What thermoplastic is
Thermoplastic is a solid material, supplied as blocks or powder, that is heated until it flows and then applied to the road surface. As it cools it solidifies into a thick, hard layer bonded to the surface. It is not paint that dries. It is a material that melts and sets.
That difference explains everything else about it. Because the material is applied several millimetres thick rather than as a film, it wears down over years instead of off in months. It is what you see on most public roads and on the high wear parts of busy commercial sites.
Where it earns its cost
- Entries and exits. Every vehicle on the site crosses these lines, so they wear first.
- Directional arrows and symbols. High visual importance, high wear, and expensive to redo often.
- Give way and stop bars. Braking and turning concentrates wear at exactly these points.
- Roundabouts and turning circles. Tyres scrub sideways here, which destroys paint quickly.
- Speed hump chevrons and thresholds. Repeated impact loading.
- Roads generally. Speed, volume and night visibility all favour a durable retroreflective system.
- Loading docks and heavy vehicle areas. Truck tyres are far harder on marking than cars.
Where it usually is not worth it: quiet bay lines in a low traffic car park, anywhere the layout is likely to change, and interior concrete floors, where other systems suit better.
Glass beads and night visibility
Thermoplastic is normally applied with glass beads, either mixed through the material, dropped onto the surface as it is laid, or both. The beads retroreflect headlight back toward the driver, which is why road markings glow in the dark and plain white paint does not.
Beads embedded through the material matter more than beads on the surface, because surface beads wear away in the first year while embedded ones keep getting exposed as the line wears down. That is part of why a thermoplastic line stays visible at night for years.
The trade-offs
Cost. Substantially more per metre than paint, both in material and in the equipment and labour needed to apply it hot.
Removal. Much harder to remove than paint because there is far more material. If a layout is likely to change, thermoplastic makes that change expensive.
Surface requirements. It needs a sound surface to bond to. On old oxidised or crumbling asphalt it can take the surface with it when it eventually fails. A primer or sealer is sometimes required.
Application conditions. The surface must be dry and above a minimum temperature. On the Sunshine Coast that mostly means avoiding the wet season and early mornings after heavy dew.
Thickness. Because it sits proud of the surface, it can be felt underfoot and by a wheelchair or pram. On pedestrian areas that occasionally matters.
How it goes down
The material is heated in a mobile boiler to its application temperature, then either screeded, extruded or sprayed depending on the line and the equipment. Stencils are used for symbols and arrows. Because it sets as it cools, the working window is short and the crew works quickly.
The practical advantage is that it is trafficable almost immediately once cooled, often within minutes rather than hours. On a live site that can outweigh the higher cost on its own, because the area reopens sooner.