When were ground glass joints invented?
When were ground glass joints invented?
1984
They are available in a variety of materials for different temperature and chemical environments. Patented in 1984 by Hermann Keck, plastic joint clips are usually made of polyacetal, and are colored according to joint sizes.
What is ground glassware?
Ground glass is glass whose surface has been ground to produce a flat but rough (matte) finish, in which the glass is in small sharp fragments.
What is the purpose of using grease on ground glass joints?
although ground-glass surfaces seal well without the use of lubricants, it is advisable to lubricate them to prevent sticking and breakage.
How are ground glass joints measured?
The first number represents the outer diameter (OD) in millimeters (mm) at the top (widest part) of the inner joint. The second number represents the ground glass length of the joint in millimeters. The most common US joints are 14/20 and 24/40. These sizes apply only to glassware in the US.
What are the different sizes of ground glass joints commercially available?
Common joint sizes are 14/20, 19/22, and 24/40. The first number refers to the inner diameter (in millimeters) of a female joint or outer diameter of a male joint. The second number refers to the length of the joint (Figure 1.1b).
How does ground glass work?
The ground glass (or plastic) screen acts as a diffuser, scattering light passing through it randomly rather than simply letting it pass through unaffected.
Why is it important to disconnect ground glass joints soon after use?
Dust in a glass joint may cause leakage and grit may even cause breakage. Therefore, before use, glass joints should be wiped free from foreign matter. After use, joints should be separated as soon as possible, preferably while still warm to prevent seizure.
Why is it important to grease the ground glass joints in the distillation and reflux apparatus?
Ground glass joints are manufactured to fit quite well with one another, and yet they are not perfectly airtight. In some situations (e.g. when using reduced pressure inside an apparatus), grease must be applied to each joint to ensure a good seal.
How do you remove ground glass joints?
Use insulated gloves or a hook to pull the joint free. Using a heat gun is usually not recommended. Heat guns will typically heat the outer joint and inner joint at a slower rate, therefore allowing the inner joint to expand at almost the same rate as the outer.
