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Plating on Plastics: ABS vs PC, Nylon, & other plastics -- What substrate to use?



An ongoing discussion from 2002 through 2015 . . .

(2002)

Q. Hello,

I just began to study some of the issues of plating plastics because next year I will do graduate studies (diploma) in Plastics Plating. I have found many papers of plating ABS but a few plating other plastics (PP, PC, PA66). Does ABS have advantages to be plated over other plastics?

Gustavo Quintanar
- Monterrey, N.L. Mexico


(2002)

A. Hi Gustavo,

Whereas I know zilch about plating plastics, I know a little bit about ABS.

ABS should have better impact properties than most other plastics (except Pe) and is eminently cementable.

Unlike PVC, for instance, you can, if you know how, edge join ABS using cement to achieve high strengths.

I'd imagine, too, that its coeff. of thermal expansion is far less than PP or Pe. In other words the chances of a plated section 'delaminating' should be less. Go check your books.

It is OK for aliphatic solvents but not, like PP, the polar solvents. It's house usage as drain pipe is excellent..

In mining applications they used a MINELINE pipe which is made of ABS ... and the fittings are CEMENTED together. Why ABS? Because of its impact strength and good abrasion resistance.

freeman newton portrait
Freeman Newton
- White Rock, British Columbia, Canada
(It is our sad duty to advise that Freeman passed away April 21, 2012. R.I.P. old friend).


simultaneous (2002)

A. The reason that most of the processes relate to ABS is because ABS can be etched chemically giving good keying and therefore adhesion. The "B" butadiene component of the ABS is microetched out with chromic/sulphuric and when the plating is pulled off in adhesion testing plastic comes away with the electroplate.


Geoff Whitelaw
- Port Melbourne, Victoria, Australia


(2002)

A. ABS is acrylonitrile-butadiene-styrene. It is the workhorse of the plastics industry and is used in a myriad of parts. The beauty about it is that it is cheap and easy to metallise.

Metallisation is achieved by etching it in chromic acid; this dissolves out the butadiene particles to leave a micropitted surface. The etchant also chemically reacts with the surface of the polymer to give chemically reactive sites. Other chemical etchants, such as permanganate are also known and can be as effective as chromic acid, but they are not as universal. The surface can then be easily metallised by conventional plating on plastics processes.

Other plastics can also be treated in this manner and it is possible to get good metal adhesion. The polymers you mention (PP, PC and PA66) are a mixed bag. PP is very difficult to metallise, although it can be done; however, adhesion is not brilliant and it has a large coefficient of expansion,so delamination can be a problem, especially with high thermal cycling. PA66 is a nylon and readily adsorbs water; this makes it dimensionally unstable and not very suitable for wet processing; it also runs the risk of adsorbing chromic acid and this will not do any good to the products long term integrity. PC can be metallised by the above method with a great deal of success, but it is expensive (relatively). Other good plastics are MIPS and HIPS, acetal, etc. However, it is essential that before metallising plastics you are sure the plastic is fit for purpose in the final product. It is also possible to activate plastics by more sophisticated methods such as plasma etching.

Plating of Plastics, Recent Developments


Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK


(2002)

A. Dear Sir,

ABS was not only one of the first polymers to be metallized but it is also one of the easiest. It's full name is [A/crylene B/utadiene S/tyrene ] as you see it is acopolymer which contains rubber and that make etching very easy and so the adhesion will be good and that is the key in any satisfactorily plating technique.

Thanks,

RAAFAT ALBENDARY
- CAIRO, EGYPT


(2002)

A. Hi, Gustavo,

If you are to graduate on Plating On Plastics(POP) then you should already be aware that ABS is perhaps the only plastic readily available that has three components, one of them (butadiene) is a sort of rubber, the other two are plastic. This rubber is discretely and randomly dispersed in the form of round particles in a matrix formed by the other two components. When you immerse it in the proper chemical only those rubber balls are dissolved leaving tiny rounded pits over the plastic part. Maximum adherence is obtained at those pits where the orifice is smaller that the inside. This creates a mechanical counterlock when metal builds .inside them. No other roughening or etching can produce this geometry.

Guillermo Marrufo
Monterrey, NL, Mexico

Plating Plastics with Metals



To minimize searching and thrashing, and to provide multiple points of view, Finishing.com combined formerly separate threads into the single dialog you are now viewing. Please forgive any resultant repetition.



Chrome-plateable plastic alternatives to ABS and PC/ABS

(2003)

Q. Hello,

I work for a manufacturer of injection-moulded plastic fasteners for the automotive industry. We have a customer that we currently make a plating-grade ABS component for. This part is chrome-plated by an outside plater. Our customer would now like to over-mould the chromed part with EPDM but the ABS cannot take the surface temperature of the second mould and melts. Has anyone had any successful experience chrome-plating other thermoplastics than ABS or PC/ABS? The plastic would need to be able to handle 200 °C (390 °F) and be able to pass an exterior automotive chrome plating spec. Any info on chrome-plating other plastics seems limited. I gather so are the platers willing to handle alternate materials. Any help would be greatly appreciated.

Thanks,

Mark L [last name deleted for privacy by Editor]
- Concord, Ontario, Canada


(2003)

A. Some grades of Allied Chemical's (Honeywell Plastics) "Capron" Nylon-6 are plateable, and as I read it are apparently good for 390-410 °F. Some chrome plated parts of this material are already used in the auto industry.

Ted Mooney
Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey


(2003)

A. I work in the automotive industry and PA (Polyamide) is plated for the automotive Industry. In France there is a company called "Sarrel" that plates it.

