introduction to the extrusion process - clextral · history of innovation in twin screw extrusion...
TRANSCRIPT
INTRODUCTION TO THE
EXTRUSION PROCESS
All rights reserved – Part or full reproduction is forbidden.
SUMMARY
• Basic description of a twin screw extruder
• Introduction to the extrusion process
• Preconditioning
• Thermomechanical Cooking and Expansion
Part 1: Extrusion variables and effects on the process/product
Part 2: Screw profile design
Part 3: Die-level expansion/texturing
2
All rights reserved – Part or full reproduction is forbidden.
HISTORY OF INNOVATION IN TWIN SCREW EXTRUSION
TECHNOLOGY
FOOD EXTRUSION-
COOKING
IN SSE
00’s 90’s 80’s 70’s 60’s 50’s 40’s 30’s
PLASTICS PROCESS IN TSE
FOOD
EXTRUSION-
COOKING
IN TSE
PAPER PULP
PROCESS
IN TSE
EXTRUSION
POROSIFICATION
IN TSE
PLASTICS
PROCESS
IN SSE
COLD
EXTRUSION
PASTA PROCESS
TWIN SCREW EXTRUDER (TSE)
SINGLE SCREW EXTRUDER (SSE)
3 3
All rights reserved – Part or full reproduction is forbidden.
DEFINITION
Extrusion is a thermomechanical process consisting in forcing a
product through a small size hole, under pressure and temperature
thanks to a mechanical device type Archimede screw.
Functions of an extruder: feeding, conveying, compressing,
cooking, shaping...
Expansion is due to the water flash off caused by the pressure
difference out of the die.
DIE
EXPANSION
SHRINKAGE
MELT
4
All rights reserved – Part or full reproduction is forbidden.
MIXING
SHAPING
COOKING EXTRUSION
TWIN SCREW EXTRUSION (TSE) TECHNOLOGY: MAIN
OPERATIONS
5
All rights reserved – Part or full reproduction is forbidden.
Barrel modules Die assembly
Motor Operator
Interface
Gearbox Heating
collars
Cooling
circuit
TWIN SCREW EXTRUDER: BASIC DESCRIPTION
6
All rights reserved – Part or full reproduction is forbidden.
MODULE DETAIL
The module, which houses the screws, is comprised
of several modular parts
AB
FER
Different types available :
AB1 (First feeding barrel)
FER (closed barrel)
VAP (vapour injection barrel )
ABF (lateral feeding barrel)
….
7
All rights reserved – Part or full reproduction is forbidden.
BARREL TEMPERATURE CONTROL
Cooling circuit outlet
Electric Resistance
Cooling circuit inlet
Feeding barrel
Temperature sensor
INDEPENDENT temperature control (cooling/heating) of each barrel of the extruder
8
All rights reserved – Part or full reproduction is forbidden.
BARREL COOLING SYSTEM
BC: Serial flow EV: Parallel flow
12 pass 2 pass Barrel axis
Cooling fluid temperature
Barrel axis
Cooling fluid temperature
1
12
outlet
inlet
inlet outlet
ADVANTAGES: - Homogenisation of the temperature - Improvement of the thermal exchange
9
All rights reserved – Part or full reproduction is forbidden.
INTERPENETRATING SCREWS
FLOW
COUNTER-ROTATING CO-ROTATING
FLOW
Interpenetrating → SELF-CLEANING
10
All rights reserved – Part or full reproduction is forbidden.
SCREWS DETAILS
Wide range of screws available to optimize the
thermomechanical cooking of the melt
C1F
BL22
C2F
Screw elements mounted on splined shafts:
Modular screw profile
Perfect continuity of the profile
11
All rights reserved – Part or full reproduction is forbidden.
Intermeshing zone
Flow
Gap barrel-screws
VERY EFFICIENT MICRO-MIXING :
MIXING IN THE TSE
12
All rights reserved – Part or full reproduction is forbidden.
The new standard for Extrusion Excellence
13
All rights reserved – Part or full reproduction is forbidden.
EVOLUM+ KEY ASPECTS
Evolum Key Aspects
Larger operation window:
Torque power-RPM
Optimal Cooling
Direct Scaling
With improved benefits
Greater productivity:
(Output: + 30-40%)
Advanced Thermal Control
Hygienic Design
14
All rights reserved – Part or full reproduction is forbidden.
Continuous auto-adjustment to
the recipe and variations =
Self-learning device
Optimum response when
disturbance, no compromise
between response time and
stability
Stability improved by 70 %
Energy saving up to 20 %
EVOLUM+ Advanced Thermal Control (ATC)*
* Availability depending on PLC brand
Time Te
mp
era
ture
ATC response
PID response
Perfect response
Enhanced temperature control:
No additional PID settings with ATC
15
All rights reserved – Part or full reproduction is forbidden.
Innovative hygienic design for optimal cleanability
EVOLUM+ hygienic design
16
All rights reserved – Part or full reproduction is forbidden.
Use of open profile instead hollow body for
main frame and all structures (beam excepted)
EVOLUM+ hygienic design
Spacing between
components
Open corners
All rights reserved – Part or full reproduction is forbidden.
EVOLUM+ hygienic design
Visual management
Stainless steel cooling pipes or
armoured flexible with elastomer cover
18
All rights reserved – Part or full reproduction is forbidden.
