Vanconol® PH-1008 / PH-46 Recommended Application Scheme for Alkaline Bleaching Baths
In textile pretreatment, industrial cleaning and related fields, alkaline bleaching baths (bath pH≈10, containing bleaching oxidants, high ionic strength) impose stringent requirements on surfactants in terms of alkali resistance, electrolyte tolerance and oxidation resistance. Vanconol® PH-1008 and PH-46, two polyether-type nonionic surfactants, leverage their nonionic structure (non-ionizing, resistant to alkali and salts) and differentiated cloud point and foaming characteristics to provide wetting, penetration and scouring support for such systems. Based on typical operating conditions (washing temperature 11–18°C, working solution prepared by 1000-fold dilution of the concentrate), this document offers targeted selection and dosage recommendations.
Differentiated Positioning of the Two Products
Both products are polyether-type nonionic surfactants with good tolerance to alkaline, high-electrolyte environments, meeting the basic requirements of pH 10 bath solutions. The core differences lie in cloud point, water solubility and foaming characteristics:
| Parameter | Vanconol® PH-1008 (Preferred) | Vanconol® PH-46 (Alternative) |
|---|---|---|
| Chemical type | Polyether nonionic | Polyether nonionic |
| Cloud point (5% aqueous solution) | 52.8°C — no phase separation risk in summer | 37.2°C, close to the 35°C target |
| Water solubility | Clear across 0.3%–5% concentrations | Milky/opalescent at 0.3%–5% (usable at low concentrations) |
| Static surface tension (0.3%) | 30.8 mN/m | 28.5 mN/m (slightly better wetting) |
| Foam (1% aqueous solution) | Initial >100 mL, reduced to 4 mL after 5 min (high initial foam – fast collapse) | Initial 35 mL, reduced to 7 mL after 5 min (low foam) |
| Conductivity (10%) | 284 μS/cm | 12.78 μS/cm (extremely low ionic residue) |
| pH (1% aqueous solution) | 8.07 | 7.51 (near neutral) |
| Recommended dosage | 0.1%–1.0% of total formulation | 0.1%–1.0% of total formulation |
Selection Recommendations
Preferred — PH-1008: With a cloud point of 52.8°C, it fully eliminates the risk of surfactant separation (“oiling out”) caused by high summer temperatures. It offers the best water solubility (lowest risk when compounded into the concentrate), and its “high initial foam – fast collapse” profile is well suited for washing cycles that benefit from soil carrying, followed by rapid foam collapse for efficient rinsing. Suitable for soak, overflow and drum-type washing where a certain level of initial foam is acceptable.
Alternative — PH-46: With a cloud point of 37.2°C, it is closest to the specified 35°C target. It generates lower, quieter foam, making it suitable for spray, circulation or foam-sensitive equipment. Its “extremely low ionic residue” feature is not essential in high-ionic bath systems, and since concentrated aqueous solutions appear milky, a small-scale compatibility test is required before compounding into the concentrate.
If the customer is foam-sensitive or requires stronger alkali/salt resistance data, comparative evaluation may also include Vanconol® LFS-2501 (alkali resistance ≥300 g/L NaOH, salt precipitation resistance, low foam, cloud point ≥90°C); Toynol® Superwet-340 (acetylenic diol gemini structure, low foam, excellent dynamic wetting) can serve as a reference sample for “low foam + dynamic wetting enhancement”.
Dosage Calculation
Based on a concentrate active surfactant content of approximately 240 g/L and a dilution ratio of 300 g concentrate / 300 kg water (1000-fold), the conversion rule is: adding X kg of product per tonne of concentrate corresponds to approximately X ppm (X mg/L) in the working solution.
| Addition per tonne of concentrate | Corresponding working solution concentration | Assessment |
|---|---|---|
| 10 kg (1%) | 10 ppm | Relatively low |
| 20 kg (2%) | 20 ppm | Economic starting point |
| 30 kg (3%) | 30 ppm | Lower end of recommended range |
| 50 kg (5%) | 50 ppm | Upper end of recommended range |
| 100 kg (10%) | 100 ppm | Fully effective but costlier |
Recommended approach: For the concentrate-addition route, add 20–50 kg per tonne of concentrate (20–50 ppm in working solution); alternatively, for the more economical direct-to-working-solution route, add 50–100 g per tonne of working solution (i.e., 15–30 g for a 300 kg bath). The synergistic effect is pronounced with minimal usage. Given the high dilution factor of 1000×, the contribution of concentrate-side addition to working solution concentration is limited; beyond 5%, the cost-benefit ratio diminishes, and indiscriminate overdosing is not recommended.
Usage and Compounding Recommendations
- Addition sequence: Add after the main bath components (alkali agents, builders) with slow stirring until homogeneous; bleaching agents (oxidants) should ideally be added last, immediately before use, to minimize their co-existence time with the surfactant.
- Compounding compatibility: PH-1008 has good water solubility and low risk when compounded into the concentrate; PH-46 appears milky at high concentrations, so a room-temperature compatibility test is required before the concentrate-addition route is adopted.
- Cloud point verification: High electrolyte levels lower the actual cloud point of nonionic surfactants. It is recommended to re-verify the cloud point in the customer’s actual working solution (containing alkali + salt + oxidant) to confirm it remains above the maximum summer operating temperature.
- Low-temperature operation: At 11–18°C, the temperature is well below the cloud points of both products, so no cloud point effects are expected and wetting/penetration performance proceeds normally.
Key Considerations
- Oxidation resistance is the core parameter requiring validation: Both products should avoid direct mixing with strong oxidants. In bleaching systems, polyether chains are subject to degradation risk under prolonged exposure to strong oxidants. The risk is lower at low temperatures, low concentrations and short contact times, but small-scale validation testing is required; long-term co-existence stability should not be claimed without verification.
- Low foam ≠ detergency: Low-foam or wetting performance does not represent degreasing/scouring power. Detergency rates must be measured against the customer’s actual soils.
- Foam and equipment matching: PH-1008 exhibits relatively high initial foam; for spray or high-pressure circulating equipment, PH-46 or a defoamer combination is recommended.
Samples of Vanconol® PH-1008 and PH-46 are now available upon request. We welcome enquiries regarding specific operating conditions and system requirements; our application technical team will assist with small-scale verification testing and product selection confirmation.
