Methods used to improve the bonding characteristic includes:
- oxidation by means of chemical or flame treatment ( former is more commonly used)
- electrical discharge to leave a more reactive surface
- ionised inert gas , whick strengthen the surface by crosslinking and leaves it more reactive (read more on activated gas surface treatment of polymer
- metal ion treatment
Ethylene chlorotrifluorethylene copolymer (E-CTFE) (HALAR-allied corporation)
This fluropolymer has excellent chemical resistance , its surface is difficult to prepare due to its high surface tension and non polar condition.
-wipe with acetone
-treat with sodium naphthalene(commercially avaliable) complex for 15min at room temperature
when used with sodium naphthalene , should be kept tightly stopped glass container to exclude air and moisture
-remove from solution with tongs
-wash with acetone to remove excess organic material
-wash with distilled water to remove last trace of metallic saltsfrom the treated surfaces
-dry in an air circulation oven 37c +/- 3c for 1hour
EVA, Ethylene vinyl acetate
SIRA methods
-degrease in methanol
-prime with epoxy adhesive
-fuse into the surface by heating for 30mins at 100C
The basic building for polyethylene are H and C atoms, these carbon are combined to form ethylene monomer, C2H2, in polymerisation process, the double bond C=C are broken , under the right condition these bonds rebond to form with other
FEP, Fluorinated ethylene propylene copolymer
supplied by du pont company as Teflon FEP, it is a thermoplastic and is a copolymer of tetrafluoroethylene and hexafluoropropylene. FEP can be heat sealed , heat bonded, laminated and combined with many materials. can be used as a hot melt adhesive
surface preparation is the same as E-CTFE.
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