FEASIBILITY OF USING PULSED ULTRA VIOLET STERILIZATION FOR MILK PACKAGING

CONTAINERS

Presented by Vanarin Suvattipunth

18 May 2009Asian Institute of Technology

PRESENTATION OUTLINE

Introduction

PUV sterilization mechanism

PUV regulation & optimization

Study procedure and its results

Conclusion

INTRODUCTION Packaging containers sterilizing technique

Thermal treatmenttechnique

Non-thermal treatment

technique

Chemical injection technique

Non-chemical (alternative) technique

Autoclave

Long/Short period heat treatment

Optimization of using PUV sterilization with target milk bottle integrated optimization treatment

Theoretical calculation approach of dispersion action

Objectives of the study

Electric line

in

AC/DC convert

er

Capacitor

banks

Pulse formin

g (switc

h)

Flashlamp

Target

Low-power,Low-voltage,

Low AC continuous current

Low-power,High-voltage,

Low DC continuous current

Low-power,High-voltage,

High DC continuous current

High-power,High-voltage,

High DC pulse current

PUV STERILIZATION MECHANISM

Sunshine versus Lightning bolt

Energy deliver mechanisms

1200 Watt-Seconds TotalSingle Pulse3 millisecond Pulse Width

1200 Watt-Seconds TotalMulti Pulse Train, 100 Watt-seconds/Pulse1 millisecond Pulse Width

1200 Watt-Seconds TotalContinuous UV Light

30 45 60 75 90 105 120

10

100,000

400,000

PE

AK

PO

WE

R (

Watt

s)

Time (Seconds)

1 m

s

12

ms

Power delivering mechanism of PUV

Inactivation mechanism of PUV

International regulation [FDA: CFR179.45-sp/b]

Cumulative fluence 120 kJ/m2

Pulse duration < 2 msWavelength range 200-1,000 nm

Boundaries[reference sources]200- 1,000 nm Wavelength range

0.001 ms to 0.1 ms Pulse duration0.1 to 5 s (recm. 2 s) Cool down duration

less than 50 OC Surface temp. control

PUV Regulations & Optimizations

Craters  around  spores  formed  by  sinking  of heated  spores into  the  PET  substrate

STUDY PROCEDURE AND ITS RESULTS

2-D drawing CAD model Mesh model

Dutch Mill ® 200 cc pasteurized milk bottle

Clark (13 kJ/m2) Wekhof & Dunn (40 kJ/m2)

Mimouni (90 kJ/m2) FDA (120 kJ/m2)0

20

40

60

80

100

120

140

MinimumMaximum

Tem

pera

ture

(oC

)

Optimum PUV treatment for target milk bottle

5

15

25

35

45

55

65

75

85

Mean temp Maximum temp HDPE service temp

Tem

pera

ture

(O

C)

First flash First cool down time (CDT)

Second flash Second CDT Third flash

Mean temp 35.605 35.609 46.188 46.21 56.7960000000001

Maximum temp 56.291 46.478 77.407 64.485 95.214

HDPE service temp

85 85 85 85 85

5

15

25

35

45

55

65

75

85

95

Mean temp Maximum temp HDPE service temp

tem

pera

ture

(O

C)

1st Flash 1st CDT 2nd Flash 2nd CDT 3rd Flash

Max temp 56.291 34.38 55.218 42.188 62.994

Average temp 35.576 27.897 38.452 30.842 41.394

HDPE service temp 85 85 85 85 85

5

15

25

35

45

55

65

75

85

Max tempAverage tempHDPE service temp

Study steps

Tem

pera

ture

(oC

)

Microorganisms dispersion action from PUV treatment

Define solid angle

Define the force from radiation pressure

Define the initial velocity

of treated microorganisms

0 10 20 30 40 50 60 70 80 90 1000.000E+00

2.000E-05

4.000E-05

6.000E-05

8.000E-05

1.000E-04

1.200E-04

1.400E-04

1.600E-04

1.800E-04

Clark (13000 J/m2)Dunn & Wekhof (40000 J/m2)Mimouni (90000 J/m2)FDA (120000 J/m2)

Attack angle (deg.)

Radia

tion p

ressure

(P

a)

0 10 20 30 40 50 60 70 80 90 1000.00

100.00

200.00

300.00

400.00

500.00

600.00

Clark (13000 J/m2)Dunn & Wekof (40000 J/m2)Mimouni (90000 J/m2)FDA ((120000 J/m2)

Attack angle (deg.)

Velo

cit

y (

mm

/s)

Result of calculations

CONCLUSION

Sterility achievement

Key point for the packaging development

Various applications of PUV for packaging field

Spores of Aspergillus Niger

Spores of Basillus Subtilis

Blow molding m/c

Chemical supply unit

Filling m/c

Capping m/s

THANK YOU FOR YOUR

ATTENTION