How it Works
Magnum Venus Plastech
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RTM Pro
User Manual
72 pgs4.63 Mb0

Magnum Venus Plastech RTM Pro User Manual

Plastech Manufacturing Facility
www.mvpind.com
www.plastech.co.uk
Table of contents
Section 1 – Introduction
1.1. Machine Overview
Section 2 – Commissioning
2.1. Connecting to Services
2.1.1. Electrical Supply
2.1.2. Air Supply
2.2. Loading Materials
2.3. Switching on the machine
2.4. Priming the system
2.5. System test
2.6. Pump calibration
Section 3 – Machine Operating Procedures
3.1. Emergency Stop
3.2. Emergency Flush
3.3. Connection Options
3.4. Recirculation
3.5. Manual Injection Setup
3.6. Manual Mould Pressure Controlled Injection
3.7. Manual Head Pressure Controlled Injection
3.8. Manual Flush
3.9. Working with recipes
3.10. Automatic injections
4.11. Shutdown
4.12. Graphs
4.13. Values screen
Section 4 – Configuration
4.1. Recirculation
4.2. Flush
4.3. Catal Alarm
4.4. Resin Alarms
4.5. Head Pressure Clipping
4.6. Calibration
Section 5 – Alarms & Faults
5.1. Release E-Stop and press reset button
5.2. Recirculation pump stall
5.3. Resin gel alarm (RGA) – Flush machine!
5.4. Autosprue 1 position error
5.5. Autosprue 2 position error
5.6. Autosprue 3 position error
5.7 Autosprue 4 position error
5.8. Motor comms error
5.9. Motor fault
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5.10. Catal alarm!
5.11. Cat over pressure
5.12. Air pressure < 5 bar
5.13. Air pressure > 7 bar
5.14. Resin low
5.15. Catalyst level low
5.16. Solvent level low
5.17. Motor reference lost – re-home
5.18. Head valve position fault
Section 6 – Maintenance
6.1. Health & Safety
6.2. Routine Maintenance of Fluid and Mechanical Systems
6.2.1. Resin Pump
6.2.2. Catalyst Pump
6.2.3. Resin & Catalyst Pipework
6.2.4. Solvent Pump System
6.3. Resin System Re-priming
6.4. Preparing the Machine for a Period of Inactivity
6.5. Replacing Resin Pump Seals
6.6. Replacing Catalyst Pump Seals
6.7. Catalyst Over-pressure Valve Service
6.8. Solvent Pump Service
6.9. Injection Head Assembly Service
6.10. Progressive Catalyst Ratio (PCR) System
6.11. Maintenance Screens
6.11.1. Motor configuration screen
6.11.2. I/O check screen
6.11.3. Diagnostics
Section 7 – Fault Finding
7.1. Programmable Logic Controller (PLC) System
7.2. Wiring Fault – Diagnosis Example
7.3. Common Problems – Non-electrical
Appendices
Appendix A – Air Circuits Appendix B – Electrical Schematics Appendix C – PLC I/O Connections Appendix D – Motor connector pin-out Appendix E – Megaject RTM Pro Manual Revision History Appendix F – Contact Plastech TT Ltd
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Safety Notes
• Read all instructions before operating machine.
• Keep cabinet doors locked at all times unless maintenance is being carried out
by qualified personnel.
• Always wear suitable protective equipment for operating and maintaining
machine.
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1. Introduction
The RTM Megaject Pro, has been designed for injecting polyester, vinylester and methacrylate resin systems under automatic control. The unit uses the proven Megaject pumping system, which mixes resin and catalyst on demand at the injection head, with the catalyst ratio adjustable from 0.5% to 4.5%.
The machine incorporates the programmable progressive catalyst ratio (PCR) facility, which is motor driven and provides automatic catalyst ratio adjustment between 200:1 and 22:1. Interfaced with the machine’s control system, it responds to individual mould programs and adjusts the percentage of catalyst based upon the settings in the selected program.
