NEW BLENDER-BASED YIELD
CONTROL GOVERNS TOTAL EXTRUSION PROCESS, BOOSTING PRODUCT QUALITY AND SAVING ON
Blenders with New-Generation LineMaster™ Software Are First System to Control
Yield by Adjusting Throughput and Line Speed Simultaneously
JUNE 23, 2003
blenders powered by new LineMaster™ software from Maguire Products, Inc. raise
extrusion yield control to a new level of simplicity and accuracy and enable
processors to enhance product consistency, save on raw material, shorten setup
times, and reduce scrap, the company announced at NPE 2003 (Booth 9101).
The yield control system has already been used commercially#--see
accompanying news release on blown film producer Coextruded Film Technologies
for an example.
new technology makes advanced yield control available without need for large,
complex, and costly hardware systems such as loss-in-weight blenders, according
to B. Patrick Smith, vice president of marketing and sales. "It is now
possible to achieve consistent accuracy in material consumption and product
quality using nothing more elaborate than the Maguire® Weigh Scale Blender,"
Smith said. "The simplicity, ease
of use, and low cost of this system have made it by far the most widely used
blender in the world, yet its precision and reliability also make it eminently
suitable for governing the entire extrusion process with unvarying accuracy."
LineMaster system combines advanced blender controller software with Maguire's
Gravimetric Gateway™, or "G2," software for integrating blenders in a
computer controlled network. This
integrated system makes it possible for the blender controller to adjust two
critical process parameters simultaneously.
standard extrusion control, the blender controller automatically adjusts only
one parameter - extruder speed - to achieve a manually set target throughput
(weight of raw material processed per unit of time).
Somewhat more advanced is a basic type of yield control, in which the
controller once again automatically adjusts only extruder speed, but does so by
first calculating target throughput on the basis of two manually set parameters:
target line speed (length of
product per unit of time) and target yield (weight per length of extruded
product). In contrast with these
systems, the LineMaster system simultaneously adjusts both throughput and line
speed to achieve target yield, providing complete control of the process.
the advent of our LineMaster technology, the vast middle ground of extrusion
processors have had to choose between cumbersome and costly loss-in-weight yield
control systems or very basic forms of extrusion control," said Smith.
"Now any extrusion processor armed with our software can lock in
desired product yields via simple connections between a standard Maguire blender
and the extruder-screw and hauloff-speed controls. Once set up, this system
quickly establishes control over the amount of material per length of product,
without need for prolonged setups in which operators must optimize speed
yield-control configurations are possible with the LineMaster system, in each of
which 1) the blender is connected to the downstream speed control and
automatically adjusts it to maintain line speed; and 2) the desired yield is
entered by the operator. The three configurations vary according to which other
parameter is to be set as a target by the operator:
▪ Line speed. Blender calculates required extruder throughput based on pre-set line speed and yield and automatically adjusts the extruder speed control.
▪ Extruder throughput. Blender calculates required line speed based on pre-set throughput rate and yield and automatically adjusts the extruder speed control.
▪ Extruder speed. Blender calculates required line speed based on pre-set extruder speed and yield and automatically adjusts downstream speed control.
Gain-in-Weight Blending and Advanced Software Are Keys to Precision Yield Control
Mounted directly over the throat of an extruder, a Maguire® Weigh Scale Blender controls raw-material metering by weighing each recipe batch. Recipe ratios can be varied from 0.01 to 100% with simple thumb-wheel settings. In operation, the blender sequentially dispenses all ingredients, in their targeted recipe proportions, from separate hopper bins into a weigh chamber (hence the term "gain-in-weight"). From the weigh chamber the batch falls into a mixing chamber, then is fed directly into the extruder. In subsequent batches, small corrections are made automatically. Added to this precise information about the weight of each batch (in grams) is information about the exact time (in tenths of a second) required for each batch to be consumed by the process.
enable the blender to adjust the speed of the extruder screw to maintain a
targeted throughput rate. To carry
out coordinated, simultaneous adjustments of both line speed and throughput to
ensure maintenance of targeted product yield, the blender must be used in
combination with G2 software.
PRODUCTS, INC., headquartered in Aston, Pennsylvania, U.S.A., is the world's
largest supplier of gravimetric blenders and liquid color pumps and also
manufactures loading systems, granulators, dryers, auger feeders, and related
equipment. Its customers include
injection, blow, and rotational molders, extrusion processors, and compounders.
Founded in 1977, Maguire operates five manufacturing facilities in Aston
and Smithfield, Rhode Island, U.S.A. The company maintains a network of
distributors in the Americas and overseas.
Europe, a sales and service subsidiary that supports customers
throughout Europe, operates a distribution center in Tamworth, Staffordshire,
United Kingdom. Maguire Asia, based in Singapore, serves customers throughout
South Asia and the Pacific Rim. Visit the Maguire Products web site: www.maguire.com