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EXTRUDER STARTUP CHECKLIST
Technical Bulletin
STARTUP CHECKLIST
EXTRUDER STARTUP
Turn on power to the Extruder (Tooling included).
Check to see if all guards (barrel cover, screw coupling, motor coupling, etc.) guards are snugly in place. Replace them if they are not.
Check/clean filters for motor blower and electrical cabinet. These will not get hot until you have run for a while, so check them now before they cause an unexpected shutdown.
Extruder Barrel and Screw temperatures should be at least 330°F for startup even if you run colder later. This includes screw oil.
Tooling (Adapter, Y-block, Pipe Heads, etc.) run temperatures should be set at 360°F.
Allow the Extruder and tooling to soak at run temperatures for at least one hour after reaching set point.
Spin Extruder screws a few seconds at low speed before turning on the screw oil (to rotate the seals).
Be sure the pressure tap is in place (if used). It does not need to be very tight, no tighter than an oil filter. A quarter turn past hand tight.
Check Barrel Nut; should be locked.
Check all Heat Transfer Oil Reservoirs; should show oil at bottom of sight glass if cold, or at top of sight glass if hot.
Check to make sure all tooling bolts are properly torqued (Adapter, Split Collar, Y-block, Pipe Heads, etc.). Most tooling will have to be retorqued once it is hot.
Check the vacuum pump water supply strainer screen for debris.
Clean out the vent canister. Be sure all hose clamps are tight. Clear out the vent block and clean the sight glasses.
Start and stop the vacuum pump to make sure it is working properly. It requires 3gpm of water, no more, no less. The colder the water the better the vacuum.
Check the hopper loading system and regrind feeders for proper operation. Check the air and vacuum lines for kinks and bad connections. Be sure the blowback filters are clean so the blowback doesn’t jackpot the machine with plastic.
Check that the gearboxes are full of oil and that their cooling water supply lines are cold (not clogged). The oil can be a little low in the glass before things warm up.
DOWNSTREAM STARTUP
Turn on power to pullers and saws. Make sure they work before you string up the line.
Flood the cooling tanks; you will want to fill them to just below the hole in the gasket. Turn on the vacuum sleeve spraybars. Check all vacuum pumps and filters for proper operation.
PROCESSING STARTUP (Example, for CPVC; contact marty_grohman@milacron.com for *.doc file so you can customize)
Check that you have plenty of purge, heat gloves, and acid neutralizer handy.
Have 10, 14, 17, and 19mm allen wrenches and heater band wrenches handy in case the tooling must be disassembled quickly.
Set the Extruder drive RPM at 20% and begin feeding purge.
Feed the purge slowly and by hand. Purge will come out the vent if you feed it too quickly.
Continue feeding purge until it is coming out of both heads. This is done to ensure there are no hotspots in the die, and to fill any nicks or mismatches in the tooling.
Begin feeding pipe grade PVC into the machine. You may feed this as quickly as you like, and should be able to flood feed.
Once PVC is coming out of the heads, you can begin adjusting the walls of the pipe. Try to get the pipe shooting straight out of the pipe head (PVC will point to the thin side). Turn the vacuum pump on.
Increase the Extruder drive RPM to 750-1000, and begin feeding CPVC through the main feeder system (don't use any regrind yet).
Keep the Motor amps low initially to make sure you don't amp out.
Don’t start up too slow or the residence time will be too long and you’ll get a burn streak.
The line should be ready to string up and run. Increase Extruder drive speed and add regrind as necessary.
Prepared by Chris Surface and Marty Grohman.
