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This is the complete lecture note for ICH 319 Glass blowing Practical. You can read it online below, open it in the full viewer, or download the PDF for offline study. It pairs with the course's video lectures, so you can read and watch together.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Course code: ICH 319 Course title: Glassblowing Practical Course unit: 1 Unit Series 1: Properties and Types of Glass for Laboratory Use Part 1 Properties of glass in general use 1.1.1 Physical and chemical properties of glass 1.1.2 Thermal properties: annealing, thermal resistance, and expansion 1.1.3 Manufacturers’ symbols and what they represent Part 2 Types of glass used for laboratory wares 1.2.1 Common types of laboratory glass (e.g., borosilicate, soda-lime) 1.2.2 Specialised glass types (e.g., quartz, lead glass) 1.2.3 Comparative advantages of different glass types Part 3 Identification methods for laboratory glass 1.3.1 Visual and physical identification methods 1.3.2 Testing for working temperatures and coefficient of expansion 1.3.3 Correlation of properties for laboratory applications Introduction Glass is one of the most versatile materials used in laboratories, yet its properties and types are often taken for granted. From test tubes to specialised apparatus, the choice of glass determines how safely and effectively experiments can be carried out. Understanding the properties of glass, the symbols used by manufacturers, and the different types available for laboratory use is therefore essential for anyone learning the art and science of glassblowing. This Series sets the foundation for practical skills by helping you appreciate the material you will be working with. The aim of this Series is to introduce you to the properties and types of laboratory glass, and to equip you with the knowledge needed to identify, classify, and evaluate glass materials for practical applications in laboratory settings. We shall commence this Series by examining the properties of glass in general use, including its physical, chemical, and thermal characteristics, as well as the meaning of manufacturers’
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS symbols. Next, we will move on to the types of glass commonly used for laboratory wares, considering both standard and specialised varieties and their comparative advantages. Finally, we will wrap up by exploring identification methods, focusing on visual and physical techniques, working temperatures, and the coefficient of expansion, so that you can confidently select and apply the right glass for laboratory practice. Series Learning Outcomes Upon completing this Series, you should be able to: define the physical and chemical properties of glass in general use, explain the thermal properties of glass, including annealing, thermal resistance, and expansion, interpret manufacturers’ symbols and state what they represent, classify the types of glass commonly used for laboratory wares, describe specialised types of laboratory glass and their distinctive features, analyse the comparative advantages of different types of laboratory glass, demonstrate methods for identifying laboratory glass through visual and physical examination, determine the working temperatures and coefficient of expansion of selected glass types, and evaluate how the correlation of glass properties influences its suitability for laboratory applications. 1.1 Properties of Glass in General Use 1.1.1 Physical and chemical properties of glass Glass is a non-crystalline, often transparent material formed by cooling molten substances without allowing them to crystallise. Its physical properties include transparency, hardness, brittleness, and resistance to chemical attack. Its chemical properties vary depending on composition, but generally glass is resistant to many acids, though it can be attacked by strong alkalis and hydrofluoric acid. These properties make glass suitable for laboratory wares, where clarity and chemical resistance are essential. Fill in the blank: Glass is resistant to many __________ but can be attacked by strong alkalis and hydrofluoric acid.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Figure 1.1 Physical and chemical properties of glass 1.1.2 Thermal properties: annealing, thermal resistance, and expansion Annealing is the process of slowly cooling heated glass to relieve internal stresses. This ensures durability and reduces the risk of cracking. Thermal resistance refers to the ability of glass to withstand rapid temperature changes without breaking. Coefficient of expansion is a measure of how much glass expands when heated. Laboratory glass must have a low coefficient of expansion to resist thermal shock during heating and cooling. Fill in the blank: The process of slowly cooling heated glass to relieve internal stresses is called __________.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Plate 1.1 Annealing process in glass production 1.1.3 Manufacturers’ symbols and what they represent Manufacturers often mark laboratory glassware with symbols that indicate its properties. These may include the type of glass, its coefficient of expansion, recommended working temperature, and resistance to chemicals. Recognising these symbols helps users select the right glassware for specific laboratory tasks. For example, borosilicate glass may be marked with a symbol indicating its low expansion and high thermal resistance. Fill in the blank: Manufacturers’ symbols on laboratory glassware indicate properties such as coefficient of __________ and working temperature. Common manufacturers’ symbols on laboratory glassware Borosilicate glass: low expansion, high thermal resistance. Soda-lime glass: moderate expansion, lower thermal resistance. Quartz glass: very high thermal resistance, negligible expansion.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Pilot questions 1.1 Define glass and state two of its physical properties. Which acid can attack glass? What is annealing? Why must laboratory glass have a low coefficient of expansion? What information do manufacturers’ symbols provide on laboratory glassware? 1.2 Types of Glass Used for Laboratory Wares 1.2.1 Common types of laboratory glass Borosilicate glass is a type of glass containing silica and boron trioxide, known for its low coefficient of expansion and high resistance to thermal shock. It is widely used in laboratory wares such as beakers, flasks, and test tubes. Soda-lime glass is composed mainly of silica, soda, and lime. It is cheaper and more common but less resistant to heat and chemicals compared to borosilicate glass. Fill in the blank: The type of glass that contains silica and boron trioxide, and resists thermal shock, is called __________ glass. Figure 1.2 Common types of laboratory glass 1.2.2 Specialised glass types
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Quartz glass is made from pure silica and has very high thermal resistance, making it suitable for high-temperature applications. It is often used in furnaces and specialised laboratory equipment. Lead glass, which contains lead oxide, is valued for its high refractive index and is sometimes used in optical instruments. These specialised glasses are chosen when ordinary laboratory glass cannot meet the demands of specific experiments. Fill in the blank: Glass made from pure silica with very high thermal resistance is called __________ glass. Plate 1.2 Specialised laboratory glass types 1.2.3 Comparative advantages of different glass types Each type of laboratory glass has its own comparative advantages. Borosilicate glass is durable and resistant to heat, making it ideal for general laboratory use. Soda-lime glass is inexpensive and suitable for simple applications where high thermal resistance is not required. Quartz glass withstands extreme temperatures, while lead glass is useful in optical applications. Selecting the right glass depends on the intended use, cost considerations, and safety requirements. Fill in the blank: The type of glass most suitable for general laboratory use due to its durability and heat resistance is __________ glass.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Comparative advantages of laboratory glass types Borosilicate glass: durable, heat resistant, widely used. Soda-lime glass: inexpensive, suitable for simple applications. Quartz glass: withstands extreme temperatures. Lead glass: high refractive index, useful in optics. Pilot questions 1.2 What is borosilicate glass commonly used for in laboratories? State one limitation of soda-lime glass. Which type of glass is made from pure silica? What property makes lead glass useful in optical instruments? Why is borosilicate glass preferred for general laboratory use? 1.3 Identification Methods for Laboratory Glass 1.3.1 Visual and physical identification methods Identification methods are techniques used to recognise the type and properties of laboratory glass. Visual identification involves observing the colour, clarity, and markings on the glass. For example, borosilicate glass often has a clear appearance and may carry manufacturer symbols indicating low expansion. Physical identification includes checking the weight, thickness, and feel of the glass. These methods are quick and practical for everyday laboratory use. Fill in the blank: Observing the colour, clarity, and markings on glass is known as __________ identification.
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