Question

How to use papermaking defoamer XS-02, polyether ester defoamer?

Answer

The core of using papermaking defoamer XS-02 lies in "continuous dilution and addition". No complex equipment is needed. It can be directly diluted with water and then efficiently defoam and suppress foam in various processes.

Detailed Explanation

Papermaking defoamer XS-02 is a high-concentration (active ingredient ≥99%), non-ionic polyether ester defoamer, appearing as a milky white to light yellow viscous liquid. Its most prominent usage feature is good self-emulsifying and dispersing performance, easily soluble in cold or warm water. In practical applications, it is strongly recommended to adopt the method of "on-site dilution, continuous addition". This can fully utilize its high-efficiency defoaming and foam-suppressing ability at extremely low dosages, and ensure perfect compatibility with the papermaking system without causing precipitation or oil spots. Avoid pouring large amounts of undiluted concentrate at once, which may lead to local high concentration, uneven dispersion, and conversely affect the effect.

Since the product's molecular structure contains ester bonds, it may undergo slow hydrolysis in high-temperature and strong alkaline environments (such as pulping black liquor), but this characteristic also endows it with good biodegradability and environmental compatibility. Therefore, under such extreme working conditions, the usage principle of "prepare as needed, feed continuously" should be followed even more strictly, avoiding prolonged static settling or deactivation of the diluted emulsion, ensuring that the fresh emulsion fully contacts the foam layer, achieving instant bubble breaking and long-term foam suppression.

Recommended Addition Process and Reference Dosage

The following are reference data based on the general characteristics of the product and conventional practices in the paper industry, for you to adjust the process according to actual foam conditions:

Application Process Recommended Addition Point Reference Dosage and Method
Pulping Black Liquor Washing machine spray pipe, black liquor tank inlet, foam overflow port Higher dosage, usually 0.02% ~ 0.1% (200~1000 ppm) of the total system. It is recommended to dilute with cold water to a 10%~20% emulsion and continuously drip-feed via a metering pump to the foam generation source.
Paper Machine White Water White water tray, water seal tank, under-wire white water pit Very low dosage, usually 0.005% ~ 0.03% (50~300 ppm). Dilute to 5%~10% concentration and add continuously, effectively eliminating microbubbles and improving retention rate.
Coating Color / Sizing Liquid Coating mixing tank, feed tank, return tank Dosage is 0.01% ~ 0.05% (100~500 ppm). It is recommended to slowly add the diluted liquid during the pigment dispersion stage to completely remove bubbles from the color, preventing pinholes in the coating.
Industrial Water Treatment Aeration tank inlet, circulating water return port Dosage 0.1 ~ 0.5 g/L. Either the concentrate or the diluted liquid can be added directly, with no adverse effect on the microbial community.

Dilution and Operation Key Points

  • Dilution Temperature: It is recommended to use room temperature cold or warm water (<30°C). The cloud point of this product is 15~30°C. Excessive temperature will cause precipitation and turbidity, affecting dispersion effect.
  • Mixing Method: Slow stirring can spontaneously form a milky white emulsion, no need for high-speed shear emulsification equipment.
  • Metering Equipment: It is recommended to use a diaphragm metering pump or peristaltic pump for continuous and precise addition, avoiding dosage fluctuations and unstable effects caused by manual feeding.
  • Addition Point Selection: It should be selected before massive foam generation or in turbulent areas, such as the pump suction port or pipe elbows, using fluid kinetic energy to assist instantaneous dispersion of the defoamer.

Technical Parameters

The following are key technical parameters related to dilution and operation (source: Guoli Chemical Product Database)

Parameter Item Specification Value
AppearanceMilky white to light yellow viscous liquid
Active Content≥99%
Ionic TypeNon-ionic
1% Aqueous Solution pH5.0 ~ 8.0
Cloud Point15 ~ 30 °C
Density (20°C)0.85 ~ 1.05 g/cm³
SolubilityEasily dispersible in cold or warm water
Stability in Alkali SolutionGeneral, ester bonds may slowly hydrolyze under strong alkali (recommend preparing immediately before use)

Precautions

  • Freeze Prevention and Stratification Prevention: The recommended storage temperature for the product is 5~35°C. If slight stratification or low-temperature solidification occurs before use, it is a normal physical phenomenon. Simply warm the container to room temperature and stir evenly before use; defoaming effect is not affected.
  • Compatibility Test: Although the non-ionic nature gives it excellent compatibility, it is recommended to conduct a small-scale compatibility test before use in special sizing agents or new coatings to avoid demulsification in very few sensitive systems.
  • Safety Protection: Although it is a low-toxicity, non-irritating product, it is still recommended to wear protective gloves and goggles according to chemical operation specifications during operation to avoid prolonged contact with the concentrate causing skin dryness.
  • Avoid Cross-Contamination: The diluted emulsion should be used within 24-48 hours. For long-term storage, add an appropriate amount of preservative and seal and refrigerate to prevent bacterial growth and inactivation.