Rockwell Automation 1771-QDC, D17716.5.93 User Manual

Plastic Molding Module

(Cat. No. 1771-QDC)

Inject, Clamp, and Eject Mode

Important User Information

Because of the variety of uses for the products described in this publication,
those responsible for the application and use of this control equipment must
satisfy themselves that all necessary steps have been taken to assure that
each application and use meets all performance and safety requirements,
including any applicable laws, regulations, codes and standards.

The illustrations, charts, sample programs and layout examples shown in
this guide are intended solely for purposes of example. Since there are
many variables and requirements associated with any particular installation,
Allen-Bradley does not assume responsibility or liability (to include
intellectual property liability) for actual use based upon the examples shown
in this publication.

Allen-Bradley publication SGI-1.1, Safety Guidelines for the Application,
Installation, and Maintenance of Solid State Control (available from your
local Allen-Bradley office), describes some important differences between
solid-state equipment and electromechanical devices that should be taken
into consideration when applying products such as those described in this
publication.

Reproduction of the contents of this copyrighted publication, in whole or in
part,

without written permission of Allen-Bradley Company, Inc. is prohibited.

Throughout this manual we use ATTENTION and Important to alert you
to the following:

ATTENTION: Tells readers where people may be hurt,
machinery may be damaged, or economic loss may occur, if
procedures are not followed properly.

ATTENTION helps you:

- identify a hazard

- avoid the hazard

- recognize the consequences

Important: Identifies information that is especially important for successful
application and understanding of the product.

Important: We recommend that you frequently back up your application
programs on an appropriate storage medium to avoid possible data loss.

PLC is a registered trademark of Allen-Bradley Company, Inc.
PanelView, and PanelBuider are trademarks of Allen-Bradley Company, Inc

Table of Contents

Important Information P1. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Manual

Objectives
Audience P2
Use
Related

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

of T

erms P2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Publications

Overview of Inject, Clamp, and Eject Mode 11. . . . . . . . . . . .

P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

P5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Inject Control 11
Clamp Control 19
Ejector Control 113
System Pressure 115
Example
Summary

Objectives

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Hydraulic Circuits for the Inject, Clamp, and Eject Mode

of Inject, Clamp, and Eject Mode of Operation

11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

116. .

120. . . . . . . .

Install the QDC Module 21. . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Record
Set Module Jumpers 22
Key
Install
Wire
Ground and Shield Your I/O Devices 29
Plan for ESTOPs and Machine Interlocks 211

Configure the QDC Module'

Chapter
Select Module Parameters and I/O Ranges 32
Determine Initial Sensorconfiguration Values 34
Download MCC Parameters to the QDC Module 35
Use Setoutput Operation to Move the Ram (screw),

Complete your Sensor Configuration 38
Select

Objectives

I/O Ranges

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

the I/O Chassis

the QDC Module

I/O Devices

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s I/O

Objectives

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Clamp, and Ejector 37

Optional Configurations

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21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31. . . . . . . . . . . . . . . . . . . .

31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

314. . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contentsii

Overview of Remaining Configuration Procedures 41. . . . . .

Chapter
Configuration Concepts 41
System Command and Status Blocks 42
Overview of Procedures 43
Enter Data Table Values and Download Data Blocks 44

Objectives

41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Jog Your Machine 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
About Jogging 51
Use These Worksheets 51
Determine
Write Ladder Logic 55
Jog Your Ram (Screw), Clamp, and Ejector 57
Configure Screwrotate Jogs for Indirect Control 57
Write Ladder Logic to Assist with Screwrotate Jogs 58
Rotate the Screw 59

Objectives

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Initial Jog V

51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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alues 52. . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Select Command and Status Bits to Sequence

Machine Operation 61. . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Assess Your Logic Requirements 61
Use
Chapter
Use These Worksheets 72
Procedure to Determine and Record Initial Values 719
Determine

Select the T
Determine Word Values:

Determine Unselected Valve Setoutput Values 722
Set Your Acceleration/Deceleration Ramp Rates 724
Determine Setoutput Values for End of Profiles 725
Set Pressure Control Limits 726
Set V
Set Profile Gain Constants, PressureAlarm Setpoints,

Enter and Download your Worksheet Values 731

Objectives

. . . . . . . . . . . . . . . . . . . . . . . .

