POWDER COATING BY http://www.polychemindustries.com and http://www.batchglow.co.uk

 

Powder Coating On Wood, Plastic, and Glass by http://www.polychemindustries.com

Several powder coat manufacturers have worked extensively on developing systems for powder coating wood, especially MDF (medium density fiberboard), for use in furniture and shelving. One concern is the retained moisture in the wood. If you have the time and patience, you can preheat the wood, spray hot (250F or so), cure at an elevated temperature (say 350). The moisture in the wood will blister out and show as blow holes in the coating. You could then sand the coating and repeat the operation. The second coat should come out okay. If not, repeat. Morton Powder Coatings [800-842-1994] and others have developed a low temperature cure powder for wood coatings. As I understand it, you first must sign a non-disclosure agreement with Morton promising your first born child if you reveal what you are about to be told. It is hard to fool the laws of physics, so I don't believe they are doing anything that radical. This may be a combination of pre-heat (possibly with infra-red) and low temperature cure powders. They do make powders which will cross link at close to the boiling point of water, but these tend to be quite touchy at room temperature, and during transit.
The same questions apply to the powder coating of plastic. Since plastics tend to be non-conductive, the electrostatic charge will not be transferred to ground, and the powder will tend to not stick to the plastic unless it is preheated. The softening point of the plastic will be the constraint on doing this. If it is an engineering plastic, it may take a 300+ preheat and post heat. If it is a commercial molded product, it probably won't. I spoke with a coater a few days ago who is coating cast pewter parts. The pewter tends to melt at the standard 400 oven temp. Since the part was dense and solid, I guessed that it would not do any flexing after being coated, and the coater could get by on less than a full cure. He will try coating at 275 to 300. The only down side is poor impact resistance, but he said that should not be a problem.
So, wood and plastic can be coated, but probably not with a standard procedure and cure schedule.
Glass should not be a problem as long as the coater can get the powder on the part. Armstrong Powder Coatings (since purchased by Morton) used to produce a flat black epoxy which was used on a Tequila bottle. One coater I know said he would put a "grounding rod" down the center of glass lamp bases to enhance electrostatic attraction. Others routinely spray hot to get the powder to adhere to the glass, then do a conventional cure. It may take two coats for complete coverage. After the first coat is applied and melted (not cured), it is easier to get the second coat to stick to the first.
David Collander
Polychem Industries

Powder Coating: Epoxy, Polyester and Nylon Coatings from Batchglow   http://www.batchglow.co.uk 

Batchglow are powder coating specialists. We offer a wide variety of finishes by both dip and spray application, including:

Epoxy Coating and Polyester Coating

Epoxy coatings and polyester coatings feature hard, abrasion-resistant properties to provide an attractive finish which make them ideal for such applications as shopfittings, handrails and roller shutter doors.

Nylon Coating

Nylon coatings are glossy and tough, with outstanding adhesion and superb resistance to solvents and oils. The non-contaminatory nature of nylon coatings lends itself to food manufacturing industries, whilst the thickness of coating enables it to be applied to most metal surfaces. Typical applications are stadium seating and disabled vehicles.

Powder Coating MDF

We have a new fully automatic powder coating plant with our sister company MDF Specialised Coatings Ltd. MDF Specialised Coatings provides both textured and smooth powder coatings including flame-retardant coatings and BioCote anti-bacteria coatings. Powder coating of MDF provies a swift and affordable surface finish which is being increasingly used by furniture and woodworking manufacturers for products such as shop fitting, doors, office furniture, wall panels, shelving and nursery furniture.

Superior Quality, Speedy Service

Items of up to 6 metres in length are regularly processed, and a 24-hour turnaround is available when required.

Batchglow's reputation for superior quality combined with fast, reliable throughput has resulted in our undertaking work on behalf of major suppliers to such prestigious companies as Marks & Spencer, Next Retail, Asda, Midland Bank, Meadowhall Shopping Centre, Manchester Airport, Hallam University, Wembley Stadium... and many others.

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Meadowhall, Sheffield

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