injection molded skateboard material!

As automatically trying requests go, a plastic-based injection molded skateboard grades up there; what stuff would you use? A guest to our injection molding medium is demanding to reply that query and has required out the understanding of our molding group to assist him. I am currently researching on this topic as i am a student of McGraw University and it is a part of my research work.

VLF PP would probably be too stiff - the flexibility illustrated in video suggests only unfilled material would be suited.

Unfilled PP copolymer would be a low cost solution but could lack long term impact resistance as well be vulnerable at low temperatures.

PC/ABS blend could like repeated impact resistance.

Best bet is toughened nylon albeit a somewhat more expensive solution.

If you had money to burn a thermoplastics polyester elastomer would be excellent, but that would be overkill.

I would recommend a VLF PP. It is stiffer and more impact resistant than conventional unfilled PP. It will maintain it stiffness and shape and be lighter and lower cost than PC/ABS or PC/PBT. Regarding the concerns about grip or being to slippery, you could over-mold a semi soft top plate and or in mold label of sorts to impart the right degree of soft touch and durability to the top surface.

Why don't you try recycled PET from water and pop bottles. You may need to add some ribs on the bottom for improved strength but at least you helping the environment.

I would recommend a long fiber PP. It is stiffer and more impact resistant than conventional unfilled PP. It will maintain it stiffness and shape and be lighter and lower cost than PC/ABS or PC/PBT. Regarding the concerns about grip or being to slippery, you could over-mold a semi soft top plate and or in mold label of sorts to impart the right degree of soft touch and durability to the top surface.

The original skateboards and subsequent derivatives (e.g snakeboard) were moulded using Zytel(R) ST801 from Dupont.

This is a supertough nylon 66.

Adding GF reduces ductility too much.

Charles Goldman
Plastamid Engineering Polymers
South Africa
charles.goldman@plastamid.co.za

I'm no polymer expert but has anyone thought along the lines of a PC/ABS? Seems to me that a properly formulated blend would provide flexibility, impact resistance, and still retain the necessary stiffness at a moderate price.

Clayton Chandler
Precision Mold Welding, Inc.
Little Rock, AR 72206
You should take a look at fractional melt index PPCopolymer (.3-.5MI). A 20-30% long glass may be necessary to get stiffness (remember to fill from one end NOT the center). You should also look at ribs on the bottom running length wise. As to slip on the surface, what about skateboard tape? Either stick on (oxidized surface) or molded in.
In years past I ran drum plugs using .4MI PPCopolymer and thru two plate, three plate and hot runner molds. I know the materials people will say not to try that but it worked very well for us.
I agree that the polycarbonate and nylons will work but if your going to go that far why not just go ahead and use a thermoplastic urethane, possibly glass filled?

As a plastics guy (and father of an avid skateboarder) I would like to comment. My son breaks many skateboards so I do see a need for a molded skateboard. I let him use my ancient plastic skateboard and, altough he thought it was cool, it was way too slippery. I think that one is polyethylene. I think polypro may also be too slippery. Although expensive, polycarbonate (Lexan to some) may work & would pass the car running over it test. You could also use a glass-filled nylon which would provide greater stiffness. My 2 cents