Command and Status Bit T

Objectives

Bit Selections: Assign Module Outputs for

Your Control Valves 719. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ype of PID Algorithm

Select V

and Watchdog Timer Presets 729

alues for Expert Response Compensation (ERC) 722. . . . .

elocity Control Limits

ables 62. . . . . . . . . . . . . . . . . . . . . .

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61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

721. . . . . . . . . . . . . . . . . . . . . . . . .

728. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Load

Initial Profile Setpoints

Table of Contents iii

81. . . . . . . . . . . . . . . . . . . . . . .

Chapter
Use These Worksheets 81
Determine and Record Setpoints for the Clamp Close Profile (CPC) 82

Determine Bit Selections for Worksheet 8A 85. . . . . . . . . . . . . . . . .

Determine Word Values for Worksheet 8A 87
Enter and Download Your Worksheet Values 89
Determine and Record Setpoints for the Injection Profile (IPC) 810
Determine Bit Selections for Worksheet 8B 813
Determine Word Values for Worksheet 8B 814
Enter and Download your Worksheet Values 818
Determine and Record Setpoints for the Pack/Hold Profile (HPC) 818
Determine Bit Selections for Worksheet 8C 821
Determine Word Values for Worksheet 8C 822
Enter and Download your Worksheet Values 823
Determine and Record Setpoints for the Plastication Profile (PPC) 824
Determine Bit Selections for Worksheet 8D 827
Determine Word Values for Worksheet 8D 828
Enter and Download your Worksheet Values 830
Determine and Record Setpoints for the Clamp Open Profile (OPC) 831

Determine Bit Selections for Worksheet 8E 834. . . . . . . . . . . . . . . . .

Determine Word Values for Worksheet 8E 836
Enter and Download Your Worksheet Values 838
Determine and Record Setpoints for the Ejector Profile (EPC) 839
Determine Bit Selections for Worksheet 8F 842
Determine Word Values for Worksheet 8F 845
Enter and Download Your Worksheet Values 849

Objectives

81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Span Your V

Chapter
Choose Only Applicable ValveSpanning Procedures 91
Referenced Worksheets 93
LPC Profile - Low Pressure Valve 94
FCC, SCC, TCC Profiles - Pressure Valve(s) 910
FCC,

SCC, TCC Profiles - V

INC Profile - Pressure Valve 920

Profile - V

INC
PKC and HDC Profiles - Pressure Valves 931
PLC Profile - Pressure Valve 937
FOC,

SOC, T

FOC,

SOC, T
EAC, ERC Profiles - Pressure Valve(s) 953
EAC, ERC Profiles - Velocity (Flow) Valve(s) 958

alves 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Objectives

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elocity (Flow) Valve(s) 915. . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

elocity V

OC, OSC Profiles - Pressure Valve(s) 942. . . . . . . . . . .

OC, OSC Profiles - V

alve 925. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . .

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elocity (Flow) Valve(s) 948. . . . . . .

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91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contentsiv

Tune Your Machine 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Closedloop Tuning 102
Injection Tuning Considerations for Producing Parts 1010
Tuning Considerations for Clamp and Ejector Operations 1023

Objectives

101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Table of Contents v

Troubleshoot with LEDs 111. . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter
Use LEDs to Troubleshoot Your QDC Module 111

Objectives

111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

Blank Worksheets A1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Preface

Important Information

Manual

Objectives

Use this preface to familiarize yourself with this manual so you can use it
effectively. This manual shows you how to apply the QDC module to your
molding machine in a reasonable length of time.

Since this manual is task oriented, we recommend that you perform these
tasks in the following order:

Perform this task: As discussed in this chapter:

Browse through the entire manual to become familiar with
its contents.

Learn about the inject, clamp, and eject process.
This describes how the QDC module controls your
injection molding system.

Install the QDC module.
This includes such tasks as wiring and setting jumpers.

Learn about the configuration process.
This describes procedures you perform using this
manual.

Configure the QDC module mode of operation to match
your specific application, and its communication with its
inputs and outputs.

Jog the ram (screw), clamp, and ejector.
This task requires that you configure jog setpoints and
pressure alarm setpoints.

Set up communications between your PLC5 processor
and the QDC module. You write ladder logic to handle
command bit interaction between the two devices.

Prepare to run your machine in open loop.
This task requires that you determine and enter initial
values into the ram (screw), clamp, and ejector
configuration blocks.

Prepare to run and tune your machine in open loop.
This task requires that you determine and enter initial
values into ram (screw), clamp, and ejector profile blocks.

