PEF Preform Wall Thickness for Injection Stretch Blow Molding
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Solution Overview
Problem
Current PolyEthylene Furanoate (PEF) containers produced by injection stretch blow molding lack advanced mechanical properties and lightness compared to PET containers, and require improvements in processability, transparency, food safety, and airtightness.
Innovation Solution
Development of PEF containers and preforms using a thermoplastic polymer composed of 2,5-FuranDiCarboxylic Acid (FDCA) and monoethylene glycol (MEG) monomers, with specific axial and hoop stretch ratios, and design features such as imprints and reinforcements, to achieve improved mechanical strength and reduced weight, while maintaining industrial processability and safety standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PEF containers are made with basic design and standard processing, then production is simple, but mechanical properties and lightness are insufficient compared to PET containers
Solution Approach 1:
The patent applies local quality by varying the wall thickness distribution in different regions of the container. Specifically, the bottom wall thickness is increased (1.5-2.5mm) while the side wall thickness is reduced (0.5-1.5mm), creating localized structural reinforcement where mechanical strength is most needed while maintaining lightness in other areas. This resolves the contradiction by providing enhanced mechanical properties through strategic local thickening rather than uniform thickening throughout the entire container.
Solution Approach 2:
The patent employs composite material strategies by combining PEF polymer with specific additive packages including nucleating agents, processing aids, and reinforcement fillers. The use of biaxially oriented polyethylene terephthalate (BOPET) liners in combination with PEF creates a composite structure that enhances mechanical properties, barrier performance, and heat resistance while maintaining the biosourced advantage of PEF. This composite approach enables achievement of PET-level mechanical properties.
2Loss of substance
If PEF containers are made lighter to save raw material, then material usage is reduced, but mechanical strength decreases
Solution Approach 1:
The patent implements local quality through non-uniform wall thickness distribution, with the bottom wall thickness specified as 1.5-2.5mm and side wall thickness as 0.5-1.5mm. This localized reinforcement strategy provides enhanced mechanical strength at the bottom where it is most critical for drop resistance and stacking, while minimizing material usage in the side walls. The result is optimal material efficiency with sufficient mechanical strength.
Solution Approach 2:
The patent applies preliminary action through pre-stretching and pre-heating of the PEF preform before the actual blow molding process. The preform is heated to 80-120°C and pre-stretched in the axial direction by a factor of 2-5 before being expanded radially. This preliminary preparation creates favorable stress distributions and molecular orientations that enable the final container to achieve high mechanical strength with reduced wall thickness, effectively preparing the material structure in advance to maximize strength-to-weight ratio.
3Strength
If advanced mechanical properties and lightness are achieved, then performance is improved, but processability and manufacturing complexity increase
Solution Approach 1:
The patent utilizes parameter changes by optimizing the molecular weight, polydispersity index, and thermal processing parameters of the PEF polymer. The intrinsic viscosity is controlled within 0.6-1.2 dL/g and the polymer is processed at specific temperature ranges (80-120°C pre-heating, blow molding at controlled rates). These parameter optimizations enable the material to achieve advanced mechanical properties while remaining processable using standard injection stretch blow molding equipment, balancing performance with ease of manufacture.
4Adaptability or versatility
If PEF is used to replace PET for biosourcing, then sustainability is improved, but mechanical properties and processability need improvement
Solution Approach 1:
The patent employs composite material strategies by combining PEF polymer with specific additive packages including nucleating agents, processing aids, and reinforcement fillers. The use of biaxially oriented polyethylene terephthalate (BOPET) liners in combination with PEF creates a composite structure that enhances mechanical properties, barrier performance, and heat resistance while maintaining the biosourced advantage of PEF. This composite approach enables achievement of PET-level mechanical properties.
Solution Approach 2:
The patent applies local quality by varying the wall thickness distribution in different regions of the container. Specifically, the bottom wall thickness is increased (1.5-2.5mm) while the side wall thickness is reduced (0.5-1.5mm), creating localized structural reinforcement where mechanical strength is most needed while maintaining lightness in other areas. This resolves the contradiction by providing enhanced mechanical properties through strategic local thickening rather than uniform thickening throughout the entire container.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution enables the production of PEF containers with enhanced mechanical properties and reduced weight, meeting the requirements of industrial manufacturing while ensuring processability, transparency, and food safety, as demonstrated by improved drop test results and efficient blow molding processes.
Implementation Method 1
the preforms are heated above their glass transition temperature, then blown using high pressure air into bottles
Implementation Method 2
The blowing device includes a blowpipe which injects pressurized air inside the preform to expand it and to fit the mold
Implementation Method 3
The blowpipe also participates to the stretching by leaning and pressing on the bottom of preform during stretching and blowing
Data Source
Figure 1~1r
Figure 2
Figure 3~4
AI summary
A preform (1) made by injection molding of at least one thermoplastic polymer of at least one FuranDiCarboxylic Acid (FDCA) monomer, preferably 2,5-FuranDiCarboxylic Acid (2,5-FDCA) monomer, and at least one diol monomer, preferably monoethylene glycol (MEG) monomer, and said preform comprising: • a neck end 2; • a neck support ring 3; • and a closed tubular body portion 4; said preform having a ratio Ø / L, wherein Ø is a specific outer diameter of the closed tubular body portion and L is the generatrix length of the preform closed tubular body portion; Ø / L being such that 0.10 < (Ø / L) ≤ 0.50.