Structural glass-timber composite beams and shear wall elements were investigated in terms of their mechanical behaviour, energy performance and their LCA performance. The load bearing components were manufactured using annealed float glass which was adhesively bonded to the timber with different adhesives. The results show, among other things, that is is possible to join the two materials glass and timber and obtaining a non-brittle failure of the beams. The shear wall elements have the potential of being used as stabilising elements and load bearing walls in buildings of up to 4 storeys height. It is possible to combine glass and timber in a load bearing shear wall without loss of energy performance of a building or without loosing LCA performance. In addition to these benefits, the timber glass composite wall has, of course the benefit of being transparent.

The preceding part [M. Edén, J. Non.-Cryst. Solids, 357, (2011) 1595-1602] introduced the "split network" strategy for estimating the network polymerization degree (r A) and mean number of bridging oxygen (BO) atoms (N̄BOA) for a network former A, given that these parameters are known for all other network builders in the multi-component oxide glass. However, as the detailed ordering of BO and non-bridging oxygen (NBO) species is often difficult to assess experimentally, we summarize some "rules of thumb" for predicting the coordination number and tendency to accept NBO ions for Al 3+, B 3+, Si 4+ and P 5+ cations: they are helpful in scenarios devoid of experimental data. Using the parameters r and N̄BO, we present expressions for the BO/NBO distributions among tetrahedrally coordinated cations, as predicted from the binary and random models. Multinuclear 11B, 27Al and 29Si solid-state NMR is exploited to derive the split network representations of a set of Na-Ca-(Al)-(B)-Si-O glasses. These results are subsequently used to gain structural insight into two commercial glass-wool fibers that constitute alumino-borosilicate networks modified by Na +, K +, Ca 2+ and Mg 2+ ions. © 2010 Elsevier B.V.

The number of bubbles was monitored in antimony oxide fined R 2O-MxOy-SiO2 and R 2O-CaO-Al2O3-SiO2 glasses (R=Na, K; M=Ca, Mg, Ba, Sr, Zn, B, Al, Ti, x=1 or 2, y=1, 2 or 3) in order to evaluate the fining efficiency. Electrochemical measurements of oxygen activity were used to, in situ, monitor the fining characteristics and conditions in some of the investigated glass melts. The results showed that an increase of the calculated optical basicity was related to an increased number of bubbles in the glass samples. The oxygen activity in the melt during fining decreased with increased optical basicity.

The most widely used Standards to test the inner surface of glass containers for pharmaceutical use, European Pharmacopoeia and ISO 4802, may differ significantly in the results because of relevant differences in the procedures. In this study the rinsing procedures, effect of prolonging the cooling time to 95 °C, as prescribed by EN norms on safe operation practice, and the combination of the two factors were investigated. Nine laboratories participated in the collaborative study, the resulting extract solutions were analyzed both by titration and flame photometry. Results were evaluated by two way ANOVA with the aim of estimating three sources of variation: between procedures, between laboratories and random variation due to experimental error. For soda-lime-silica glass there is evidence that the different procedures influence the hydrolytic resistance of the inner surface of glass containers whichever method is used. Differences between laboratories were, however, much greater and results vary more due to which laboratory conducted the measurement rather than which procedure is employed. For borosilicate glass variations between procedures were found not to be significant. It is strongly recommended that ISO and EP shall adopt measures to minimize those factors that proved to exert great influence on reproducibility of results.

XRF spectrometry is extensively used for production factory control because of its high precision and rapidity of response. For very accurate boron determinations in glass, classical wet chemical methods are still the preferred method of choice as the x-ray irradiation of light elements produces only a weak fluorescent response. However, the new generation XRF instruments employing enhanced matrix correction models plus the greater availability of certified reference materials may significantly improve the analytical performance of XRF spectrometers for the determination of "difficult" elements like boron.