Span your ram (screw), clamp, and ejector valves.
This is done using setoutput and openloop control.

Tune the machine for parts production. Chapter 10

Troubleshoot problems that may occur with QDC module. Chapter 11

Refer to this appendix for a blank copy of each worksheet
contained in this manual.

All chapters

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Appendix A

P-1

Preface

Audience

of T

Use

erms

Before attempting to apply the QDC module to a molding machine we
assume that you are:

an injection molding professional

an experienced PLC programmer

(especially with the Allen-Bradley PLC-5 family of processors)

an hydraulics designer or technician

We use abbreviated catalog numbers when referring to Allen-Bradley
equipment:

Abbreviated Name: Title:

QDC module 1771QDC Plastic Molding Module

PLC5 processor PLC5 Programmable Controller

T45 or T47
T50 oe T53 terminal

ProSet 600 Software

PanelView Color display
ERC Expert Response Compensation

1784T45 or 47 Portable Programming Terminal
1784T50 or 53 Industrial Terminal

6500PS600
ProSet 600 Injection Molding Operator Interface Software

2711KC1 PanelView Operator Interface Terminal

The next table presents other terms we commonly use in this manual:

Term: Definition:

Selected Valve In multivalve systems, depending on the configured profile, the QDC

module controls one valve and presets the setting of the remaining
valves to produce moldingmachine profiles. We call the valve being
controlled by the QDC modules algorithms the selected valve.

Unselected Valves In multivalve systems, depending on the configured profile, the QDC

module controls one valve and presets the setting of the remaining
valves to produce moldingmachine profiles. We call the valves that are
preset with an openloop percentage setpoint the unselected valves.

Profile A group of mold/part setpoints which define a given machine operation

to the QDC module.

Command Block Data blocks downloaded from the PLC5 data table to the QDC module

to make configuration changes or to initiate machine actions.

Status Block Data blocks used by the QDC module to relay information to the PLC5

processor about the QDC module's current operating status.

Profile Block Command block containing mold/part setpoints.

Configuration Block Command block containing machine setpoints.

Direct Acting Valve An analog control valve that delivers increasing velocity or pressure with

increasing signal input.

Reverse Acting Valve An analog control valve that delivers increasing velocity or pressure with

decreasing signal input.

P-2

Preface

Command Blocks

Command blocks provide the parameters that control machine operation.
They are transferred from the PLC-5 processor to the QDC module by
means of block transfer write (BTW) instructions in software ladder logic.
Command block abbreviations are:

Acronym: Description:

MCC Module Configuration Command Block

JGC Jog Configuration Command Block

FCC First Clamp Close Configuration Command Block

SCC Second Clamp Close Configuration Command Block

TCC Third Clamp Close Configuration Command Block

LPC Clamp Low Pressure Close Configuration Command Block

CFC Clamp Close Profile Command Block

INC Injection Configuration Command Block

IPC Injection Profile Command Block

PKC Pack Configuration Command Block

HDC Hold Configuration Command Block

HPC Pack/Hold Profile Command Block

PRC Predecompression Configuration Command Block

PLC Plastication Configuration Command Block

PPC Plastication Profile Command Block

PSC Postdecompression Configuration Command Block

FOC First Clamp Open Configuration Command Block

SOC Second Clamp Open Configuration Command Block

TOC Third Clamp Open Configuration Command Block

OSC Clamp Open Slow Configuration Command Block

OPC Clamp Open Profile Command Block

EAC Ejector Advance Command Block

ERC Ejector Retract Command Block

EPC Ejector Profile Command Block

DYC Dynamic Command Block

RLC Inject ERC Values Command Block

CLC Clamp and Eject ERC Values Command Block

P-3

Preface

Status Blocks

Status blocks report current status of molding-machine operation. They
are returned from the QDC module to the PLC-5 processor by means of
block transfer read (BTR) instructions in software ladder logic. Status
block abbreviations are:

Acronym: Description:

SYS System Status Block

CPS Clamp Close Profile Status Block

IPS Injection Profile Status Block

HPS Pack/Hold Profile Status Block

PPS Plastication Profile Status Block

OPS Clamp Open Profile Status Block

EPS Ejector Profile Status block

RLS Inject ERC Values Status Block

CLS Clamp and Eject ERC Values Status Block

Word and bit Numbering

The QDC module stores data in command and status blocks. Each word
location in a command or status block is identified by an alphanumeric
code containing the block acronym and word number. For example, word
09 of the Module Configuration Command Block (MCC) is identified as
MCC09.

