Problems at a Coating Factory Can Also Originate from Factory Facilities

Problems at a Coating Factory Can Also Originate from Factory Facilities

An Improvement Perspective on Energy Saving, Plant Layout, and Waste

When a coating problem occurs, many manufacturing sites first check the paint, thinner, application method, drying conditions, and surface pretreatment.

Of course, these factors are important.

However, problems occurring at a coating factory are not caused only by paint or operating conditions.

In reality, the factory facilities themselves can become the cause of quality defects, increased worker burden, higher costs, safety risks, and environmental impact.

For example:

Heat from a drying oven spreads into the work area and increases the burden on workers.

Excessive spray-booth exhaust increases the load on air conditioning and electricity costs.

Conversely, insufficient exhaust allows odors and paint mist to remain in the work area.

If the distance between surface pretreatment and the coating process is too long, the workpiece may become contaminated again.

If the paint warehouse or paint mixing room is too far away, temporary storage of paint and thinner at the manufacturing site increases.

Areas for pre-coating products, post-coating products, defective products, and products waiting for rework are unclear.

If inspection results take too long to return to the coating process, the factory continues producing the same defect.

The amount of waste paint, waste thinner, used filters, and paint sludge generated by each process is not known.

These are not simply issues of workplace organization and cleaning.

They are issues involving factory design, equipment layout, transportation routes, storage areas, working environment, and waste management.

To stabilize coating quality, the entire factory facility needs to be reconsidered, not just paint and operating conditions.

1. A Coating Factory Is the Foundation for Quality, Safety, Cost, and the Environment

A coating factory is not simply “a place where coating is performed.”

A coating factory includes many elements, such as spray booths, drying ovens, baking/curing ovens, surface pretreatment equipment, exhaust equipment, supply-air equipment, air compressors, paint warehouses, paint mixing rooms, inspection areas, and waste storage areas.

These elements do not operate independently.

They are all related to coating quality, occupational safety, productivity, energy costs, and compliance with environmental requirements.

For example, if a drying oven is improperly positioned, the working area becomes hot.

As worker fatigue increases, operating errors and quality variation may also increase.

If the capacity or position of the exhaust system is inappropriate, problems with odors, paint mist, solvent vapor, and dust may occur.

If the paint warehouse is too far away, temporary storage of paint at the manufacturing site increases, and safety management can easily deteriorate.

In other words, factory-facility design at a coating factory is quality management.

At the same time, it is safety management, cost management, and environmental management.

2. Energy Saving Is Not Just About Reducing Electricity Costs

Coating factories use a large amount of energy.

In particular, drying ovens, baking/curing ovens, spray booths, exhaust fans, supply-air fans, air compressors, air conditioning, and lighting consume significant energy.

When people think about energy saving, they often imagine turning off lights, lowering temperatures, or stopping equipment.

However, in a coating process, cutting necessary energy too much can lead to quality defects or safety risks.

If drying temperature is reduced excessively, insufficient curing, adhesion defects, or insufficient durability may occur.

If exhaust airflow is reduced excessively, solvent vapor or odors may remain in the working area, worsening the environment and safety conditions.

If lighting is too dim, dust, dirt nibs, uneven color, or uneven gloss may be missed.

The important point in energy saving at a coating factory is to reduce wasted energy while maintaining the necessary level of quality and safety.

For example:

• Is heat from the drying oven leaking into the work area?
• Are insulation materials and the oven door condition appropriate?
• Is the exhaust fan always operating at maximum capacity?
• When production stops, do the spray booth and conveyor continue running?
• Is there leakage or excessive use of compressed air?
• Are lighting fixtures dirty, reducing illumination even though they consume the same amount of electricity?
• Are fans selected only based on purchase price while annual electricity costs are ignored?

Energy saving is not an activity that trades off quality.

It is the optimization of heat, air, electricity, and compressed air while maintaining quality and safety.

3. Plant Layout Is Not About Placing Equipment; It Is About Designing Flow

When reviewing the layout of a coating factory, a common mistake is to think only about where equipment can physically be installed.

Of course, it is important to determine whether spray booths, drying ovens, surface pretreatment equipment, and conveyors can be installed inside the building.

But this alone does not create a well-functioning manufacturing site.

The important point is flow.

Where do untreated products enter?

What route does the workpiece take after surface pretreatment to reach the coating process?

Can pre-coating and post-coating products become mixed?

Where do finished products go?

Where are defective products and products waiting for rework placed?

Where are paint, thinner, jigs, tools, and masking materials supplied from?

