Ambassador for Glass … Talking Prompts (#7)
Spun glass fibres
The fluctuating supply and prices of raw silk prompted a search for man-made alternatives. Fabrics using spun glass were manufactured for furnishings from the 1830s (there’s a skein of spun glass in the V&A dated c1847). Fibres are produced by flameworking: a glass rod is heated to a workable temperature and drawn into minute fibres with a diameter of 10 to 40 micrometres. The end of the fibre is fixed to a rotating wheel and thereby endless filaments can be produced when the glass rod is fed continuously into the flame. The picture shows Princess Eulalia of Spain wearing a spun-glass dress made in the US by The Libbey Glass Company in 1893.
Sources: Corning Museum of Glass and V&A
Ambassador for Glass … Talking Prompts (#8)
Role of Glass in Sportswear
With the help of glass tubes, natural latex is transformed into threads, notably to satisfy the textile flexibility needed by sportswear and underwear industries. Liquid latex is injected through dozens of thin tubes to produce threads by machine, forming numerous continuous threads lying side by side, which are then passed through further processing stages. The tubes are permanently immersed in a liquid of sulphuric acid, which hardens the liquid latex immediately after injection. Chemical and rust resistant borosilicate glass capillaries are replacing stainless steel ones in this process. And the capillaries also offer narrow and stable tolerances of their inner diameter to ensure precise thread strengths and smooth textile surfaces.
Source: Schott AG
Photo: World Flex Public Company Limited
Ambassador for Glass … Talking Prompts (#9)
Perplexing strength of glass
Category: Physics of glass
Glass is one of the most fascinating materials for scientists. It is no ordinary solid – nor is it a liquid. It lies somewhere in a somewhat enigmatic hybrid zone, known as an amorphous solid. In some applications, it might shatter quite easily but actually it is a lot more rigid and strong than it technically should be, if we consider its molecular make-up. Now, scientists have come closer to revealing the source of this secret strength. Using a newly devised computer model to figure out how the atomic particles in glass keep it together, despite lacking a conventionally ordered structure, they observe that these particles can put a force-carrying “backbone” in place before the glass fully cools from its unstable, viscous state. A small proportion of the overall particles take the strain, in the midst of general disorder from a microscopic perspective. Particles in this critical network must be connected by at least two strong bonds, the scientists explain, at which point a network can form that links the entire system together – even if most of the molecular arrangement is chaotic.
Ambassador for Glass … Talking Prompts (#10)
Glass vials critical for COVID vaccine
Borosilicate glass (mainly silica and 7 – 13% boron trioxide) with its excellent properties of chemical and thermal resistance will be the material of choice for the supply of COVID-19 vaccines. (We hear the Pfizer vaccine has to be stored at -70degC). Millions of multi-dose vials will be needed, each typically holding 5 – 10 doses. The glass industry produces about 15-20 billion vials a year today, even without a pandemic. German manufacturer Schott AG, a leader in medical glass containers whose founder Otto Schott invented heavy-duty borosilicate glass in the 1890s, said it was pulling out all the stops for its part in supplying an expected extra billion multi-dose vials for the global immunisation drive.