What is the tensile strength of a No 6 widgit ?

Answer 1

Not even sure how you spell widgit. but it keeps the froth coming up on top !!!

Answer 2

Try this!

WIDGETS FOR BEER



You've all no doubt seen the adverts for beer cans with widgets. Some of you may even have tried several of them. The widget is here to stay, it's big business (about 100 million per year) and, surprisingly, it involves some very clever materials engineering. The development of the widget has come about for several reasons:

1) The British like beer to have a low dissolved CO2 content when poured (i.e. not gassy) but to have a good head due to large numbers of gas bubbles produced when pouring.

2) With draught beer, this is easy to achieve by passing the beer through a venturi nozzle to introduce lots of air bubbles when pouring.

3) Canned beer needs to have a higher internal CO2 pressure to ensure that the cans have sufficient strength for stacking and also to provide some form of head when poured. The problem was to develop some way of getting the dissolved gas out of solution rapidly when the can was opened, to give the creamy head and low gas content that typifies the "just served by the landlord" appearance.



The answer to this was the widget.



The Guinness Widget
Guinness were the first to develop a widget, which consists of a hollow capsule fitted at the bottom of each can. Each capsule has a very small hole in it, through which some liquid enters at the high pressures involved in filling the can. When the can is opened, the liquid in the widget (still under pressure) is forced out through the very small hole. This causes a large number of very small bubbles to be formed from the dissolved CO2, which give the creamy consistency and thick head.







The main problem with this design is that the amount of bubbles produced depends on the temperature. Unless the can is cold when opened, excessive amounts of foam are produced, with very messy consequences.



The Whitbread Widget
The Whitbread widget (illustrated below) uses some clever materials engineering to overcome this problem with a different design. High pressure nitrogen gas is injected into the widget through a one way valve before it is placed in the can. The can is then filled, sealed and pasteurised (at 62° C). When the can is opened, the nitrogen in the widget has to get out the wrong way through the one-way valve.

You might like to consider ways in which this might be achieved.

[Answer] :

The temperature of pasteurisation changes the properties of the widget material, making it more flexible and allowing the nitrogen to escape through the one-way valve (after the liquid pressure above it has been reduced on opening).







The material to be used for the widget has to satisfy some special requirements. Consider what these might be.

[Answer] :

a) Low toxicity and to be compatible with beer.

b) Easily mouldable to accurate dimensions (to ensure good operation of the one-way valve) at a very rapid rate (roughly 1/2 million are produced per day).

c) Cheap.

d) Light (to reduce transport costs).

e) To be a material that doesn't creep (see box) at storage temperatures as this would allow gas to escape. However at 62 °C, it must be flexible enough to relax and so allow the nitrogen to escape.

Creep
Any material under a continual load will gradually stretch (as atoms slowly rearrange themselves and slip past one another). This is known as creep. It is only a problem at high temperatures for metals, but with plastics, it can occur at room temperature. reducing the temperature slows the process, but in this case, storing widgets becomes more expensive with more refrigeration.



Material
In order to get the relaxation required at 62 °C, a plastic is needed. Polypropylene best satisfies all the other criteria, though very careful control of properties (such as molecular weight, structure and additive concentration) is needed to ensure consistent operation of widgets.

Answer 3

Twice that of a number 3 and half that of a number 12.

Answer 4

6 kebabs per pint glass squared

Answer 5

63 ft.lbs

Answer 6

bottle of wine

Answer 7

12 per cent proof...

Answer 8

5 tonne, i dunno. I though widgets, were in beer tins. Just ignore this, i'm writing a lot of cr*p.