SHEET
EXTRUSION LINES
Our history
Bandera was established in 1947 by Luigi Bandera and soon
proved to be a strongly expanding company, thus contributing to
the development of the plastics processing industry in Europe.
In 1950 Bandera became a joint-stock company.
In the 1960s and 1970s, the company’s activities underwent
remarkable expansion and reached production on an industrial
scale, offering a wide and diverse range of extrusion products
(pipes, profiles, sheet).
In the 1980s and 1990s the company was recognized as one of the
leading companies in the field of extrusion line manufacturing, in
Italy and worldwide.
In 1998 Bandera received the ISO 9001 Quality Certificate.
Bandera has recently focussed its product range on three main
fields: blown film, foil & sheet, and pipes (including specific
technology for steel pipe coating).
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News
Bandera’s headquarters are in Busto Arsizio (VA), just a 10-minute
drive from Milan Malpensa International Airport. Bandera’s facilities
were recently renovated to combine industrial series production with
quality check procedures. The company is currently managed by
Piero and Franco Bandera, the founder’s sons, who continually invest
in technical improvements to the production tools and machinery,
and in the company’s key component: human resources.
Please find below a brief description of Bandera.
3 production areas (100,000 sqm)
175 employees
ISO 9001 certified manufacture methods and procedures
A wide and complete range of full extrusion lines (pipes, blown film,
sheet and foil)
Engineering and R&D Depts, keeping Bandera on the cutting edge
of innovation
Bandera has recently allocated its manufacturing process in three
sites:
B1: Administration and marketing offices, assembly department, test
room, and shipping department
B2: Screw, barrel, and extrusion head (CNC instrumentation)
manufacturing site
B3: R&D Department, with dedicated test rooms
Sheet extrusion lines
Bandera is widely acknowledged as a world leading
manufacturer of sheet extrusion lines.
Building on its broad expertise acquired over many years,
its customer-oriented philosophy and its R&D Dept efforts
focussed on new applications and technologies, Bandera
is today able to satisfy the broadest range of production
needs. The configuration of the extrusion lines offered can
be arranged to suit the most demanding requirements in
terms of layout, automation, and ancillary equipment.
Best-selling standard sheet extrusion lines are outlined
in this brochure.
Bandera is definitely proud of the top technical standards
applied to its extrusion lines. Any bandera extrusion line
is manufactured to suit the broadest customer needs.
Perfectly tailor-made.
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Sheet extrusion line
for shockproof products
Process materials: ABS, HIPS, PE, PP, ASA
Standard thickness range: 1,5 mm ÷ 12 mm
Sheet width: up to 3000 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 1200 Kg/h
Sheet extrusion line
for refrigerators
Process materials: PS
Standard thickness range: 1,5 mm ÷ 7,0 mm
Sheet width: up to 900 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 1200 Kg/h
Worldwide construction standardization of home appliances has led
to an optimization of the extrusion process size.
Finished product width ranges between 600 mm and 900 mm.
The extrusion line is equipped to provide high outputs. Production line
control is facilitated by standardized width of sheet.
4
Sheet extrusion line for caravan
and sanitaryware applications
Process materials: ABS, PS, PS-K, PMMA
Standard thickness range: 1,5 mm ÷ 12,0 mm
Sheet width: up to 3000 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 1200 Kg/h
Sheet extrusion line for building
and industrial applications
Process materials: polyolefin resins
Standard thickness range: depending on finished product embossing
Sheet width: up to 3200 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 800 Kg/h
Available selection of finished product grammage, and non-wovens coupling
grammage to suit any customer requirements.
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High optical quality sheet extrusion line
and for acrylic products
Process materials: PMMA, PC, PET-G, PS-K, SAN
Standard thickness range: 1,2 mm ÷ 12,0 mm
Sheet width: up to 3000 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 1000 Kg/h
The production of high quality acrylic sheet from PMMA and PC
intended for top-level prestigious architectural applications require
specifically arranged extrusion lines. Besides standard - and suitable
- chemical and physical-mechanical features, the finished product in order to be classified as fine optically superior product - must have
outstanding aesthetic characteristics, among others:
No blend residues
Requirement compliant hue
Brightness and transparency
Perfect blend of master batches and additives
No optical distortions
The must-have features for a valuable product.