A summary of the machine’s specification is as follows:
• Resin and catalyst pump system with automatic adjustable ratio.
• On board 25 litre solvent and catalyst containers with non intrusive level
sensors.
• Compact automatic injection head with re-circulation and low mix wastage.
• Full colour 6” Allen & Bradley PanelView 600 touch screen operator terminal.
• Allen & Bradley CompactLogix PLC system with Ethernet connectivity.
• Multi-level user interface with password protection.
• In-built commissioning and testing software.
• Automatic control of injection/flushing cycle.
• User inputs of required injection pressure (mixing head or mould selectable)
and volume.
• Safe Closed loop control of injection head pressure with injection progress
indication.
• Connection for PV sensor to allow precise closed loop control of mould
pressure.
• Program control for individual settings for multiple moulds.
• Programs are stored in the PLC memory for selection recall.
• Automatic re-circulation feature.
• Easy connection to stand alone data logging system via Ethernet.
• Catalyst alarm and monitoring system (Catal).
• Catalyst temperature compensation system, automatically adjusts catalyst
percentage based on workshop temperature and user predefined table of values.
• Fully enclosed lockable wheeled enclosure with separate internal bays for
electronic and fluid systems.
• Heavy-duty stainless steel top, with centrally positioned heavy duty e-stop.
• Touch screen is mounted in rotational and adjustable screen housing,
incorporating push start and stop buttons, providing ease of access to operator.
• Automatic flush sequencer capable of flushing up to 4 autosprues.
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1.1. Machine overview
The touch screen, or Human Machine Interface (HMI) is mounted in an adjustable housing on the top of the machine, along with the START and STOP buttons. This unit, shown in Figure 1.0 provides the operator interface for the machine, from which all machine operations are controlled.
The e-stop button is mounted next to the screen housing on the top of the machine, to facilitate easy access in an emergency.
Start button
Stop button
E-Stop
Figure 1.0 – Operator interface.
Bay 1 is shown in Figure 1.1 and contains all of the electrical control equipment such as the Programmable Logic Controller (PLC).
Figure 1.1 – Bay 1
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E-Stop RESET
Resin level sensor connection
Air supply
Figure 1.2 illustrates the main electrical isolator, power and air connections for the Megaject RTM Pro. These are located on the side of Bay 1.
Power indicator
Isolator switch
Electrical supply
Figure 1.2 – Electrical isolator and service connections
Above the electrical isolator, towards the top of the machine, is the panel shown in Figure 1.3. A connector is provided to allow an external resin level sensor to be connected to the machine in addition to an Ethernet socket, which allows a PC to connect to the control system. The blue RESET button is used for the safety circuit, and must be pressed when the machine is first powered-up, or after an emergency stop condition, when the e-stop button has been released.
Button
Ethernet socket
Bay 2 contains the resin pump, catalyst pump, progressive catalyst ratio system and pneumatic control and preparation components, and is shown in Figure 1.4.
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Figure 1.3 – Reset button and external connections
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Solvent
Emergency
Figure 1.4 – Bay 2
Bay 3 is shown in Figure 1.5 and holds the catalyst and solvent containers. The sounder beacon and connection for the emergency flush system are also in this bay.
Flush Sounder Beacon
Container
Catalyst Container
Figure 1.5 – Bay 3
The injection head is shown in Figure 1.6, with the key elements identified.
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Resin
Catalyst
Head Pressure
Electrical Head
Injection/Recirculation Valve
Injection/Recirculation Valve
Mixer
Connector
Sensor
Figure 1.6 – Injection head
Pneumatic Head Connector
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2. Commissioning
CAUTION
Overalls and eye protection must be worn at all times during operation of the machine. Suitable gloves must be worn when carrying out operations which may result in contact with fluids.
The Megaject RTM Pro is tested and secured against leaks prior to dispatch. It is essential that all pipes and fittings remain tight and sealed at all times to prevent air ingress into or leakage from the system.
