What is HEMC for Gypsum Plaster?
HEMC, a non-toxic, white or light yellow, fibrous or powdered nonionic compound, is renowned for its exceptional solubility in both cold and hot water. Unlike some other cellulose derivatives, HEMC does not possess gel characteristics. One of its standout features is the wide range of substitution, solubility, and viscosity it offers. Additionally, HEMC exhibits excellent heat stability up to temperatures below 140°C and remains unaffected under acidic conditions. Its non-ionic nature ensures compatibility with both positive and negative ions, making it a popular choice for various applications, including coatings, binders, cement and gypsum additives, thickeners, suspending agents, excipients in medicine, antifogging agents, and even in the oil well fracturing and drilling treatment processes.
Performance of HEMC in Gypsum Plastering
Improved Workability and Plasticity
When incorporated into gypsum plaster, HEMC significantly enhances workability and plasticity. The plaster gains an impressive “oiliness” after HEMC addition, resulting in smoother surfaces and fuller wall joints. This attribute proves especially advantageous for large-scale construction projects, making HEMC an invaluable asset for achieving optimal results.
Enhanced Water Retention and Strength
In gypsum-based products, water plays a crucial role in the hydration reaction, leading to the setting and hardening of the plaster. HEMC aids in water retention, ensuring sufficient water is available for efficient hydration. This, in turn, improves the strength of the plaster. Adequate water retention also prevents water loss on the concrete surface, reduces cracks, and enhances adhesion and overall construction performance.
HEMC significantly enhances the bonding between gypsum plaster and substrates. It augments the initial bond force, ensuring firm adherence of ceramic tiles or bricks to the base and seamless bonding of plaster to walls. Proper dosage of HEMC is crucial to avoid inconveniences during construction and prevent hollow defects in plaster and caulking materials.
HEMC can be employed as a set retarder for cement-based building materials, including mortar, plaster, binders, and caulking materials. This effect proves particularly useful when a longer construction time is required, fulfilling specific project needs. Additionally, HEMC exhibits certain set-retarding properties in gypsum-based products, further adding to its versatility.