MOHAMMED ALZAYERCHRIS CLAY

XINHANG SHEN

Mat E 453December 11th, 2014

PROCESSING OF PET BOTTLES

Outline • Background

AmcorBlow MoldingRecycling

• Fluid MechanicsTemperatureMolecular Weight

• Bottle ProcessingPurificationPreformsBottles

• Conclusions

• Global Company– Australian

• 1860 as Australian Paper Manufacturers

• 1986 changed name

– 90% Food industry– 43 countries

• West EU and NA

– 180 plants– 27,000 employees

• Ames– 1997– 175 Employees– 10% of Ames Power– Primarily Preform

Background: AMCOR

Background: Blow Molding• Blow Molding:

Using gas pressure to expand a polymer to a desired shape.

• History [1]:Developed: 1800s (baby rattles!)1st PET bottle: December, 1942

• Today [1]:30-40 billion plastic bottles/year(US alone) Figure 1: Blue baby rattle [2]

Background: Blow Molding• General Process [1]:1. Melt thermoplastic resin2. Extrude through die head3. Form hollow Parison4. Drop Parison through mold halves5. Mold halves close around Parison6. Plastic solidifies inside mold7. Mold opens to get final component

Figure 2: Blow molding [1]

Background: Blow Molding• Variations [1]:1. Injection blow molding

2. Stretch blow molding

3. Extrusion blow molding

4. Reheat and blow molding

Bolded: involved in beverage bottle processing

Background: Recycling• ‘PCR’: post-consumer recycled• Advantages:

1. Less amount of waste in landfills2. Less carbon footprint than ‘virgin’3. Less natural resources needed• Disadvantage: Food residue• Solution: Heat to sterilize,

Use pure PETFigure 3: Pellets [3] flakes [4] PCR

Fluid Mechanics: Temperature

• PET Tmelt: 250-260 °C [8]

• Viscosity:Optimize T, just above Tmelt, low enough for PET to flow (but not too easily)

Equation 1: Temperature dependent viscosity [9]

Fluid Mechanics: Molecular Weight

• PET Typical Mw: ~20-40K g/mol [10]

• Viscosity:The lower the MW the less viscous. PET critical MW is unknown

Equation 2: Temperature dependent viscosity [9]

Bottle Processing: Overview• Simply known as:

Injection Stretch Blow Molding• Injection (Preform):

Inject hot PET into cavity• Stretch (Bottle):

Blow preform to get bottleFigure 4: Preform [5]

Figure 5: Final product [6]

• PET pellets come by railcarMoved into Silos by Suction

• Dried for 6-10 hoursRate limiting step for the process~ 0.2 % Moisture

• Additives Colorant, Plasticizers, Release Agents

Bottle Processing: Purification

Bottle Processing: Preform

Figure 6: First two steps involved in injection stretch blow molding [7]

• Injection Stretch Blow Molding:Summarized in 4 steps

Bottle Processing: Bottle• Injection Stretch Blow Molding:

Summarized in 4 steps

Figure 7: The rest of steps involved in injection stretch blow molding [7]

• AMCOR Makes PET Preforms/ Bottles• Receive PET pellets and dry them• Preforms made via injection molding• Bottles made from preforms by blow molding

Conclusions

[1] Manufacturing: Plastic Molding & Forming. Engineer's Handbook. Web. [2] Blue Baby Rattle Shower Favor Holders. Factorydirectcraft. Web. [3] Recycled HDPE Resins. Envision Plastics. Web. [4] PCR PET Flakes Decontamination. Viscotec. Web. [5] PET Preform Injection Molding Machine: SZ-1600A. Web. [6] Pepsi Introduces New Shape for Bottle After 16 Years. Designboom. Web. [7] Injection Stretch Blow Moulding. Plastipedia. Web. [8] Polyethlene Terephthatate: Melting Point. Web. [9] Mendoza, J. D., Mat E 453 Lecture, Iowa State University.[10] Pearl Engineering PEPLEPET B-103C PET Bottle Grade. MatWeb.

References