Identify bits in a word location by adding bit numbering to the abbreviated
word location. For example:

Specific: MCC09-B15 General: MCCxx-Byy

where:

MCC = Module Configuration Command Block
xx=word number (01-64)
B = bit identifier
yy = bit number (00-15)

P-4

Preface

Related

Publications

The following table lists documentation necessary for the successful
application of the QDC Module:

Publication Use this documentation: To :

17856.6.1 PLC5 Family Programmable

Controller Installation Manual

6200N8.001 6200 PLC5 Programming

Software Documentation Set

17714.10 Plastic Molding Module

Application Guide

17716.5.85
17716.5.86
17716.5.87

17716.5.88 Plastic Molding Module

Plastic Molding Module User
Manuals for other modes.

Reference Manual

Install the PLC5 processor and I/O modules.

Select instructions and organize memory when
writing ladder logic to run your machine.

Help select the module mode and match your
QDC module to your hydraulic layout.

Configure, program, install, and operate your
QDC module to control molding operations.

Program block transfers between PLC5
processor and QDC module. Also, information on
PLC5 data transfer logic.

Take time now to familiarize yourself with the Reference Manual
(publication 1771-6.5.88). The four sections include:

a summary of each data block used by the QDC module

(abbreviated command and status blocks)

programming error codes returned by the QDC module for each data

block, and recommended procedures to correct these errors

detailed listing and explanation of each command word and bit used by,

and each status word and bit returned from, the QDC module

operational, electrical, and environmental specifications of your module

If you purchased the Pro-Set 600 software, you also need the following:

Publication Use this documentation: To :

65006.5.11 ProSet 600 Software

Designers Guide

65006.5.12 ProSet 600 Software

Assembly Manual

65006.5.13 ProSet 600 Software

Overlay Installation Manual

65006.5.14 ProSet 600 Software

Customization Manual

65006.5.15 ProSet 600 Software

Reference Manual

Select the ProSet 600 software that matches
the requirements of your molding machine.

Transfer your ProSet 600 software from a
floppy disk to your hard drive. Add Overlays into
your PLC5 and PanelView application files.

Install ProSet 600 overlays into your application
files.

Customize your ProSet 600 build for your
machine control requirements.

Support customizing your software control
system.

P-5

Chapter

1

Overview of Inject, Clamp, and Eject Mode

Chapter

Objectives

Inject Control

This chapter presents an overview of the 1771-QDC Plastic Molding
Module in the inject, clamp, and eject mode. We present a summary of
operating features followed by sample applications.

Important: This chapter assumes you have already read your Plastic
Molding Module Application Guide (publication 1771-4.10) and have
chosen inject, clamp, and eject as your QDC module’s mode of operation.

Next we describe the control operations of this mode.

You can control the inject operation with these phases:

injection
transition
pack
hold
pre-decompression
plastication
post-decompression

Figure 1.1

Operation of a T

Inject

ypical Machine Cycle

Clamp
& Eject
Operation

Injection Pack Hold

Post- Pre­Decompression Decompression

Transition to
Pack or Hold

Plastication

(Reload)

1-1

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Injection Phase

You can vary the velocity of the ram (screw), or the pressure driving it, so
the leading edge of the melt moves through the mold cavity at the desired
speed. The pattern of velocity or pressure variation during injection is
called the injection profile. The QDC module lets you chose from four
different injection profiles:

velocity vs. position
pressure-limited velocity vs. position
pressure vs. position
pressure vs. time

Figure 1.2
Example

Injection Profile

11 10 9

Velocity or Pressure

87654321

Position or Time

You enter setpoints to create a profile. You can select from 1 to 11
segments of position or time. Segment numbers represent the order of
operation. By convention the ram (screw) injects plastic by moving from
right to left.

With this Profile: You Control Injection: With up to 11 Segments

Velocity vs. Position Speed Length of the shot

Distributed over the:

1-2

Pressurelimited1
Velocity vs. position

Pressure vs. Position Pressure Length of the shot

Pressure vs. Time Pressure Time for a shot

1

Pressurelimited velocity vs. position profile differs from the velocity vs. position profile as follows:
During any segment, if the pressure exceeds a preset limit, the module switches to PID pressure
control with the pressure limit as the setpoint. Then if velocity exceeds the velocity setpoint, the
module returns to velocity control.