2.1. Connecting to services
Air and electrical connections must be made by a suitably qualified person.
2.1.1. Electrical Supply
The machine should be connected to either a 110VAC 60Hz or 220VAC 50Hz
0.8kVA single phase supply, depending on the voltage specified on the machine. This machine must be correctly earthed.
2.1.2. Air Supply
The supply must be dry filtered clean air. A lubricator must NOT be used in the air supply to the machine. When the machine is powered up and the safety circuit has been reset, the regulator in bay 2 should be set to approximately 6 bar. This value can also be read on the touch screen human machine interface (HMI) in the VALUES screen.
Connection of the air supply should be made to the fitting on the side of bay 1. Supply pressure should be between 6 - 9 bar and capable of supplying a flow of between 350 l/min to 1200 l/min for maximum injection flow rate.
2.2. Loading materials
Resin Pump Lubricant (Bay 2)
Half fill resin pump upper collar (item 0546) with Plastech Pump Lubricant (supplied) to maintain pump shaft and top seal in a clean and lubricated condition.
Acetone (Bay 3 – Rear of Machine – White polypropylene tank)
NOTE: Solvents are flammable; follow all applicable health and safety regulations when using solvents.
Remove small white filler cap from solvent tank. Fill tank to approximately 4/5 full. Solvent level must always be high enough to cover the top of the internal pump chamber inside the tank. Replace cap.
Sufficient solvent levels are essential for the correct flushing of the machine. The solvent level must not be allowed to fall below 5 litres as this may cause inefficient flushing. Level is monitored by a non-intrusive proximity level sensor.
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We recommend the use of Acetone as the primary choice of cleaning solvent. If a different solvent system is to be used please contact Plastech for details of changes required.
Catalyst
SAFETY NOTE: The catalyst flow sensor in bay 2 and the catalyst over pressure sensor mounted on the small catalyst ratio pump should remain without adjustments having to be made. Do not adjust this overpressure valve. If in any doubt about operation or adjustment of any part of this machine please contact Plastech TT.
When priming pump from empty condition, first loosen catalyst flow output pipe union. This is necessary to ensure sufficient suction is created to first lift catalyst into pump. Disconnect the catalyst piston from the upper ratio arm, and operate the pump manually until catalyst flows from the outlet union. This should be done into a suitable container to avoid spillage. Retighten the union and reconnect the piston to the upper ration arm.
Resin
Place the resin pick-up and resin recirculation pipes into resin drum. Firmly anchor both pipes. The resin pump should generate sufficient suction to self-prime during recirculation.
2.3. Switching On the Machine
Ensure bay doors are closed and that air at the correct pressure is being supplied to the machine. Turn mains isolator ON (side of bay 1). The touch screen will begin to load the application. To reset the machine’s safety circuit, the e-stop must be released (pulled upwards) and then the reset button on the side of the machine must be pressed to supply air and power to the system. This can be done while the screen is starting.
Figure 2.0 – Welcome screen
When welcome screen, shown in Figure 2.0, has appeared on the display, touch anywhere on the touch screen to move to the login screen shown in Figure 2.1.
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NOTE: At the bottom left of the welcome screen, the current versions for the PAC (Programmable Automation Controller, which is also referred to as a Programmable Logic Controller (PLC)) and the Human Machine Interface (HMI) are shown. Please refer to these versions when seeking technical assistance from Plastech.
NOTE: If any alarms are generated when the system is started, please refer to section
5. A common error is the “Emergency Stop” alarm, which will be triggered if the safety circuit has not been reset, as described above, before the welcome screen has been displayed on the HMI.
Figure 2.1 – Login screen
Press the LOGIN button to bring up the login screen, shown in Figure 2.2, and then enter your user name and password. These details will have been supplied to you when the machine was commissioned by a Plastech employee and must be entered correctly before the machine can be operated. Version 1.00 of the screen software supports only one level of security i.e. when the operator has logged on, all features can be accessed.