Enforcement of the Packaging Directive 62194 has required the development of reliable reference methods for the determination of heavy metals in glass. After considering Pb, Cd and Hg TC2 has undertaken a collaborative study for the determination of hexavelent chromium. In this recommended procedure the glass sample is digested with a mixture of sulphuric acid and ammonium hydrogen fluoride at room temperature, then diphenylcarbazide is added to form a violet complex which is measured with a spectrophotometer. Decomposition efficiency, matrix effect and interferences produced by foreign ions are discussed. For container glasses of common production no alteration of the chromium valence state was highlighted due to the dissolution process. This is not assured for glasses containing other redox pairs that should be examined case by case. The final round robin conducted on a glass containing given amounts of barium, did not reveal any significant absorption of hexavalent chromium on the low soluble salts that are formed during the dissolution process. The method is sensible down to 2 mgCr6+/kg of glass.

Six crystal glass compositions without added lead were used to prepare standard beakers having a volume of ca. 240 ml. The experimentally determined concentrations of the elements in the glass beakers were in satisfactory agreement with the theoretically predicted values. The degree of leaching of selected elements from these beakers was determined using 4% acetic acid as described in the ISO 7086-1:2000 standard test. In addition, to the degree of leaching by 4% acetic acid, migration into cola, red wine, 40% ethanol and 0.3% citric acid was also determined. Elements tested included antimony, barium, bismuth and zinc as these were considered to be of most interest. The results show that it is possible to produce durable glass containing no added lead. The overall quality of the glasses was good and the concentrations of the various elements migrating (leaching) into the various test solutions used was very small and it is clear that they would not present a hazard to consumers in the event that they were to use glasses of any of these compositions for consumption of either alcoholic or non-alcoholic beverages. The original ISO7086-1:2000 test using a 4% acetic acid leaching solution was developed to test for lead migration from crystal containing added lead and ceramic ware containing lead glazes or colouring. This work also shows that it is an excellent leaching agent for assessing the safety of crystal containing no added lead as it gave the highest degree of migration for all the glass compositions and all the elements tested. In the case of glasses containing ZnO, it was shown that the degree of zinc migration was linearly related to the mole-% of ZnO in the glass. With respect to the durability of glasses, it was shown that the degree of attack increases when the degree of silica depolymerisation increases. © 2003 Elsevier B.V. All rights reserved.

By use of data from both our own measurements in different Glafo projects and from literature its is possible to calculate optimised compositions. The main point is to be able to calculate the viscosity in a sufficiently exact way. This is possible by separating glass in different well defined glass systems. Comparisons between calculated data and measuring test results are made.

Candidate lead free glass enamels have been sought within the glass system described in general terms by the mole fractions 0·25R 2O.0·16(R'O, R2"O3). 0·59SiO2 where R=Li, Na, K; R'=Ba, Zn and R"=B, Bi. Glass compositions containing high mole fractions of Li2O were found to devitrify when they were heated to temperatures up to 530°C typical for the procedure used when fusing enamels to tableware glasses. The devitrification characteristics are complex and several peaks atributed to crystallisation were found by DSC characterisation. The thermal expansion coefficient(α) within the system ranges from 11-14×10-6 K-1 and the glass transition temperatures(Tg) between 410-460°C. The measured data could be fitted to the chemical composition by multiple regression analysis with a general equation of the form:(α, Tg)=K(α/T g)+Σ(cR×fR) in which K is a constant, c is the oxide mole fraction and f is an oxide specific factor. The statistical analysis correlation coefficients(r2) were around 0·9.

The strength of glass designs are relying on good surfaces. Complex shapes and small holes calls for new polishing methods. Polishing of glass using fluid jet polishing is well known as a suitable method for acquiring high quality surfaces. In this study the combination of higher pressure and aluminum oxide as polishing material is tested in terms of higher polishing performance. A design of experiment study is done where important process parameters are varied. The results are compared to fluid jet polishing using cerium oxide. The polishing effect on the float glass is evaluated using visual grading and by using optical profilometry. In addition an analysis of sustainability aspects are done comparing the two different polishing materials. It is clearly shown that aluminum oxide is increasing the polishing performance. © 2012 The authors and IOS Press. All rights reserved.