L. Bandera has been investing in technical innovation for over 20
years to offer superior-product manufacturing machines, focussing
on high-tech research aimed at ongoing process enhancement.
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Sheet extrusion line
for furniture industry
Process materials: ABS, PMMA, PET
Standard thickness range: 0,4 mm ÷ 12,0 mm
Sheet width: up to 2200 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 1500 Kg/h
Masking unit for the application of sheet protective film
Due to optimal PET characteristics required for furniture applications,
Bandera extrusion lines feature co-rotating twin-screws - of which
Bandera is world-leading manufacturer.
The innovative corotating twin screw extruder L/D:52 grants multiple
advantages:
Outstanding venting efficiency: larger vacuum areas prevent
process material pre-treatments (drying and dehumidification
process)
Quick colour switching over, due to minimized material residence
time
Excellent mixing capacity
Power saving (-30% if compared to a single-screw extruder)
Multi material processing capacity obtained with standardized
screw geometry
Complete 3-layer ABS/PMMA extrusion line
Co-rotating
twin-screw extruder
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Sheet extrusion line for geoliners
Process materials: polyolefin resins
Standard thickness range: 0,5 mm ÷ 2,5 mm
Sheet width: up to 7000 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 2000 Kg/h
Possibility of surface embossing, brushing and corrugating.
The extruded product shall guarantee weldability, resistance to
atmospheric agents, and suitable mechanical strength. The extrusion
line can be designed and manufactured to meet any customer
requirements.
Geomembrane extrusion line.
Standard configuration layout
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Sheet extrusion line for
waterproofing applications
Process materials: polyolefin resins, polyesters, glass fibres and
mineral fillers
Standard thickness range: 0.2 mm ÷ 3.0 mm
Sheet width: up to 2200 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 1000 Kg/h
The line is equipped with no. 2 flat die heads.
Further to product application studies carried out by Bandera R&D
Dept, the mechanical resistance to elongation, tear, punching and
drilling of the extruded product is maximized.
Resistance to light, ozone, chemical agents, high and low
temperatures, fire (halogen and mineral filler free composition) and needless to say - water, is 100% guaranteed. The application range is
extremely wide: foundations, tunnels, subways, swimming pools, etc.
Extrusion line for waterproof applications.
Standard configuration layout
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Sheet extrusion line for automotive
Process materials: polyolefin resins, mineral fillers and powder
stabilizers, liquid plasticizers
Standard thickness range: 0.5 mm ÷ 3.5 mm
Sheet width: up to 2500 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 3000 Kg/h
Exclusive cutting edge technology for internal lining with both
aesthetic and functional purposes, intended for top-class vehicles
Dimensional stability even after thermoforming
High-performance soundproofing and thermal insulation
Over fifteen applicable formulations
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Sheet extrusion line
for coating lamination
Process materials: polyolefin resins
Standard thickness range: depends on composite finished product
to be obtained
Sheet width: depending on composite finished product to be obtained
Sheet structure: composite, single-layer or coextruded
Hourly output: depends on composite finished product to be obtained
(coupling material grammage, and extrusion line output)
The line core feature consists in the in-line manufacture of a
finished product via “in-calender” coupling of semifinished reels
(nonwovens, paper, aluminium, etc.) with polyolefin sheet exiting the
flat head.
Line accuracy and user-friendliness depends on the high level of
design and construction. The finished product, besides complying
with coupling chemical and mechanical requirements, features
extremely refined aesthetics.
Composite products obtained with coating extrusion lines have a wide
application range (from building and construction fields to food and
industry sectors).
Extrusion line for coating applications.
Standard configuration layout
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High-thick sheet extrusion line
Process materials: HDPE, PP (and high molecular weight resins
ensuring elevated chemical and physical-mechanical features)
Standard thickness range: 1.0 mm ÷ 40.0 mm (2 flat heads)
Sheet width: up to 3000 max
Sheet structure: single-layer or coextruded (twin-screw and/or
single-screw extruders)
Hourly output: up to 2000 Kg/h
The line is intended for semi-finished products for chemical-industrial
applications (liquid tanks), cut flatbeds, technical components (e.g.
flanges, gears, outsoles, etc.).
