Filament-laying techniques originated in the Yuan dynasty (1271–1368) and flourished in the Ming dynasty (1368–1644), before being introduced to the Boshan region of China. After this technology was introduced to Boshan, glass artisans in the area used the well-developed local methods of glass production to pull out ultra-fine glass filaments, replacing original fibre or silk filaments with glass filaments. As a result, Boshan's speciality of glass-filament-laying was born. Products made using this technique include plaques, table lamps, palace lamps and screens. Glass-filament-laying is the melting of transparent glass into fine filaments of uniform thickness, dividing the filaments into two layers, closely arranged and bonded in different orders, with calligraphy and paintings on paper or silk sandwiched in between them. The glass-filament-laying process is highly complex and there are fewer and fewer master artisans of this skill today, with it being close to being lost. This paper mainly studies and discusses the development of glass-filament-laying in Boshan and the contemporary innovative methods of glass-filament-laying.

E-glass fibre glass products have found a wide range of applications in composite markets, including automobile parts, printed circuit boards, construction materials, wind turbine blades, pipes, etc. One of the commonly used major ingredients of E-glass batch is kaolin, which provides sources of silica and alumina. This paper focuses on the evaluation of alternative silicate minerals that may benefit the fibre glass production in terms of kinetics of batch-to-melt (BtM) conversion, stable and lower impurity iron, and lower BtM conversion energy. Using kaolin (free quartz less than 1 wt%) as a control, four new natural minerals are investigated, high silica kaolin (quartz greater than 50 wt%), pyrophyllite, anorthosite and wollastonite. In our study, a newly established FTIR protocol has been applied to track intermediate phase formation and final glass melt conversion. Literature reported XRD results and limited XRD analysis are used to support the IR characterization. According to our study, for E-glass of C a O???Al 2 O 3 ???SiO 2 based system, independent of the source of the natural silicate minerals used, BtM kinetics is primarily controlled by the availability of “free silica” to react with ???free calcium oxide??? derived from limestone in the batch at high temperature above 1000°C.

The energy intensive and CO 2 -generating nature of commercial mineral wool and glass production necessitates advances and changes in materials and processes. The derivation of raw materials from waste products arising from biomass energy generation offers the possibility of a two-fold environmental benefit: partial replacement of carbonate raw minerals in production, leading to lower CO 2 release during melting; and the utilisation and valorisation of byproducts which may otherwise be sent to landfill. Glass samples with a basaltic mineral wool composition were produced with additions to the raw materials of 0, 1, 5 and 10 wt% of a fly ash and a bottom ash arising from biomass combustion. The resulting glasses were analysed by x-ray fluorescence (XRF), x-ray diffraction (XRD), dilatometry, 57 Fe Mössbauer and Raman spectroscopies, and their densities, molar volumes and viscosity–temperature profiles were calculated and compared against benchmark glass samples. All biomass ash-containing glasses were closely similar in both composition and properties to the benchmark glass, with up to 10 wt% ash additions to the raw materials. In addition, the use of the biomass fly ash led to a reduction in batch CO 2 content estimated to be 1 · 5 kg CO 2 per tonne of batch for each 1 wt% addition. These initial results provide evidence supporting the further development of these ash materials as potential value-added raw materials for mineral wool manufacture.

Sulphuric acid–water glass slurry is a type of chemical slurry. The gel time of sulfuric acid–water glass slurry is affected by many factors. However, few researchers have addressed the influence of temperature. Through a series of laboratory tests, the viscosity and gel time of sulfuric acid–water glass slurry were studied at temperatures of 20, 30, 40, 50, 60, 70, and 80°C, with sulfuric acid concentrations of 4·75, 5·0, 5·25, and 5·5%. In the tests, the viscosity of the slurry was reduced from 7 to 3 mPas with a temperature increase of 20–80°C. Gel time increased before the temperature reached 40°C. Above 40°C, the gel time began to decrease. Different concentrations of sulphuric acid slurry resulted in various reactions at sudden temperatures. Abrupt temperature changes caused the slurry gel time to increase over the previous temperature; as the temperature continued to increase, slurry gel time began to decrease. The greater the concentra- tion of sulfuric acid, the greater the strength of the gel, however, as the temperature increased, the strength of the gel decreased continually. Temperature thus has a major influence on the strength of the gel relative to the concentration of sulphuric acid.