Speed with a
maximum pressure

Length of the shot

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Example Benefits of Profiling an Injection Phase

The injection phase should force the melt through the mold as fast as
possible without flashing the mold or burning the melt at a mold gate.
Here are two examples of how you can achieve this by profiling the
injection phase:

Velocity Example - As the leading edge of the melt enters different mold
cavities, the flow of plastic through the gate should increase or decrease
accordingly to keep the melt front at maximum desired speed without
flashing the mold. This reduces injection time and minimizes surface
stress due to surface cooling. You achieve this by shaping the injection
profile to suit the mold cavity (Figure 1.3).

Mold Cavity

54 3

Flow into mold

Figure 1.3
Velocity

1

2

Example

Gate

Mold
End

Injection Profile

5

4

Position

Sequence of execution

Velocity

23

1

Back
Point

1-3

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Flash Prevention Example - With a velocity profile (Figure 1.4 part 1),
the pressure may reach a peak and flash the mold at ram (screw) position
segments that correspond to events such as:

the initial surge (2.a)
when the melt front enters a constriction in the mold cavity (2.b)

You can remedy this (part 3) by decreasing the ram (screw) velocity at
segments (3.a) and (3.b) that correspond to flash points. Conversely, you
can boost velocity at segment (3.c) where the resulting pressure is well
below the flash point.

Figure 1.4
Flash

Prevention Example

1. Initial Velocity Profile

Velocity

bca

Position Position

3. Final Velocity Profile

Velocity

b ca

Position

2. Resulting Pressure Profile

ba

4. Resulting Pressure Profile

ba

Position

Flash
Point

Pressure

c

Flash
Point

c

Pressure

1-4

Optionally, you may select pressure limited velocity versus position as
your method of injection control. With your pressure limit setpoint just
below the flash point, the module switches over to pressure control prior to
flashing the mold.

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Injectiontopack Transition

The QDC module ends the injection phase and automatically starts the
pack or hold phase when it detects the first of up to three events occurred:

Ram (screw) position exceeds a preset limit
Ram (screw) pressure exceeds a preset limit
Injection phase elapsed time exceeds a preset limit

You select which of these events you want monitored for transition by
entering the appropriate setpoint, or zero for ignoring the event. You also
may specify the zone of ram (screw) travel over which the QDC module
inhibits or allows a pressure transition.

Pack Phase

The QDC module controls the pack phase with a pressure vs. time profile.
You create the profile based on controlling the hydraulic pressure against
the ram (screw). You can control pressure with up to five segments. By
convention, events occur from right to left on the time axis (Figure 1.5).
You determine the pressure setpoints and time durations for the pack
profile based on molding requirements. The pack phase is optional.

Figure 1.5

Phase Example

Pack

Pressure

4

5

Time

123

1-5

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Example Benefit of Profiling the Pack Phase

Molten plastic may cool unevenly in the mold causing variations in density
with the end result of warpage and distortion as shown in Figure 1.6.

Figure 1.6
Uneven

Lower density
(last zone filled)

Density in Mold Cavity

Cooling in Pack Phase

Pack Profile

Higher density
(gate zone,
greater pressure)

Pressure

Gate

You can remedy this by decreasing the pack pressure with time so plastic
can back out of the mold as shown in Figure 1.7. This is to alleviate
gradations in density as the plastic cools from the low-density end of the
mold (last zone filled) to the high-density end of the mold cavity (gate
zone where pressure is greater).

Figure 1.7

Cooling in Pack Phase

Even

Constant Pressure over entire Mold Cavity

Density in Mold Cavity

Gate

5

5

Pack Profile

Time

Time

234

1

Pressure

234

1

1-6

After completing the last segment of the pack phase, the QDC module
automatically starts the hold phase.

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Hold Phase

The QDC module controls the hold phase with a pressure vs. time profile.
You create the profile based on controlling the hydraulic pressure against
the ram (screw). The pressure can be controlled using up to five segments.
You determine the pressure setpoints and time durations for the hold
profile based on molding requirements.

After completing the last segment of the hold phase, the QDC module
either immediately starts the optional pre-decompression movement, skips
the pre-decompression movement if none is required and immediately
starts the plastication phase, or waits for a command from your PLC-5
program to continue.