Being stress-cracking, and cut-, abrasion- and impact-resistant
(typical characteristic of some materials), high-thick sheet can be
used in the automotive field for external covers (e.g. pick-ups).
High-thick sheet extrusion lines outstand for their specific design.
Extremely high thicknesses require dedicated post-sizing in-calender
sheet processing and thermal stress relieving (for sheet dimensional
stability) to avoid issues at cutting and thermoforming stages.
Possibility to obtain blends with mineral fillers and straighteners
directly in line (extrusion line with co-rotating twin-screw extruders)
Calender equipped with hydraulic system for up-down
displacement (available sheet path up to down or down to up)
Movable and power-driven double roller bed. Independently
temperature controlled rollers
Multi-emission point X-ray heating system for sheet molecular
thermal stress relieving
High-thick sheet
extrusion line
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Sheet extrusion lines
for paper and cardboard industry
Process materials: PP, PET
Standard thickness range: 200 μm ÷ 1.2 mm
Sheet width: up to 1200 mm max
Sheet structure: single-layer or coextruded
Hourly output: up to 1200 Kg/h
Calenders in vertical, inclined or horizontal configuration, equipped
with chromium-plated (and super-finishing), satinized or embossed
rollers.Air blade systems and simple or double effect vacuum box for
thin sheet.
Sheet extrusion line for solar panels
Process materials: EVA (Ethylene Vinyl Acetate)
Standard thickness range: depends on finished product to be
obtained
Sheet width: up to 2500 mm
Sheet structure: single-layer or coextruded
Hourly output depends on finished product to be obtained
The silicon photovoltaic module is normally obtained with sandwiched
together material layers - the so-called “laminated layer” - and with
other ancillary materials making the sandwich suitable for use.
As a standard, the laminated layer is made of the following materials:
Glass (4 mm thick, as a standard)
EVA - Ethylene Vinyl Acetate
Monocrystalline or polycrystalline cells
Backsheet (made of PET or glass)
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Co-rotating twin-screw extruders
Sheet extrusion lines are increasingly provided with co-rotating
twin-screw extruders. A choice due to top flexibility and versatility
offered by twin-screw technology.
Co-rotating twin-screw extruders are thoroughly designed and
manufactured by Bandera. Extrusion screws are made in high
performance wear resistant XDBD steel, and extrusion barrels are
made in nitrided steel and/or bimetal alloy (screws and barrels
consisting of independent modular sections, accurately assembled).
Co-rotating twin-screw technical features - the result of R&D studies
and yearly expertise - offer the extrusion line several advantages, as
follows.
Versatility and flexibility
The standardized geometry of the extrusion screws enables
various materials processing (PET, PP, PS, ABS, HDPE,LDPE, …)
and ensures no material stress, besides easing production control
and schedule.
Possibility to process up to 100% ground skeleton material
(industrial waste), to manufacture products obtained by Chemical
(dedicated additives) or physical (gas injection) foaming processes,
and to use mineral filler powders, e.g. talc, calcium carbonate,
titanium dioxide (see photo here beside)
Mixing and self-cleaning
The intermeshing and co-rotating extrusion screws guarantee
minimized material residence time, together with quick and easy
colour switching, thus resulting in outstanding time and material
waste reduction - a particular characteristic deriving from the
compounding sector
Melt purification
The outstanding efficiency of the venting system (up to 10mBar ÷
15mBar residual vacuum, sufficient for the whole extrusion barrel)
allows for hygroscopic material processing with no need for material
pre-treatment (dehumidification, drying, crystallization, …).
Furthermore, it is undoubtedly worth mentioning that Bandera
technology is FDA approved in the food packaging sector
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Power saving
The important power saving which is generated by co-rotating twinscrew extruders is due to the reduced motor torque as compared with
single-screw extruders.
Power saving can be up to 35%, depending on process material.
Bandera’s twin-screw extruder production range is detailed in the
table below.
