SURFACE ROUGHNESS OF LITHIUM DISILICATE PRESS CERAMICS AFTER DIFFERENT TYPES OF POLISHING

INTRODUCTION: The smoothness of a ceramic’s surface is very important of its esthetic and prophylactic qualities. AIM: The purpose of this investigation is to study the possibilities of polishing lithium disilicate ceramics after making a correction on the glazed ceramic surface. MATERIALS AND METHODS: The subject of the study were 20 test samples made of lithium disilicate press ceramics. They were divided into 4 groups according to the method of processing and polishing. Group 1 was treated with a red diamond bur and polishing set; Group 2 was treated with a green diamond bur and polishing set; Group 3 was treated with a red diamond bur, polishing set and diamond paste; Group 4 was treated with a diamond bur with green coding, polishing set and diamond paste. The samples were examined with an atomic force microscope to observe the change in surface relief. The reference point for comparison was the surface of the glazed ceramic. RESULTS: After polishing with diamond paste, the surface became smoother compared to the treatment of the surface with a polishing kit alone. CONCLUSION: Regardless of the polishing protocol used, there was a difference in the topography of the ceramic surface before and after treatment.

Glass-based pigments in painting: smalt blue and lead–tin yellow type II

Glass-based pigments have an important role in the panorama of artistic production due to the fact that their manufacturing processes involve a combination of different skills and understanding, and they have a role in disciplines ranging from glass technology to metallurgy, from glazed ceramic to stone imitation and from vitreous mosaic tesserae to painting materials. The main goal of this manuscript is to present a critical review of the literature relating to blue smalt and “yellow glass” (lead–tin yellow type II) pigments: presenting their historical background, the analytical protocol, the processes of alteration and decay and finally tracing issues. Several case studies analyzed by the authors will be presented. Particular attention was devoted to the correlation between micro-textural features and decay processes affecting the studied pigments, though the widespread heterogeneity of the analyzed materials and the variability of the artistic techniques in which the pigments were used as well as the effect of the relevant (micro-)environmental conditions dictate a cautious approach. These studies are presented in the context of information about the chain of production, the selection of the raw materials and relevant provenance studies.

Nested Hierarchical Design Application in Production of Ceramic Glazed Floor Tiles

The challenges of using locally available materials in Nigeria to meet the tiles demand that will be affordable and compete favourably with imported products will no doubt not only contribute to our Gross Domestic Product but also meet the yearning of the Federal Government on her local content policy. This necessitated this study to aim at the production of ceramic floor tiles with clays modified with naturally occurring materials. An experimental method was adopted to carry out this research work. Different clay samples were purposively gotten from Mbaukwu town, Anambra State, Nigeria. Rice husk, silt, feldspar, quartz was obtained to serve as modifiers. An elaborate nested experimental design, structured as an analytical hierarchy process, and festooned with three base materials, 4-modifiers, and with replications, facilitated the achievement of the production. The nested design was developed to guide in the optimum combination of materials that will give the best yield of tiles. The base materials were used in combination with the four modifiers at different percentage levels. The tiles produced were subjected to same test in order to ascertain their behavior in terms of weather, resistance to abrasion, compatibility with mortar, water absorption, dilute acid, Sodium Hydroxide and detergent. The experimental tiles produced compete favorably with any foreign product as it was seen to match up with “Vetrified tiles” and “Gomex tile” from Italy and satisfies NIS 427: 2000. Glazed ceramic floor tiles have been successfully manufactured locally using clay and other naturally occurring materials and it has given excellent performance characteristics.

Faith and Devotion: Reading the Ceramic Architectural Programs of the Baroque

In Portugal, the use of azulejos (glazed ceramic tiles) in architecture has a long history, extending uninterruptedly from the late 15th century to the present 21st century. For more than five centuries, the azulejo reinvented itself periodically to meet the demands of different historical periods, and one of its most expressive transformations took place in the Baroque period (1675–1750). Baroque azulejos stand out not only for the almost exclusive use of blue and white painting, but above all for the exploration of narrative programs, which were displayed in vast ceramic walls. These decorations covered the interiors of different buildings, but mostly churches. The use of azulejos, dominating the interiors or in connection with other arts, was instrumental in creating a unique spatial form, which echoed Baroque spirituality by appealing directly to the senses and exploring the brightness and color of the tiled surfaces within majestic and lusciously decorated settings. But the azulejo was also a medium for religious painting and, as such, a vehicle for the doctrine and values of the Counter-Reformation, which were dominant at the time. Therefore, these ceramic architectural programs resort both to devotional and visual discourses. On the one hand, azulejo compositions relate to central aspects of Christian faith and liturgy, and particularly to the religious discourse and practice of the Baroque period. On the other hand, their visual features add new layers of meaning, mostly related to the organization of azulejos within a church’s architecture, the frames and inspirational sources, as well as issues linked with the creation and running of azulejo workshops.

