Why use ABS, PMMA, PC for road markers?
During my career in road safety reflectors, the most frequent questions from customers are about raw materials besides road stud price, especially the customers who have plastic injection machines.
So many customers were asking me to take a video when their orders were in production, the plastic raw material part.
Well, there are various kinds of plastics, for road stud reflectors, commonly use are ABS (Acrylonitrile Butadiene Styrene plastic), PMMA (Polymethylmethacrylate), and PC (Polycarbonate). And why them? I’m sure you know the key factors for evaluating the raised pavement marker are Loading Capacity and Reflective Luminous.
The more reflective(bright), the better for road guiding. If it’s poor reflective, then it’s no different with a stone.
The higher the loading capacity, the longer time it will last on a road. You don’t want to see a truck come across, and the road studs flip off. Especially for road studs at pedestrian crossings.
So those 2 factors determine the species of plastic used for a road stud.
Which one has the best light transmittance? As it’s retro-reflective, so light transmittance matters. The answer is PMMA. The light transmittance can be over 92% light source.
Which one is the strongest? The answer is PC, as you may know, the well-known 3M road stud lenses are made from PC.
Ok, then from above, obviously the best group should be PC shell (highest loading capacity)+ PMMA lens (best reflective).
However, no one is perfect, nor are plastics, the PC(Polycarbonate) is not easy for machine injection. Plastic injection is about temperature, humidity, compactness, pressure, and so many other factors. And for road studs, it’s not an ordinate shape, like a square, there are curved corners designed on the shell and some different logo markings.
Then what’s the better choice? Here comes ABS, easy injection, flexible to any shape, so it’s most widely used, same as Road Stud 3M.
ABS: A-Acrylonitrile ensures chemical corrosion resistance, heat resistant, and hardening on the surface.
B-Butadiene ensures high elasticity and toughness.
S-Styrene ensures the molding property of thermoplastic.
Mostly, a factory uses ABS shell and PMMA lens, that ultrasonic welding is perfect, ensure waterproof, dustproof, etc.
So ABS shell and PMMA lens reflector is the best choice for highway road markers.
F&Q
1. Can I mix raw material PC and PMMA for making the lens? — No, you can’t. Because their property is different, they are not compatible.
2. Can I keep the light transmittance and improve the loading capacity for PMMA? — Yes, there is an update PMMA, it’s stronger, but cost higher. Some customers would like this option, for heavy traffic lane.
3. Can I produce with a PMMA shell and a PMMA lens? — No, it’s not a good choice, the PMMA is not strong enough for the shell, which may cause broken in traffic lanes.
4. Can I use an ABS shell and PC lens? — No, it’s not a good choice, because ABS and PC are not very compatible, it may cause some defective products in mass production. As you know for highway road construction, it’s in bulk.
5. What’s the raw material cost for ABS, PMMA, and PC? — Well, price fluctuation, and if you want to know what’s the price this season, you are welcome to send us an email: [email protected]
