 Molders
today are constantly in the search for ways to squeeze inefficiencies
out of every step in the manufacturing process. The pressure to reduce
downtime and scrap, leverage the know-how of experienced die-setters,
and implement systems that maximize the productivity of every machine
and every operator at every site, regardless of location, is constant.
Increasingly, this industry is turning to technology to provide the
solution to their problems.
Custom and captive injection molders want a suite of products from
one global supplier that provides injection molding manufacturing
personnel with all the tools necessary for scheduling, setup, optimization,
control, and reporting of the injection molding process. Specifically,
customers pointed out that existing molding practices often resulted
in:
- Inefficient scheduling of mold, machine, and labor resources.
- Long process setup times and associated scrap.
- Non-optimized cycle times.
- Unacceptable molded part quality.
- Unacceptable production scrap rates.
- Poor or inconsistent control of the molding process.
- Lack of part traceability.
- Lack of manufacturing management information.
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Moldflow's Manufacturing Solutions products address all of these problems
with scalable solutions that will work for small, custom injection
molders, and large, multi-national corporations.
Plastic injection molding
The plastic injection molding process is integral to many of today's
mainstream manufacturing processes. Industries such as telecommunications,
consumer electronics, medical devices, computers, and automotive all
have large, constantly increasing demands for injection molded plastic
parts. In addition, these industries continually must decrease time-to-market
as product life cycles are being compressed.
While demand for injection molded plastic parts is increasing, the
problems associated with the process often can cause significant time
delays and cost increases. This is because the injection molding process
is a complex mix of machine variables, mold complexity, operator skills,
and plastic material properties. In addition, there are constant pressures
to reduce mold setup times and scrap, improve part quality, and maximize
the productivity of every injection molding machine. Due to these
pressures, it is becoming increasingly important to have systems in
place to allow the molding process to be scheduled, set up, optimized,
controlled, and monitored using an intuitive, systematic, documentable,
and globally supported methodology.
Intuitive — so machine operators can maximize productivity
by not having to be experts on every machine/mold combination they
are responsible for running.
Systematic — so the process of setting up and optimizing the
molding process can be done with a scientific method that does not
rely solely on the skills of the machine operator.
Documentable — to meet the strict quality control reporting
requirements that are commonplace today.
Globally Supported — so that large, multi-national corporations
can source these solutions from one supplier and implement company-wide
standards across their enterprises.
In response to market feedback regarding these pressures and existing
plastics manufacturing practices Moldflow Corporation has developed
a complete suite of Manufacturing Solutions for the automation, control,
and monitoring of the injection molding. These products consist of:
Moldflow Plastics Xpert — a process automation and control
system that decreases mold setup time, cycle time, and scrap; and
improves molded part quality and labor productivity.
Shotscope — a process monitoring and analysis system that
collects critical data in real time from the injection molding machine
and then records, analyzes, and reports on that data.
EZ-Track — a real time production monitoring and reporting
system that can be attached to virtually any cyclic manufacturing
equipment.
Moldflow Plastics Xpert
Throughout the injection molding industry today, the number of molds
that must be set up and optimized for high-volume part production
is far outpacing the number of process engineers or trained technicians
qualified to do so. It is not uncommon for a molding operation to
have a small number of individuals who have the education or experience
to set up the injection molding process. And, even those who can
set up the process often do not have time to optimize it due to
production pressures. This scenario results in problems such as
long process setup times and associated scrap, non-optimized cycle
times, unacceptable molded part quality, unacceptable production
scrap rates, and poor or inconsistent control of the molding process.
Moldflow Plastics Xpert (MPX) process automation and control technology
provides machine operators with an easy-to-learn and easy-to-use
tool for the setup, optimization, and control of the injection molding
process. MPX allows a less-experienced operator to set up molds,
optimize the process, and control production.
MPX functionality is arranged into three modules
I: The Setup Xpert module allows users to perform a variety of injection-velocity
and pressure-phase-related setup routines to fix certain defects,
such as short shots, flash, burn marks, sink marks, etc. Setup Xpert
helps users achieve one good molded part with no defects. A user
molds a part, then provides feedback to the MPX system regarding
molded part quality. MPX processes this feedback along with data
being collected from the machine and (if necessary) determines a
process change that will improve the result.
After completing Setup Xpert and determining a combination of processing
parameters that results in a single, satisfactorily molded part,
the user still does not know if these parameters are within a robust
processing window. For example, any process parameter drift or variation
could easily result in parts of unacceptable quality. In the injection
molding process, variation is inherent. Whether the material, machine,
process, operator, or environment causes it, there will always be
some variation. This variation may or may not result in the production
of bad parts. The variation is normal, so the processing window
must be robust enough to compensate for it without producing bad
parts.
Design of experiments (DOE) is a useful tool in determining a robust
processing window. The process window is defined as the maximum
amount of allowable process variation — allowable, because it will
not result in the production of bad parts.
However, the historical perception of DOE is that it can be complicated,
resulting in extensive training requirements and costs for those
responsible for running it. DOE is also time consuming, thus increasing
the time required to put a given mold into production.
II: Optimize Xpert is an automated design of
experiments (DOE) that can be run quickly and easily. The software
does not require any special training in statistical process
control. The goal of using Optimize Xpert is to obtain a robust
processing window that will compensate for normal process variation
and ensure that acceptable quality parts are produced consistently.
