HPMC For Gypsum Finishing Plaster

Due to its special structure and groups, the water retention of HPMC is irreplaceable by other substances. No matter what kind of filler is mixed in, as long as it is mixed in large amount, its water retention will be greatly reduced. Water retention is an important indicator of the merits of HPMC, whether it is good or bad, as long as it is added to the mortar, it will be clear at a glance.

The following differences exist between pure HPMC and adulterated HPMC

1. Pure HPMC aqueous solution is clarified and highly translucent, with water retention rate ≥ 97%. Adulterated HPMC aqueous solution ro cloudy, water retention rate is difficult to reach 80%.

2. Pure HPMC powder is fibrous under the microscope or magnifying glass. Adulterated HPMC can be observed under a microscope or magnifying glass granular solids or crystals.

3. pure HPMC is visually fluffy and has a small bulk density, ranging from 0.3-0.4g/ml. adulterated HPMC has better fluidity and a heavier feel. There are obvious differences with the appearance of genuine products.

4. Pure HPMC should not smell of ammonia, starch and alcohols. Adulterated HPMC can often smell all kinds of flavors. Even if it is odorless, it will feel heavier in the hand.

Common adulteration methods and identification methods

1. The addition of polyvinyl alcohol powder. Polyvinyl alcohol powder such as 2488, 1788 market price is often lower than cellulose ether, mixed with polyvinyl alcohol powder can reduce the cost of cellulose ether.

Identification method: such cellulose ether tends to be granular and denser. Dissolve quickly with water, pick the solution with a glass rod, there will be a more obvious drawing phenomenon.

2. Add cellulose ether of starch. Starch is generally insoluble in water, and the solution tends to have poor transmittance.

Identification method: use iodine drops into the cellulose ether solution, the color becomes blue can be considered to have added starch.

3. The addition of amide cellulose ether, can make the cellulose ether solution viscosity increases rapidly, resulting in the inability to identify by viscometer.

Identification method: due to the characteristics of amide, such cellulose ether solution often appears pulling phenomenon, and good cellulose ether dissolved will not appear pulling phenomenon, the solution is like jelly, the so-called sticky but not connected.

Mortar industry competition is becoming increasingly fierce. Due to the lax market supervision, some merchants adulterate a lot of low-cost substances to meet the market and produce cheap cellulose ether. As a Hydroxypropyl Methylcellulose Supplier, we are obliged to remind our customers that not to pursue low prices, so as not to be deceived and cause engineering accidents, which will eventually outweigh the losses. Please feel free to contact us if you need high quality HPMC.