Contract coating for mass-produced small parts: Efficient surface finishing in large volumes

Ten thousand parts. One hundred thousand parts. Millions of parts. Industrial manufacturing operates with volumes that are hard to imagine. Every single part has to be coated. Evenly. Reliably. Cost-effectively. Contract coating for mass-produced small parts makes exactly that possible.

Not every company can or wants to run its own coating line. The investment is high. The know-how is specialized. Utilization is not always guaranteed. The solution: a specialized contract coater that takes over surface finishing. Professional. Flexible. On demand.

What is meant by mass-produced small parts

The term is broad. Mass-produced small parts are components made in large quantities that are small enough to be processed as bulk goods. The boundaries are fluid, but typically we are talking about parts up to around 150 millimeters in size.

• Caps and closures. For cosmetics, pharma, food. Different materials (plastic, wood) in all colors, textures and finishes.
• Furniture fittings. Handles, knobs, hinge covers, shelf supports, damping systems. Decorative and functional.
• Seals and O-rings. With low-friction coatings for easier assembly and longer service life.
• Writing instrument components. Barrels, caps, clips. Million-piece runs for promotional items and premium products.
• Wooden blocks, toy figures, beads. Safe according to EN 71 Part 3.
• Technical small parts. Bushings, sleeves, spacers, fasteners.
• Housing parts, covers, control elements.

What these parts have in common: they are needed in large quantities. Hanging and coating them individually would be far too time-consuming. Drum coating is the answer to this challenge.

How drum coating works

Drum coating is a specialized process for bulk goods. The parts are not hung individually, but coated together in a rotating drum. That makes the process fast and economical.

The principle: the parts are loaded as bulk goods into the drum. The drum rotates slowly and tumbles the parts. At the same time, coating material is sprayed in. The parts are heated; the coating dries directly on the warm surface and is built up layer by layer. Rotation ensures every part is reached from all sides. No holding points. No shadow areas. No runs. Uniform all-around coating.

The SC-Coater® operates using the hot-spray process. The parts are heated before coating. This improves wetting and accelerates drying. The coating is finely atomized and applied evenly. Process parameters are precisely controlled: temperature, rotational speed, spray rate in g/min, coating amount per cycle, drying time. Everything is defined and reproducible.

Why contract coating makes sense

The alternative to contract coating would be an in-house line. That requires six-figure investments. Plus building space. Plus staff. Plus know-how. Plus ongoing maintenance and servicing. For many companies, it simply does not pay off.

• No investment. You use our equipment. Your capital remains available for your core business.
• No staffing effort. Coating requires specialists. We have them. You do not need to hire and train your own.
• Flexible capacity. Demand fluctuates? No problem. We adjust capacity without idle costs for you.
• Available immediately. No waiting time for building a line. No ramp-up phase. We can start right away.
• Professional quality. Coating is our core business. We do nothing else. Every day. For decades.
• Wide range of options. Colors, effects, functions. We have the know-how and coating systems for almost any requirement.

Detailed information about our services can be found on the Contract coating page.

Industries we serve

Contract coating of small parts is in demand across industries. Wherever mass-produced small parts are manufactured, there is a need for professional coating.

• Packaging is the brand’s showcase. Premium surfaces are a must.
• Furniture industry. Fittings define the overall impression. From chrome to antique looks, everything is in demand.
• Functional coatings for seals, plain bearings, composite components.
• Ballpoint pens and fountain pens in every finish. From promotional to premium.
• Colorful, safe surfaces for children. Compliant with EN 71 Part 3.
• Electrical and electronics industry. Housings, control elements, connectors. Decorative and functional.
• Special requirements for biocompatibility and cleanability.

An overview of typical applications can be found on our Applications page.

Decorative and functional coatings

Drum coating can do both. Sometimes it’s about aesthetics. Sometimes it’s about function. Often it’s both at the same time.

Decorative coatings

Here, appearance is the focus. Colors, effects, surface textures. The range is huge. High-gloss or matte. Metallic or solid colors. Textured or smooth. Antique look or modern. Coating turns a simple plastic part into a premium design element.

Learn more on our decorative surfaces page.

Functional coatings

Here, technical properties matter: low friction, adhesion, corrosion protection, chemical resistance. The coating changes the surface properties of the part and enables applications that would not be possible without coating.

Learn more on our functional surfaces page.

Consistent quality in series production

Large volumes require stable processes. Every part from the first batch must look exactly like every part from the hundredth batch. That is our standard. And our promise.

The basis is defined and documented processes. Every parameter is fixed: temperature, time, coating quantity, spray rates, drum speed. Everything is controlled. Deviations are detected and corrected. The result: consistent quality across all batches.

Quality checks are performed regularly: film thickness, adhesion, appearance, functionality. What is tested depends on the application and is agreed in the specification. Results are documented. Traceability is standard.

How a contract coating project works

From first contact to series delivery, the path is structured. We guide you through every step.

• Inquiry and consultation. What needs to be coated? Which finish is required? What volumes are planned? We clarify requirements and advise on options.
• Sampling. We coat sample parts. You can see and feel the result. You can test and compare. If needed, we optimize.
• The sample becomes the reference. It defines the standard for series: color, gloss level, film thickness, feel.
• Series production on call-off. We produce according to your call-off. Small lots. Large lots. Regularly or as needed.
• Quality assurance. Every batch is tested. Results are documented. If deviations occur, we inform you immediately.
• Packing and delivery. The finished parts are packed and shipped. Or you collect them—whatever works best for you.

All details about working with us can be found on our Project planning and Sampling pages.

Cost efficiency through process efficiency

Drum coating is an efficient process. That shows up directly in unit costs. But there are additional factors that influence overall economics.

High coating transfer efficiency. Around 95 percent of the coating ends up on the parts—not in the exhaust, not as overspray in filters. This saves material and therefore cost.

Short throughput times. The hot-spray process is fast. Parts are coated and dried within minutes. That enables high daily capacity.

Minimal rework. Stable processes mean low scrap. No holding points means no rework for uncoated areas.

Scalability. Unit costs decrease with volume. The more parts per batch, the more economical it becomes.

Your partner for mass-produced small parts

Contract coating for mass-produced small parts is our core business. For decades. For customers across a wide range of industries. With experience from millions of coated parts.

We see ourselves as a partner—not just a supplier. We advise. We develop solutions. We optimize processes. We deliver quality. Reliable. On time. In the volumes you need.

_____________________________________________________________

Frequently asked questions

What are mass-produced small parts?

Mass-produced small parts are components made in large quantities that are small enough to be processed as bulk goods—typically up to around 150 millimeters in size. Examples include caps, fittings, seals, writing instrument components and technical small parts.

How does drum coating work?

The parts are loaded as bulk goods into a rotating drum. There, they are heated and sprayed with coating material. Rotation ensures each part is coated evenly from all sides. No holding points, no shadow areas.

From what volume does contract coating make sense?

That depends on the specific part and the required coating. Drum coating is designed for medium to large volumes. The economically sensible minimum quantity is clarified during the project discussion.

Which materials can be coated?

All kinds of plastics, metals such as steel, zinc die-cast and aluminum, elastomers such as rubber and silicone, and also wood. The coating system is tailored to the specific material.

How long does it take from inquiry to series production?

For standard applications using established coating systems, the first series can be delivered within a few weeks. For new developments with extensive sampling, it takes correspondingly longer. A realistic schedule is defined after requirements clarification.

Can both decorative and functional coatings be realized?

Yes. Drum coating is suitable for decorative finishes such as colors, effects and textures, as well as functional coatings such as low-friction coatings, adhesion promoters or corrosion protection. Often, both aspects are combined.