Chromium-free zinc-aluminum coating refers to applying a coating containing zinc-aluminum flakes to the surface of parts through dipping, brushing, or spraying.
Compared with electroplating and hot-dip galvanizing processes, zinc-aluminum coating has the following advantages when applied to fasteners: thin thickness, corrosion resistance, high performance, no hydrogen embrittlement, and no wastewater or waste generated during the production process.
After the base coating, a top coating is generally applied. The top coating has the functions of enhancing the corrosion resistance and chemical resistance of the base coating, reducing electrochemical corrosion, meeting the appearance requirements for color differentiation, and controlling the stability of the friction coefficient.
The top coating mainly adjusts the surface state of the coating by distributing materials such as PE and PTFE in the silicate coating or organic coating. It effectively adjusts the friction coefficient of parts according to different types and contents of lubricants. The process parameters of the top coating have a certain impact on the friction coefficient. If the solid content is low, it will cause missing coating. A small amount of lubricating components in the coating will lead to a large friction coefficient.
Zincover®9131 water-based transparent friction coefficient topcoat is a new type of water-based functional topcoat independently developed by Junhe Technology. It can be used with undercoating and pretreatment processes such as Dacromet, chromium-free zinc-aluminum, hot-dip galvanizing, electroplated parts, and blackened parts, and is widely applied in the processing of various fasteners and hardware. When used in conjunction with undercoating, this topcoat improves the disadvantage of low strength in zinc-aluminum coating solutions (Dacromet, chromium-free zinc-aluminum). This product not only enhances the surface hardness and salt spray resistance of the products but also ensures a stable friction coefficient. In particular, its baking temperature is extremely low, saving energy costs for customers.
High hardness and high strength, with excellent scratch resistance, bump resistance, abrasion resistance, and impact resistance;
High permeability, high density, and excellent sealing performance. It effectively improves the salt spray resistance of workpieces, and when combined with the primer coating process, enhances the anti-corrosion performance.
Coefficient of friction in the range of 0.09-0.15.
Good coating performance, suitable for dip coating and spray coating. The dry film coating thickness is 1-3μm, with low coating amount and low usage cost.
| pH | 10±1 |
|---|---|
| Specific gravity(25℃) | 1.0±0.03g/ml |
| Solid content (180℃ for 20min) | 16±2% |
| Viscosity (Chai's No. 2 Cup) | Approximately 15s |
Coating of fasteners, hardware, wind power, photovoltaics, and auto parts;
Used in conjunction 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 proportion according to the customer's on-site conditions;
Dipping: Recommended thinning ratio (≥30%). Dipping and spinning speed: 210-270 rpm, time: 10-20 seconds;
Baking conditions: 80℃ for 15 minutes (workpiece temperature) or room temperature for more than 2 hours.
Supplement of chemicals: Prepare chemicals with the required solid content, and supplement if the liquid level is insufficient. If the solid content is found to be too high after analysis, add water to dilute it to the required controlled concentration. If the solid content is found to be too low 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.
Osoba kontaktowa: Mrs. June
Tel: +86 13915018025
Polish
