Letter 13023

Plastisol vs. powder coating 

Hello,

We are a company in Turkey which want to work with plastisol coating. But our mind is a bit confused. Could you help us about plastisol coating? I mean its detail. And what is difference between plastisol coating and powder coating? Which one is more useful? Please give some information

Thank You, Best Regards,

EMINE ERSOY
- Maltepe, Istanbul, Turkey

Powder coat and plastisol are very different. Powder coat is an electrostatic paint spray process. The details for this process can be found in the Organic Metal Finishing Guidebook put out by Metal Finishing Magazine.

Plastisol is a very thick coating of plastic applied by dipping a part into a liquid solution. Plastisol is used on bare tools (wrenches, pliers, etc.) to give it a nicer grip area. It is also used to coat plating racks to prevent the rack from picking up plating each time is goes through the plating tank.

Powder coat is much cheaper, and I imagine that this is what your customers are looking for. Plastisol is only used for more specialized applications when a thick non-conductive plastic coating is desired.

Tim Neveau Rochester Hills, Michigan

Generally, these topcoats are a thick tough surface finish with a flexible system and good adhesion. They are applied through dip molding, Plastisol bed coating and fluidized bed coating. They can be custom compounds to achieve hardness, flexibility, color, surface appearance, abrasion resistance, flame retardation, insulation and other desired characteristics to meet customer specifications. These compounds plastisols (PVC) can be designed for a wide variety of industrial and commercial applications serving the medical, toy, leisure, recreational, construction, textile, and automotive markets including:

Plastic coated
Handle grips
End caps
Hose protectors
Garlic peelers
Trailer ball covers
Diving tank protectors

To apply a PVC type coating, the metal part or rack that will be coated must be physically clean prior to application of the primer and plastisol.(PVC's generally require a primer before topcoat application but can also be applied with powder equipment).

Dip, spray or brush primer onto the metal part making sure the area that will receive the plastisol is covered with the primer. Place the part into an oven that has been pre-heated to 350-375 degrees F. The primer is cured when the metal part reaches 350 degrees F. The time for this occurs depends upon the mass of the metal part, the efficiency of the oven and other factors. Remove the heated part from the oven and immerse it into the liquid plastisol. Slowly withdraw the part moving it sideways very slowly to make sure the desired area is covered. The thickness of the coating will depend upon the mass of the metal part and the rate of withdrawal rate. Allow the part to drip so as to minimize any "tear drops."

Place the coated part into a pre-heated 350-370 degree F oven and bake until the internal temperature of the plastisol reaches 350 degrees F. Baking time will vary depending upon the size and mass of the part as well as the efficiency of the oven. One indicator that the plastisol has cured is that the coating will become glossy in color.

Also please note that many company's use molten salt as a cure for their PVC lines and in a dip system. The primers are then generally a water-based primer.

Plastisols are measured using a Durometer. Some of the coatings carry vinyl dispersion containing MEK and MIBK. PVC carries Plastisol, vinyl and nylon materials and are usually developed for ultra thickness and durability.

Powder coats on the other hand are generally developed for less physical type durability and more cosmetic appeal, especially with thermo-setting topcoats. Thermo-plastics are generally designed for more frictionless type functions and do not see the thickness that PVC can acquire.

Bob Utech Brooklyn Park, MN

Editor's note:  Mr. Utech is the author of -->

A Guide to High Performance Powder Coating [link is to Amazon]

I think you have not answering correctly about "plastisol coating". In fact "plastisol coating" has very little to do with "dipping" but mainly to "knife coating" to produce synthetic leather.If you want to know more please don't hesitate.

Regards,

PASQUALE CARLINO
- VERONA, ITALY

Sometimes a term can have more than one meaning, and that may be the case with 'plastisol coating', Mr. Carlino. But the previous responders are correct that, in one context at least, plastisol coating involves dipping the object into a hot tank containing liquid, plasticized, polyvinyl chloride. This is widely used as a tank lining, a coating for electroplating racks, a corrosion resistant coating for steel parts that will be exposed to acids, etc.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Hello,

I would like to know about the primer used for the dip coating.

1. Is it 1-pack or 2-pack?
2. Is it solvent-based?
3. what kind of resin system does it consist of (eg acrylics, epoxy etc)?
4. can any additives be added to improve adhesion?

I hope someone can answer these or perhaps recommend some suitable technology.

Thanks,

KC Chew
PVC products - Shah Alam, Selangor, Malaysia

When adhesion is concerned on metal parts, either steel, aluminum or alloys, every coating process have a suitable pre-treatment on the metal parts. Regarding adhesion for plastisol coating, there is a waterbase phosphating conversion compound which is able to withstand high temperature about 280 degree Celsius prior to plastisol coating. It is supplied to the outdoor playground industries.

Andy Lim
- Kang,Selangor,Mlaysia

Is there a plastisol that can be sprayed from standard painting equipment.I have been asked to apply a type 1 ,class 2 to mil-p-20689 .03 to .09 thick.

Greg Dehart
- York, SC, USA

Are you opposed to using a dip process to coat your part? With plastisol, getting the desired thickness and feel may require the right combination of material (viscosity) and temperature for curing the part. Plastisol requires heat to cure. .

Bethany freeland
- Saline, Michigan

I want to make plastisol coating. But I don't know how to make a solution of plastisol . Can you help me to prepare a solution and steps of the process?

Korhan ERKAN
- Ankara , Turkey

Plastisol is a simple solution of PVC in plasticizer.
Additive like heat stabilizers and antioxidants are normally added. Colouration is done immediately before applying.
Plastisol can be "coated", "sprayed", by brush, deep coated, printed (textile screen printing).
Best way to produce it is asking to PVC supplier for a right "K" value depending on article/performance to be obtained.
Normally plastisol are available on the market "ready to use"...
Good Luck

luca tagliabue
- milano - italy