EVOLUM+ HMI
Automatic Start-up & Shutdown
Process optimization via
repeatable start sequences
Independent of the operator
know-how
Optimized lifetime on screws
& barrels
Recipes management
Historical data management
Fitsys+ V2: user-friendly
19
All rights reserved – Part or full reproduction is forbidden.
F: Fixed frame Trade-off for the best technical and economical compromise
D: Direct opening or H: 2-step opening Hydraulic barrel opening for easy maintenance and cleaning
M: Modular configuration & 2-step opening Ideal for R&D purpose
EVOLUM + Frame options EVOLUM+ frame options
Type
Materials
Paint coating RAL 9006 Stainless steel
20
All rights reserved – Part or full reproduction is forbidden.
MAIN FEATURES OF EVOLUM+ EXTRUDERS
Proven features of the EVOLUM® Extruder
High capacity due to increased Do/Di effect
Heat transfer management thanks to Advanced Thermal Control
Food safety achieved with a specific Hygienic Design
Range
EV44+ EV56+ EV72+ EV93+ EV119+ EV153+
21
All rights reserved – Part or full reproduction is forbidden.
2 FAMILIES OF EXTRUDED PRODUCTS
DIRECTLY EXPANDED= DX
NON-EXPANDED / INDIRECTLY EXPANDED
22
All rights reserved – Part or full reproduction is forbidden.
PRECONDITIONING - Pre-humidification and heating of
raw materials
- Biopolymer preparation (glass-rubber transition) to improve the process
(max flow; shearing, product quality,
wear, etc.)
THERMOMECHANICAL COOKING (Et & Em)
- Starches: loss of crystallinity and of the whole
state of the starch granules, depolymerisation,
formation of the amylose-lipid complex
- Proteins : denaturalisation and aggregation,
possibility of forming covalent bonds
TEXTURING - Expansion: Mechanism
dependent on the flash off
- Die face cutting or remote
cutting
STEAM
DEGASIFICATION
Motor (Em)
Et
RAW MATERIALS
TEXTURED PRODUCT
STEAM
TYPICAL CONFIGURATION OF AN EXTRUDER
WATER / LIQUIDS
WATER
23
All rights reserved – Part or full reproduction is forbidden.
DIRECTLY EXPANDED PRODUCTS
Snacks, Breakfast Cereals and Ingredients
Pet Food and Fish feed
Textured Vegetable Protein
24
All rights reserved – Part or full reproduction is forbidden.
MULTIPLE SECTIONS OF A SERIAL PROCESS thanks to the various restrictions generated by the work of
the screws. High mixing levels, heat transfer and shearing
Motor
P
Axial Distance
Conveying & Compression
Section
Mixing & Cooking
Section
Compression, Shaping &
Texturing
Section
WORK STAGES IN AN EXTRUDER Expanded Products
EXPANSION
25
All rights reserved – Part or full reproduction is forbidden.
EXPANSION AT THE FRONT PLATE ASSEMBLY OUTPUT - MATRIX: definition
Water evaporation
SEI
LEI
26
All rights reserved – Part or full reproduction is forbidden.
DX CHARACTERISTICS
Airy texture - cellular structure - crunchy texture
Expansion or texturing (cell structure vs. fibrated structure)
Expansion factor > 1.5 to 5.
Low density :
• Snacks and cereals: from 30g/L to 150 g/L
• Pet food and Fish feed: from 300g/L to 700 g/L
27
All rights reserved – Part or full reproduction is forbidden.
DIRECT EXPANDED SNACKS
Raw material preparation Coating device Twin screw extruder Belt dryer
350 – 1 700 kg/h
28
All rights reserved – Part or full reproduction is forbidden.
NON-EXPANDED OR INDIRECTLY EXPANDED
Pellet snacks
Extruded flakes
Ingredients
Fruit pieces/rolls
Cheese
Pet treats
High Moisture Extrusion Cooking (HMEC)
29
All rights reserved – Part or full reproduction is forbidden.
VAPOUR
DEGASIFICATION
Motor (Em)
Et
RAW
MATERIALS
TEXTURED
PRODUCT
VAPOUR
WORK STAGES IN AN EXTRUDER Non-Expanded Products
WATER /
LIQUIDS
WATER
Conveying &
Compression
Section
Mixing & Cooking
Section
Compression,
Shaping &
Texturing
Section
P
Axial Distance
Cooling
Section
30
All rights reserved – Part or full reproduction is forbidden.
CHARACTERISTICS OF NON-EXPANDED PRODUCTS
Dense Structure
Limited or non-existent expansion
• Expansion factor < 1.5
• High density (> 600 g/L)
May need additional treatment
31
All rights reserved – Part or full reproduction is forbidden.
FLAKES
250 – 1 200 kg/h
200 to 2000 kg/h
Twin screw extruder
Flaker Conveyor & nib cutter
Dryer toaster
Tempering drum
Coater dryer
Cooler
optional
32
All rights reserved – Part or full reproduction is forbidden.
PET TREATS
200 – 1 200 kg/h Twin screw extruder Dryer Cutter Cooler
33
www.clextral.com
Tous droits réservés – Reproduction intégrale ou partielle interdite. All rights reserved – Part or full reproduction is forbidden.
Thank you for your attention