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Mystery of the Vanishing Foam

Mystery of the Vanishing Foam
A lab developed a new type of foam mattress. Samples were shipped to a customer, but upon arrival the foam had disappeared. What happened?
Mysteries of Science


This case begins at a chemical plant where many raw materials were made for other industries. One of these materials was urethane foam, a self-foaming plastic.

The polyurethane reaction generates gas as the polymer forms, producing the foam. The foamed plastic is used mainly in beds and furniture. This plant offered additional services making up formulas, producing customer samples and sending data on the properties. The lab was working on developing a very foamy mattress for one customer.

The formula was sent and big slabs were poured into mattress-sized boxes. The boxes were coated with a waxy release material and the box was later be stripped away leaving the foam mattress.

The mattress samples were then shipped by rail to the customer.

Two weeks later the salesman got a call from the customer. They had just received a shipment of empty boxes. What happened to the mattress samples?

Here's the rest of the story.

One chemist asked,"How hot does a boxcar get in Texas?" "At least 150 degrees F, probably closer to 200 F", was the answer. He headed for the lab and turned the oven to 175 degrees where he intended to simulate a Texas boxcar. In went a slab of the same foam.

The next morning, the chemist opened the oven door and found NOTHING! Well, almost nothing. There was some powder on the oven floor. The urethane, being mostly empty space, had disintegrated under the heat, and the once-strong polymer was a now powdery product that looked like light-brown dirt.

Although the extra foamy formula appeared sound, it was thermally unstable. The Texas boxcar was not empty. There was certainly some powder on the floor and had been assumed to be the normal dirt that ends up in well-used boxcars.


Some beds are not meant to be slept in. This is proof in the making.
Carla Meyer

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