to be the application of clever innovation from one aspect of life to another, shaped through personal observations and/or experiences. The ‘invention’ of metallurgy, for example, did not simply spring from the earth one morning, but rather evolved from observations of and experiences in other pyrotechnological processes. Past scholars have speculated on the invention of various early pyrotechnological activities, such as glass making and glaze production. What has not been fully explored, however, are the aspects of cross-craft interactions linking these and other pyrotechnologies. An example of this is the limited research exploring the technological connections between the advent and development of glass technologies and developments in metallurgical and other vitreous technologies. In this paper, these connections will be explored from pyrotechnological and craft technique perspectives. Ideas concerning connections between glass and non-ferrous metallurgy and glazing are discussed.

Sol-gel glasses in quaternary silica–sodium–calcium–phosphorous systems have been synthesized using a rotary evaporator for rapid drying without ageing. This novel fast drying method drastically decreases the total drying and ageing time from several weeks to only 1 hour, thus overcoming a serious drawback in sol-gel preparation procedures for bioglasses. This work investigates the bioactivity behavior of two glasses synthesized by this fast method, with Ca:P ratios of 1.5 and 1.67. X-ray diffraction (XRD), Inductive coupled plasma, Fourier-transform infrared, and Raman spectroscopy were used to confirm the bioactivity of the synthesized powders. MAS-NMR was also used to assess the degree of silica polymerization. The composition with a higher Ca:P = 1.67 ratio showed better bioactivity in comparison to the one with Ca:P = 1.5, which exhibited little bio-response with up to 4 weeks of immersion in SBF (simulated body fluid). It was also found that an orbital agitation rate of 120 rpm favors the interfacial bio-mineralization reactions, promoting the formation of a crystalline hydroxyapatite (HAp) layer at the surface of the (Ca:P = 1.67) composition after 2 weeks immersion in SBF.
J Biomed Mater Res Part A: 106: 510–520 (2018).

Chemically strengthened lithium magnesium alumino-silicate glasses have been prepared by ion-exchange in sodium nitrate at 385 ~C, and the stress profiles of the resultant materials have been measured using the scattered light and etching technique.

After well succeeded preliminary work, an upgrade is under way to enable laser sintering and laser pattern sintering, by including cylindrical optics, beam scanning and XYZ sample positioning.
Laser processing of materials is increasingly gaining importance in R&D and industrial activities. In our group, it was initially used for growing superconductors by laser floating zone (LFZ), for which a setup was home built, based on a Nd:Yag laser. A CO2 laser was added afterwards to expand the range of materials to be processed. Many oxide materials (mullite, zirconia, YAG, CCTO, manganites, ferrites, cobaltites, galates, etc.) were successfully grown by LFZ. The fibres are highly textured or even monocrystalline in selected cases. A pioneering growth parameter, the applied electrical current during growth (EALFZ), was used to effectively enhance/reduce texture. Eutectic and/or glass ceramics were also grown, their microstructure being strongly dependent on the growth rate. The system is fitted with controlled atmosphere capabilities to increase versatility and to allow processing of non-oxide materials. The peripherals (2 colour pyrometer, high magnification CCD camera) allow assessing the materials melting temperature and thermal shrinkage.

A forgotten glass & crystal factory in Chantilly dating from the revolutionary period. Christopher Potter (1750-1817) for to improve the incomes of his business of ceramic, started to experiment a crystal and opaline production at Chantilly (France) in 1796, with the help of a chemist named Gass. It is the shards' discovery in the vicinity of this manufacture in 2010 that allow to the author an understanding of  this secret and unknown production during the Revolutionary period.
Une manufacture oubliée de verre & cristal à Chantilly datant de la période révolutionnaire. Christopher Potter (1750-1817) pour améliorer les revenus de son entreprise de céramique a commencé à expérimenter une production de cristal et d'opaline à Chantilly (France) dès 1796, avec l'aide de son chimiste nommé Gass. C'est la découverte de tessons à proximité de la manufacture en 2010 qui a permis à l'auteur de commencer à comprendre les caractéristiques de cette fabrication secrète et méconnue.

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified t...

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified t...

