Types of PU foam and Methods of Judging the Quality of the Products
PU foam, commonly known as Styrofoam, is a one-component, moisture-curing, multi-purpose polyurethane foam-filled elastic sealing material. Polyurethane foam gap filler is a special polyurethane product filled with polyurethane prepolymer, foaming agent, catalyst and other components in pressure-resistant aerosol cans. So how do we judge the quality of polyurethane foam in our daily life?
According to the foaming tool, there are two types: gun type and tube type, as well as one-piece barrel type. The gun-type foam needs to purchase a special spray gun to spray out the foam. After the spray gun is used, it needs to be cleaned with a special cleaner which is generally used in large-scale construction projects; the tube-type foam is equipped with a foaming nozzle which is simply easy to use, suitable for home decoration and various DIY operations.
Types and characteristics of PU foam:
*Universal type: imported raw materials, unique formula, good comprehensive performance, long shelf life
*Economical: economical, with various properties such as sound insulation, waterproof, shock resistance, etc.
*Engineering type: large amount of foaming, small cells, good stability, not easy to fall off
*Wooden type: high bonding strength, not easy to shrink, fast and firm installation
*Winter type: Minimum construction temperature: -10 degrees
*Flame retardant type: self-extinguishing from fire
Generally speaking, it is necessary to judge the quality of PU foam from the following 7 aspects:
1. Judging from the color. High-quality Styrofoam is milky white after being punched out. White or yellow color is not very good;
2. Gun type, when spraying foam, the sprayed foam should not be too thin or too thick, too thin foam will not collapse, too thick foam will dry, and the foam will shrink easily;
3. Cut the foam and look at the cells. The cells are uniform and fine, which is a good foam. If the cells are large and the density is not good, it is not good;
4. Looking at the surface of the foam, the surface of the good foam is gully-shaped, smooth but not very shiny; the surface of the poor foam is smooth and wrinkled;
5. Look at the size of the foam, the good foam is full and round; the poor foam is small and collapsed;
6. Look at the adhesion. Good foam has strong adhesion, and poor foam has poor adhesion.
7. Squeeze the Styrofoam block by hand, the dimensional stability of the good glue is good. It is elastic after fully cured, and neither soft nor hard;