Durable plastic for cold weather toys?
Durable plastic for cold weather toys?
(OP)
I am seeking advice regarding what type of plastic to use for two snow toys. These toys are small hand held toys that need to be durable, not brittle, and slightly flexible. These toys which are targeted for ages 3+ would be produced with injection molding. I appriciate any help that I can get.





RE: Durable plastic for cold weather toys?
RE: Durable plastic for cold weather toys?
RE: Durable plastic for cold weather toys?
The lower the density, the more flexible, and the tougher the part will be at low temperature. For more flexibility still, Vinyl Acetate can be added to produce Ethylene Vinyl Acetate or EVA. The more the Vinyl Acetate, the softer the material right through hot melt adhesives to liquid at room temperature.
ABS is considerable more expensive than PE and more rigid than HDPE.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Durable plastic for cold weather toys?
RE: Durable plastic for cold weather toys?
RE: Durable plastic for cold weather toys?
Yes, you may be able to get an impact modified ABS that will be tough (not brittle) at low temperatures -- but you'll need to do your homework to ensure getting something truly durable. I believe refer shells are molded from impact-modified ABS. My freezer at home has some cracks in the shell where something got dropped...
You'll want to work closely with a molding shop and resin supplier. You will need to specify a lowest use temperature and then look at what the modulus and strength of the material choices are. Oh, and cost too.
RE: Durable plastic for cold weather toys?
Best regards, Aaron
RE: Durable plastic for cold weather toys?
The addition of a little EVA in the compound will help.
EVA is sometimes included, but the manufacturer does not advertise the fact. It is often in the so called "environmental stress crack resistant" compounds.
Just a point that is often misunderstood, Molecular weight and density have nothing to do with each other.
You can get High or low molecular weights in LDPE, MDPE and HDPE.
Generally, high molecular weight is extrusion grade and low molecular weight is easy flow injection grade. Molecular weight is inversely proportional to melt flow index.
All things being equal, higher molecular weight (lower Melt Flow Index or MFI) is tougher with no loss of other properties, but it is also harder to injection mould in thin or long parts.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Durable plastic for cold weather toys?
I've also seen ski bases in a clear (or mostly clear) PE, with a decal or paint job beneath that shows through.
Finally, my current pair of snow skis have a PE base, with what appears to be an emblem in a contrasting color (white) PE. I think they may over-mold the emblem with the base material (black PE)? Ski bases are typically finished by grinding/sanding off the base smooth, so any flash from the overmolding would be swept away.
RE: Durable plastic for cold weather toys?
Best regards and thank you for the flow of information,
Aaron
RE: Durable plastic for cold weather toys?
RE: Durable plastic for cold weather toys?
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.