Glass is a common material in the everyday life. It is widely used in a variety ofapplications e.g. architectural, automotive, containers, drinking vessels, displays,insulation and optical fibers due to its universal forming ability, transparency, chemicaldurability, form stability, hardness and relatively low price. Flat glass is a wide market ofthe glass industry and generally ninety percent of all flat glass produced worldwide ismanufactured using the float forming process. There is a large market strive for thinnerand stronger glass in order to reduce costs, save energy, reduce environmental footprint,find new applications and to improve the working environment for labour working withmounting flat glass.

This study comprises the modification of flat/float glass surface by a novel route;exchange of ionic species originating from in-line vapour deposition of salt compared tothe conventional route of immersing the glass in molten salt baths. The aim of this workis to develop a novel process in order to improve the mechanical strength of flat/floatglass by introducing external material to the surface in a process with the obviouspotential to be automatic in industrial processes. Chemical strengthening has beenperformed by applying potassium chloride to the glass surface by vapour deposition andthermally activated ion exchange. The method presented here is anticipated to be used inproduction in the future and would make it possible to produce larger quantities ofchemically strengthened flat glass to a considerably lower cost.

Titania is widely considered as an alternative constituent for replacing heavy metal oxides in optical glasses. Its effect on optical properties, however, is complex. This is due to the dielectric properties of the prevalent ionic species, Ti⁴⁺, the potential co-existence of trivalent titanium, Ti³⁺, giving rise to intrinsic and extrinsic charge transfer reactions, and the existence of different coordination polyhedra, depending on matrix composition. Here, we present a systematic study of the optical properties of the soda-lime-silicate glass system as a function of TiO₂ addition. We consider the silica-rich region of the SiO₂-Na₂O-CaO-TiO₂ quaternary, which may be taken as model for a variety of technical glasses. Trends are described in the refractive index, the Abbe number, the optical bandgap and the Urbach energy. The addition of TiO₂ increases the refractive index and the optical dispersion while it lowers the optical bandgap and the Urbach Energy. Results are discussed in relation to relevant literature data towards using titania silicate glasses as high-index replacements for heavy metal – containing oxide glasses.

The effect of single-side ion exchange (using a KNO3:KCl mixture) on the ring-on-ring flexural strength of float glass has been studied. Two ion exchanged series, treated at 450 and 515°C, were investigated. The ion exchanged samples showed approximately 160 respectively 100% increases in their arithmetic mean strength compared to as-received float glass. Furthermore, a series of samples containing drilled holes were studied in order to investigate the effect of singleside ion exchange on such common construction elements. The samples that contained drilled holes were ion exchanged at 450°C and showed around 140% increase of the fracture load compared to the untreated samples containing drilled holes. As a general observation, the ion exchange treatment induced ∼110 MPa compressive stresses (515°C) and ∼180 MPa compressive stresses (450°C). The ion exchanged samples showed no significant increase in stiffness.

In this paper, colouration of the tin side of commercial soda-lime-silica float glass by copper ion exchange is described and characterised. Data on the resulting concentration versus depth profiles, absorbance versus depth profiles, UV-Vis spectra and CIE-Lab colour coordinates are reported. Fundamental aspects of the process of colouration are described and discussed. Optimum saturation of the colour is achieved after ion exchange at 520°C for 10 h or at 500°C for 20 h. The depth of the coloured layer increases with increasing treatment time. At the same time, a linear dependency is found between the values of a and b in the CIE-Lab colour space for variations of treatment time and temperature. The later indicates broad tunability of colouration between different shades of ruby and varying colour saturation. It is shown that colour arises from a redox reaction between copper species and residual tin ions, and that the depth of the coloured layer is governed by the position of the tin hump. The critical concentration of tin and copper to achieve colour formation was found to be ∼0·25 mol% and >1 mol%, respectively.