Predecompression Movement

You select a length of pullback for the ram (screw) prior to the plastication
phase to separate plastic solidifying in the sprue from molten cushion
remaining in the barrel.

After completing the pre-decompression movement, the QDC module
either immediately starts the plastication phase or waits for a command
from your PLC-5 program to continue.

Plastication Phase

The plastication phase lets you achieve a melt temperature gradient in the
barrel containing the ram (screw). To program the desired temperatures,
you consult backup rate (backpressure) vs. temperature tables. You can
create the profile with up to 11 segments of position or time (figure 1.8).

You chose from two plastication profiles:

Backpressure vs. position
Backpressure vs. time

1-7

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Figure 1.8
Plastication

BackPressure

Mold
End

Phase Example

12 34 5

Position or Time

hotter

Temperature Gradient

Barrel Containing the Melt

6

7891011

cooler

Back
Point

Example Benefits of Profiling a Plastication Phase

The higher the backpressure during plastication, the slower the backup rate
and higher the resultant temperature of the melt. You can achieve the
desired temperature gradient by lowering ram (screw) backpressure to
accelerate the backup rate and decrease the temperature of the melt along
the length of the barrel.

After completing the last segment of the plastication phase, the QDC
module either immediately starts the post-decompression movement or
waits for a command from your PLC-5 program to continue.

Postdecompression Movement

You select a length of pullback of the ram (screw) after the plastication
phase to guard against drooling molten plastic into the open mold during
ejection. The QDC module notifies your PLC-5 program when the
post-decompression movement is complete.

1-8

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Clamp Control

Ejector advance

Ejector retract

You control clamp operation with these phases:

clamp close
low pressure close
clamp open
open slow

Figure 1.9
Clamp

1st
Close

Open
Slow

Portion of a T

ypical Machine Cycle

2nd
Close

3rd
Open

3rd
Close

2nd
Open

Low Pressure
Close

1st
Open

Clamp Close

Inject

Clamp
Cylinder

You may configure three separate clamp close profiles:

first close
second close
third close

You may select from these control modes:

velocity vs. position
pressure vs. position

Use clamp close to move the platen from the fully open position (L) to
some position X at a relatively high velocity or pressure. X is a position
relatively close to the stationary platen yet far enough away to allow
deceleration into low pressure close. This prevents the platens from
coming together at a high velocity (Figure 1.10).

Figure 1.10
Example

Moving
Platen

Clamp Close

Stationary
Platen

Velocity

1st Close
Profile

2nd

Close

Profile

3rd

Close

Profile

L

Position

1-9

Chapter 1

Overview of Inject, Clamp, and Eject Mode

You may start these operations between the three clamp close profiles:

pick up the 3rd plate of a mold (on a floating 3-plate mold) or set cores
program other events for all valves
automatically bridge between profiles, or let ladder logic decide when to

begin the next profile

You can subdivide each clamp close profile into three position segments
(Figure 1.11). You can change clamp velocity or pressure up to three times
in each profile, or up to nine times for the entire clamp close phase.

Clamp
Cylinder

L

Moving
Platen

Figure 1.11
Example

Clamp Close Position Segments

Stationary
Platen

0

X

Velocity

2

1

1st Close
Profile

3

Segments

2

1

2nd

Close

Profile

Position

3

1

2

3

3rd

Close

Profile

Important: You may use as many or as few profiles and/or segments
within profiles as needed for your molding application. If using a single
close fast motion, use the first segment of the 1st close profile. The low
pressure close profile must follow.

After completing the last segment in each profile, the QDC module either
switches immediately to the next programmed segment of the next
programmed profile or waits for a command from your PLC-5 program to
continue.

1-10

After completing the last configured close profile, the QDC module either
switches immediately to the first programmed segment of low pressure
close, or waits for a command from your PLC-5 program to continue.

Low Pressure Close

Use the low pressure close profile to decelerate closing motion to guard
against damaging the mold halves and detect for part obstructions. The
pressure setpoint(s) that you select to control low pressure close should
prohibit the mold from fully closing if there is an obstruction. You may
use one or two low pressure close profile segments (Figure 1.12).

You must use pressure vs. position for low pressure close.

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Clamp
Cylinder

Figure 1.12
Example

Low Pressure Close

Moving
Platen

L

0

X

Stationary
Platen

Low Pressure Close

Segments

1

2

Pressure

Position

Important: If you need only one low pressure close segment, configure
the 1st segment of the low pressure close profile.

