
Method of Application: The road markings shall be applied with a screed box either hand operated or with an applicator machine.
Hand Screed Method Cleaning Remove sand, dust, oil and grease to ensure that the road surface is absolutely clean, Dry and free of pot holes, protrusions, etc. Positions of lines to be marked Deside the position take measurement and Premark the lines with a string markar.( A string coated with white chalk or power ) or a wheel markar.
Pretreatment Apply Primer uniformly with a roller or applicator, especially for concrete road surface. Apply primer slightly wider than the width of the line to be marked with thermoplastic. Allow primer to dry completely. Avoid any deposit of sand and dust on printer surface. Primer coverage shall be 20g/m for 15 cm width line.
Melting of Thermoplastic Material Feed sally thermoplastic , white or yellow , into preheater(using separate preheater for different color) then heat and stir well until uniform viscosity is obtained. Melting tempature shall be controlled between 180° c to 200° C.
Application Drain the molten thermoplastic into storage tank of the applicator machine. Keep the storage tank hot by means of the gas fire at a consistent temperature(180 ° c -200° c). During application , ensure that the glass beads are dropped from the beads dispenser.(25 g/m for line with 15 cm width)
Drying Drying time is about 1 minute for 1.5 mm thick line . Thicker line or markings take a bit longer to dry. Release suspension of traffic after drying of the line is confirmed.(Preferably after 5 to 10 minutes). Standard coverage Average coverage of one metric ton of thermoplastic is about 280 sq. metre of 1.5 mm thickness.
Machine Spray Method à Application Equipments , tools and materials Safety & Cleaning Tools Cleaning tools (brooms or besom) Safety beacons, flashlight, Sign boards

Pretreament and application equipement

Preheaters mounted on truck. Normally twin preheters are used , one for white and the other for yellow.
Applicator machines complete with heating gas.
Push type with interchangeable laying/marking shoes.
Reverse action type with fixed shoe (this is recommended for marking directional arrows pedestrian crossing and chevron markings.)
Automatic spray truck.

Materials

Thermoplastic white and yellow
Glass beads for drop-on application.

Irregularity and possible reasons

Irregularity	Possible reasons
1.insufficient paint	blocking of equipment lift of pistol needle too low paint container pressure too low excessive viscosity, e.g. under low pressure
2. pistol spitting	air in the paint conduit because paint container empty of rinsing agent container empty and rinsing valve leaking
3. line thicker on one side	atomizer nozzle blocked on one side air leaving paint nozzle on one side due to partly blocked air holes nozzle worn out atomizer nozzle slanted or loose pistol in wrong position with use of two pistols irregular adjustment, differing paint doses differing quantity of air passing through
4. line too thick in the middle	nozzle slot blocked paint dried on nozzle worn out, i.e. widened atomizer air pressure too low
5. line too thin at the border	pistol held too low nozzle spray angle too small nozzle slot blocked paint dried on too little atomizer air
6. line frayed on each side	wrong pistol adjustment so that impact point in front of or behind side demarcation (roller discs) too much paint paint too thin unsufficient viscosity blocked roller discs therefore jamming paint
7. paint running out	rinsing system leaking so that rinsing agent penetrates paint conduit (usually during idle times)
8. paint mist beside line	too much atomizer air paint too thin (unsufficient viscosity)
9. beginning of line, end of line widened	pistol and roller disc not synchronized pistol spraying before discs on ground and vice versa pistol opening or closing too slowly paint needle heavy-going or damaged air control defective marker working (lifting and lowering too slowly) excessive driving speed
10. roller discs producing paint tracks (stripes or drips)	paint stripper not closing tightly too much paint on discs due to high spraying pistol too high or slanted.
11. distribution of beads uneven (cloudy)	roller discs slipping bead distribution blocked drop-on aggregates in lumps spraying roller blocked in the gaps side wind too strong
12. distribution of beads only on one side at the border or in the center of the line	bead distributor or bead pistol not centered side wind uneven thickness of lines so that one side thicker, beads sunk in bead pistol dirty or distributor worn out
13. no cohesion of material on the road surface at the beginning of the line and formation of swellings	temperature in the container and in the marker too low temperature too low only in the marker because of excessive oil cooling oil taps not sufficiently opened pump failure too little oil in the container driving speed too fast carriageway dusty or sandy carriageway too cold
14. gaps(grooves stripes) in the surface of the marking)	foreign particles or material crusts sitting in the slot of the marker and dragged along
15. dissolved line crumbly borders of the line	material too cold driving speed excessive line thickness adjusted too thin
16. surface of line too rough crumbly borders	material too cold
17. bubbles in the line	material overheated road surface too moist so that there is condensation
18. traces of drops in gap of line and frayed ends of line	closing cap does not close properly, e.g. foreign particles trapped pressure cylinder too heavy going
19. line swollen, running out at the side, beginnings of line rounded	material too hot material too thin
20. tracing of paint on the side	material under glider because suspension of marker too high road very corrugated marker too heavy-going stabilizer missing or wrongly adjusted (slanted)
21. line wavy	carriage way corrugated strongly on the sides missing stabilizer marker heavy-going bad driving
22. different lengths of lines	closing cap clamping pressure cylinder heavy-going control air pressure too low automatic device for line separation defective

