Against the backdrop of increasingly stringent global environmental regulations—such as the EU ban on fluorinated polymers containing PFOA, a conventional raw material for friction coefficient adjustment—and coupled with domestic requirements for zero heavy metal emissions, the coatings industry is being driven toward a shift to green water-based technologies. On the other hand, fastener application scenarios, especially in the automotive industry, impose rigorous standards of “precise controllability and high stability” for friction coefficients. For instance, the German VDA standard mandates that the friction coefficient of threaded fasteners must fall within the range of 0.09–0.16 to accommodate automated tightening operations. Traditional coatings, however, often struggle to meet this requirement, and are also plagued by issues including wide friction coefficient dispersion, high baking energy consumption, and insufficient bonding strength when used in conjunction with zinc-aluminum primers.
- High hardness and high strength, with excellent scratch resistance, bump resistance, abrasion resistance and impact resistance.
- High permeability and high compactness, along with outstanding sealing performance. It effectively enhances the salt spray resistance of workpieces and improves anti-corrosion performance when combined with primer coating processes.
- Friction coefficient ranges from 0.09 to 0.15.
- Excellent coating performance, compatible with dip coating and spray coating processes. The dry film thickness is 1–3 μm, featuring low coating consumption and reduced application costs.
Technical Parameters
| PH | 10±1 | Specific gravity (25℃) | 1.0±0.03 g/ml |
| Solid Content (180℃, 20 min) | 16±2% | Viscosity (Zahn Cup No.2) | Approximately 15 s |
Application fields
Coating of fasteners, hardware, wind power, photovoltaic, and auto parts;
It can be used with zinc-aluminum micro-coating primer, dacromet primer, hot-dip galvanizing primer, electroplating, blackening, or directly on metal substrate workpieces.
Spraying: It is recommended to adjust the ratio according to the customer’s on-site conditions; Dipping: It is recommended to have a thinning ratio (≥30%), a dipping and spinning speed of 210-270 rpm, and a time of 10-20 seconds; Baking conditions: 80℃ for 15 minutes (workpiece temperature) or room temperature for more than 2 hours.
Management Measures
- Supplement of chemicals: Prepare chemicals with the required solid content, and replenish if the liquid level is insufficient. If the solid content is higher than required after analysis, add water to dilute it to the required controlled concentration. If the solid content is lower than required after analysis, add the stock solution to reach the required controlled concentration.
- Filtration: Zinc powder, impurities, etc. brought in by fasteners are the causes of poor coating surfaces; regular filtration can be carried out with a 50–100 mesh screen.
- pH control: The pH must be maintained between 9-10; if the pH of the chemical is too high or too low, precipitation will occur, affecting its service life; attention must be paid to whether the fasteners are cleaned thoroughly during water washing.
Post time: Dec-08-2025