To enter the username, press the User button, and enter the username on the keypad followed by return. The keypad is shown in Figure 2.3. If you make an error while entering the username, simply press the backspace key to delete the character that was entered last. To navigate away from the screen, without making an entry, press the ESC key. Repeat these steps for the password and then press return on the login screen to attempt to log onto the machine.
Figure 2.2 – Login screen
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Return key (Enter)
Backspace
Figure 2.3 - Alphanumeric keypad
After the user has successfully logged in to the machine, an INITIALISE button will appear on the login screen. Press this button in order to navigate to the initialise screen shown in Figure 2.4. Press the Yes button to begin the initialisation sequence, which will perform a number operations to prepare the machine for service, including homing the motors that drive the Progressive Catalyst System (PCR).
NOTE: If any alarms are generated before or during the initialisation process, please refer to section 5 for guidance.
Figure 2.4 – Initialisation screen
If the machine is successfully initialised, a confirmation message will be displayed, and an OK button will be displayed. Press this to advance to the main menu screen, shown in Figure 2.5, which is the central access point for all of the screens used to operate the Megaject RTM Pro system.
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Figure 2.5 – Main menu screen
2.4. Priming the system
In order to correctly prime the resin and catalyst systems, it is necessary to operate the machine in recirculation mode. To navigate to the recirculation screen illustrated in Figure 2.6, press the RECIRCULATION button on the main menu screen.
Figure 2.6 – Recirculation screen
Press the Recirculation on time button, and enter 15 on the numeric keypad shown in Figure 2.7 and then press return. Then enter a recirculation off time of 1 minute and an initial recirculation rate of 10%.
Press the START button on the screen housing to start the machine. The sounder beacon will operate to warn the operator the machine is about to start, and then the pumps should start to recirculate.
If the pumps do not move, increase the recirculation rate. If the pumps are recirculating too quickly, reduce the recirculation rate. If the pumps do not move at all, when a recirculation rate of 100% has been entered, please refer to sections 3.4 and 4.1 for further information as it is possible that configuration settings may be incorrectly set.
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When the machine is recirculating, it will run for 15 minutes and then rest for 1 minute using these settings. To stop the machine press the STOP button located on the screen housing. The Catal bar should rise and fall to indicate catalyst flow, refer to section 3.4 for further information.
Recirculate until a bubble free fluid flow is observed at both the resin and catalyst containers, and pump output is even on both strokes. If any air is observed in either return pipes press red STOP button and check tightness and vacuum security of all intake pipe-work and fittings from containers to lower pump inlets.
Return key (Enter)
Figure 2.7 – Numeric input keypad
2.5. System Test
To check that the machine is working correctly, a manual head pressure controlled injection should be carried out. Refer to section 3.5 and 3.7 for a detailed description of how to run the machine in this mode.
In the manual injection setup screen, ensure all the sprues are disabled, and then press the HEAD PRESSURE CONTROL button to navigate to the head pressure controlled manual injection screen.
Enter the following values:
• Head pressure SP = 1000mbar
• Pump power = 15%
• Catalyst = 2% (or other suitable value for the resin system being used)
Once the machine has been correctly configured, direct the injection nozzle into a waste container.
Press the START button and dispense from the mixer at least 1 litre of fluid into the waste container and then press STOP.
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Next, place the injection nozzle into a suitable test cup
Press START button and pump approximately 0.2 litres into the test cup and then press STOP. DO NOT STIR!
The injection head must then be flushed. Direct the injection nozzle into a safe waste container. Press the FLUSH button and allow the machine to complete it’s solvent/air flush cycle.
Ensure that the resin in the test cup is suitably catalysed and that the mixture gels as expected for the resin system in use.
