Impregnation

PROCESS DATA BULLETIN

GENERAL

The following is information on the equipment, procedure, expected results etc. regarding Usona Metal Finishing’s impregnation system.  This bulletin is intended to answer questions most frequently asked by our customers.

EQUIPMENT

Autoclave A (24” DIA x 30” depth) Working pressure down to 30 in. Hg – negative pressure

Autoclave B (42” DIA x 54” depth) Working pressure down to 30 in. Hg – negative pressure

PART SIZE

Parts up to the size of Autoclave B may be impregnated.  Parts larger than this can be impregnated using an alternate technique.

MACHINED PARTS

Parts should be machined prior to impregnation as machining after impregnation sometimes opens up new porosity.  Care must be taken during processing to insure machined surfaces are not damaged and blind holes are kept free of all resin.  Parts with blind holes must often be blown on an individual basis to remove all trapped resin.

PROCESS YIELD

90% to 94% on most castings – single pass.  Where 100% yield is essential, pressure testing and re-impregnating may be required.  Specific yield and procedure should be determined on a par-by-part basis from production runs.  A 100% yield can be achieved in a single pass when porosity is small in size.

PRESSURE TESTING

Periodic sample lot pressure testing will be done at no extra charge providing a fixture can be rigged (simple shapes) or is available from the customer for complex shapes.  Pressure testing can be done on all parts upon special arrangement with the customer for an additional charge.

CHEMICAL RESISTANCE

See “1000-95A Product Data Bulletin”

APPEARANCE PARTS

Impregnated to eliminate air pockets.  Eliminates “fish eyes” in painted castings and corrosive acid bleed out from plating operations.  Any secondary finishing operations such as buffing, painting etc. can be done per normal procedure after impregnation.

SAMPLE TESTING

Usona Metal Finishing will impregnate small sample runs, as no cost, to aid the customer in determining the effectiveness of the process and the economics of impregnating a particular part.  In almost all cases it is more practical to impregnate leaking parts than to scrap them.