The main role of each material
- HPMC is a cellulose ether used mainly for water retention and thickening. It reduces rapid moisture loss from mortar.
- HPS is a starch ether that adjusts consistency and resists sag, helping reduce tile slip on walls.
- RDP is a redispersible polymer powder used mainly to improve mortar adhesion and flexibility.
- PVA 2488 is a water-soluble polymer used for adhesion and film formation. It also helps reduce surface dusting in wall putty.
An example in tile adhesive
In tile adhesive, HPMC helps retain water, HPS helps reduce tile slip, and RDP improves adhesion and flexibility. They perform different jobs and can be used together.