2.6. Pump calibration
The Megaject RTM Pro gives the user the facility to enter a calibration value to adjust how the volume of delivered resin is calculated, based upon the volume of liquid per stroke.
The volume of resin is generally referred to, when injecting components, and is the reference volume used for manual and automatic injections. However, it must be remembered that the volume of fluid being delivered through the mixing head also includes the volume of catalyst. However, in most cases the quantity of catalyst can be considered to be negligible. For example, if 2 litres of resin is dispensed during calibration tests, with a catalyst ratio of 2%, a theoretical volume of 2040 millilitres would be dispensed. The accuracy of the machine is at best +/-100 millilitres, and therefore it is acceptable to ignore the catalyst percentage in the resin volume calculation.
To calibrate the machine, please refer to sections 3.9 and 3.10. Use the 2 litre bucket example in section 3.9 as a starting point for machine calibration.
It is advised that the operator performs the following steps to calibrate the machine:
1. Set up the “2 litre bucket” example recipe.
2. Perform an automatic injection into a sample container using this recipe.
Please remember to have a suitable waste container available for the flush sequence after the injection.
3. Measure the volume of the sample, and record the result.
4. Repeat steps 2-3 until 3 samples have been produced.
5. Calculate the average volume using the following equation (all volumes in
millilitres): (VOLUME
6. The theoretical volume of resin per pump stroke is 100 millilitres, therefore
use the following equation to calculate the actual volume of resin per stroke: VOLUMEAV / (1000 * Litres) = VOLUMEAV / 2000 = Litres per pump stroke.
7. Enter this value on the resin calibration screen (see section 4.6).
8. Perform a further 3 tests to ensure that calibration has been performed
correctly. The volume delivered should be within +/- 100 millilitres of the quantity of resin specified in the recipe.
Sample1
+ VOLUME
Sample2
+ VOLUME
)/3 = VOLUMEAV
Sample3
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3. Machine Operating Procedures
This section discusses all of the operating modes of the Megaject RTM Pro in addition to common procedures.
3.1. Emergency Stop
The emergency stop button is provided to allow the machine to be rapidly de­energised in the result of an emergency. When this button is pressed air pressure is vented from the system, mechanical movement is ceased and the DC electrical supplies to components outside of Bay 1 and the screen housing are de-energised.
The safety circuit also comprises of a reset button on the side of Bay 1. To reset the safety circuit (after an e-stop or on power-up), the e-stop button must be de-activated (pulled up) and then the reset button pressed. If these steps do not reset the safety circuit, check that the machine is correctly connected to a suitable air and electrical supply. If these steps do not clear the fault, a qualified maintenance technician should inspect the machine.
NOTE: The safety circuit is designed to protect the operator and prevent reset if a component has failed. Modifying the safety circuit in order to make the machine operate, could result in serious injury or death.
3.2. Emergency Flush
This procedure should be carried out in the event of electrical supply failure when the machine has mixed resin in the injection head.
Ensure injection head or flush line is attached securely to a suitable waste tank.
Connect factory mains air supply (6-9 bar pressure, clean dry air) to emergency flush port (6mm connector) located in bay 3 above the solvent tank. Turn on supply. The solvent pump will operate and flush injection head. Keep air supply on for 30-40 seconds.
Turn off supply and remove pipe from the emergency flush connector.
This operation may be repeated if necessary. The main air line must be exhausted after each flush operation in order to enable the solvent pump to refill. This can be done by removing the main air line from the emergency flush connector.
NOTE: Flush sequence valves signals are not operated during an emergency flush operation. In these cases it will be necessary to repeat the above for each set of autosprue and sequence valves in order to flush them. Connect air to each sequence valve in turn and re-flush through the head. Repeat this operation for all autosprues in turn, until all are flushed clean.
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3.3. Connection Options
This machine features the following connections at the mixing head:
• Fluid line (for delivering catalysed resin to autosprue(s))
• 6 – way pneumatic connector
• 12 – way electrical connector
For the most basic dispensing operations, such as filling a container with a pre­defined quantity of resin for calibration purposes, the air and electrical connections may be ignored. However, for more sophisticated procedures, these connections must be made.
