Author Question: Describe how foamed plastic egg cartons are made. What will be an ideal ... (Read 22 times)

kshipps · **on:** Aug 19, 2018

Describe how foamed plastic egg cartons are made.

What will be an ideal response?

Question 2

What is an integral skin, and how is it controlled?

What will be an ideal response?

Loise Hard · **Reply #1 on:** Aug 19, 2018

Answer to Question 1

Foamed egg cartons are often made by thermoforming extruded foam sheets. The sheet is made by the normal extruded foam process. The thickness would be the same as that desired in the finished product. After the foam has stabilized, the foamed sheet can be thermoformed in-line so that the operation will move at the speed of the extrusion. The cartons can be trimmed from the sheet and the remaining material can be chopped and re-extruded.

Answer to Question 2

An integral skin is a tough outer layer of the foam that is formed when the cells collapse due to contact with the mold, with air, or with any other substance other than the foam. The amount of cellular collapse to create the integral foam can be controlled by adjusting the pressure and temperatures surrounding the foam, the temperature of the foreign material touched by the foam, and the presence of any other foreign substance, such as water or dust that might cause the cells to collapse.