Can HPMC Still Be Used in The Construction Industry After It Gets Damp?

In the construction industry, Hydroxypropyl Methylcellulose (HPMC) is an indispensable additive, widely used in building materials such as mortar, tile adhesive, and putty. Its primary functions are thickening, water retention, and improving the workability. However, due to its high hygroscopicity, moisture during storage or transportation may affect its effectiveness. So, can HPMC still be used in the construction industry after it gets damp? Today, we will explore this question from the perspective of construction applications.

Potential Impacts of HPMC on Construction Materials

1. Reduced Solubility: Damp HPMC may clump, resulting in uneven dispersion in mortar or putty, affecting the uniformity and bond strength of the final product.

2. Reduced Water Retention: HPMC's core function is to lock in moisture and prevent the mortar from drying out too quickly. However, moisture can damage its molecular structure, weakening its water retention and leading to cracking or hollowing.

3. Poor workability: If HPMC clumps due to moisture, the mortar's fluidity and spreadability may deteriorate, making application more difficult.

How to determine if HPMC is damp?

- Observe the appearance: Normal HPMC should be a fine powder, but it may clump or darken in color when damp.

- Flowability test: Damp HPMC has reduced fluidity and may form lumps when poured.

- Dissolution test: Take a small amount of sample and dissolve it in water. If it dissolves slowly or undissolved particles appear, it may be damp.

Can HPMC still be used in the construction industry after being damp?

If the HPMC is only slightly damp, you can try the following methods to restore its use:

✅Low-temperature drying: Dry at 50-60°C to prevent high temperatures from damaging its properties.

✅ Sieving: Remove lumps and retain usable powder.

✅ Adjust the formulation: Increase the mixing time or adjust the dosage to ensure complete dissolution.

However, if HPMC is severely clumped, moldy, or has extremely poor solubility, it is recommended that it be discarded. Otherwise, it may affect the mortar's strength, adhesion, and application results.

How to prevent HPMC from getting damp?

- Strictly seal: Tighten the packaging bag immediately after use or transfer it to a moisture-proof container.

- Control the storage environment: Store in a dry, well-ventilated area, avoiding high temperatures and humidity.

- First-in-first-out: Avoid long-term storage and prioritize using HPMC from earlier batches.

Have you ever encountered HPMC getting damp during a construction project? How did you handle it? Share your experience in the comments! If this article is helpful, please like and share it with your colleagues.