The electrical connector allows the machine to monitor the open/closed status of up to four autosprues. This connector also allows a mould pressure transducer to be connected to the machine, to enable closed-loop mould pressure injections to be performed. It is recommended that a connection box, supplied by Plastech is used to make the electrical connections between the mould and the machine.
The pneumatic multi-way connector allows six 4mm air lines to be connected to the machine. The connections are numbered and are utilised as follows:
1. Autosprue open/close signal
2. Autosprue open/close signal
3. Flush sequencer valve 1
4. Flush sequencer valve 2
5. Flush sequencer valve 3
6. Flush sequencer valve 4
The autosprue signal has been doubled-up to increase flow and should be connected to in common to all of the autosprues in the system.
In order to flush multiple autosprues individually, which are supplied by the same line, a suitable normally closed pneumatically operated process valve should be fitted in the flush line of the autosprue. The signal port on the process valve should then be connected to the corresponding flush sequencer output on the machine. Thus, when all connected autosprues are in the closed position, and a flush has be initiated, fluid can only flow through the autosprues that have their corresponding flush sequencer valves open. See the Appendix A for a drawing showing suggested flush sequencer connections.
It is recommended that an electrical connection box, pneumatic connector and autosprue system are permanently mounted on each mould. This machine has been designed to allow an operator to safely connect the machine to a mould in three simple steps:
1. Connect fluid line
2. Connect electrical cable
3. Connect pneumatics
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3.4. Recirculation
Recirculation of the machine should be carried out on a regular basis to ensure resin and catalyst flows are even, free of air bubbles (observed through recirculation returns) and to prevent if used, sedimentation of any fillers/additives in the resin system.
Recirculation should be carried out at the start of each shift or if new material has been added to either the resin or catalyst containers.
NOTE: Unnecessary and excessive use of recirculation will result in unnecessary pump seal wear.
The recirculation screen shown in Figure 3.0, can be reached by pressing the RECIRCULATION button on the main menu screen.
Figure 3.0 – Recirculation screen
It is possible for the user to set the on and off durations during a recirculation cycle, in addition to the rate at which the pumps operate.
Change the recirculation on and off times by pressing the appropriate button, and then entering the required value on the numeric input.
The recirculation rate can also be modified, and represents the percentage of air pressure supplied to the air cylinder. The maximum amount of pressure available is determined by the recirculation configuration (see section 4.1 for more information). These settings will be dependent on the viscosity of the resin being used as well as the desired circulation rate. The higher the recirculation rate % is set, the faster the pumps will recirculate.
To begin recirculation, press the START button. Before the machine starts, the machine will operate the sounder beacon as a warning.
The Catal bar at the right hand side of the screen ranges from 0-100%, and should be used in addition to visual checks to ensure catalyst is flowing correctly. The bar should rise for each stroke of the pump, and fall momentarily at the end of a stroke.
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All three values can be changed while the machine is recirculating.
3.5. Manual Injection Setup
When the user wishes to perform a manually controlled injection, they must firstly press the MANUAL INJECTION button on the main menu screen. This will navigate to the manual injection setup screen, which can be seen in Figure 3.1. This screen gives the operator the ability to select what is connected to the mixing head, manually flush the machine and select between either a mould pressure or head pressure controlled injection modes.
Initially the user should configure what is connected to the system. Pressing a sprue button will toggle it between disabled and enabled. When a sprue is enabled, the operator also has the option to enable or disable the limit switch checking function. Once any sprue is enabled, the machine will provide the open/close signal to control the action of any connected sprues.
This system allows a great deal of flexibility for the user and configures how the machine will flush in manual mode. Connection options range from a simple dispense from the head into a container with no signal to open a sprue (all sprues disabled), through to a fully sequenced and monitored configuration featuring four Turbo Autosprues (TASs) with position monitoring and flush sequencing. See section 3.3 to review the connection options.