While the Optimize Xpert DOE is automated, easy to use, and
relatively fast to complete, it is far from simple. There are
five process parameters that can be used as DOE factors: packing
pressure, mean (or average) injection velocity, velocity stroke,
packing time, and cooling time. In addition, there are a number
of molding defects that can be used to measure part quality
criteria, including short shots, flash, sink marks, burn marks,
poor weld line appearance, weight, dimension, and warpage problems.
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Assuming a robust processing window is determined using the Optimize
Xpert, control mechanisms are still required to make sure that the
process stays within its specified limits.
III: Production Xpert is a comprehensive process control system that
maintains the optimized processing conditions determined with Optimize
Xpert. Production Xpert allows the user to maintain the production
process consistently, resulting in reduced reject rates, higher part
quality, and more efficient use of machine time. If desired, Production
Xpert will correct the process automatically should it drift or go
out of control.
There are still many functions required in a manufacturing operation,
including production scheduling, process monitoring, statistical process
control (SPC), statistical quality control (SQC), scrap tracking,
production monitoring and reporting, preventive maintenance scheduling,
and more.
Moldflow Shotscope
The Moldflow Shotscope process monitoring and analysis system is
a comprehensive product suite that collects critical data in real
time from molding machines on the factory floor. The software then
records, analyzes, reports,and allows access to the information
for use in critical decision making. Additionally, the product can
be used for both plastic injection molding and metal die casting
operations.
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Shotscope allows molders to maximize their
productivity by providing necessary tools to schedule mold
and machine resources efficiently. The software also monitors
the status and efficiency of any mold/machine combination.
By monitoring the efficiency of a given mold/machine combination,
molders can schedule jobs based on a number of criteria, including
minimum cycle times, highest production yields, and so on.
Users also can define periodic maintenance schedules for molds
and machines, and, after a pre-determined number of cycles
or operating hours, Shotscope will signal that preventative
maintenance is required.
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Shotscope also maintains and displays statistical process control
(SPC) data in a variety of formats, including trend charts, X-bar
and R charts, histograms, and scatter diagrams. This information provides
molders with the knowledge that their processes are in control, and,
should they go out of control, Shotscope can alert to an out-of-control
condition and divert suspect-quality parts. Furthermore, because the
Shotscope system can measure and archive up to 50 process parameters
(such as pressures, temperatures, times, etc.) for every shot monitored,
the processing "fingerprint" for any part can be stored and retrieved
at any time in the future. This functionality is extremely important
to any manufacturers concerned with the potential failure of a molded
part in its end-use application (for example, a medical device).
Shotscope maintains a reporting mechanism that communicates all the
data collected and entered into the system across a manufacturing
enterprise. As a result, informed decisions can be made. Users can
generate production, scrap, downtime, efficiency, and job summary
reports, any of which also can be used as documentation that accompanies
part shipments.
Moldflow EZ-Track
Moldflow EZ-Track is software for real-time, plant-wide production
monitoring and reporting. The EZ-Track system can be attached to virtually
any cyclic manufacturing equipment and machinery, such as ultrasonic
welders, assembly machines, packaging equipment, etc., in addition
to injection molding machines. The EZ-Track system provides a scalable
solution for production monitoring, which can be used by small, custom
molders with fewer than 10 machines or by large, multi-national corporations
with distributed injection molding and manufacturing operations around
the world. There are extensive setup capabilities that allow complete
definition of resources and flexible customization of most displays
and reports.
The EZ-Track system collects data on cycle times, cycle/part counts,
and number of rejects, and it uses this data as the foundation to
perform powerful scheduling tasks. The EZ-Track scheduler can check
for mold conflicts and machine feasibility and highlight any problems.
The product continuously updates estimates of job completion times
based on actual cycle time, downtime, rejects, and cavitation. In
addition, the scheduler supports family molds.
EZ-Track monitors machine status,
downtime, scrap, raw material usage, and labor activity. The
product can also be used to track machine efficiencies and compute
yield efficiencies. Labor, time, and attendance can be tracked
by employee and associated with machines, jobs, and activities.
In this way, manufacturing managers can determine what jobs,
machines, or activities require more labor resources than others
require. This capability can allow managers to investigate areas
where more efficiency, possibly in the form of process automation,
could be introduced into their manufacturing operations.
EZ-Track can be used to count good parts, diverted parts, packed
cases, and other variables. Downtime is measured automatically
and can be classified into an unlimited number of causes. Once
production data is collected, there is an extensive set of Web-based
reports that can incorporate trend charts, tabular reports,
pie charts, and Pareto charts. It is possible to interface the
EZ-Track system to ERP/MRP systems via an advanced SQL database
that is open, fully documented, and ODBC-compliant. |
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There are many companies today across a broad range of industries
for which plastic injection molding and related upstream and downstream
manufacturing processes are on the critical path to achieving successful
and profitable product launches. These companies face a variety of
issues that make it difficult to remain competitive:
- Product life cycles are decreasing while short-term volume
requirements are increasing exponentially.
- Customers continue to demand increased quality at lower
costs.
- There is a shortage of skilled labor to run ever-more-sophisticated
injection molding equipment.
- Inefficiencies in the scheduling, monitoring, and reporting
of production do not allow for efficient manufacturing management.
- Molded part process documentation and traceability increasingly
are becoming a standard requirement.
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Competitive companies require tools that are intuitive, systematic,
documentable, and globally supported, such as the Moldflow Manufacturing
Solutions products, to remain globally successful.
For the latest information on Moldflow Manufacturing Solutions products,
visit www.moldflow.com. |
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Moldflow
Manufacturing Solutions for the Automation, Control, and Monitoring of
the Injection Molding Process