The QDC module notifies your PLC-5 program when this profile is
complete and automatically uses set-output values at the end of low
pressure close to build tonnage (hydraulic machine) or lockup your toggle
(toggle machine).

Clamp Open

Clamp
Cylinder

Moving
Platen

You can open the mold fast with three profiles of the clamp open phase:

first open
second open
third open

You may select from these control modes:

velocity vs. position
pressure vs. position

Use clamp open to move the platen from the fully closed position (0) to
some position Y at relatively high velocity or pressure (Figure 1.13). Y is
close to your fully open position (L), yet far enough away for deceleration
into the open slow profile. This aids positioning accuracy at position (L).

Figure 1.13
Example

Clamp Open

Stationary
Platen

Velocity

3rd

Open

Profile

2nd

Open

Profile

1st Open
Profile

L0

Y

Position

1-11

Chapter 1

Overview of Inject, Clamp, and Eject Mode

You may start these operations between the three clamp open profiles:

drop the third plate of a mold (on a floating 3-plate mold) or pull cores
program other events for all valves
automatically bridge between profiles, or let ladder logic decide when to

begin the next profile.

Each clamp open profile can be subdivided into three position segments
(Figure 1.14). You can change clamp velocity or pressure up to three times
in each profile, or up to nine times for the entire clamp open phase.

Clamp
Cylinder

Moving
Platen

Figure 1.14
Example

L0

Y

Clamp Open Position Segments

Stationary
Platen

Velocity

2

3

3rd Open
Profile

1

Segments

2

3

2nd Open
Profile

Position

1

3

1st Open
Profile

Important: You may use as many or as few profiles and/or segments
within profiles as needed. If using a single open motion, use the first
segment of the 1st open profile. The open slow profile must follow.

After completing the last segment in each profile, the QDC module either
switches immediately to the next programmed segment of the next
programmed profile or waits for a command from your PLC-5 program to
continue.

2

1

1-12

After completing the last configured open profile, the QDC module either
switches immediately to the first programmed segment of the open slow
profile, or waits for a command from your PLC-5 program to continue.

Open Slow

Use the open slow profile to accurately position the clamp for ejecting the
part(s). You may decelerate clamp motion twice with this profile using up
to two profile segments (Figure 1.15).

You may select from these control modes:

velocity vs. position
pressure vs. position

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Ejector Control

Figure 1.15
Example

Clamp
Cylinder

Open Slow

Moving
Platen

L0Y

Open Slow

Segments

Stationary
Platen

2

Velocity

Position

Important: If you need only one open slow motion, configure only the 1st
segment of the open slow profile.

In this section, we describe the eject operation for expelling molded parts.
The operation consists of:

ejector advance
ejector retract

1

Ejector retract

Ejector advance

Figure 1.16

and Eject Portion of a T

Clamp

Clamp Close

Open Slow

ypical Machine Cycle

Low Pressure
Close

Inject

Clamp Open

Ejector Advance

The QDC module starts advancing the ejector after detecting either one of
these events that you configure/program:

clamp position reaching a pre-determined setpoint
command from your PLC program

You may advance the ejector while the clamp is still opening the mold, or
wait until the mold is fully open.

1-13

Chapter 1

Overview of Inject, Clamp, and Eject Mode

You may use up to three ejector-advance profile segments, and select from
these control modes:

velocity vs. position
pressure vs. position

Figure 1.17
Example

Ejector

Ejector Advance

0

Velocity

Fully Advanced Position

Ejector Advance

Segments

1

Velocity

Position

2

3

Important: If you need only one ejector-advance motion, configure only
the 1st advance segment.

Ejector Retract

After ejector advance is completed, the QDC module executes ejector
retract. Similar to ejector advance, you retract the ejector with up to three
profile segments. You may select from these control modes:

velocity vs. position
pressure vs. position

1-14

Figure 1.18
Example

Ejector

Ejector Retract

Ejector Retract

Segments

Velocity

3

Velocity

0

Fully Advanced Position

Position

1

2

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Other Eject Features

The QDC module gives you the following additional features:

Multiple Cycles – the ability to repeat the ejector cycle a number of

times, changing from advance to retract determined either automatically
or by command from your PLC program

Ejector Forward Dwell - the ability to pause after completing the first or

last advance stroke. Use this feature so a robot can pick off a part when
ejectors are fully extended

