Insulated concrete forms (ICF) manufacturing process comprises the following stages:
1. Raw material preexpansion.
This is one of the most important stages of the whole process and it influences the quality of the end product tremendously. The preexpander is filled with the necessary amount of raw material and then forced steam is fed to the preexpander. As the result raw beads increase manifold in diameter (they get “expanded”). As the expanded granules reach the volume of 1 m3 steam supply is cut, the preexpander gets unloaded and the expanded granules are fed to silo bunkers by suction. Depending on the desired EPS density brand raw material is fed to the preexpander at the respective rates. Raw material brand is also of great importance as the brands differ in sizes (fractions).
2. Beads aging in silo bunkers.
There internal stresses of the beads are stabilized and the preexpanded material is dried after steam treatment. The aging time is between 12 and 24 hours depending on the raw material brand.
3. ICF block molding.
Once the beads have aged they are loaded to the blockmold with the help of a measuring tank. There they are treated by heat and as the result beads get expanded once again and thus are molded into an ICF block. The molded block is then cooled inside the blockmold by water.
4. Block aging.
The molded block is aged in normal condition for 12-24 hours in order to stabilize internal stresses and to reduce its moisture content.
5. Waste grinding.
Waste is ground in the grinding machine and is then fed to a separate storage bunker by suction. Ground EPS can be reused to manufacture ICF blocks, it should be added to the new beads in the ratio of not less than 3 per cent.