DELTA PROTEKT®: Corrosion protection using the zinc flake process from BENSELER
In the area of surface technology, the process with the product DELTA PROTEKT® is the most widely used solvent-based zinc flake process.
Find out more about services in the field of thin-film technology with DÖRKEN below.
What is DELTA PROTEKT®?
A DÖRKEN zinc flake coating is an anti-corrosion coating composed of zinc and aluminum flakes held together by an inorganic matrix.
At BENSELER, DELTA PROTEKT® is applied using various techniques: The process offers very high corrosion protection with low coating thicknesses.
Combined with different topcoats, customized solutions are obtained in terms of corrosion resistance and friction behavior of the components.
Features of DELTA PROTEKT® are:
- 5-25 µm average value of layer thicknesses, depending on requirements
- meets the global specifications of the automotive industry
- Over 1500 hours salt spray test according to DIN EN ISO 9227 NSS possible
- Reliable solution thanks to the cathodic corrosion protection, which acts as a barrier: In the event of a corrosion attack, the zinc sacrifices itself due to the low electrochemical potential and thus protects the steel component
- No risk of hydrogen embrittlement
- Can be painted with common value paints and cataphoretic paints
- High resistance to coolants and brake fluids, diesel and petrol, engine oils, organic solvents
- metallic silver-grey
- Other colors also possible in combination with topcoat
- Adaptation to specific requirements in combination with different topcoats
Application process flow with DELTA PROTEKT®
DELTA PROTEKT® coatings are produced by applying a liquid medium to pre-treated parts with final drying. The coating can be applied using bulk material and rack technology.
DELTA PROTEKT®: Process bulk goods dip-spin technology
At BENSELER, coating with DELTA-PROTEKT® for bulk goods is carried out automatically in large-scale production systems. The pre-treatment, base coat and top coat are applied one after the other.
In the first step, the order is divided into batches. The components are transported automatically via a basket and tray system. The specialists at BENSELER ensure the lowest possible drop heights and gentle handling of the parts (soft handling).
The raw materials are assessed depending on their condition upon delivery. The pre-treatment is defined on this basis. Pre-treatment involves a multi-stage alkaline hot degreasing process with rinsing and final drying. Depending on the delivery condition, blasting may also be carried out.
This is followed by coating in a solvent-based medium by dipping the basket with the bulk goods into the coating system. In this way, each component is wetted and a subsequent defined spinning process takes place. This process removes the excess material from the component before drying takes place in the oven: The parts are cured at a specified curing temperature and for a specific duration.
Depending on the corrosion resistance requirements, BENSELER repeats the coating process with the basecoat at least once more.
After the cooling process, the parts are coated with a basecoat layer of the paint system. This layer is cross-linked with the substrate metal.
To finish the surface, a topcoat is applied, which allows specific characteristics to be set and has a sealing effect.
This allows friction value windows to be set for threaded parts or to create a colored final finish. BENESLER uses the same coating technology for the topcoat: Dipping, spinning, drying and cooling.
Finally, the goods are filled from the system into the labeled customer containers and subjected to a documented quality inspection and approval process before being made available in the finished goods warehouse.
Requirements for an application on bulk goods using DELTA PROTEKT®:
In order to be able to apply the DELTA PROTEKT KL120 thin-film corrosion protection process to bulk goods, the components should:
• have a rotationally symmetrical geometry
• be non-interlocking
• have a weight of less than 300 g/part
• or alternatively be bulk material compatible
BENSELER mainly uses the DELTA PROTEKT® KL100 and DELTA PROTEKT® KL120 systems
DELTA-PROTEKT® KL100 and DELTA-PROTEKT® KL120 are the most frequently used products from DÖRKEN in zinc flake coating. They are used for the corrosion protection of fasteners and for a wide variety of metal components. The DÖRKEN products can be combined with the DELTA-PROTEKT® VH/VL series or DELTA-SEAL® series top coats to achieve specific characteristics, such as set friction coefficient windows.
DELTA PROTEKT® KL120, especially with the topcoat VH301.1, is the system that is most frequently specified in the German automotive industry. The main advantage of this system is the good coverage of the bolting requirements according to the VDA recommendations as well as the specifications of the OEMs.
Advantages of the DELTA PROTEKT® product family at a glance:
- DELTA PROTEKT ® Products offer high corrosion protection from 600h to >1500h according to DIN EN ISO 9227 at low layer thicknesses of 5-25 µm
- DELTA PROTEKT ® Products meet automotive industry specifications worldwide
- DELTA PROTEKT ® Products are REACH compliant and fulfill the EU End-of-Life Vehicle Regulation 2000/53
- DELTA PROTEKT ® Products have a continuous temperature resistance of 200°C while maintaining corrosion protection
- The setting of defined friction coefficient windows leads to very good screw connection properties of threaded parts, even with multiple screw connections
- No risk of hydrogen embrittlement as the coating is not applied electrolytically
- In comparison to paint coatings, there is no corrosion infiltration of the coating
- The lower hardness of the zinc flake layer compared to galvanized zinc layers can be an advantage for subsequent assembly processes
- Good chemical resistance to organic solvents, oils, greases and brake fluids, for example
Additional Services for DELTA Protekt®
In addition to coating with DELTA PROTEKT® and other DÖRKEN products, BENSELER offers you the following customer services:
• Individual testing and packaging
• Measuring 100% sorting
• Thread-locking coating of screws and nuts
• Packaging and labeling for the end customer
• Direct delivery to the end customer or consignment warehouse
Further special services are available on customer request!
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BENSELER technical information for DELTA PROTEKT® coating
To ensure that the product is perfectly suited to your requirements, the BENSELER sales team will be happy to provide you with personal advice at any time.