When designing a powder coating line, customers often focus first on booth size, oven size, conveyor speed, and production capacity.

However, one important factor is sometimes overlooked:

How will the workpiece be hung during the coating process?

The hanging method affects far more than material handling. It can influence spraying quality, line capacity, conveyor load, oven dimensions, grounding performance, and even the overall layout of the coating line.

For this reason, hanging design should be considered at the beginning of the project rather than after the main equipment has already been selected.

1. Hanging Orientation Affects the Actual Workpiece Envelope

A product may have fixed physical dimensions, but its effective size inside the coating line depends on how it is suspended.

For example, a long workpiece can sometimes be hung:

• Vertically

• Horizontally

• At an angle

• In groups on one hanger

Each option creates a different operating envelope.

This directly affects:

• Spray booth opening size

• Oven entrance dimensions

• Conveyor clearance

• Required workshop height

• Distance between adjacent workpieces

A product measuring 2,000 mm in length may require very different equipment dimensions depending on whether the 2,000 mm dimension is vertical or horizontal during conveying.

This is why product drawings alone are sometimes not enough. The planned hanging orientation should also be confirmed.

2. Hanging Pitch Directly Affects Production Capacity

The distance between hangers is one of the key parameters used to calculate line capacity.

If the conveyor speed is fixed, reducing the hanger pitch can increase the number of workpieces passing through the line per hour.

However, hanger spacing cannot simply be reduced without limit.

Enough clearance must remain between products to avoid:

• Workpieces touching each other

• Poor spray gun access

• Uneven powder deposition

• Excessive swinging

• Collision at curves or transfer sections

Therefore, production capacity is closely connected to both conveyor speed and actual hanging arrangement.

For many projects, optimizing the number of parts per hanger can be more effective than simply increasing conveyor speed.

3. Hanging Position Affects Spray Coverage

Automatic spray guns need sufficient access to all important product surfaces.

If a workpiece is hung in an unsuitable orientation, some areas may become difficult for the powder cloud to reach.

Typical problem areas include:

• Deep corners

• Internal channels

• Recesses

• Closely spaced surfaces

• Areas blocked by the hanger itself

This becomes especially important for complex fabricated products, frames, cabinets, pipes, racks, and welded structures.

A better hanging orientation can sometimes significantly improve coating consistency without increasing the number of automatic guns.

For this reason, hanging design and spray gun arrangement should be considered together.

4. Hanging Design Can Reduce the Faraday Cage Effect

Electrostatic powder coating naturally has difficulty depositing powder into deep corners and recessed areas because of the Faraday cage effect.

Workpiece orientation can either improve or worsen this issue.

If deep recesses directly face the spray guns and sufficient space is available around the product, coating penetration can usually be improved.

If these areas are blocked by adjacent workpieces or positioned away from the spray direction, manual touch-up may become necessary.

Therefore, when automatic spraying is required, the engineering team should evaluate:

• Product geometry

• Hanging angle

• Gun direction

• Gun-to-workpiece distance

• Spacing between products

Good hanging design cannot completely eliminate every electrostatic coating challenge, but it can reduce unnecessary spraying difficulties.

5. Hanger Design Affects Grounding

Good electrical grounding is essential for stable electrostatic powder coating.

The electrical path normally runs through:

Conveyor → trolley → hanger → workpiece

If the contact point between the hanger and workpiece becomes covered with powder or coating residue, grounding resistance can increase.

Poor grounding may lead to:

• Reduced powder attraction

• Unstable transfer efficiency

• Uneven coating thickness

• Increased powder consumption

For this reason, hanger contact points should provide reliable metal-to-metal contact.

Regular hanger cleaning or stripping is also normally required during long-term production.

The hanging point should therefore be selected not only for mechanical strength but also for electrical performance.

6. Hanger Quantity and Load Affect Conveyor Selection

The conveyor is selected according to the total operating load, not only the weight of one product.