Best regards,

Joao Teixeira
- Portugal



To minimize searching and thrashing, and to provide multiple points of view, Finishing.com combined formerly separate threads into the single dialog you are now viewing. Please forgive any resultant repetition.



Plastic compounder finds that Platable Nylon isn't platable

(2003)

Q. I am searching to find information pertaining to Platable Nylon plastic materials. DuPont states their Minlon grade (mineral filled Nylon 6\6) is suitable for plating. We have a highly filled (metal very dense) Nylon that our customer would like plated, but is running into difficulty. Any suggestions would be helpful.

Thanks,

Brian Marcoulier
Plastic Compounder - Worcester, Massachusetts, US


(2003)

A. It would help if we knew what you were doing so we can perhaps identify why it isn't working.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK


(2003)

A. Plating on plastics is extremely difficult, and many of the process chemistry, such as hydrofluoric or peroxide will have detrimental effects on the metal fillers (which may be why it is not working). Usually only ABS and Polycarbonate blends are plated. I have not heard of anyone plating on Nylon 66.

Michael Zuraw
- Georgetown, Ontario


(2003)

A. Nylon is soluble (hence degradable) in Sulfuric Acid and Fluoboric Acid so stay out of those two.

Editor's note:    
   Mr. Probert is the
   author of
Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina



(2003)

A. I believe Michael Zulaw's reply saying that "I have not heard of anyone plating Nylon 66" was somewhat misleading. There are quite a few applicators doing plating on Nylon 66, Nylon 6 + others. Moreover you can also do plating on Nylon/ABS blend. Check out with the major POP process suppliers and you will get a better picture.

Also make sure the Nylon 66 resin is plateable in order to give a better etching and adhesion performance (i.e. to provide mechanical "interlocking" properties for subsequent catalyzed reaction for "seeding" process. The etching process is essentially not of a conventional chromic/sulfuric type. Proper pre-plate process for Nylon substrate will lead to fine metallizing performance as other resins like ABS, ABS/PC blend which primarily is a conditional metal layer for onward electrolytic copper or nickel plating.

Fred YEUNG
Plating process supplier - Hong Kong SAR, PR China

How to Electroplate Non-Metallics


(2003)

A. Nylon 66 is not usually metallised because it (like most other nylons) has a high propensity towards swelling in water and therefore losing dimensional stability. That is not to say it cannot be metallised, only that its tolerances and properties will be difficult to maintain.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK



What determines if PC/ABS plastic is plateable?

(2004)

Q. I am a materials engineer for a plastics company. My company makes a PC/ABS (similar to GE's MC8002 product). A customer has asked me if this product would be "chrome plateable" and I don't see any reason why this product would not.

Do you have any reasons why a particular plastic wouldn't be plateable -- and PC/ABS in particular? (As in there are "platable ABS's and non-Platable PC/ABS" -- what makes them more readily platable)?

Kind Regards

William Atwood
- Grand Rapids, Michigan


(2004)

A. I thought someone like you, working for a plastic manufacturer should know better. Most of the people participating in this forum deal more with plating processes. Plastic manufacturing trade secrets or tricks are not our specialty. Ask your peers or competitors what they put in it to make it platable (and then tell us to increase our knowledge).

Guillermo Marrufo
Monterrey, NL, Mexico


(2004)

A. Hello Mr. William Atwood,

We electroplate on (PC/ABS). Actually it all depends on the mixing of the PC in the ABS, the percentage of mixing. The higher the PC percent (%) in ABS, the more difficult the process will be.

Regards

Ahsen Salam
- Karachi, Pakistan


(2004)

A. Dear sir

PLATABLE OR NOT? That depends (in my opinion) on two things:

1- Etching: If you can make suitable holes then you have a good key to plating this polymer; but these holes (in most cases) depend on something dissolving out and leaving in its place a hole. In case of ABS, butadiene plays this role (actually it is Ideal for this role because its particles are spherical; when dissolved in acids it leaves wonderful spherical holes.

Polystyrene is not platable with the usual procedure, but when butadiene is added it is converted to polystyrene high impact and plated with the same method as ABS.

Polyester is too difficult for plating but when when some carbonate is added as a filler it will be easy to make a hole on its surface.

It was found that if etching will be two stages.

Pre-etching [SWILLING] & etching most polymers give a Good results for pre etching solution it always contains amines, strong alkali,and Glycols this solution is very active against poly carbonate as a pre etchant. 2- Activation: We have to chose the suitable manner of activation.

Some materials are weak against acids so alkaline activation is preferred. Some materials the acidic activation is very successful like the ABS/PC you mentioned.

GOOD LUCK

Raafat Albendary
plating of plastics - Cairo, Egypt



(2007)

Q. How can I test to see if the material is ABS or HIPS plastic?
Thank you,

John
working in shop selling finishing touch - Morristown, New Jersey



Grain depth in ABS parts

September 21, 2014

Q. We are plating on decorative plastic engineering parts. We are plating on ABS and PC+ABS and Hex/Tri and Satin finish on emblems, logos, grills, garnishes, fog lamps, hood strips and door handles.

I want to know what are the grain size allowed in any Grill or Garnish which will easily pass all plating tests as applicable in plain surface. Actually Grills have both shiny and matte surfaces. After plating we are facing an issue in matte surface areas where grain structure for matte finish. That area fails in thermal cycle test. Etching parameters Cr2O3 = 410 gm/lit , H2SO4 = 410 gm/lit , Cr+3 = 8 gm/lit , Temp 67 °C.

Chandan Singh Rawat
Electroplating plant - Pune , Maharshtra , India
  ^- Privately contact this inquirer -^

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