The methods of chemical strengthening for improving the mechanical properties of oxide glasses are reviewed. Chemical strengthening is compared with thermal strengthening and different methods of measuring strength are discussed. Different ions, salts and other related methods for improving the ion exchange process and mechanical properties are described as well as applications of strengthening.

The surface ablation cell (SAC), a laboratory equipment for determining surface concentration profiles, has been utilised to characterise surface ion exchange processes in float glass. In this paper, single-side ion exchange is reported. Data on the ion concentration profiles were used to calculate diffusion coefficients as well as the activation energy for K +-Na+ ion exchange. The air-sides of float glass samples were treated with two different salt mixtures, (I) 2:1 KNO3:KCI, and (II) 1:2 KNO3:KCl, (both by weight), and heated to different temperatures below Tg, 460-520°C. The diffusion coefficients calculated using a Green's function approach were in the ranges (I) 1.4×10-11 to 6.8×10-11 and (II) 1.8×10-11 to 6.0×10-11 cm2/s while those calculated using Boltzmann-Matano were in the ranges (I) 5.7×10 -11 to 14×10-12 and (II) 3.4×10-12 to 6.0×10-12 cm2/s. Average values of the activation energies obtained through the Green's function were (I) 111.0 kJ/mol and (II) 99.8 kJ/mol for the different salt mixtures.

This study suggests a different route for the modification of flat/float glass surfaces; i.e. exchange of ionic species originating from in-line vapour deposition of salt as compared to the conventional route of immersing the glass in a molten salt bath. The aim of this work is to develop a more flexible and, eventually, more rapid process for improving the mechanical strength of flat glass by introducing external material into the surface. We discuss how chemical strengthening can be performed through the application of potassium chloride on the glass surface by vapour deposition, and in-line thermally activated ion exchange. The method presented here has the potential to be up-scaled and to be used in in-line production in the future, which would make it possible to produce large quantities of chemically strengthened flat glass at a considerably lower cost.

Alkali cation exchange have received significant attention throughout the years, primarily with respect to introducing compressive stresses into the surface layer and for tailoring the refractive index surface profile. In the present paper, we discuss the trends in the effective diffusion coefficients when exchanging Na+ for monovalent cations (K+, Cu+, Ag+, Rb+ and Cs+) in the surface of soda-lime-silicate float glass. The discussion is based on structural glass chemistry data.

The abrasion resistance of coated glass surfaces is an important parameter for judging lifetime performance, but practical testing procedures remain overly simplistic and do often not allow for direct conclusions on real-world degradation. Here, we combine quantitative two-dimensional image analysis and mechanical abrasion into a facile tool for probing the abrasion resistance of anti-reflective (AR) coatings. We determine variations in the average coated area, during and after controlled abrasion. Through comparison with other experimental techniques, we show that this method provides a practical, rapid and versatile tool for the evaluation of the abrasion resistance of sol-gel-derived thin films on glass. The method yields informative data, which correlates with measurements of diffuse reflectance and is further supported by qualitative investigations through scanning electron microscopy. In particular, the method directly addresses degradation of coating performance, i.e., the gradual areal loss of antireflective functionality. As an exemplary subject, we studied the abrasion resistance of state-of-the-art nanoporous SiO₂ thin films which were derived from 5–6 wt% aqueous solutions of potassium silicates, or from colloidal suspensions of SiO₂ nanoparticles. It is shown how abrasion resistance is governed by coating density and film adhesion, defining the trade-off between optimal AR performance and acceptable mechanical performance.

Osseointegration is a prerequisite for achieving a stable long-term fixation and load-bearing capacity of bone anchored implants. Removal torque measurements are often used experimentally to evaluate the fixation of osseointegrated screw-shaped implants. However, a detailed understanding of the way different factors influence the result of removal torque measurements is lacking. The present study aims to identify the main factors contributing to anchorage. Individual factors important for implant fixation were identified using a model system with an experimental design in which cylindrical or screw-shaped samples were embedded in thermosetting polymers, in order to eliminate biological variation. Within the limits of the present study, it is concluded that surface topography and the mechanical properties of the medium surrounding the implant affect the maximum removal torque. In addition to displaying effects individually, these factors demonstrate interplay between them. The rotational speed was found not to influence the removal torque measurements within the investigated range.

