Eli5: How are double walled glasses made?


As an example, bodum makes coffee / tea glasses with an air space between two walls, insulating the drink, making it easy to hold the glass. How do they make it?

In: 3

This may or may not be disappointingly simple to you, but the answer is that they literally just make two regular glasses, one slightly smaller than the other, and then melt the rims together. Here’s a link to a video from a Chinese manufacturer where people do this by hand, but the manufacturing process will be the same fundamental steps anywhere, it’s just that they may be done by machines in other countries.


One method is to make a tube with a sealed end, then wrap the open end back onto itself similarly to aluminum metal spinning. Like pulling off a sock from the top until it is half inside out. This is probably impossible by hand but a machine with the right tooling could do it.