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Acrylic vs Polycarbonate – Differences?
Hi,
Can someone please advise me on the difference between Acrylic and Polybarbonate.
I have been sent a sample of acylic and I am wondering if I should be using it instead of polycarb for my applications
The main areas I am concerned with are:
Outdoor and weather resistant properties (UV etc)
Impact Resistant properties?
Ageing, Fading, Yellowing?
Clarity?Or is polycarb the best for the above area’s
Thanks in advance.
Daz….
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6 Replies
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Daz
The difference between the two, is that polycarb is class 1 fire rated, and Acrylic is not.
You would use polycarb over acrylic in:
Back trays in letters if you are using neon (halo illumination), acrylic in not fire rated, and is not safe to use
For menu box’s, as polycarb is more than less unbreakable (but so were Tonka toys, and i managed it!)
There are numerous applications for polycarb, and im sure others on here can help you out more than what i have listed.
Hope this helps
ps polycarb is more expensive!
Vince
(hot) (hot) (hot) (hot) (hot) (hot)
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Daz, the only real difference between the two going by what you have listed above is the impact resistance.
Acrylic is quite a brittle material and can be broken fairly easily if hit right, where polycarbonate is almost bullet proof, in fact some polycarbonates are bullet proof!!
Mind you that isn’t to say that acrylic wouldn’t be suitable for your needs, the best way would be for you to give us a better idea of what you want it for, that way someone might be able to give you more specific help. Or if you don’t want to post that much detail on the boards try contacting a manufacturer rather than a supplier as you will probably get a less biased opinion. -
Polycarbonate is really only useful in terms of impact damage resistance and flexibility as it has some undesirable properties too , like very little resistance to chemical attack , especially solvents. It has to have uv stabilisers added for UV resistance and gets degraded quite badly under UV , its expensive , machines badly (clogs cutters , doesnt saw particularily well and is very difficult to laser cut)
Its really not a signage material per se , far better in engineering applications or areas where you need to be vandal and or impact reisistant. Stucturally , its not strong due to its elasticity. It can be blow moulded and extruded which some acrylics cant be. Heat expansion and warpage is a little problematic with polys
Polys come in various flavours and can have various fillers etc , like GRP.
Acrylics are a far more forgiving material , especially cast acrylic , it has VERY good uv propertys , is easily machineable , bendable , thermoformable and glueable , is generally cheaper , comes in a huge variation of colours and translucents , etc etc. It is a stressed material after machining or heat and the biggest problem is this stress and the prescence of solvents as it can develop stress cracks. Its not particualrily flexible unless you get High impact acrylic which has modifiers that make it almost as good as polycarbonate.
Depends what you want to do , yellowing and UV degradation is a huge problem with poly , acrylics will remain clear for decades.
We never use poly unless there are specific applications for example the clear face of a reverse printed membrane switch , various automotive shields and lenses , impact resistant display case faces , guage protectors and the like. We almost NEVER use it in signage apps. -
Polycarbonate scratches very easily. Never wipe it with a dry cloth. A damp chamois is best for cleaning and “killing” static.
Polycarbonate used out doors must have a “uv” coating or it will yellow.
We use a lot of polycarbonate because it can be installed in very cold weather without breaking. Also our supplier stocks it in 38″, 51″ 80″ and 100″ rolls, so we can fabricate very large one piece faces. It lays flat when unrolled, unlike roll acrylic.
Polycarbonate does not bond well with adhesives. We rivet hanger strips.
Always let polycarbonate “outgas” overnight, after removing protective mask, before applying graphics.
Polycarbonate requires a lot more heat when bending or forming.
Deep scratches or knife cuts seriously effect the break resistance.There are 3 types of acrylic; Extruded (cheapest) Continuous cast and Cast (Most expensive),
Cast routs beautifully, the cut edges of extruded usually need to be dressed to make smooth. Cost vs. Labor question.Acrylic cements beautifully and is resistant to most “hot” thinners like lacquer thinner. Polycarbonate must not be touched by “hot” thinners. Only alcohol or specific thinners such as Gripflex T2003 thinner.
There are other variations such as Marguard….polycarbonate with a scratch resistant coating. Really expensive, but great product.
Both materials have distinct advanages.
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Thanks for the responses, thats helped me quite a lot
Thanks
Daz…
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I try to use Acrylic as much as possible before I try and use Poly-carb.
My experience has been unless you buy “Sign” grade Lexan, the poly-carb will fade.
Where as Sign grade Cyro for example will not, or take longer. Cyro has a high impact acylic which I like using, the downside it has a slight orange peel texture to it.
I will usually only use poly carb in high impact or high wind factor locations, or when acrylic is to small. I hate making seams.
Oh and I hate using it on my Panel Saw, you need a lot of teeth on your blade.
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