Virtual Glass Academy - a pedagogical model for e-learning with multimedia support, is a pilot project which provides education over the web for glass workers. The goal of the project is to develop and test a pedagogical model for short, problem-oriented, interactive, web-based courses with multimedia support for the glass industry. The participants in the pilot course come from the three partner glassworks and the college.

Colour development of gold ruby alkali silicate glasses, when various elements are added to the batch, has been investigated. Elements used in the study are selenium, iron, tin, lead, antimony, cerium, titanium and bismuth. The colours are presented and compared by their Lab coordinates. Among the elements selenium and iron are found to be important, and the role of these elements in colour development is discussed. Thermodynamic calculations show that important oxidation states are Fe2+ for iron and Se0 and Se 2- for selenium, and that higher melting temperature improves the colour, as it affects the oxidation states of both Fe and Se.

A fluid jet with 50% by weight of aluminum oxide is used to polish float glass. Both water cut edges and holes as well as drilled holes are polished. Using a pressure of 3.5 MPa, a 1.26 mm nozzle and 64 passes of the jet over the surface a bright appearance is achieved. The polishing result is evaluated both with the naked eye and an optical profiler. During mechanical testing of untreated holes it was found that a drilled hole can withstand 20% higher forces than a water cut hole before failure. The condition of the edge where the tensile stresses appear is very important and future work includes polishing this edge. © 2012 The authors and IOS Press. All rights reserved.

The CIEL*a*b* coordinate system has been demonstrated as useful for describing the colour characteristics of decolourised flint glass. The amounts of cobalt and erbium oxides necessary for sufficient decolourising of additions of recycled coloured cullet can be calculated from the apparent linear dependence of the CIE a * and b* coordinates on the amounts of cobalt and erbium oxides added to the batch. For the success of such a calculation the colour point of the added cullet must be determined.

Planar ground float glass surfaces and the surfaces within holes are polished using fluid jet polishing (FJP) in order to improve their visual appearance or material strength. The large flexibility of FJP makes it suitable for polishing holes and other complex geometries. The influence of polishing speed, incident angle, distance, pressure, abrasive concentration, and nozzle diameter are investigated. Al2 O 3 is the abrasive used. The surface quality is evaluated visually and also measured with an optical profiler. The mechanical strength of the polished holes are evaluated with an MTS testing machine. Planar surfaces, and the surfaces of drilled and water cut holes are greatly improved by polishing. For a planar surface the lowest root mean square surface slope, Sdq, value achieved is 0•5 deg using 50% abrasive and 1000 mesh grains. The failure load of the glass with drilled holes increased 20% with FJP.

In this paper, the use of a surface ablation cell (SAC) to quantify the elemental compositional depth profile of float glass is presented. High spatial resolution data of 10-20 nm is reported. Elemental resolution is also high so that, for example, the tin hump, which is not normally observed in low iron borofloat glasses, is recorded with good resolution. The technique is based on a wet dissolution of the glass surface on a layer by layer basis using ordinary equipment available in most chemical laboratories. Due to its simple nature, the procedure required further collaborative investigation with other instrumental surface analytical techniques. The results obtained compare very favourably with those obtained by secondary ion mass spectrometry (SIMS). It is shown that sample pretreatment is important and directly affects the outcome of the investigation. The effects of acid concentration, and probably most other experimental parameters, are also shown to affect the step length in the profiling process. The future use of the SAC as a complementary technique for surface studies is foreseen both in laboratories and also in the production environment as a reliable off-line technique for surface characterisation. The technique was developed through a collaborative workprogramme devised by Technical Committee 2 (Chemical Durability and Analysis) a technical sub-committee of the International Commission on Glass (ICG/TC-02).