This study compares the degradation behaviour of toughened (chemically and thermally) and not toughened glasses. Soda–lime–silica float glasses were artificially weathered in a climate chamber for up to seven days and investigated by optical microscopy, atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). For all glasses, two specific carbonates were found to develop during weathering: dendritic trona (Na 3 (HCO 3 )(CO 3 ).2H 2 O) and a several nm thick layer containing sodium bicarbonate (NaHCO 3 ). Furthermore, this work shows that Mg diffusion in the surface near region of tempered and untempered glasses does occur. It is enabled by the accumulation of Na and Ca species on the glass surfaces and the accompanying changes in the glass structure in that region. While the thermal toughening of glass showed no significant effect on the degradation behaviour compared to the untoughened glass, the chemical toughening procedure leads to dramatic changes in the corrosion behaviour: lateral changes in the surface chemistry are more pronounced while vertically chemical changes do not occur as deep as in the case of tempered and untoughened glasses. This is related to the integration of K atoms in the glass network during the toughening process replacing the smaller Na species and hence reducing the interstitial spaces within the glass network and so mitigate the corrosive attack of water in the depth.

In this paper, melt film dynamics in rock wool spinning machines are investigated. High-speed visualization of the melt film structure was performed for a model spinning wheel and two industrial spinning machines. The quality of the melt film adhesion to the wheel and related heat transfer parameters were assessed by time series analysis of the image gray level for different operating conditions. During the warmup procedure for the spinning wheels investigated in laboratory experiments, the best wetting of the wheel surface (i.e.with least voids in the melt film) was observed at the lowest rotational speed and melt viscosity. In this transitional period, melt adhesion can be improved by preheating of the wheel surface and by gradual increase of the wheel rotational speed. Once the wheel surface has reached its working temperature, melt temperature and viscosity seem to have the largest effect on the melt adhesion process. The cooling rate of the melt film was observed to increase with its initial temperature and circumferential velocity. Regardless of the operating regime, no significant melt slippage against the wheel surface was observed, with melt film structure preserved over multiple spinner wheel rotations.

In float glass production, the homogeneity of molten glass significantly influences the product quality. Usually, stirrers are used to diminish the inhomogeneity of molten glass. In this study, the vertical stirring process in a float glass furnace was simulated and analysed using the ANSYS Fluent 14·0 software. The particle track method was used to qualitatively describe the stirring effect. The stretch rate was used to quantitatively evaluate the stirring effect. The influence of stirring on the waist backward flow was studied. The relationship between the stirrer insertion depth and the optimal rotational speed was obtained. The particles presented an S-shaped distribution after stirring. The rotation effect of the stirrer can bring the backward flow upward into the forward flow at a high rotational speed. The optimal rotational speed decreased with the insertion depth of the stirrer and presented a linear relationship. The physical simulation method was used to verify the correctness of the particle tracks obtained in the numerical simulation.

Fine particles of glass cullet (fines) arising during glass recycling cannot presently be recycled into glass manufacture due to the potential for bubble formation and foaming. Consolidation of glass fines into briquettes could enable their re-introduction into furnaces, reducing waste and glass melting energies. Properties of briquetted cullet fines and briquette melting behaviour in soda–lime–silica glass batches are presented. Morphology and density of glass fines and briquettes; and briquette mass and mechanical properties as functions of time after formation were analyzed. Compressive strength increases linearly with time after briquette formation. With slight batch modifications to maintain the same final glass composition, up to 15 wt% briquettes were successfully added to a representative container glass batch and melted. Results confirm that briquette batch additions can provide equivalent final glass composition, optical absorption characteristics and redox to briquette-free batches, supporting their industrial uptake.