In construction, plaster materials are widely used in plastering, wall leveling, and decorative coatings due to their environmental friendliness and light weight. However, one of the most common and headache-inducing problems at construction sites is hollow drums, delamination, and flaking. The underlying cause is often insufficient plaster adhesion and poor water retention.
So, how can this problem be addressed at its root? HPMC (hydroxypropyl methylcellulose) provides the solution.
I. The “invisible killer” of insufficient bonding strength of plaster materials
In building decoration, plaster-based leveling materials are widely used in interior wall and ceiling construction due to their light weight and environmental friendliness. However, in actual construction, plaster materials are prone to quality problems such as hollows, delamination, and peeling, which cause many problems in subsequent processes. The root cause of the problem often lies in the poor water retention and insufficient bonding strength ofplaster.
Most wall substrates have strong water absorption capabilities, such as aerated concrete, brick walls, and cement walls. When plaster materials are scraped and coated on them, moisture is quickly absorbed, and the plaster begins to dry and solidify before it has fully hydrated, forming dry cracks and cavities, which weaken the interface bonding strength and ultimately lead to hollows and peeling. This problem is even more obvious in large-area construction or high-temperature dry environments.
II. HPMC: Creating a strong water-retaining film to stabilize plaster hydration
Hydroxypropyl methylcellulose (HPMC) is a high-performance water-soluble polymer widely used in dry powder building material systems. Adding an appropriate amount of HPMC to plaster materials forms a “water-retaining film” in the mortar, effectively locking in water, delaying moisture loss, and allowing the plaster to undergo a sufficient and uniform hydration reaction before initial setting.
This highly efficient water retention can significantly reduce the negative effects of water absorption by the base layer, making the plaster more adhesive and the interface more solid. Actual measurement data shows that HPMC has a water retention rate of over 98%, which is 30% to 50% higher than ordinary materials, effectively reducing problems such as dry cracking, hollow drumming, and powder shedding caused by excessive water loss.
In addition, good water retention also brings a more stable setting time, which helps construction personnel operate flexibly and improves work efficiency.