Do worker routes intersect with forklift routes?

Can inspection results quickly return to the coating process?

The productivity of a coating line is not determined only by equipment capability.

Even if equipment capacity is sufficient, poor workpiece flow can still cause bottlenecks.

This is particularly important in high-mix, low-volume production, where color changes, cleaning, setup changes, and mixed-model production occur frequently.

If storage areas and transportation routes are not well organized, worker travel time increases, cleaning time increases, and mistakes become more likely.

A coating-factory layout is not about arranging equipment so that it looks good.

It is about creating a condition in which materials, people, paint, air, hazardous substances, and waste can move safely and efficiently.

4. Dust Contamination Should Not Be Investigated Only Inside the Spray Booth

One of the common defects at coating sites is dust, dirt nibs, and dust contamination.

When this happens, the manufacturing site often checks inside the spray booth.

Is the filter clogged?

Is the spray booth dirty?

Are the operator’s clothes or gloves contaminated with dust?

Is air blowing before coating sufficient?

Of course, these factors are important.

However, the cause of dust contamination is not necessarily located only inside the spray booth.

Other possible sources include:

• Doors that allow outside air to enter easily
• Forklift and cart routes
• Upstream processes such as sanding, cutting, or assembly that generate dust
• Temporary storage areas for products before coating
• Dust accumulated on ceilings, beams, and above lighting equipment
• Floor cleanliness
• The condition of supply-air filtration
• Airflow throughout the factory

All of these can become sources of dust contamination.

Even if the spray booth is thoroughly cleaned, dust will continue to enter if dust from outside is brought into the area.

To reduce dust contamination, it is necessary to look beyond the spray booth and consider the entire factory, doors, transportation routes, storage areas, and airflow.

5. The Location of the Paint Warehouse and Mixing Room Affects Safety and Work Efficiency

A coating factory uses paint, thinner, hardeners, cleaning agents, and other materials.

These are materials related to quality, but they are also chemicals that require safe management.

If the paint warehouse or mixing room is too far from the working area, worker travel increases.

As a result, paint and thinner may be temporarily stored at the manufacturing site.

Conversely, if paint or thinner is placed too close to the spray booth simply for operating convenience, fire-safety risks increase.

Distances from drying ovens, baking/curing ovens, ignition sources, and high-temperature equipment need to be checked, along with ventilation, storage quantities, firefighting equipment, and emergency exits.

In other words, the location of the paint warehouse and mixing room cannot be decided simply according to the principle that “closer is more convenient.”

The location needs to be designed so that it is safely close, easy to manage, and practical to use.

If this balance is poor, temporary storage at the manufacturing site, incorrect usage, poor management of leftover paint, or poor management of hazardous chemicals may occur.

6. If Inspection Results Do Not Return to the Process, the Same Defects Will Continue to Be Produced

Coating processes may include inspection of appearance, color, gloss, film thickness, and other characteristics.

Inspection is not only intended to find defective products.

Essentially, inspection provides information for quickly adjusting the process.

For example:

Dirt nibs increase.

Sagging appears.

Color becomes uneven.

Gloss becomes inappropriate.

Insufficient drying is suspected.

Film thickness becomes too thick or too thin.

Even when these conditions are detected in the inspection area, if the information is not quickly fed back to the coating process, the manufacturing site will continue coating under the same conditions.

As a result, the same defect continues to occur.

Therefore, in the layout of a coating factory, the relationship between the inspection area and the coating process is also very important.

If the inspection area is too far away, communication is slow, or the criteria for stopping the process when a defect occurs are unclear, quality losses increase.

Inspection is not only intended to prevent defects at the output stage.

Inspection also exists to return information quickly to the process.

7. Waste Was Originally Purchased Material

Coating factories generate many types of waste:

• Waste paint
• Waste thinner
• Cleaning thinner
• Paint residue
• Paint sludge in spray booths
• Used filters
• Contaminated wiping cloths
• Used masking materials
• Empty containers
• Waste solution from surface pretreatment
• Sludge from wastewater treatment

All of these generate treatment costs.

But there is another perspective.

Waste originally consists of paint, thinner, chemicals, and auxiliary materials that the factory purchased.

In other words, more waste means more purchased materials that failed to create value for the product and were ultimately discarded.

Reducing waste is both an environmental activity and a cost-improvement activity.

Reduce waste paint.

Reduce excess mixing.

Reduce excessive use of cleaning thinner.

Review the color-change sequence.

Improve transfer efficiency.