Figure 3.1 – Manual injection setup screen
3.6. Manual Mould Pressure Controlled Injection
Once the sprue configuration has been set on the manual injection setup screen (see section 3.5), the MOULD PRESSURE CONTROL button can be pressed to access the manual injection screen for mould pressure control, which can be seen in Figure
3.2.
The four square indicators at the top right of screen illustrate the configuration of each sprue, from left to right sprue 1 to sprue 4 respectively. A grey box containing a D indicates the sprue is disabled. A green filled box indicates an enabled sprue; while a
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green box, containing an L shows that the sprue is enabled with limit switch monitoring.
The screen displays the volume of resin injected, elapsed time of injection, actual pressure in the mould cavity and the current resin flow rate. The resin volume and elapsed time readings retain there final values from the previous injection, which can be useful, and are only reset when a new injection is commenced by pressing the START button.
Figure 3.2 – Manual injection screen, mould control
The mould pressure set point (SP) value is the desired pressure to be maintained in the mould during the injection. This value is in mbar absolute, and for a typical LRTM injection, it is suggested that good starting point would be to set this value to approximately 100mbar below atmospheric pressure (around 910 mbar).
Pump power sets the maximum air pressure available to the air cylinder to drive the resin and catalyst pumps. This value will vary depending on the type of resin used, length of pipe to the mould and tooling design etc. It is recommended that a low percentage is entered initially (<10%) and then modified based upon the response of the machine.
During the initial phase of the injection, as resin is first introduced into the mould, the mould pressure will take some time to build. At this time the flow rate will be mainly determined by the pump power setting. If head pressure clipping is enabled (see section 4.5), unsmooth operation of the pumps may indicate that the pump power should be reduced. If head clipping is disabled, care should be taken not to over pressurise the supply line by increasing the pump power value excessively.
The catalyst ratio can be changed to a value between 0.5% - 4.5%.
To begin the injection, press the START button. The sounder beacon will operate for a period, to warn the operator that the machine is about to start. The catalyst pump will then move to the position on the ratio arms specified by the current catalyst percentage. At this point the head valves change over to the inject position, if enabled any connected sprues are opened, and then the machine begins to inject.
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The injection parameters can be modified during the injection and the machine can be paused or restarted, by pressing the STOP and START buttons respectively.
When the injection is paused, a FLUSH button appears at the bottom right of the screen. To finish the injection the user must press the FLUSH button (see section 3.8) to close any connected autosprues, return the head valves to the recirculate position and to initiate the flush sequence.
3.7. Manual Head Pressure Controlled Injection
Once the sprue configuration has been set on the manual injection setup screen (see section 3.5), the HEAD PRESSURE CONTROL button can be pressed to access the manual injection screen for head pressure control, illustrated in Figure 3.3.
The four square indicators at the top right of screen illustrate the configuration of each sprue, from left to right sprue 1 to sprue 4 respectively. A grey box containing a D indicates the sprue is disabled. A green filled box indicates an enabled sprue; while a green box, containing an L shows that the sprue is enabled with limit switch monitoring.
Figure 3.3 – Manual injection screen, head control
The screen displays the volume of resin injected, elapsed time of injection, actual head pressure and the current resin flow rate. The resin volume and elapsed time readings retain there final values from the previous injection, which can be useful, and are only reset when a new injection is commenced by pressing the START button.
Select the head pressure SP button to enter the desired head pressure for the injection. A catalyst percentage between 0.5% - 4.5% can also be set.
The pump power value represents the maximum air pressure available to the air cylinder operating the pumps. This can be adjusted to change the behaviour of the machine and affects both the flow rate and response of the control system.
It is advised that an initially a low value (<10%) is chosen, and then adjusted to optimise the performance of the system.
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