This document discusses microprocessor control of injection molding machines. It begins by introducing microprocessors and their ability to process both analog and digital signals. It then explains that microprocessor control offers improved accuracy, efficiency and versatility. It describes the components of a microprocessor control unit and its functions like sequence control and monitoring. It differentiates between open loop and closed loop control systems, listing their advantages and disadvantages. Finally, it discusses some advantages of microprocessor control like multi-stage pressure and speed regulation, and applications in various industries including automation using robotic systems.

1. MICROPROCESSOR CONTROLLED
INJECTION MOULDING MACHINE
CIPET-HAJIPUR
CREATED BY-AVINASH KUMAR
COURSE-PGD-PPT
Guided by:- Dhananjay Kumar Singh

2. CONTENTS
 Introduction
 Microprocessor control unit
 Open loop control system
 Close loop control system
 Difference between open loop & close loop system
 Advantages of microprocessor
 Disadvantages
 Application
 Process automation by help of Robotics System

3. INTRODUCTION
 The microprocessor is capable of accepting, processing &
giving out put in both analogue & digital signals.
 Analogue signals are comparable to time shown by two hands
of a mechanical watch.
 Digital signal can be compared to the time shown on a digital
quartz watch.
 Microprocessor control offers improved accuracy,
efficiency & versatility because of its high speed reasons,
programmability & computational ability.

4. WHY MICROPROCESSOR REQUIRED
 To ensure consistency of quality of injection molded parts one
has to look at the controls like pressure, speed, stroke &
temperature.
 This is the repeatability of the product quality with close
tolerance on dimension & with throughout long production run.
 The injection molding process controls is quite complex
because of the interplay among the process parameters, i.e.
melt tempreture, viscosity, pressure, speed, residence time etc.

5. MICROPROCESSOR CONTROL UNIT
 The advance semiconductor technology enables to get large
scale integrated logic circuit in a tiny silicon wafer enclosed in a
small plastic case.
 This micro processor has replaced conventional hard wired
contractor logic circuits.
CONTD..

6. CONTD..
The micro processor based programmable logic controls
includes.
 Micro processor to perform logic operation.
 Memory to hold program and data.
 Input output device that is alpha numeric keypad etc.
 Peripheral device i.e. limit switches, digital switches, proximity.
 Switches, thumbwheel switches
Contd..

7. CONTD..
The micro processor can carry out following functions
 Sequence control
 Process control
 Monitoring control
 Alarm function
 Display of current as well as past status of actual process
parameters.
 Graphic display

8. OPEN LOOP CONTROL SYSTEM
 At times, one may want the process to operate at a fixed value
of temperature, the control used is called open loop control
 Set the process parameters in open loop controls influences the
process but does not make any correction by providing feed
back, if there is any disturbance affecting the process.
 In open loop controls the effect of disturbance is held constant
or eliminated to ensure in uniformly in the process.

10. OPEN LOOP CONTROL SYSTEM
Advantages
 Open loop system are
very simple.
 Open loop system are
economical.
 Requires less
maintenance.
Disadvantages
 Open loop control
system are inaccurate.
 Not reliable.
 Optimization is not
possible.
 These are slow.

11. CLOSE LOOP CONTROL SYSTEM
 A Closed-loop Control System, also known as a
feedback control system is a control system which uses the
concept of an open loop system as its forward path but has
one or more feedback loops.
 In close loop control system control the effect of disturbance in
the process is eliminated by counter acting or by opposing the
effect of the disturbance, by automatic triggering certain
reaction.
 This is done in response to the feedback, which is compared
with the set value to take the required corrective action.
“Note:- The reference to “feedback” simply means that
some portion of the output is returned “back” to the input
to form part of the system excitation.”

13. CLOSED LOOP CONTROL SYSTEM
Advantages
 More reliable.
 More faster.
 Optimization is
available
Disadvantages
 More expensive
compared to open loop
control system
 Complicated
connection.
 Difficult maintenance.

14. DIFFERENCE BETWEEN OPEN LOOP &
CLOSED LOOP SYSTEM
OPEN LOOP
 It have no feedback.
 Data flow in one way.
 No automatic adjusting
system.
 It modify the output at
variable rate.
 Parameter set:
1. screw speed
2.clamp closing speed
3.cooling time etc.
CLOSED LOOP
 It have feedback.
 Data doesn’t flow in one
way.
 Automatic adjusting system.
 It modify the output at
consistent rate.
 Parameter set :
1. Barrel temperature
2. Two stages of back
pressure.
3.Two stages screw of
rpm etc.

15. ADVANTAGES OF MICROPROCESSOR
Microprocessor control offers/enables the processor :
 To regulate the injection speed profile in multi stages.
 To regulate the follow-up pressure in multi stages.
 To regulate screw rpm in three or more stages.
 To regulate back pressure in three or more stages.
Contd..

16. CONTD..
 Freely programmable hydraulic core pulling and air ejection
sequence.
 Alarm on deviation of set parameter beyond set tolerance.
 Fault diagnostics by clear text
 Temperature control on feed throat.
Contd..

17. CONTD..
 Additional temperature control on hot runner mould.
 Storage process parameters for 60 moulds.
 Control of auxiliary equipment like mould
temperature controller, dryer, material handling
equipment, robot etc.
 It gives high production rate.
 It gives product with closed accuracy.

18. DISADVANTAGES
 It is expensive.
 Its repairing cost is high.
 It also affect production rate.
 Wrong parameter set in microprocessor affect the
product.
 Highly skilled operator required.

19. APPLICATION
 In plastic industry
 In washing machine
 In automobile
 In mobile
 In computer sector
 In toys
 In Television
 Microwave oven
 satellite

20. PROCESS AUTOMATION BY HELP
OF ROBOTIC SYSTEM
Robotics industrial automation is
changing the face of production.
Manufacturers around the globe are
implementing some form of automation
to become more efficient, safe and
ultimately to increase revenues.

22. ADVANTAGES OF INDUSTRIAL AUTOMATION:-
 Quality Control - no one likes purchasing an item,
only to be disappointed by the poor quality. Robots
are a great solution for higher quality production.
Quality builds trust from customers as well as pride
knowing that we are contributing something of
value.
 Repeatability - Being consistent and knowing that
you will get the same quality end product is critical
to efficiency. A robot is able to perform the exact
same task, exactly the same way, over and over
again. Less errors means less wasted time.
Contd..

23. CONTD..
 Waste Reduction - Consistent repeatability allows
manufacturers to reduce overall waste. Less errors
not only saves time, but it also reduces the amount
of material required to produce the product
 Faster Cycle Times - Unfortunately humans have
their limitations. Robots have been known to greatly
improve production cycle speeds.
Contd..

24. CONTD..
 Improved Workplace Safety - There are so many
dangerous work environments that can have
horrible side effects on a human body. Separating
workers from lifting too much weight, exposure to
fumes and gases, close interaction with lasers or
blades, can tremendously decrease the possibility
of injury.
Contd..

25. CONTD..
 Reduction of Labor Costs - Labor can be
expensive, especially when you factor in
medical benefits, paid time off, injury comp time,
etc... Robots can replace certain jobs, but that
doesn't mean they are going to take over the world.
Contd..

26. CONTD..
 Reduced Floor Space - It's easy to start sprawling
out across the shop floor with extra materials, tools,
and machinery. Robots can help reduce the
footprint of the required workspace by optimizing
everything into a smaller, confined space.
Contd..

27. PIC.S OF MICROPROCESSOR

28. HUARONG 200

29. OMEGA 350W

30. JSW 180AD

31. THANK YOU