A typical load calculation may include:

• Workpiece weight

• Number of workpieces per hanger

• Hanger weight

• Carrier or trolley weight

For example, a 20 kg product may appear relatively light. But if four products are carried on one fixture, the actual load becomes much higher.

This can affect:

• Conveyor track specification

• Trolley quantity

• Drive selection

• Structural support

• Safety factor

Heavy or irregular products may also require two supporting points rather than a single hook.

In some applications, one workpiece may need to be carried by multiple trolleys to maintain stability.

7. Workpiece Swinging Must Be Considered

Suspended workpieces can swing during conveyor movement.

This is particularly common with:

• Long parts

• Lightweight panels

• Curved components

• Products with an uneven center of gravity

Excessive movement can create several problems:

• Collision with booth walls

• Inconsistent spray distance

• Contact between adjacent parts

• Instability at conveyor curves

• Difficulty during automatic spraying

For certain products, anti-sway devices, double-point hanging, or specially designed fixtures may be required.

The faster the conveyor transfer movement, the more important workpiece stability becomes.

8. Hanging Method Influences Oven Design

The oven must provide enough space for the complete suspended workpiece envelope, including:

• Product height

• Hanger length

• Conveyor track position

• Required clearance

• Product movement

A change in hanging method can therefore directly change the oven opening height or width.

This can affect both equipment investment and operating cost.

For example, unnecessarily hanging a relatively flat product vertically may increase the required oven height considerably.

A taller oven generally means:

• More structural material

• Larger heated volume

• More heat loss

• Potentially higher energy consumption

Therefore, product orientation should be optimized from both production and energy-efficiency perspectives.

9. One Hanger Design May Not Suit Every Product

Factories often produce several product families on the same coating line.

Using one universal hanger for all products may appear simple, but it is not always the best solution.

Different products may require:

• Different hanging points

• Different spacing

• Different load capacity

• Different orientations

• Different numbers of pieces per hanger

In many cases, developing several dedicated hanger types can improve line efficiency.

For example, a factory may use one fixture for large frames and another for smaller brackets.

The conveyor system remains the same, while the hanger configuration changes according to the production schedule.

10. When Is a Power and Free Conveyor Helpful?

For simple production with similar workpieces, a continuous overhead conveyor may be sufficient.

However, more complex production can benefit from a Power and Free conveyor.

A Power and Free system can allow carriers to:

• Stop independently

• Accumulate without stopping the complete line

• Travel at different speeds in different sections

• Be routed to different process areas

• Support more flexible production sequences

This can be useful when products require different loading, spraying, curing, inspection, or unloading times.

However, not every project requires this level of conveyor flexibility.

The correct choice depends on actual production requirements, product variety, and process flow.

11. Information That Helps Determine the Hanging Method

During the initial design stage, it is useful to provide:

• Product drawings

• Product photographs

• Maximum dimensions

• Product weight

• Existing lifting or mounting holes

• Areas that must remain uncoated

• Important cosmetic surfaces

• Required production capacity

• Number of product types

If possible, customers should also indicate whether certain holes or structural features can be used as hanging points.

This information allows the engineering team to evaluate the product arrangement before finalizing conveyor spacing, booth dimensions, and oven size.

Conclusion

The workpiece hanger may look like a relatively small component of a powder coating line, but its influence extends throughout the complete system.

A well-designed hanging method can help improve:

• Production capacity

• Spray coverage

• Grounding

• Workpiece stability

• Conveyor utilization

• Oven size

• Overall operating efficiency

For this reason, hanging design should be developed together with the conveyor, spray system, and overall coating line layout.

CHG designs customized powder coating lines according to actual workpiece dimensions, weight, hanging method, production capacity, and factory conditions.

For a preliminary evaluation, customers can provide product drawings, photographs, dimensions, weight, and production requirements so that the suitable hanging and conveying concept can be considered from the beginning.