SOFTWARE PROVIDES FILM PRODUCER WITH 'EXTREMELY PRECISE' LAYER RATIOS AND
Control Software Is South African Processor's Latest Addition to Three-Layer
Blown Film Line that Incorporates Wide Range of other Maguire Systems
June 23, 2003
newly installed yield control system from Maguire has already made possible
outstanding product quality and consistency in a three-layer blown film
coextrusion line operated by Coextruded Film Technologies [Pty] Ltd. (CFT),
according to Bob Boden, managing director of this relatively new producer of
polyolefin packaging and industrial films.
The yield control system, based on new Maguire® LineMaster™ software
(see accompanying news release), is the latest Maguire technology to be
installed in the company's initial production line, which also includes three
Maguire® weigh scale blenders (one for each extruder), a Clear-Vu™ loader, an
LPD™ resin dryer, and Maguire® Extrusion Control Network™ network software.
LineMaster system has enabled us to maintain extremely precise layer ratios and
to produce rollstock with weights that are virtually identical from one roll to
the next," said Boden. "Our
control over layer ratios has resulted in films with consistent heat sealing and
mechanical properties - an achievement which has proved invaluable for supplying
quality film for high-speed wicketted bag production."
Maguire's Extrusion Control Network controls product thickness by monitoring
the weight of raw material metered to the extruder per unit of time and using
this data to adjust extruder throughput, LineMaster software provides more
advanced control by adjusting both extruder throughput and line speed (length of
product per unit of time) to maintain target yield (weight per length of
Extrusion Control Enhanced Quality, Saved Material,
and Increased Level of Automation
December of 2000, Coextruded Film Technologies is focused on developing specialized
multi-layer polyolefin films. "We
set up our plant to maximize three capabilities: technological excellence for
innovation, quality assurance for customers, and efficient, precision control of
all operations by management," said Boden.
"Maguire equipment and systems are at the heart of these capabilities
and play a critical role in our current program to institute ISO 9002, EN ISO
14001, and OHSAS 18001. In the meantime, CFT is deliberating the installation of
a second, larger three-layer line."
blown film line centers on three 55-mm (2.17-in.) extruders feeding a 300 mm
(11.81-in) die and includes oscillating nip, web guide, and tension control.
The system is configured to produce film with overall thickness of 10 to
120 microns with three layers of equal thickness.
Monthly output is around 70 metric tons (155,000 lb.), according to Boden.
installing Maguire's Extrusion Control Network, CFT had set all three
extruders to operate at a screw speed of 87 rpm, with the assumption that the
three brand-new machines would yield layers of equivalent thickness, according
to Chris Crittenden, sales manager of Maguire Europe, which worked with CFT to
install Maguire systems. "Even at
identical screw speeds, however, layer thicknesses differ because of differences
in the melt indices and bulk densities of the resins and in conditions inside
the extruders," said Crittenden. "Once CFT installed our Extrusion Control
Network and set thickness targets at 33% of overall gauge for each layer, they
found that screw speeds now varied from one extruder to another to offset resin
and process differences and produce layer thicknesses on-target.
This increased control also made possible raw material savings that we
estimate roughly at 12%."
LineMaster™ Software Extends Capabilities of
Extrusion Control Technology
became even more precise with installation of LineMaster yield control software,
Crittenden noted, and CFT achieved a new level of process automation. "Besides
coordinating the operations of all blenders in the extrusion line for precise
control over key end-product parameters, LineMaster software simplifies setups
by downloading recipes and settings, provides extensive documentation of raw
material consumption for inventory control, cost accounting, and quality
assurance, and permits remote access for monitoring extrusion line operation,"
the core- or "B"-layer extruder is a Maguire® WSB 140 R gravimetric
blender; the "A-" and "C-"layer extruders are each surmounted by a
Maguire® Microblender™. Loading
all three blenders is a Clear-Vu™ MLS 288 loader, a compact mini-system.
For additives that require pre-drying, CFT uses a Maguire® LPD™ 100
vacuum resin dryer.
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