Co-rotating twin screw
L:D ratio
2C 55 mm
2C 70 mm
2C 85 mm
2C 105 mm
34:1, 42:1, 52:1
2C 135 mm
2C 170 mm
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Single-screw extruders
Single-screw extruders currently play an important role in sheet
extrusion line manufacturing. Today, Bandera offers its customers a
wide range of extruders to comply with all market needs in terms of
productivity, efficiency, and quality.
Bandera designs, manufactures and tests its machines independently
and manufactures extruders up to 380 mm in screw size.
Extrusion screws are made in nitrided steel. Possibility to apply
special wear resistant alloys onto the thread edge (Stellite or
Colmonoy 56/57). Extrusion barrels are made in nitrided steel and/
or bimetal alloy.
Thanks to its long-lasting experience (Bandera single-screw extruder
No. 3 dates back to 1943 and is proudly displayed at Bandera
premises) and to several technological innovative enhancements over
the years, Bandera has always been a leading company in this field.
Sheet extrusion line production range is mainly divided into 2
categories:
Single-screw extruders for polyolefins and polyamide (PE, PP, PA, ...)
non vented (for processing non-hygroscopic materials)
Single-screw extruders for styrene and acrylic polymers (PS,
ABS, PC, PMMA, ...) vented (for processing hygroscopic materials)
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Single-screw extruders for polyolefins and polyamide (PE, PP, PA, ...)
Single screw extruder
L:D ratio
TR 35 mm
TR 45 mm
TR 50 mm
25:1, 28:1, 30:1
TR 60 mm
TR 65 mm
TR 75 mm
TR 80 mm
TR 85 mm
TR 90 mm
TR 100 mm
30:1, 35:1
TR 120 mm
TR 140 mm
TR 160 mm
TR 180 mm
TR 200 mm
Single-screw extruders for styrene and acrylic polymers
(PS, ABS, PC, PMMA, ...)
Single screw extruder
L:D ratio
TR 50 mm
TR 60 mm
TR 65 mm
TR 75 mm
TR 80 mm
TR 85 mm
TR 90 mm
35:1, 38:1
TR 100 mm
TR 120 mm
TR 140 mm
TR 160 mm
TR 180 mm
TR 200 mm
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Dosing and loading systems
Proper material loading and dosing into the extruder is undoubtedly
one of the key factors to be taken into account - in fact, it is considered
the first process variable. Single- and twin-screw extruders are
equipped with different dosing systems:
Continuous gravimetric dosing system, of the loss-in-weight
type, for co-rotating twin-screw extruders (the so-called starve-fed
extruders)
Volumetric dosing system for single-screw and co-rotating twinscrew extruders
Gravimetric dosing system of the batch type (by weights) for singlescrew extruders
Bandera carefully designs and sizes various dosing systems to meet
any customer needs: the material can be dosed in different forms,
e.g. granules, production waste, flakes, additives, masterbatch,
filler powders (mineral or otherwise). In case of low-density ground
materials, the single-screw extruder is completed with a force feeder
to ensure the utmost process efficiency. Bandera prefers to include
the above equipment into the scope of the supply, so as to integrate
full extrusion line control in the general control desk.
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Melt filtering
Melt filtering is a key step of the extrusion process to ensure final
product quality. Besides, it is important to safeguard gear pump,
extrusion head and calender roller integrity, especially in case of
recycled materials.
Standard filtering systems are hydraulically operated, and equipped
with filtering screen plates (2, 4, 8, …) for screen changing without
production interruption (continuous filtering) and without altering of
foil/sheet quality.
Process stability is ensured by melt pressure and temperature
control, arranged upstream and downstream of the filter.
Melt gear pump
The basic function of the melt gear pump is to grant constant melt
flow (i.e. under precise and constant pressure and output conditions)
from the extrusion head: high precision gearing is aimed at ensuring
the finest accuracy tolerances.
Gear pump dimensioning and design depend on process material
features and required outputs.
Due the integrated control system provided by Bandera control
panel, the operator can easily control production variables by
regulating melt gear pump parameters.
Process stability is ensured by melt pressure and temperature
control, arranged upstream and downstream of the pump.
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Sheet extrusion line feedblocks
Manufactured for the very wide range of products required by the
sheet sector (raw materials, structures, thickness an width ranges,
outputs, …), Bandera flat heads are ad hoc designed and manufactured for each extrusion line. In addition, they are equipped with a
feedblock whenever the sheet structure is multi-layer.
