The Expandable Polystyrene (EPS) Thermal Insulation Rendering System (ETIRS), as a widely used site-applied insulation system, derives its core performance from the quality of the dry-mixed bonding powder. This powder, when mixed on-site with recycled EPS beads, forms an insulating plaster that combines excellent thermal insulation, mechanical strength, and workability.

A typical formulation system for high-performance bonding powder is:
Cement + Supplementary Cementitious Materials + Fillers + Cellulose Ether + Modified Polyethylene Oxide (PEO) + Redispersible Polymer Powder (RDP) + Polyvinyl Alcohol (PVA) + Wood Fiber + Polypropylene Fiber.

Each component plays an indispensable role:

• Cement, SCMs & Fillers: Form the strength foundation and skeleton of the system.

• Cellulose Ether: Provides crucial water retention and thickening, ensuring plaster workability, preventing rapid water loss, and enhancing cohesion.

• Modified Polyethylene Oxide (PEO): Significantly improves plaster viscosity and rheology, enhancing anti-sag properties for easier, more uniform application.

• Redispersible Polymer Powder (RDP) & Polyvinyl Alcohol (PVA): These two work synergistically to provide exceptional adhesive strength, flexibility, and film-forming properties. They are key to achieving high bond strength, crack resistance, and impact resistance in the plaster.

• Wood Fiber & Polypropylene Fiber: Provide three-dimensional reinforcement and crack resistance. Wood fiber improves wet mortar anti-sag and application feel, while polypropylene fiber effectively inhibits plastic and drying shrinkage cracking, enhancing the toughness of the hardened material.

Addressing the technical requirements of bonding powder formulations, SidleyChem offers proven specialized products:

• Cellulose Ethers:

  • Hydroxyethyl Methyl Cellulose (HEMC): e.g., ME 36M10, offering high water retention and excellent application smoothness.

  • Hydroxypropyl Methyl Cellulose (HPMC): e.g., MP 36M10, providing good water retention, thickening performance, and cost-effectiveness.

• Polymeric Bonding & Enhancing Components:

• • Redispersible Polymer Powder (RDP): Options include 7028 (Economy Grade), 66145/66155 (Standard/Enhanced Grade), etc., to meet different adhesive strength and flexibility demands.

  • Polyvinyl Alcohol (PVA): 2488 (High viscosity, high bond strength), 1788 (Fast-dissolving, high flexibility), used to further enhance plaster adhesion and cohesive strength.

• Rheology Modifier:

  • Modified Polyethylene Oxide (PEO): GH 5596, specifically designed to improve the rheological properties of insulating plaster, effectively enhancing workability and anti-sag resistance.

• Crack-Resistance Fibers:

  • Wood Fiber: W500 / G500, improves wet mortar workability and reduces early-stage cracking.

  • Polypropylene Fiber: PP 6mm / 12mm, provides long-term physical reinforcement, significantly improving the crack and impact resistance of the hardened plaster.