Ideas about the designing process of PET bottles

1. José L. Giráldez
Independent Thinker
DESIGN PROCESS OFDESIGN PROCESS OF
PET PACAKGINGPET PACAKGING
One step after the other…

2. Design process of PET packaging
1. Product Design
2. Product Properties
3. First CAD design
4. Design of the production process
5. Verification of 3D through FEM
6. Mould type selection
7. Laboratory tests

3. DESIGN PROCESS OF THE PRODUCT
-Product life cycle
• Is it going to be a long life cycle Premium product?
• Is it going to be a short seasonal life cycle?
• Are we talking about a non-returnable packaging?
-Competitors
• Are we going to paste & copy an existing design?
• Are we going to modify an existing design?
• Are we going to design a Brand new product?
-Product to pack + Properties
• Carbonated/non-carbonated product?
• Filling temperature
• Water, Beer, Tea, Soda, Milk, Spirit …
-Filling process
• Aseptic
• Hot filling
• The bottle: Is it going to be pressurized?
• In order to avoid the O2 on the bottle neck: Are we going to inject NO2?
• The content: does it produce foam during the filling process?
• What system are we going to use to avoid the foam? (long tube or spreader)
Design process of PET packaging

4. - Transport within the factory
• What method are will de used? (air conveyor/conveyor belt)
• What kind of conveyor?
• What’s the Surface material?
• What’s its speed?
- Preform
• New or already existing preform?
• Will it be produced within the Company or bought?
- Quantity
• Bottles to fill in? (or amount of liters)
• Optimization of the filler machune
• Bottle volumen (just one bottle or a range of bottles?)
• Market (domestic/International)
- Shape of the base
• Petaloid? (mainly for carbonted drinks / CSDs)
• For mineral water? (or non carbonated produc)
• For champagne?
• For hot filling products?
• Does the bottle need to be positioned? (LUGS)
• …
Design process of PET packaging

5. - Neck finish/neck/closure (external/internal diameter - height)
• PCO (for CSDs / Plastic closure / 1,5 turns)
• Neck for mineral water
• Wide neck
- Bottle decoration (label, sleeve, BOPP label, screenprit, …)
- Emballage
- Approval/Communication procedures
- Time Frame
Design process of PET packaging

6. PRODUCT PROPERTIES
-Vertical load
• Closure
• Inbore
• Store (take care of base layer)
• Transport
• Is it currently a production line for glass?
-Internal pressure
• Carbonated product?
• How much CO2 does it dissolve?
• Filling temperatura/humidity (Does it need reinforcement panels?)
Design process of PET packaging

7. - Stability
• What kind of grip is needed?
- Stress Cracking
• Take care if exposed to alkaline solutions:
 During the rinsing process (returnable bolltes)
 Lubricants used for conveyor belts
• Geometric design of the base
• Design of the preform
• Parameters of the stretch blow molding process
- Barrier
• Product life cycle?
• Protection against the loss of CO2?
• Protection against the ingress of O2?
• Protection against wáter vapor?
• Multiple layers?
• UV protección?
• Tinted preform?
• More pronounced on smaller bottles (the Surface/volumen ratio is high)
Design process of PET packaging

8. - Inbore
• Type
• Pouring rate
• Dimensions
• Non refillable?
- Profile?
- Thickness/Resistance/Stability
- Neck ring needed?
- Height/Width
- Capacity
- Material
Design process of PET packaging

9. FIRST DESIGN IN CAD
-Are we talking about an existing design? Is it completely new?
• ”Reverse Engineering” procedure?
• Cretion of a Brand new design?
-Creation of a Brand new design
• 2D Design
• 3D CAD Design (¿Class A surfaces?)
• FEM (Finite Element Method)
• Digital Mock-up
Design process of PET packaging

10. DESIGN OF THE PREFORM
-Are we talhing about an existing design of preform? Purpose made preform?
• ”Reverse Engineering” procedure? (3D laser scan)
-We need info about neck and sizes:
• Height
• Diameter
• Capacity
• Final weight
• Shoulder zone =>+20% material than label zone
• Base zone =>+50% material tan shoulder zone
-Limiting variables in the design
• Neck ring needed?
• Filling method (shoulder’s shape – transition zone from neck to shoulder)
• Conveyor belt (contact bottle to bottle)
• Speed of the conveyor belt (Geometry ans stability of the bottle)
• Required Filling level (zero space?)
• Label zone (required thickness and Surface profile)
Design process of PET packaging

11. VERIFICATION OF THE 3D DESIGN THROUGH FEM (FINE ELEMENT METHOD)
-Maximum Capacity (identifies posible breaking points)
-Effects of grooves or drawings on the Surface ot the bottle
-Behaviour of different geometries on the shoulder zone
-Behaviour of the bottle against pressure conditions (hot products)
-Behaviour of the bottle against temperatura changes
-Thickness of the Wall thickness of the preform
-Product life cycle simulation on store
-Required time: 2-3 days (FEM) vs. 4 weeks (Real test)
-What FEM CNNOT DO
• Predcit the exact Wall thickness distribution based on the info about:
 The preform
 The geometry of the bottle
 The heating conditions
• The optimum adjustements of heating pannels in the oven system of the blow molder
Design process of PET packaging

12. MOLD CONCEPT SELECTION
-Based on:
• Equipment to be used
• Type of process (hot, aseptic, …¿?)
• Size of the bottle
• Frequency of product changeover…
-Molds:
• Aluminium
 Shell
 Full body
 Small Cavities
• Steel
 Hot-Fill
Design process of PET packaging

13. LABORATORY TESTS ON SAMPE BOTTLES
-Verification of:
• Main dimensions
• Capacity
• Top load
• Internal pressure (Burst pressure test)
• Stress Cracking Resistance
• Fillability
• Cristalinity (temperatura resistance)
• Drop test
• Barrier properties
 Against ingress of O2
 Against loss of CO2
 Segment weight distribution
Design process of PET packaging

14. Could I help you?
José-Luis Giráldez
Independent Thinker
jl.giraldez@gualaclosures.es
+34 609 20 23 12 (Mobile)
Some of the graphics and ideas come from public documents or web sites, and have been used with the sole
intention of delivering the messsage There are no commercial purposes behind this document