The Importance of Water Retention of HPMC
April 24th 2024
Regarding the problem that putty powder is easy to powder, or the strength is not up to anything. It is known that cellulose ether needs to be added to make putty powder, and many users do not add redispersible latex powder. Many people do not add redispersible polymer powder to save costs, but this is also the key to why ordinary putty is easy to powder and product quality problems are prone to occur!
Ordinary putty (such as 821 putty) is mainly made of white powder, a little starch glue and CMC (hydroxymethyl cellulose), and some are made of methyl cellulose and double fly powder. This type of putty has no adhesion and is not water resistant.
HPMC can absorb water and swell after dissolving. Different manufacturers’ products have different water absorption rates. Cellulose ether plays a role of water Retaining Agent in the putty. The dried putty only has a certain strength temporarily, but it will slowly depowder after a long time. This is closely related to the molecular structure of cellulose itself. Such putty is loose, high water absorption, easy to pulverize, no strength, no elasticity. If the topcoat is applied on it, low PVC is easy to burst and foam; high PVC is easy to shrink and crack; due to its high water absorption, it will affect the film formation and construction effect of the topcoat.
If you want to improve the above problems of putty, you can adjust the putty formula, add some redispersible polymer powder appropriately to improve the late strength of the putty, and choose a high-quality HPMC with quality assurance. Longou company’s hydroxypropyl methyl cellulose has the excellent water retention rate of high-quality cellulose, which can fully hydrate the putty raw materials and improve the quality of the putty.
In the production process of putty, if the amount of redispersible latex powder added is not enough, or the inferior special latex powder for putty is used, what impact will it have on the putty powder?
Insufficient amount of redispersible polymer powder or used inferior polymer powder, the most direct manifestation is that the putty layer is loose, the surface is chalked, the paint consumption is large when painting the top coat, the leveling is poor, the surface is rough after film formation, and it is difficult to form a dense paint film. Such walls are prone to peeling, blistering, shedding, and cracking of the paint film. If you choose low-quality putty powder, it is obvious that harmful gases such as formaldehyde generated on the wall will cause physical damage to others. Longou company, professional redispersible polymer powder manufacturer, provide high-quality redispersible polymer powder, improve adhesion strength, enhance the flexibility of putty, not easy off powder.
In order to avoid unnecessary losses, Customers try their best to choose products of big brands and quality assurance in Building Construction Chemicals selection.
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