vacuum formed plastic with gloss exterior

[mrlizzard]

Hi all,

I am looking for 2.5mm abs or polycarbonate sheet that will be vacuum formed to produce a luggage hard shell. This will be formed in China and I have been contacting via email my requirements to the vac formers. The trouble is that the Chinese do not understand my requirement for a high gloss appearance. I want the exterior to be very high gloss/shinny and in vibrant colors, much as you see on some bright trendy luggage cases in the market today. Would this be a sheet with a thin gloss layer extruded with the abs? Is the shiny layer added after forming? What do you think the common method to get this affect is?

I have spent a lot of time looking on the web etc, but wanted a better understanding before I contact a serious supplier.

I have posted a similar thread some time ago, but didn’t understand my full requirements at that time.

Any help would be appreciated.

 

[mrlizzard]

I have attached a picture of what I want - its almost metalic.

 

[patprimmer]

It is most likely mar resistant polycarbonate clear painted on the inside. You need to use special paints with PC so you don't cause solvent stress crack.

Co extrusion with a clear plastic over a coloured plastic is another possibility, but you would have to find an exiting source or or have sufficient quantities to warrant a production run. Those quantities would be substantial.

Buy a piece of luggage as an example and send it to them. If they still don't get it then, they don't want to, so you need an alternative supplier.

Regards

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.

 

[Demon3]

You might be able to get a good appearance using a sheet of MABS (transparent ABS). That's used for lipstick by Channel etc.. Because the plastic is transparent, when you add color you get a depth to the appearance without having to use a transparent colorless top coat. It will cost more than ABS but about the same as PC. It will have better chemical resistance than PC. Sounds weird I know but they actually use transparent plastic and add color to it to get that depth. The same black added to ABS (I have plaques here for a side-by-side comparison) gives a milkly appearance.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[btrueblood]

Pat and Demon can probably correct me - I've seen a PVC/ABS blend sheet material (Kydex?) with that kind of depth, and with metal-flake or pearescense. Like Demon said, it is a 2-ply or more material, with a clear layer over the color layer. We also would routinely get thermoformed PC with a high gloss finish, and I would expect the PC to hold up better to wear than ABS, if that is a concern.

Getting the gloss finish of the sheet material to hold up through the vacuum/thermoforming operations is a bit of a trick, requiring a really good mold polish and attention to process variables for the sheet. The material vendor should be able to help with that, but you need to have a thermoforming house that knows what they are doing to make it happen.

"The trouble is that the Chinese do not understand my requirement for a high gloss appearance."

That means they don't know what they're doing. Keep looking. Good luck.

 

[patprimmer]

If it is PC, the sheet must be dried before it is heated enough to thermoformed. I have never thermoformed ABS, so I don't know, but I expect it also requires to be dried.

PC actually has very poor scratch resistance unless it has a special coating to improve this.

I know the expensive high gloss luggage I have seen was back painted PC

Regards

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.

 

[mrlizzard]

Thanks,

Kydex seem to have a good selection of ABS with decorative layers, and a distribution channel in China so I’m going to contact them.

I am going to try and find a supplier who produced capped abs in a metallic range (if they exist). My initial quantities will be to low (1 tonne) to warrant a special order at the moment. The only suppliers I have found that produce standard Capped ABS in metallic only seem to offer silver, black and a carbon fiber effect!!

Painting may get me the best effect but with a low budget and risks associated for startup I think it may not be best at the moment - but I may be forced that way. I only just meet my target cost without painting, so until my orders are higher I assume it will not be viable at this stage.

Any more input would be appreciated and I will keep you updated.

Thanks

 

[HDS]

As patprimer said the issue is your vendor.

Remember you need UV and weatherability. Look at the Spartech catalog for ideas. They are the biggest extruder but have many competitors. Paint films are another option.

 

[mrlizzard]

I have contacted many suppliers but due to the low volume and non standard coloures needed its a no go at the moment!

Started looking into paint films - thanks HDS. Do you think I (supplier) could vac form a film in between to clear sheets? Is this the norm? The shape is fairly simple with no deep draws(max 60mm).

I would look into painting the inside but because the supplier will be in China, I think paint film could be a safer option than painting.

 

[Demon3]

Try ASA, it's like ABS but with great UV resistance. You can get it already colored even in small orders. Because the material is colored all the way through, it will still look OK when scratched whereas a colored film on an uncolored substrate will not because you scratch through the colored layer.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[mrlizzard]

Thanks Demon3

Started looking into ASA – they make car roof boxes from this but it is co extruded with ABS to give it its impact strength.

My case is only small 500mmx400mm – do you think I would need the ABS substrate for the impact strength?

Hopefully I can get ASA or ABS/ASA in a variety of strong Standard colors. I’m not going to get the metallic look though.

 

[Demon3]

ASA is what car wing mirror housings are made of so it stands up well in automotive use. You don't have to coextrude ASA with ABS to get impact resistance. The impact resistance of ABS and ASA are the same. The reason they are coextruded is that ASA is more expensive but has better UV resistance so they use a thin layer on the outside that gets exposed to sunlight.

In your shoes I would probably make the part from ABS with a thin cap layer of ASA coextruded on top for UV resistance. It depends on what market you are going for, high end or low. For a low end market try UV stabilized ABS instead of ASA.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[mrlizzard]

I have contacted extruders, plastic wholesales and visited Vac formers. As explained my low quantities are the issue and I just can’t get hold of what I want. As suggested it seems as I will have to paint. A Vac former has suggested painting the outer surface of 3mm high impact abs as they produce mudd guards to a supplier who does this. I can’t believe that this will be practical for its application and flexibility its surly going to badly scratch/flake?? Or will a good lacquer prevent this? The Chinese are claiming to use a special rubberized paint on some luggage?

The other preferred option is back painting the Scratch resistance ABS or PC but material is very expensive. Do you think standard clear PC suffice?

Thanks for all the help so far!

 

[patprimmer]

No

Regards

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Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.