Reduce excessive film thickness.

Reduce repainting caused by defects.

Reduce the amount of used packaging that must be discarded.

All of these improve the environment while also helping protect factory profitability.

8. Dealing with Industrial Waste Starts by Looking at the Generation Source

When discussing industrial waste management, people may think of waste-treatment contractors, waste-storage areas, waste-management documentation, and legal compliance.

Of course, these elements are important.

However, from the perspective of coating-factory improvement, the first thing to examine is the source of generation.

At which process is waste paint generated?

During which color change is cleaning thinner used most?

Which products are likely to have excessive film thickness?

Which spray booth generates a large amount of paint sludge?

Which process requires frequent filter replacement?

Which packaged paint products are often left partially unused?

Waste cannot be reduced if the generation source is not visible.

If waste is only treated after it has been generated, the factory will continue to pay treatment costs.

If generation sources are reviewed, it is possible to simultaneously reduce material costs, treatment costs, operating burden, storage space, and environmental risks.

9. Powder Coating, Waterborne Paint, and Low-VOC Paint Are Options Worth Considering

From an environmental perspective, powder coating, waterborne paint, low-VOC paint, and high-solids paint are options worth considering.

Powder coating uses little to no solvent and, in some cases, excess sprayed powder can be recovered.

Waterborne paint is an option for reducing solvent use.

Low-VOC paints and high-solids paints can help reduce solvent emissions.

However, these are not solutions for every application.

For powder coating, it is necessary to confirm whether the workpiece can withstand the curing temperature, whether the process is suitable for the required color-change frequency, and whether film-thickness and appearance requirements can be met.

For waterborne paint, drying conditions, humidity management, wastewater treatment, and paint-sludge management are very important.

Even with low-VOC paint, application properties, drying performance, coating-film performance, and compatibility with equipment need to be confirmed.

Environmentally friendly paint should not be evaluated based on the material alone.

Surface pretreatment, coating method, drying oven, exhaust system, inspection, and worker training also need to be considered.

10. CoatureVietnam’s Perspective on Coating-Factory Improvement

CoatureVietnam does not view coating-factory improvement as simply a paint issue.

In a coating factory, Material, Method, Machine, Man, and Management are interconnected.

Material

Paint, thinner, surface pretreatment chemicals, and auxiliary materials.

Method

Coating method, thinning, film thickness, drying, inspection, and standard work.

Machine

Spray booths, drying ovens, exhaust systems, surface pretreatment equipment, and conveying equipment.

Man

Operators, management, training, judgement criteria, and operator workload.

Management

Cost, safety, environment, investment decisions, and response to customer inspection requirements.

Stable coating quality is achieved when these five factors work together.

Energy saving, plant layout, and waste reduction may appear to be separate topics.

However, in an actual coating factory, they are all interconnected.

Heat management of the drying oven is both energy saving and working-environment improvement.

Reviewing the spray-booth exhaust system is both an electricity-saving measure and a safety measure.

The location of the paint warehouse and mixing room affects both work efficiency and fire safety.

Returning inspection results to the process improves both quality and waste reduction.

Reducing waste paint and waste thinner improves both environmental performance and cost.

Coating-factory improvement does not simply mean replacing old equipment.

It means reviewing heat, air, lighting, transportation routes, storage areas, inspection, and waste, and bringing the manufacturing site to a condition where it can operate stably, efficiently, and safely.

Summary

Problems at a coating factory are not caused only by paint or operating conditions.

Factory-facility design, equipment layout, energy use, airflow, workpiece transportation routes, paint storage, inspection areas, and waste management all have a major impact on quality, safety, cost, and the environment.

When reviewing a coating factory, three perspectives are particularly important.

First: Energy saving.

Optimize heat, air, electricity, and compressed air while maintaining quality and safety.

Second: Plant layout.

Create a condition in which workpieces, people, paint, air, hazardous substances, and waste can move efficiently.

Third: Waste reduction.

Do not simply treat waste paint, waste thinner, VOCs, and paint sludge after they are generated. Reduce them at the source.

A coating factory is both a place where quality is created and a place where people work.

Reducing wasted energy, dangerous transportation routes, heat, dust, and waste not only improves the factory’s competitiveness but also helps reduce the burden on workers.

CoatureVietnam views coating not simply as a task but as a process that can be improved through science.

Through such improvement, we aim to help create a manufacturing site where people involved in coating can work more safely, more efficiently, and more positively.

Science and Care in Coating.

This philosophy also applies to improving the facilities of coating factories.