MACHINERY TERMINOLOGY GLOSSARY

Plastics Injection-Moulding Machinery

Air-Blast
See Air Ejection.

Air Ejection
A solenoid valve with air pressure connected to air pressure for control to assist in blowing the moulded parts off the die after they are moulded or/and controlling an air cylinder for core-pull or unscrewing.

Auto
Full Automatic mode – An IMM, which runs unattended. This mode is used to produce moulded parts without an operator. Also called ‘Time Auto’; ‘Full Auto’. Clamp The die is fixed to the clamp platen faces. Fixed platen (Nozzle end) and moving platen (ejector end).

Clamp 2nd Chance Close
(Close 2nd, Close Program 2, Again)
Clamp Closes, and if mould protection is not made in a certain pre-set time the Clamp Opens again to Open Stop limit. Core-pull (if selected) is operated as per normal program selected. Ejector forward and back. Clamp Closes again and if for the second time the mould protection is not made in time the clamp opens again to Open Stop, obeying Core-pull sequence if selected. Control will sound an audible alarm and/or display an Alarm. There may be slight variations to the above, with each machine, if this option available.

Clamp Decompress
Clamp Lock-Up Pressure is released slowly. Occurs just before Clamp Open.
Core-pull A moving mechanical slide or pin, which is part of the die. The slide or pin covers an area in the die, which is not required to be filled with the plastic resin. The pin or slide moves In & Out as per explanation in the core-pull chapter.

Die
The Mould (or Tool) the molten plastic is injected into.

Die-Set
Die-Set Mode – This mode is similar to Manual except some pressures/speeds are reduced and some stroke settings are overridden. Used to install/uninstall a Die. Die-Height Adjust Adjustment of the moving platen to fit the Die between the 2 Platen’s when the clamp is fully closed. This is done to achieve a maximum opening stroke. On toggle machines this is more critical, as the Clamp Lock-Up is also set by this adjustment. Some machines have a spacer block fitted or removed between the Main Ram and the Moving Platen to achieve thicker or thinner Die-Heights. Die-Height Adjust Auto Sets the Die-Height Adjustment automatically.

Ejection Confirmation
See Ejection Protection

Ejection Protection
(Ejection Confirmation, Photo-Cell Detect, Product Drop Out, Sensor Auto).
The IMM Control monitors the moulded part falling out of the Die. (Using an Electric Eye Sensor or Flap with Limit Switch). If the Control sensors a moulded part during the Clamp Open Time (Clamp Open Dwell, Mould Open Time, Idle Time, Clamp Pause Time), it will continue onto the next cycle, otherwise it will stop and the Control will sound an audible/visual alarm and/or Display an Alarm, on the screen.

Ejector
Mechanical pin(s) which push the moulded part away from the die after (or during) clamp opening.

Ejector Push Rods
Steel rods, which are connected between the Ejector piston rod plate attachment and the Die Ejector plate.

Extruder
See Screw.

Extrusion
Similar to Intrusion except Screw Rotation & Injection Forward at the same time.

Heat Exchanger
A mechanical enclosed container, which the hydraulic tank oil is pumped through under low pressure (usually a return line to tank). Inside the container, either Copper (Brass or Stainless Steel) Rods or a Copper Coil, which water passes through to conduct the heat out of the oil. Some machines have a water valve, which controls the water flow through the Heat Exchanger via a temperature controller in the IMM control or by a mechanical thermostat. The sensor for both of these methods is placed inside the Hydraulic tank.

Hopper
Sits on top of the injection end over the end of the heating barrel. Stores the plastic resin material, which the screw feeds from.

IMM
Injection Moulding Machine (abbreviation).

Injection (or Injection Forward)
Screw moves forward inside barrel to Inject plastic material (resin) into die cavity.

There are 2x stages of Injection...

Injection speed dependant.
Injection pressure dependant.

The transfer from the speed stage to the pressure stage is the transfer point which is commonly referred to as...

Hold or Holding Pressure Start,
Follow-Up Pressure Start, or
Pack or Packing Pressure Start.

Inserts
Usually metal pieces, which are inserted in the die cavity before each moulding cycle closing.
e.g. A metal screw thread is inserted into the die for a plastic knob to be moulded around the head.

Interlock
An electrical, hydraulic or mechanical device, which enables or prohibits an action.

Intrusion
Screw-Rotation (Charge) before injection forward to feed extra plastic material (resin) into Die cavity. Also known as Flow-Moulding.

Related: See also Extrusion.

This control program is for increasing the Charge Size (Shot Size) past the specified limit of the machine.

Limit
Any mention of LIMIT in this glossary refers to either a limit switch, micro switch, proximity switch, thumbwheel switch stroke setting or stroke transducer setting on a screen.

Limit – Air Blast Start
A device, which signals the IMM to turn on the Air Blast circuit.

