1. Co-funded by the
European Union
Press Consolidation / Thermoforming:
Properties and Applications
Justine Beauson, Stergios Goutianos (DTU)
Hans Knudsen (COMFIL)
Laurens Van Audenaerde (SAMSONITE)
Silvia Pavlidou (MIRTEC)
2. Introduction
In the Bio4self project, 2
manufacturing routes to
produce self-reinforced PLA
composite were investigated:
injection moulding and
thermoforming
The application aimed for
thermoforming manufacturing
are suitcases. The industrial
partner COMFIL produces
organo-sheet (pre-consolidated
sheet) from the PLA fabrics,
which are then thermoformed
by Samsonite to produce
suitcases.
Now looking at the composite level…
3. Content
1. Objectives for thermoforming manufacturing in Bio4self
2. Development work
3. Properties of self reinforced PLA composite
4. Lifetime prediction
5. Potential other applications
4. 1. Objectives for thermoforming manufacturing
Thermoformed suitcase by Samsonite
• Small suitcase - Firelite SP55
• Large suitcase - Cosmolite SP75
Requirements:
• Low weight – Density < 1500 g/m2
• Stiffness / Tensile modulus ≥ 3.2 GPa
• Impact properties: Passing the Samsonite
suitcase test serie
5. 2. Development work
Description of manufacturing route,
Setting the right processing conditions,
Adjustment of other parameters
6. 2. Development work
Description of the manufacturing route
Organosheet correspond to pre-
consolidated fabric plates. Plane plates are
then used in thermoforming.
Organosheet by COMFIL
Thickness: From 0.5 mm to app. 5mm
Length:
Width: depending on the quantity, up to
650mm
One off (or a few) can be made in 1200 x
800 x 200 mm
8. 2. Development work
Setting the right processing conditions
Manufacturing challenge
Consolidation temperature: Both of the PLA filament (matrix and reinforcement)
can melt, therefore the processing temperature Tprocess should be carefully
adjusted in order not to melt the reinforcement.
Tm,1 < Tprocess < Tm,2
9. In order to find this temperature, trials were performed.
Melting temperature of low Tm PLA / matrix material: 155C
Melting temperature of high Tm PLA / reinforcement: 177C
Plan:
• Manufacture UD fiber composite using different consolidation temperature: 155,
160, 165 and 170C
• Characterize the materials and determine the best processing conditions.
Tm,1 < Tprocess < Tm,2
2. Development work
Setting the right processing conditions
10. Manufacturing at DTU
Filament winding
Unidirectional fibre composite – 2 mm thick
Drying overnight in vacuum chamber at
35C
Press consolidation
Heating: 10 min at selected temperature
under vacuum
Pressing : 1 min at 30C - Pressure: 2 MPa
2. Development work
Setting the right processing conditions
11. Characterization – Microstructure
160°C, 165°C and 170°C => microstructure look very similar.
Few dry areas, no porosities or cracks, good quality overall
160°C 170°C165°C
300 μm
2. Development work
Setting the right processing conditions
12. 155°C microstructre looks very different: porosities, unproper melting of the matrix fibres
Poor interface properties
155°C
300 μm
165°C
2. Development work
Setting the right processing conditions
14. Consolidation
temperature
Stiffness Strength
[˚C] [GPa] [MPa]
155˚C 6.3 ± 0.1 104 ± 5
160˚C 5.8 ± 0.2 106 ± 4
165˚C 5.9 ± 0.0 98 ± 2
170˚C 5.8 ± 0.1 84 ± 7
Characterization – Static tensile test 0˚
E-modulus as expected
Effect of consolidation temperature on strength properties
2. Development work
Setting the right processing conditions
15. Characterization – Static tensile test off axis
155°C not performing as well we the other composites in off axis directions
Indication of poorer interface properties
165C selected
temperature
2. Development work
Setting the right processing conditions
16. Development work related to thermoforming process and suitcase
properties:
Effect of Number of fabric layer
Effect of the fabric type and weaving pattern
Effect of temperature of press consolidation of organo-sheet and
thermoforming
Effect of PLA matrix material
…
2. Development work
Adjustment of other parameters
18. Why it is important..
Lifetime prediction assessment predicts the long term performance of
the composite materials.
One of the common drawback of biobased composite materials is
their durability in time, due to their sensitivity to moisture.
Self-reinforced PLA material developed in the Bio4self project is
stabilized for moisture intake.
4. Lifetime prediction
19. Experimental set up:
Material is tested to accelerated aging.
This is performed by exposing the material to 6 different sets of
conditions, which are a combination of temperature and humidity.
The material is then tested for the most critical property identified by
the end user. For the samsonite case, it was the tensile properties.
Failure criteria was set to a drop of 20 % in the tensile properties.
4. Lifetime prediction
21. 5. Potential other application
Key drivers: lowering the carbon footprint, recyclability, green image of
product.
Medical devices: implants, orthopedic shoe,…
Furniture: PLA SRPC has potential as material for structural components
of furniture.
Automotive: under body shields, interior panels, load floors, scuff plates
and panels for trucks and vans,…
Industrial equipment: Protection shrouds, Machine cover,…
Protective (sports) gear: Body armour, Canoes,…
22. Seat structure
Dimension (in mm): 840 x 470 x 130
Weight: 600 g
Manufacturing process: In-mold hybridization.
Thermoforming of consolidated PLA fabrics and
overmolding (rib structures including the overmolding
of metal inserts, which are used as load introduction
elements).
5. Potential other application
23. Material PLA-PLA fabric (Weave WP1-PLA-400)
Fabric area weight 420 g/m²
Planned thickness approx. 1.3 – 1,35 mm (Requirement for Samsonite suitcase SP75)
4 layers with 1850 x 1050 mm²
Automated fabric cutting on Zünd cutting table
Automated fabric cutting Manual fabric placement in Fibercon
5. Potential other application
24. IR Heating Contact cooling
Fabric loading between IR transparent
glass ceramics
5. Potential other application
26. Transport box
Dimension (in mm): 400 x 300 x 200
Weight: 400 g
Manufacturing process: The box consists of a
combination of several plastic intermediates
made via:
Extruded PLA foam process (inner foamed
structure)
Thermoforming process (outer layer of
consolidated sheets for protection)
5. Potential other application