The feedblock comprises a tempered and stabilized stainless steel
case: inner melt flow channels are superrefined and/or chrome plated.
Layer distribution is managed by interchangeable selector plugs and
apposite melt flow and orientation diverter valves.
Flow channels are designed and manufactured depending on process
material rheology and single layer output: these features are of core
importance for the utmost precise distribution of sheet layers.
A feedblock for the production of sheet featuring
A-B-A, B-A-C-D and A-B-A-C-D structure
(picture and 3D layout above).
Here below, feedblocks for the production of
3- and 7-layer sheet
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Flat heads for sheet extrusion lines
An extrusion head (either single-channel or multi-channel) is made
of tempered and stabilized stainless steel: inner melt flow channels
are superrefined and/or chrome plated.
Flow channels are designed and constructed depending on material
rheology and global machine output.
Thermoregulation of head and lips is extremely accurate and involves
specifically designed high efficiency cartridge-type resistance
heaters.
The extrusion head can be complete with several appliances,
depending on production needs, such as:
Internal or external decklers to easily and quickly adjust sheet
width
Distribution bar to evenly distribute the melt flow over the entire
sheet width
Fast-gap adjustment system to regulate the gap by moving part of
the head body
Air blade systems and vacuum box for the production of thin sheet
Pictured below is the manufacturing process and operation of a
single-channel die head for the production of mid-thick sheet.
It is worth highlighting that in the case of multi-layer sheet from
different rheology materials, the use of extrusion heads with separate
channels is of the utmost importance for high-quality extrudate.
Multi-channel extrusion heads are more complex, besides requiring
independent thermoregulation and melt flow control.
21
Calenders
In sheet extrusion and co-extrusion lines, the calender is the actual
process core, where material is sized and cooled at the extrusion
head outlet.
Calenders differentiate for several design and construction
characteristics, e.g.:
Configuration: horizontal, (15°, 30°, 45°, 60°) inclined and vertical
Roller closing system, i.e. hydraulic, pneumatic and mechanical
Roller gap adjustment, i.e. mechanical - manual, mechanical power-driven, pneumatic with special design valves
Width, diameter, and quantity of the cooling/calibrating rollers
Roller construction, i.e. spiral or transverse hole cooling
Roller cooling/thermoregulation, i.e. by water or by oil
Roller surface finishing, i.e. mirror polished, satinized, or
embossed
Drive and electronic control
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Innovative cooling and polishing
technology for composite sheet
Bandera meets diverse and demanding requests by utilizing
a number of calenders manufactured in recent years and by
the expertise the company derives from proactive cooperation
with its customers.
To continue along this positive trend and offer its customers
an ongoing professional service, Bandera has dedicated an
exclusive product-oriented staff to this series of extrusion
lines. For process optimization as well as for special production
needs, Bandera calendering systems are completed - among
others - as follows:
Hydraulic system for calender vertical displacement
(available sheet path up to down or down to up)
Movable and power-driven upper and/or lower roller beds
complete with independently thermoregulated rollers
Multi-emission point X-ray heating system for sheet
molecular thermal stress relieving
23
Downstream ancillary equipment
Ancillary downstream equipment for semi-finished product further
processing:
Bandera ultimate machinery:
Calender roller cleaning systems, power-driven, to reduce
frequency of line downtime
Idle and/or power-driven roller beds with independent
thermoregulation for calibrating high quality and high-thick sheet
Sheet ennoblement (lacquering, surface treatments…)
Infrared ray heating systems aimed at sheet thermal stress
relieving
Calender roller cleaning system, by movable
power-driven cart equipped with pneumatic
pad and detergent solution distributor
Various laminating systems for sheet ennoblement and/or
composite sheet production
Masking machine for the application of protective film on the
extruded sheet
Heavy-duty haul-off units
Multiple and combined longitudinal and transverse cutting systems
Side trim cutters and transversal sheet breakers
Blade granulators complete with granule conveying equipment
Manual stacking systems, either semi-automated or fully
automated
Thin and/or flexible sheet winding systems
Masking unit: installed on a longitudinally
sliding roller bed. Calender roll control stations
arranged underneath the roller bed
Single or multiple roller beds equipped with
power-driven rollers temperature-controlled
by dedicated thermoregulation stations
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In-line extruded sheet quality control system, via video cameras
and/or polarized lights
Longitudinal “K” cutters
with heated blades,
sliding on roller bed
Trim edge-cutting system
with breaker
and belt conveyor
to the blade granulator
Transversal cutter
for acrylic materials
Haul-off unit and transversal
cutting unit
for acrylic materials
Transversal cutter
for acrylic materials
Combined transversal
cutting unit:
Guillotine-type (shear) and
circular saw blade
Longitudinal cutting system
with power-driven circular blades
Movable transverse cutting
system with swarf exhauster
Automatic stackers
for shockproof and
embossed materials
Automatic stackers
for high quality sheets
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Line control and
centralized management
The centralized control of all extrusion line parameters has proved to
be a key factor in production management.