Limit – Clamp Close Slow
A device, which signals the IMM the position of the Clamp enable Slowing of the Clamp Closing Speed. There are sometimes two cams to switch the same limit, one is for initial Closing Slow Speed and the other is for Clamp Close Slow before Mould Protection Pressure.

Limit – Clamp Close Stop
A device, that signals the IMM that the Clamp is in the Closed position. See Limit Mould Protection.

Limit – Clamp Open Slow
A device, which signals the IMM the position of the clamp to enable slowing of the clamp opening speed. There are sometimes two cams to switch the same limit, one is for initial Clamp Slow Opening Speed and the other is for Clamp Slow Down for Knockout (Ejector).

Limit – Clamp Open Stop
A device, that signals the IMM that the Clamp has opened to its maximum stop position.

Limit – Close Stop
See ‘Limit – Clamp Close Stop’

Limit – Cores IN
A device, that signals the IMM that all Cores positions are in.

Limit – Cores IN Start
A device, which signals the IMM during clamp closing movements, to enable the Core-pull IN circuit.

Limit – Cores OUT
A device, that signals the IMM that all Core positions are OUT.

Limit – Cores OUT Start
A device, which signals the IMM during clamp movements, to enable the Core-pull OUT circuit.

Limit – Cores Start
A device, which signals the IMM during clamp movements, to enable the Core-pull circuit.

Limit – Cushion Injection Forward
A device which signals the IMM when the Screw is in a preset forward position. Usually 3 to 15mm

Limit – Cycle Start
A device, which signals the IMM that the Operator’s Safety Guard Door is closing. Typically an impulse signal. In Semi-Auto mode, this device signals the IMM to start another cycle.

Limit – Die-Clamp (Mould Fix)
A device, which signals the IMM that all Die-Clamps are in the fixed position. Hydraulically driven clamps, which fix each of the Die halves onto the stationery and moving platens. Usually 4x Die-Clamps per Die half.

Limit – Die-Height Adjust Maximum
Stops the Die-Height adjustment motor from opening - wider (Thinner should still be possible). The maximum amount of opening space between the Stationery Platen and the Moving Platen.

Limit – Die-Height Adjust Minimum
Stops the Die-Height adjustment motor from closing – thinner (Wider should still be possible). The minimum amount of opening space between the Stationery Platen and the Moving Platen.

Limit – Die-Safety
A device, that signals the IMM that the Die Ejector plate is in the back position. If this limit is off, closing is prohibited.

Limit – Ejector Back
A device, that signals the IMM that the Ejector is in the Back position.

Limit – Ejector forward
A device, that signals the IMM that the Ejector is in the Forward position.

Limit – Ejector Start
A device, which signals the IMM to turn on the Ejector circuit.

Limit – Holding Pressure
A device, which signals the machine to transfer from Injection (speed) control to Injection (pressure) control.

Limit – KO Start (Knockout)
A device, that signals the IMM that the Ejector Forward Start position is on, and enables the Ejector circuit.

Limit – Locking Plate IN
A device, which signals the IMM that the Clamp locking plate position is in. Required for Clamp High Pressure

Limit – Locking Plate OUT
A device, which signals the IMM that the Clamp locking plate position is out. Required for Clamp opening

Limit – Melt Decompression
A device setting to adjust the amount of suck-back required of the screw after reaching shot-size. Melt decompression can also occur after injection. Prevents nozzle drool.

Limit – Mid-Station Stop
A device which signals the IMM to stop Clamp Closing to allow the operator to open the Safety Guard Door, place insert(s) into Die, close door again to continue cycle.

Limit – Mould Protection
A device, that signals the IMM that the Clamp is in the closed position (Die halves just closed) and signals the clamp High Pressure Lock-Up to commence. Similar to Limit - Close Stop.

Limit – Nozzle Back
A device, which detects the Injection Carriage, position for Nozzle Hunt in Auto mode. Nozzle Hunt is used primarily used to break the sprue after injection, after screw or before opening.

Limit – Nozzle Forward
A device, which detects when the Injection carriage position is resting against the die. This Limit is required for Injection to operate. Limit – Nozzle Purge Guard Cover closed over Nozzle area to prevent burns to operator from molten plastic splatter.

Limit – Open Slow
See ‘Limit – Clamp Open Slow’

Limit – Open Stop
See ‘Limit – Clamp Open Stop’

Limit – Part Detect
A device, which detects when a moulded part has been successfully ejected from the Die.

Limit – Pressure box Over-stroke
A device, which detects if the Main Ram (Pressure Box) has exceeded its maximum forward travel. Battenfeld machines typical maximum forward is set to 20mm.

Limit – Reference Point Injection Forward
Sets the Injection stroke position encoder to 20mm when limit is made. LS29 Battenfeld Machines only.

Limit – Reject Chute
A device, which signals the IMM when a trap door is closed or open to allow rejected parts to fall into. Requires a signal from the IMM to actuate the trap door.

