Heating method for unglue end plug from frame

V. Elsha

CERN 07.02.2011

1. The idea is

V. Elsha CERN 07.02.2011

to destroy adhesive bond with external heating. See fig.1

•This is method for one straw repairing without mechanical damage of the frame hole•Others end plug need to keep bonding

Argument for

Argument against

•Big temperature gradient in the glue layer. Glue have low thermal conductivity. See fig.2 •Easy to destroy relatively weak bonding. Glue layer have internal tension as a result of free polymerization.

•Long time of the process as result of limitation power of heater. End plugs located side by side.

Fig.1

Fig.2

2. The Sample for test•Aluminum plate 150x150x20 mm with 3 glued Al end plugs. The distance between them the same like in prototype.•Bonding joint with glue -Trabond 2115

•Heating with 100W solder equipped with special adapter•Temperature control with thermometer with probe•End plug removing with special remover and screw in the thread of end plug

V. Elsha CERN 07.02.2011

3. The ResultTime and temperature for 4points was taken Point 1 – in the center of heated end plugPoint 2, 3 – on the plate surfacePoint 4 - in the center of next end plug

After 30 min heating temperature stabilized with 122 C on heated end plug and 54 C on other points.Immediately after heater putting away the end plug was removed with the help of screw.

V. Elsha CERN 07.02.2011

As may be seen from photo the used glue is on surface of hole, but end plug surface is clean

V. Elsha CERN 07.02.2011

4. Conclusion•The method seems to be work•Use it for prototype repairing is possible

The next steps

Study this method for ultem end plugs