Road marking machines are the basic equipment for pavement marking and come in a variety of types, such as thermoplastic, cold paint and convex line marking machines. Even high-quality machines from reputable manufacturers, such as Huayuan, can have operational problems due to external factors or improper maintenance. If a pavement marking machine fails to apply the correct material, it can delay a project and increase costs. Below are the most common causes and detailed solutions.
1. Mechanical failure of the marking machine
After prolonged use or accidental damage, key components of the road marking machine may fail:
- Worn or dull cutting blades – improperly cut thermoplastic beads are not fed smoothly
- Deformed screws – preventing material from advancing through the thermoplastic applicator
- Failed motor or gearbox – resulting in loss of power transfer to the dispensing system
- Damaged hoses/pumps – resulting in leaks or loss of pressure in the coating system
Solution: Schedule periodic inspections by a qualified technician. Replace worn parts immediately with genuine factory parts to ensure compatibility. For hydraulic systems, check pressure settings and look for leaks in hoses and fittings.
2. Road marking paint problems
The quality and condition of road marking paint has a significant impact on machine performance:
- Overly viscous paints – common in cold weather after solvent evaporation
- Contaminated thermoplastics – moisture or debris can cause clumping
- Improper mixing of materials – sedimentary pigments or unmelted beads cause clogging
- Expired products – degraded adhesives can alter flow characteristics
Solution: Always use fresh materials approved by the manufacturer. For coating systems:
- Stir well with a paddle for more than 5 minutes
- Add recommended thinners (usually 5-10%) in cold conditions.
- Filter through a 60-80 mesh sieve before loading.
For thermoplastic road marking machines:
- Preheat material to 180-220°C (356-428°F) until completely fluid.
- Remove skins or hardened surfaces prior to charging; 3.
3. Operational Errors and Improper Settings
Many problems stem from incorrect use of road marking machines:
- Incorrect gun height – nozzle too close to pavement causing spattering
- Incorrect pressure setting – too low a pressure resulting in intermittent spraying
- Improper temperature control – thermoplastic cools too early in the hose
- Incorrect ground speed – too much speed reduces spray line thickness
Solution: Consult your operator’s manual for
- Optimum gun height (typically 6-12 inches for paint)
- Recommended air pressure (typically 40-70 PSI for airless systems)
- Proper travel speed (adjust for desired spray line width)
- Correct melt temperature for thermoplastic coating applications
4. Inadequate cleaning and maintenance of road marking machines
Residue buildup is a major cause of long-term spraying problems:
- Drying of the coating in the nozzle – occurs when flushing is not thorough
- Hardening of the thermoplastic in the road marking machine hose – caused by inadequate cleaning after operation
- Pump wear – abrasive materials deteriorate parts
Step-by-step cleaning procedures:
1. For cold spray road marking machines:
- Cycle manufacturer’s approved cleaner through system for 10 minutes.
- Remove nozzle and soak in solvent overnight
- Clean filters and screens with a brass brush
2. For thermoplastic road marking machines:
- Wash all materials while hot
- Run cleaner through hoses
- Grease all fittings and moving parts.
3. Storage Tip:
- Store in pumps/tubes with cleaning solution
- Cover the machine to prevent dust accumulation
- Release the tension on all adjustable parts
5. Environmental factors affecting performance
Extreme conditions require special adjustments:
Cold weather (below 50°F/10°C):
- Preheat paint to 15-21°C (60-70°F) before loading.
- Use winter grade solvents
- Insulating Hoses on Thermoplastic Road Marking Machines
Hot weather (above 90°F/32°C):
- Add anti-skinning agents to coatings
- Reduce thermoplastic temperature by 10-15°C
- Work in cooler morning/evening hours
High humidity:
- Use moisture resistant coatings
- Store materials in a climate-controlled area
By understanding these common problems and implementing proper maintenance routines, you can minimize downtime and ensure consistent performance of your road marking machine. Always follow the manufacturer’s guidelines for specific models and local conditions. For long-standing problems, consult a professional service technician who specializes in the repair of road marking equipment.