Sanitary wares (Wash-basin) product industry situation and quality analysis

Sanitary ceramic products refer to glazed ceramic products used for sanitary installations. Sanitary wares products are divided into ceramic Sanitary wares and ceramic Sanitary wares according to different materials. According to use divide for implement kind, basin kind. The urinal type includes sit urinal, squat urinal, urinal; The basin category includes the Wash-basiner, washing tank, mop pool and so on. Among them, the Wash-basiner refers to the glazed ceramic products used for washing face and hands. It is a necessary sanitary equipment in family or public places and has become an essential sanitary appliance in people’s life.

Preparation, microstructure studies and mechanical properties of glazes ceramic sanitary ware based on kaolin

In this paper, the use of local kaolin coming from Djebel Debbagh (denoted DD1) in the composition of ceramic glazes for sanitary ware was examined. Because of its natural abundance, low price and good characteristics, this kaolin represents an interesting economic alternative to other mineral clays. The chemical composition showed that this kaolin contains 38.49 wt.% Al2O3 and 44.85 wt.% SiO2. Two glazes based on kaolin DD1 denoted as GaDD1 and GbDD1 were prepared with conventional ceramic processing techniques at temperature 1250 oC. As a reference, another glaze (Gref) based on kaolin Remblend was also prepared in the same conditions. The samples were characterized with X-ray diffraction and Scanning Electron Microscope. The results revealed that zircon and quartz are the crystalline phases present in these glazes. In the sample GaDD1, it was found that the degree of whiteness is very high and reaches 93.30 %. However, the water absorption coefficient is low which is about 0.19 ? 0.04 %. In addition, the flexural strength and the Vickers microhardness are respectively, about 56.07 ? 5.61 MPa and 7952.80 ? 101.76 MPa. These properties are compatible with those of the glaze reference Gref and commercial sanitary ware glazes, indicating the potential use of kaolin DD1 in the production of glazed ceramic for sanitary ware applications.

Glazed Red Clay Ceramic Ware with Images of Birds Excavated at Sudak (The Collection of the Museum Preserve of Sudak Fortress)

This paper presents a detailed analysis of the collection of red clay glazed ceramic ware featuring images of birds from the excavations of Sudak and now residing in the Museum Preserve of Sudak Fortress. The publication comprises 45 open-shaped vessels and one ceramic tile. Imported artefacts mostly from the Byzantine circle comprise 22% of them and Crimean products form 78%. Many finds are published for the first time. The products of the Byzantine circle dating back from the thirteenth and fourteenth centuries mostly show a bird of the Accipitridae (probably eagle) and Columbidae. The dove is often depicted with palm branches and/or bunches of grapes which also have important meaning in Christianity. The dove most often occurred on the fourteenth- and fifteenth-century glazed ware ring of Crimean manufacture, where its image was probably associated with Christian symbols and Byzantine tradition. Original drawings of the birds demonstrate individual creativity of local craftsmen since there are many variants of such images. Some drawings allow the one to determine the breed of bird depicted by ceramic painters. Additionally, at the products of Crimean workshops represent at least four other species of birds, presumably swan, bustard, goose or duck, and heron or crane. The research undertaken allowed us to identify a few stylistic decorative series showing bird-shaped images, to discover the origin of artefacts, and to clarify the directions of various cultural influence on local ceramic production.

Glazed Ware from the Golden Horde Period in the Central Museum of Taurida: An Attempt of Attribution of a Collection

A significant collection of ceramic wares excavated at the ancient town of Solkhat in 1925–1928 under the supervision of A. S. Bashkirov, U. A. Bodaninskii, and I. N. Borozdin is lost. In 2017, the Central Museum of Tavrida organized a temporary exhibition entitled The Crimea in the Golden Horde Period. The Crimean Yurt of the Golden Horde: The Legacy of the Vanished Empire, particularly presenting the materials originating from the excavations at the ancient town of Solkhat. Among other artefacts, there were three ceramic items of the origin still not quite clear. Probably these items belonged to the collection originating from the 1920s–1930s excavations, since they were transferred to the museum collection in the Post-War Period in result of liquidation of some museum in Staryi Krym. In total, the collection in question contains 343 items in fragments or archaeologically complete forms. The collection is rather quite comprising 240 imported items. This publication presents about 50 fragments of glazed ceramic ware: table ware is the most numerous category (99.4%). A significant part of the imported ware in this collection suggests that it originated from the excavations of either a caravanserai or the architectural and archaeological complex of the madrasah-mosque of Khan Uzbek. It is also supported by fragmentary records in U. Bodaninskii’s 1928 journals. According to the primary analysis of the collection and analysis of written sources on the history of archaeological researches of Solkhat in the 1920s, there are reasons to suppose that the museum materials in question are related to the archaeological excavations by the All-Union Association for Oriental Studies and the Bakhchisarai Museum of Turkic-Tatar Culture in Staryi Krym. Perhaps following the repressions against the participants and leaders of 1925–1928archaeological researches, the museum depository in Staryi Krym was liquidated and its materials were transferred to the Central Museum of Taurida.