Chem(Yueyang) Waterborne Additive Co., Ltd
Address: Chenglingji Linggang Industrial New Area, Yueyang, Hunan
Address: 220, He'anbao Commercial Building, No. 1105, Zhongshan Avenue
Address: Room 2415, Block B, Modern Plaza, No. 8, Weiye Road, Kunshan City, Jiangsu Province
Tel:+86 -512- 50176956
Fax:+86 -512- 50176956
Causes of Bubbles
1. For water-based formulation systems, it is very important to eliminate microbubbles and macrobubbles, and it is also difficult for formulation engineers. Because there are too many foam-stabilizing factors in the formulation of water-based coatings, inks, and adhesives, such as emulsifiers, substrate wetting agents, leveling agents, dispersants, thickeners, etc., all have interface activity and are in the system. Easy to generate and stabilize foam.
2. Mechanical bubbles brought in during production, dispersion, construction or coating.
3. Bubbles caused by the air absorbed in the porous substrate being released during construction or coating.
4. The air adsorbed on the surface when the pigment and filler are dispersed.
5. The bubbles produced by the reaction of paint film curing such as 2K and PU system.
Therefore, the defoamers selected for different ways or causes of bubbles are different. On the basis of understanding the needs of customers, we have developed a series of defoamers, foam suppressors and foam breakers to solve complex foam problems. Of course, we also strongly recommend the use of low-foaming or non-foaming fast diol surfactants to reduce the inherent tendency of foaming and foam stabilization in the formulation system.
Choice of defoamer
Long-term effectiveness of defoamers
In some water-based formulations, especially those containing very strong emulsifying surfactants, the defoamer will fail in a short time. It is well known that the defoamer is a dispersion with low surface tension and incompatible with the system. After the defoamer is emulsified by the emulsifier in the system and becomes compatible with the system, the defoaming property will decrease. At the same time, for polysiloxane The alkane defoamer divides the Si-O bond in the structure, which will slowly hydrolyze during storage, which will also affect the long-term performance of the defoamer. Therefore, the long-term effect of the defoamer is a factor that we mainly consider when designing the chemical structure or composition of the defoamer. Of course, we will recommend acetylenic diol molecular grade defoamers or acid and alkali resistant polysiloxane defoamers to meet customers' requirements for long-term defoamers.
Optimization and coordination of foam suppressor, defoamer and foam breaker
Long-lasting foam suppression is particularly critical in pigment grinding, high-shear or circulating pump feeding systems. The products we recommend are: GressolA04*, DF110 series, DF985.
For formula systems with high viscosity and thick coating film, defoaming is relatively difficult. When selecting defoaming agents, focus should be placed on defoaming agents for defoaming, such as non-silicon defoaming agents with high solid content, such as Greesol DFM , DF110, E20, DF40.
For high-speed foam breaking, such as bubbles generated during spraying construction, choose a foam breaking agent with strong instantaneous defoaming ability, such as Greesol DF82 and DF85.
For dark blisters and pinholes caused by high-temperature baking systems, GreesolA04e*, DFS, and DF904A are recommended. Of course, we need to consider more factors when choosing defoaming, such as compatibility. The defoamer cannot be precipitated or slick in the system or solution. Gloss and clarity cannot be affected in varnish or varnish formulations.
Application guide of CREESOL defoamer in water-based coatings, inks, adhesives and other fields