Markets have increasingly become sensitive about labour costs,
quality control, product traceability systems and connection to
company network (or remote connection) for production line software
check and inspection.
To meet its customers’ - and prospects’ - needs, Bandera has
designed a specific software control architecture. The control system
is based on an industrial workstation for Windows operating system.
The line master PLC, interfaced with the industrial workstation, is
in turn connected with ancillary equipment PLCs and with single
unit remote I/O module via field bus. Due to the control architecture,
all line parameters are available for remote connections aimed at
production control, material management or remote assistance by
Bandera technicians.
The user interface has been designed with special care - from
hardware, with a wide colour monitor to software, with intuitive
synoptic graphics, from which the operator interacts via the touch
screen HMI. Bandera is proud to mention that its customers have
played a key role in Bandera machine development: following their
suggestions, today Bandera machine quality definitely outstands on
the global market.
Operator Panel
EWon
Company/Factory LAN
Machine LAN
Serial
PSTN, ISDN
PLC
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REVAMPING OF
EXISTING EQUIPMENT
AND COMPLETE LINES
GUARANTEE ON
DEMAND OVER
24 MONTHS
“ON-SITE” PERSONALIZED
TRAINING FOR NEW
APPLICATIONS
OFFERS FOR
EFFECTIVE SPARE
PARTS PACKAGES
FAST AND APPROPRIATE
(MECHANICAL/
ELECTRONIC/PROCESSING)
TECHNICAL SERVICE
SERVICING
PLANTS FOR
EXTRAORDINARY
MAINTENANCE
4 SERVICE
CENTRES COVERING
THE GLOBAL MARKET
Technical service
Bandera relies upon its specialists
to support its customers with an
accurate After-Sales Service, both at
the line start-up and testing, and at
the production stage. Cutting-edge
technology is at Bandera customers’
disposal, at any time.
In order to comply with its customers’
maintenance needs, Bandera has
established a dedicated efficient
Spare Parts Division.
Prospect of a NEW R&D and wet trials facility for
rigid and flexible film lines
A dedicated new plant will be finished in 2014 to let the activities of R&D industrial
tests and complete line wet trials be executed in a detached room.
Pushing on its high tech solutions,
Bandera offers its customers turnkey
extrusion lines - from engineering
and
design
to
construction,
assistance and assembly stages.
Besides, Bandera has drawn up
specific training programs dedicated
to customers’ personnel - the best
way to understand how to operate
new machineries and to retrofit
existing ones.
27
PLASTICS MACHINERY
EXTRUSION TECHNOLOGY SINCE 1947
For further details about Bandera technology, visit us at luigibandera.it
BLOWN FILM
EXTRUDERS
PIPE COATING
EXTRUDERS
GRANULATION
REV3/FOIL/EN/10/13
Visit our website and
learn about our pluses
Costruzioni Meccaniche Luigi Bandera SpA
Corso Sempione, 120 - I-21052 Busto Arsizio (VA) Italy
t +39 0331 398111 - f +39 0331 680206
lbandera@lbandera.com - luigibandera.com
You can download this document for your own mobile use and in the interest of the environment
http://www.luigibandera.net/bandera/en/prodotti/foil-a-sheet.html
Technical specifications provided for illustrative purpose only
and subject to change without prior notice.