Envision Plastics Expert Announces Part Seven in the Series: How to Design Plastic Enclosures Using NMR Technology.
St. Paul, MN (PRWEB) July 30, 2013 -- Thus far, in defining the NMR Process specifically, the topics of enclosure types, materials, CNC milling, and CNC bending have all been addressed. The next step in the process is solvent welding, or bonding.
Solvent welding involves injecting or topically applying solvent to areas of the enclosure to secure additional components to the end product or to add back strength to a bend. Additional components would consist of mounting bosses, enclosure end caps, mounting plates, structural components like ribs or gussets, and maybe other panels used to compartmentalize the inside of the plastic housing.
The ‘injecting’ of solvent weld is simply applying solvent to the inside of the sawed “V” grooves created during the sawing/bending process. Since this material was removed (to make an accurate sharp 90 degree inside bend), it’s important to apply solvent to this area to increase its structural integrity.
The application process involves a needle tip syringe on a small hand held tube which is controlled mechanically through a fluid dispensing machine. The welder controls the amount of solvent dispensed through a foot pedal device.
Other application processes could include a hand manipulated syringe or even brushed on for large applications areas. The latter is more prevalent on large manufactured panels or enclosure units that would not fit on a general designated work area surface.
The types of solvents used vary depending on the materials being used for the NMR manufactured plastic housings. Most often, for ABS enclosures or enclosures made with high impact polystyrene (HIPS), a blend of solvents containing methylene chloride is used. Another mixture of solvents works well with polycarbonate and acrylic products. It’s important to note that some materials do not solvent weld together very well….such as HIPS and ABS. Although, it is not an issue to solvent weld polycarbonate to ABS or HIPS when a clear lens or window may be needed in a plastic enclosure.
In the next series, applying curves and radii will be discussed. These features can really dress up an enclosure, but considerations must be made to properly add these cosmetic features.
Brian DuFresne, Envision Plastics & Design, http://www.envplastics.com, 651-765-6735, [email protected]
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