Bioactive glasses and glass-ceramics consisting of CaO-MgO-P2O5-SiO2 system have been shown to be bioactive, resorbable and to exhibit appropriate mechanical properties for bone tissue engineering applications. Bioactive glass-ceramics scaffolds consisting of zinc doped-apatite/wollastonite (AW) glassceramics were prepared by coating polyurethane foams with sol-gel derived glass gels. Density and compressive strength of the scaffolds decreased with increased in zinc contents. In vitro bioactivity of Zndoped AW glass-ceramics in a simulated body fluid (SBF) showed the formation of apatite layer on the surface within 7 days of soaking. However, increasing Zn addition increased the chemical durability of the AW glass-ceramics, resulting in a decrease in the rate of apatite formation in a simulated body fluid. With observation by SEM technique microstructure of pores showed interconnected macropores in the range of 300-500 μm as depended on the type of sponge. Average pore size increase...

Graham Hay outlines studio practices arising from the properties of paper clay and the evolving material philosophy concerning its use.

Paperclay is an increasingly popular medium with artists, craftspeople, hobbyists and teachers.

It offers all the properties of a favourite clay body as well as the opportunity to use techniques borrowed from woodwork, bricklaying, candle making and metalwork.

A common problem potters face in firing gas kilns in reduction is variability of glaze results depending on where the pieces were placed in the kiln. This results from non-uniform reduction conditions in the kiln during firing. A good way to picture the variability of reduction in your kiln is to generate a kiln reduction profile. In this article, I describe the development of a reduction profile of a Geil DL-12F gas kiln using three different glazes, each color-sensitive to the level of reduction during different temperature stages of the firing. Full recipes of these three glazes can be found in John Britt's book, "The Complete Guide to High-Fire Glazes"[1]. Selected details of the three glazes are shown as follows in Table 1.

Notre Dame d'Alban, Tarn (South of France) was initiated by parish priest Henri Roussel, guardian of the building, and the mayor of the municipality, having the legal responsibility, who have contributed to calming relations between clergy and laity in Alban after the Second World War . We describe how it is today an important historical place by the choice of a facade in the form of a claustra in accordance with the art of the time.

This study aimed to compare the effects of two surface-coating methods on the shear bond strength (SBS) of veneering ceramics (VC) to zirconia. Eighty pre-sintered zirconia cubes were randomly assigned into four study groups: E60S, E60P, N60S, and N60P. The zirconia surface was coated with a mixture of two types of glaze and alumina (<60 μm) by airbrush spraying and fine- brush painting. Surface roughness (Ra), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and SBS measurements (both initial and artificial aged conditions, including one month of water storage) were performed. The Ra results revealed significant differences among all groups (p < 0.001). The N60P group exhibited higher values of Ra (5.717 ± 0.20 µm) and SBS before and after water storage with values of 37.22 ± 4.954 MPa and 34.42 ± 3.977 MPa, respectively. The fine-brush coatings showed significantly higher SBS than that of airbrush coatings, in both initial an...

Opis historycznej technologii szklarskiej i ceramicznej, dzięki której możliwe było wytworzenie szklano-ceramicznego obiektu w postaci plakiety na postumencie (ok. 1840 r.). Artykuł zawiera opis specjalnej techniki przewarstwiania ceramiki szkłem czego wynikiem jest beznaprężeniowe współistnienie obydwu materiałów.

En los últimos años los estudios radiográficos aplicados a la alfarería han ido en aumento en nuestro país, brindando información complementaria en las investigaciones destinadas a comprender distintos aspectos presentes en una vasija. La radiografía consiste en una técnica no destructiva que permite observar las características internas de la cerámica, facilitando el reconocimiento de particularidades, tales como: los procesos primarios de manufactura, arreglos, uniones y roturas que se produjeron en una pieza a lo largo de su historia. En este trabajo se exponen los resultados preliminares obtenidos en un trabajo experimental, aplicando la técnica de la radiografía digital a un conjunto alfarero perteneciente al sitio arqueológico La Florida, ubicado en el valle de Abaucán (Tinogasta, Catamarca, Argentina), perteneciente a la Cultura Saujil del Período Agroalfarero Temprano (ca. AC 200 - AD 600), representante de las primeras sociedades agroalfareras que habitaron el valle.