How to solve the issue of insufficient coating adhesion on metal and plastic substrates?
Created on 09.06
Introduction
In the industrial coating industry, adhesion between the coating and the substrate is the primary indicator of coating quality and product durability. Whether it's metal parts (such as aluminum and alloy steel) or low-polarity plastics (such as PP and PE), their surface characteristics often lead to coating peeling, blistering, and premature failure, seriously affecting product appearance, protective performance, and service life. Jiangsu Jinzhitian Composite Material Technology Co., Ltd.'s DH-7326 adhesion promoter is specifically designed for a variety of difficult-to-adhere substrates. Through its unique molecular design, it builds a strong "bridge" between the substrate and the coating, improving adhesion and overall coating performance.
I. Common Industry Pain Points
In practical coating applications, coatings and inks often face the following adhesion challenges:
Low surface energy or chemically inert substrates: Plastics like polypropylene (PP) and polyethylene (PE) have low surface energy, making them difficult for coatings to wet and penetrate. Meanwhile, the dense or chemically inert surfaces of aluminum, stainless steel, plated parts, and glass make it difficult for ordinary coatings to form a bond.
Poor coating system compatibility: Different resin systems (such as alkyd amino, acrylic amino, polyester amino, and 2K PU) have varying sensitivities to additives. Common adhesion promoters can easily cause storage instability and poor compatibility, leading to problems such as cratering and discoloration.
Inadequate performance in harsh environments: Coatings must not only maintain good initial adhesion but also maintain stable performance in harsh environments such as high temperature and humidity, salt spray corrosion, prolonged water immersion, or rapid temperature fluctuations. Otherwise, blistering and flaking are likely to occur.
Process and cost limitations: Many pretreatment processes to improve adhesion (such as corona treatment and flame treatment) require equipment, are complex to operate, and are cost-effective, resulting in limited long-term and stable results.
II. Disadvantages of Traditional Solutions
To improve adhesion, the industry has tried various methods, but all have significant limitations:
Traditional Solutions | Main Disadvantages | Problems |
Substrate surface treatment | For example, corona and flame treatments have unstable and short-term effects. Painting must be done as soon as possible after treatment. The treatment uniformity of complex workpieces is poor and the substrate may be damaged. | It increases production processes and costs and is not suitable for large-scale continuous production. |
General adhesion promoter | Most products are designed for specific substrates or systems, have a narrow range of applications, and have limited effectiveness on a variety of difficult-to-attach substrates; some products may affect the weather resistance of the coating or cause yellowing at high temperatures. | Formula adjustments are cumbersome and batch stability is a major challenge. |
Increase coating thickness or primer | Although it can provide temporary improvement, it may affect the appearance (leveling, transparency), increase internal stress, and cause the coating to become more brittle, which in turn reduces long-term durability. | It increases material costs and drying time, which may affect production efficiency. |
Use special coatings | The cost is high, limits the freedom of material selection, and makes inventory management more complicated. | It is difficult to cope with the flexible production needs of multiple varieties and small batches. |
These methods often fail to provide durable and reliable adhesion solutions while ensuring comprehensive performance, cost, and adaptability to diverse production lines
III. Innovative Product Solution: DH-7326 Adhesion Promoter
DH-7326 is a new modified phosphate-esterified polyester solution developed by Jiangsu Jinzhitian. It is designed to systematically address adhesion challenges on a variety of substrates and maintain stable coating performance in harsh environments.
- Product Features and Technical Principles
Broad-Spectrum Substrate Compatibility: Its unique molecular structure promotes excellent adhesion to non-ferrous metals (such as aluminum, galvanized steel, and various alloy steels) and low-polarity plastics (such as PET, PP, PE, and ABS).
Excellent System Compatibility and Stability: It exhibits excellent compatibility with a variety of resin systems (alkyd/amino, acrylate/amino, polyester/amino, and 2K PU systems), without compromising coating storage stability, maintaining discoloration during high-temperature baking, or compromising the film's weatherability.
Enhances coating durability: It not only improves initial adhesion but also enhances the film's chemical resistance, salt spray resistance, and water boiling resistance, while also improving film strength, elasticity, and impact resistance.
- Application Guide
Applications: Suitable for metal baking enamels (such as alkyd/amino, acrylate/amino, and polyester/amino), 2K PU systems, coil coatings, electroplating varnishes, and plastic coatings.
Instructions:
During the production process, add DH-7326 at a rate of 1.0% to 2.0% of the total formulation.
It can be added before or after grinding. Thorough mixing is recommended to ensure a uniform mix.
No changes to existing coating processes are required.
Packaging and Storage:
The product is packaged in 25kg barrels.
Store in a cool, well-ventilated, dry place away from heat and ignition sources.
If unused, seal immediately after opening.
Under normal storage conditions, the shelf life is 12 months.
Summary
DH-7326 adhesion promoter, through its unique modified phosphated polyester structure, addresses the industry's challenge of insufficient coating adhesion on various metal and plastic substrates.
It not only provides a stable adhesion boost, but also boasts excellent compatibility and enhances multiple coating resistance properties, providing a reliable solution for industrial coatings.
Contact
Leave your information and we will contact you.
WhatsApp
微信