Double wall and hot ripple cups are specifically designed to withstand much high tempuratures, the dual layers work in a similar way to a thermos flask; trapping air and isolating the customer's hand from hot drinks. In addition to this, the extra cup strength is ideally suited to 'coffee on the go'.
With different high street coffee chains and drinks providers favouring different disposable cup materials, it is interesting to find out which is the most effective insulator. Perhaps the most appropriate way to discuss the insulating properties of a paper cup is to compare it with another frequently used takeaway cups, such as the common expanded polystyrene type. This can be done by carrying out a simple test to show whether the polystyrene or paper version kept the liquid it contained hotter for the greatest length of time.
Paper cups vs Polystyrene cups
The heat retention test involves putting 200 ml of very hot water into a polystyrene cup and the same amount into a paper hot drink cup to find out which is the better insulator. For a wider comparison, you could also introduce a plastic cup into the equation to reveal how its insulation properties measure up. We all know each of these hot cups will provide a specific level of insulation, but this test will help show which is the best way to keep liquids warm.
How to Test the temperature
You can use a thermometer to test the temperature of the liquid. Taking a temperature reading every minute for at least ten minutes, then again around 20 minutes and 30 minutes, will help to show whether the paper cup is indeed the best insulator. You can record these readings as a graph if you wish to make the results clearer.
In an extremely similar test, cup and food container specialist Contexpan discovered that the liquid in both cups dropped in temperature very fast during the first five minutes, from around 100 degrees centigrade to around 90 degrees. However, at this point, the liquid in the polystyrene cup cooled at a slightly slower rate than the paper version, remaining at around 80 degrees after 25 minutes compared with the liquid in the paper cup, which had dropped to around 70 degrees.
The findings suggest that the polystyrene cup is the better insulator, with the paper cup in second place. A third cup, a plastic cup, was used in the Contexpan test and this presenting inferior insulation properties, with the water temperature falling to below 70 degrees centigrade after 25 minutes. However, some catering supplies companies are now using double-layered disposable paper cups with an air pocket in between to trap the heat and provide an extra layer of insulation. Further tests would need to be carried out to discover whether this gives the paper cups the edge over polystyrene ones.