Ejector “Tip” Strokes - the ability to shake the part off the ejector. You

may program interim single-segment advance and retract tip strokes that
occur after the first advance stroke and before the last retract stroke

System

Pressure

Figure 1.19
Advance,

Retract and T

Full
Retract

ip Strokes

First Full Advance

Tip Retract

Tip Advance

Tip Retract

:
:

Last Retract

Tip Strokes

Ejector

Ejector

Full
Advance

Forward Dwell

Forward Dwell

We define system pressure for the Inject, Clamp, and Eject mode as the
pressure continuously detected by the single pressure sensor connected to
the QDC module at input 2. Depending on machine hydraulics, a single
pressure valve may control inject, clamp, and/or eject mode profiles.

ATTENTION: Your control system may not work as expected
with possibly machine damage if you attempt to control a
pressure profile of a phase (inject, clamp, or eject) not
hydraulically plumbed for pressure control.

1-15

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Because system pressure may change from one phase to the next, we
recommend that you:

assign pressure control to phases that require pressure profiles

(and are hydraulically plumbed to support it)
place the system pressure sensor accordingly in the hydraulic circuit
configure the remaining phases with velocity profiles

We define open-loop pressure control as when the QDC module controls
phase pressure without input from the system pressure sensor. For example:
when the system pressure sensor monitors the clamp for closed-loop pressure
control, the QDC module can control:

ram (screw) pressure for pack, hold, and plastication in open loop
ejector velocity in closed- or open-loop using a position sensor

For example:

Example Hydraulic Circuits
for the Inject, Clamp, and
Eject Mode

For this Phase The QDC Module Can Control it With

clamp close and open closedloop pressure

injection openloop pressurelimited velocity

pack/hold openloop pressure

plastication openloop pressure

ejector advance and retract velocity

In general:

If your system pressure sensor
reads pressure for only ONE of
these modes:

inject clamp, eject

clamp inject , eject

eject inject, clamp

Then you must control the other modes by either of:

1. closed or openloop velocity

2. openloop pressure

We illustrate three examples of hydraulic circuits compatible with the QDC
module in the inject, clamp, and eject mode:

4-valve system with system pressure sensor
3-valve system with ram (screw) pressure sensor
2-valve system for inject phase with clamp and ejector position inputs

(clamp and ejector direction solenoid valves controlled by ladder logic)

1-16

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Example 4valve System with System Pressure Sensor

With this hydraulic system, a QDC module in the Inject, Clamp, and Eject
mode, has maximum control flexibility. It can control all profiles with:

pressure or velocity
open or closed loop

Clamp
Flow Valve

Figure 1.20
Example

Clamp

AB

PT

4valve System for Inject/Clamp/Eject Control

Ejector

Tank

Ejector
Flow Valve

AB

T

P

Ram (Screw)
Flow Valve

Tank

Ram (Screw)

AB

PT

Tank

System
Pressure Valve

Tank

Pump

P

System
Pressure
Sensor

QDC

I/O:

Input 1 Ram (screw) Position

Input 2 System Pressure

Input 3 Clamp Position

Input 4 Ejector Position

Output 1 Ram (screw) Flow

Output 2 System Pressure

Output 3 Clamp Flow

Output 4 Ejector Flow

Designation

12468I

1-17

Chapter 1

Overview of Inject, Clamp, and Eject Mode

Example 3valve System with Ram (Screw) Pressure Sensor

With this hydraulic system, one QDC module in the Inject, Clamp, and
Eject mode, can control the following:

closed-loop pressure for injection, pack, hold, and plastication profiles
closed-loop velocity for injection profiles
open-loop pressure for clamp and ejector profiles
closed-loop velocity for clamp and ejector profiles

Figure 1.21
3Valve

System for Inject and Clamp Control Example

Clamp
Flow Valve

Pump

Clamp Ram (Screw)

AB

PT

Tank

System
Flow Valve

System
Pressure
Valve

Tank

Ejector

AB

P

T

Ejector
Directional
Valve

Tank

QDC

I/O:

Input 1 Ram (Screw) Position

Input 2 System Pressure

Input 3 Clamp Position

Input 4 Ejector Pressure

Output 1 System Flow

Output 2 System Pressure

Output 3 Clamp Flow

Output 4 Not Used

AB

P

Designation

P

Pressure
Sensor

Ram (Screw)
Directional
Valve

T

Tank

1-18

12469I