Drop-on bead concerns

If line appears	Problem is	To correct
Smooth, shiny glossy	No beads, resulting in no retro-reflectivity caused by malfunctioning gun or beads sinking too deep	- repair bead applicator - increase bead application rate - move point of bead application
Smooth with slight dimples	Drop-on beads sunk too low, resulting in lower retro-reflectivity, caused by material being too hot	- increase bead application rate - cool material, staying above 180°C
Glazed with ice	Beads sit too high, not adhered well, will wear off quickly, caused by material being too cold or bead gun being positioned too far from application point	- make sure thermoplastic is between 180 - 200°C - move point of bead application
Cratered	Beads popped out, resulting in lower retro-reflectivity, caused by material being too cold and/or poor bead adhesion.	- heat thermoplastic to temperature of between 180 - 200°C
Uneven and poor reflection at night	Uneven scattering operation of glass beads and/or shortage of beads quantity. Beads may be wet.	- adjust the beads dispenser - use only dry beads

Edge Concerns

If line appears

Problem is

To correct

Rough around edges

Inconsistent bond, resulting in less durability, caused by material being applied too cold and/or too thin

- make sure thickness is as specified

- check temperature of thermoplastic, it should be 180 - 200°C

Wavy, with irregular edges

Flow-out of material. Edge is not well defined, caused by material being too hot or too liquid, application pressure being too high, extrusion gate open too wide, and/or surface being too uneven

- make sure temperature is 180 - 200°C

- adjust application equipment

- slow application rate on rough surface

Colour concerns

If line appears

Problem is

To correct

Greenish yellow

Scorching, resulting in thermoplastic becoming brittle and less durable, caused by overheating or too many reheats

- discard material

- check and control temperature to between 180 - 200°C

- do not melt thermoplastic inside preheater for too long

Dingy, dirty white

Scorching, resulting in thermoplastic becoming brittle and less durable, caused by overheating or too many reheats

discard material

- check and control temperature to between 180 - 200°C

- do not melt thermoplastic inside preheater for too long

Other concerns

If line appears	Problem is	To correct
Pitted or pinhole	Trapped moisture and/or air. Primer is still wet.	- if moisture is present: stop application - if air is trapped: slower application rate and ensure material is applied at correct temperature - if primer is being used: make sure sufficient time is allowed for primer to dry completely
Browning or bleeding	Bituminous matter oozes out from the surface of line. Temperature is too hot. Primer is applied excessively and wet.	- check temperature is 180 – 200°C - do not apply too much primer - apply thermoplastic after primer dries thoroughly
Grooved or scarred	Discharge point of trough/shoes is blocked with solid lumps of either hardened thermoplastic or foreign prticles	- remove lumps from trough/shoe - screening material before applying helps
Cracks reaching the road surface	- Cracks on road surface - Cracks paralled to the line: caused by diffeent rate of expansion and contraction between the thermoplastic and road surface - Uneven thickness of thermoplastic: causes different hardening speed of the line	- no countermeasure for the first and second causes - if cracking is caused by uneven thickness of thermoplastic: check the trough/shoe of the applicator and apply uniformly.

Machine Spray Method

Drop-on bead concerns

Edge Concerns