Limit – Robot Ready
An output signal from a Robot to the IMM to indicate the Robot is ready.
i.e. Robot has positioned itself in a home, origin or reset position.

Limit – Safety Drop-bar
A mechanical Safety device, which detects when the Safety Guard Door is Closed. When the Safety Guard Door is opened, the clamp closing is prohibited electrically and physically by a solid steel toothed bar.

Limit – Safety Guard Door
A door which when closed, the machine operates normally. When open, some functions are prohibited from operating.

Limit – Swing Disc IN
Swing disc is in position Manual Manual mode – This mode enables separate buttons to be pressed to actuate each of the separate movements of the machine. Usually uses same pressure and speeds as Auto mode. Max Die-Height Maximum Clamp opening distance from fully closed.

Melt-decompression (Suck-back)
After shot-size is made, injection reverses for a small distance to enable consistent moulding. Some machines also have melt-decompression before screw-back. Produces a better smear-head check-ring sealing and reduces drooling of nozzle into die cavity after injection has finished.

Mid-Station-Stop (MSS)
Mid-Station-Stop is for fitting inserts into the die before closing.
This sequence is for IMM’s with no hydraulic or air ejectors.

Min Die-Height
Minimum Distance possible according to the IMM’S specifications. Distance is measured between the inside of the Moving Platen and the Stationery Platen.

Mould
See Die.

MSS
See Mid-Station-Stop.

Nozzle
End of the screw barrel where the molten material spurts out.

Nozzle Forward/Back
The injection end movements forward and backward. Also commonly called hunt fwd/back.

Off mode
On some machines this is control off and is used to start the pump.
None of the other modes will allow the pump(s) to start.

Oil Cooler
See Heat Exchanger.

Photo-Cell Detect
See Ejection Protection.

Platen
There are 2 types; fixed platen (nozzle end) and moving platen. This is the area, which the die halves are fastened onto.

Product Drop Out
See Ejection Protection.

Reject Chute
A trap door, which opens to allow rejected parts to fall into.
Requires a signal from the IMM to actuate the trap door.

Robot
A device, which takes the moulded part (and/or sprue) out of the die and places it in on a conveyor or other loading area. Commonly also called a pick and place unloader (Strictly speaking, not a true robot).

Screw
Refers to the rotating screw, which feeds material from the hopper into the heating barrel. See also Extruder.

Semi-Auto
Semi-Automatic mode – A machine that runs one cycle only unattended and then needs an operator to open the guard door, take out the moulded part, shut the guard door again to continue another single cycle.
Some machines have a cycle button to be pressed to continue each cycle.

Sensor Auto
See Ejection Protection.

Sequence
The actual steps that a machine program takes to achieve its movements.

Shot-Size
The feed size of the extruder (amount of material fed into the heating barrel by the rotating screw).

Shut-Off Nozzle
A valve connected to the end of the Injection Screw Nozzle that is either hydraulically (or mechanically) driven to allow molten plastic to extrude from the Nozzle. The mechanical operation is achieved by hunting the nozzle forward to open the Shut-Off Nozzle and back to shut it off. The shut-off nozzle, in its normal state, shuts off the flow of molten plastic. Used to stop drooling from the nozzle during the cycle.

Stripper Plate
Takes the place of an ejector plate. Usually connected by chains to the nozzle platen half of the die. (Have seen it the other way around as well). When the die opens the movable stripper plate is held stationery when the chains become tight. The moving half of the die is set to continue further for the amount of stroke required for the stripper plate to eject the moulded part off.

Switch
Any mention of SWITCH in this manual refers to a switching device. Either - Push button, Selector, Main Isolator, Pressure, Level or Temperature Switch.

Unscrewing
A rotating core inside the die, which has a male or female thread. Used to mould parts with threaded cavities or protruding threads.

Solenoid – Close
Actuates the hydraulic valve for Clamp Close.

Switch – Accumulator Pressure
A Pressure Switch device, which signals the IMM that the accumulator is re-charged.

Switch – Air Pressure
A device, which signals the IMM that the system air supply is sufficient.

Switch – Clamp Pressure
A Pressure switch device, which signals the IMM that the Clamp Pressure has reached a sufficient level for Injection to take place.

Switch – Clamp Pressure 2
A 2nd Pressure switch device, which signals the IMM that the Clamp Pressure has reached a level during re-charging of the screw. This switch is a power saver to unload the pumps to a lower pressure. Not a common option.

Switch – Hydraulic Pumps On
A Contact switch, which signals the IMM that the Hydraulic pump(s) is/are on.

Switch – Nozzle Pressure
A Pressure Switch device, which signals the IMM that the Carriage has hunted forward, is resting against the Die and a set pressure built up to allow Injection. Better than a ‘Limit - Nozzle is Forward’.

Switch – Water Pressure
A Pressure Switch device, which signals the IMM that the system water pressure is sufficient.

Last Updated: Wednesday, 14 September 2005 11:23:05 PM