The role of HPMC in gypsum products
Gypsum plays a very important role in the construction materials industry. Compared to cement, gypsum has unique characteristics.
A little swelling after hydration, no hollow drums or cracks in the cementitious material.
After curing, a large number of porous structures are formed in the material, which have a respiratory, sound-absorbing and acoustic effect. This regulates the humidity in living and working places and creates a comfortable climate, so gypsum is playing an increasingly important role in interior decoration.
China is rich in natural gypsum resources and its energy consumption per unit is 78% lower than that of cement. Gypsum can be recycled.
Desulphurisation in power plants produces large amounts of gypsum, which also provides a rich source of gypsum.
It is the superior properties of gypsum that are being used more and more widely.
Impact of
HPMC for gypsum products
With the rapid development of the construction industry, there is a growing demand for new building materials. Due to the increasing awareness of environmental protection and the increasing efficiency of construction, gelling materials and plaster products have been developed rapidly. The most common plaster products nowadays are gypsum plaster, adhesive plaster, embedded gypsum and tile adhesives.
Gypsum plaster is a high quality plastering material for internal walls and ceilings. After use, the wiped wall surface is smooth and delicate, not powdered, firmly bonded with the substrate, no cracking or peeling phenomenon. And it has a fireproof function.
Adhesive plaster is a new adhesive for construction light boards, which is a sticky material made of gypsum as the base material with a variety of additives. It is suitable for bonding between all kinds of inorganic building wall materials. It is non-toxic, odourless, early, strong, fast curing and firmly bonded and can be used as a support material for building panels and buildings.
These gypsum products have a range of different functions. Gypsum and associated fillers play a role. In addition, the key issue is that the addition of cellulose ether additives plays a leading role. As gypsum can be divided into hard gypsum and hemihydrate gypsum, different types of gypsum have different effects on the performance of the product, so properties such as thickening, water retention and slow setting determine the quality of gypsum building materials.
The common problems in these materials are hollowing cracks and not reaching the initial strength. In order to solve this problem, the compound of the model of celluloses with the retarder can be chosen for use.
In this regard, hydroxy propyl methyl cellulose 30000-60000cps is generally chosen, and the addition amount is 1.5% – 2%. In it, the cellulose plays a main role in water retention, retarding and lubrication. However, in this process, the cellulose ether alone as the retarder cannot reach the effects, and the mixing use with the citric acid retarder will not affect the initial strength. we can provide more gypsum grade
HPMC.
The role of
HPMC in gypsum products
1. Improves water retention and processability and improves adhesion to substrates.
2. Insensitive to the alkalinity of gypsum, it can quickly penetrate into various gypsum products without lumping.
3. No negative impact on the porosity of cooked gypsum products, ensuring the breathing performance of gypsum products.
4. Good retarding effect, does not affect the growth of gypsum crystals.
5. Suitable wet adhesion to ensure the bonding ability of the material to the substrate.
6. Greatly improves the construction performance of plaster products, easy to spread, no sticky knife.
