this slide is about Pet resin information and preform manufacturing. you get the idea of preform production and testing parameter of preform and machine details which is used to test preform parameters for further information mail me or contact with me at ahrimon1000@gmail.com
2. 1.CSD PET RESIN= Carbonated Soft Drinks preparing
preforms needs high level IV to bare the CO2 pressure
we provide in the CSD production. IV value=0.84 ± 0.02 dl/g
2. Packaged Drinking Water (PDW) Pet Resins: Aquafina
preforms resin contains IV value of 0.76 ± 0.02 dl/g
3. HOT FILL Resin (HF) = HF resin has almost the same IV
value as Water resin.
COLORS:
UV-colour: Ratio 0.150% , use by M/O
Green: Ratio 0.050% , use by 7up
Neon Green: Ratio 0.021% , use by M. Dew
PET Meaning : POLY ETHYLENE TEREPHTHALATE
Types of Resin :
3. Brand Grade Type Manufacturer Country Shelf life
Relpet
5841M CSD
Reliance India 2 year
5761M AF
H7761M Hot fill
Aspet
AS-21-CF CSD
IVL Dhunshiri Petrochem India 2year
AS-19-C AF
AS-21-HF Hot fill
Gatronova A-84 CSD Novatex Ltd Pakistan 1year
A-76 AF
YS-C01 CR 8828 CSD China Resource China 2 year
Jade CZ-328 CSD Xinghua China 2year
Different Types of Resin & Shelf life:
4. PET RESIN IDENTIFICATION STICKER:
Bag is B22Z100088 Here blue 22 is MFG year 2022 & the red alphabet Z is MFG month.
7. Drying Procedure of PET Resin
Heating: 160-180°C
PET Resin
PET Resin
Receipt
& Storage
PET Resin
Drying
Dew point: Above (-30°C)
Moisture: <50ppm
Cone Temperature: 130°C to160°C
Residence Time: (6-8) hrs.
RESIN DRYING HEATING PROFILE: 1ST ONE HOUR 120°C + 2ND TWO HOURS 150 °C + 3RD THREE
HOURS 170 °C = TOTAL SIX HOURS
8. PET Resin Injection Molding
of Preforms
Preform
Preform
Handling &
Storage
PET Resin
Receipt
&
Storage
Moisture: <50ppm
PET Resin
Drying
I.V. reduction between
resin and preform
(< 0.02dl/gr. Max.)
Average AA < 10ppm,
no one cavity > 14ppm
• I.V.: 0.80-0.84+/-0.02
dl/gr.
• Acetaldehyde:
< 1 ppm
How are Preforms Made and Their Critical Parameters :
9. Injection Moulding of Preforms
PET Resin
Screw
Barrel (~ 290C/554F to 320C/608F)
Preform
Gate section
Sprue Extruder
Cavity
Core
Mold (~ 290C/554F to 320C/608F) & Nozzle (~ 40-60%)
Mold
10. Preform Handling and Storage : -
Normally packed in polyethylene plastic bags which
are closed to the surrounding environment
Polyethylene liner is used to prevent dust and dirt
contamination
Preforms should not be stored in direct sunlight
Stored in a covered/closed warehouse with ideal
temperatures of between 5°C/41°F to 35°C/ 95°F at
Relative Humidity < 60%
12 months maximum for storage of preforms is
recommended (from date of preform manufacture)
11. 1.Visual Check of preform and resin
2.Moisture content of preform & resin
3.Preform light inspection
4.Physical parameters of preforms:
Weight
Neck Height
Neck Diameter( Internal, External & thread)
Length
Body diameter
Gate length
Wall thickness (body & bottom)
5. Content of acetaldehyde in Preform
6. Intrinsic Viscosity of preform & resin
Quality Control tests :
13. Range:
Not more than 10ppm
Effect of Acetaldehyde :
Give a bad odor if it is present out of range in Pre form. Sensory test may fail
Cause:
Over heating in hopper.
If resin contain high moisture in Screw barrel
Corrective Action :
Drying should be controlled.
Drying time and drying temperature should be observed frequently.
Maintain minimum back pressure & screw RPM
Acetaldehyde Analysis :
GC
Analyze
r
14. IV(Intrinsic Viscosity) : IV is average molecular weight of PET Resin. Resin IV measured by comparing zero
concentration of kinetic viscosity which is measured in dl/g. It is also depends upon length of polymeric chain.
Range:
For resin: 0.84±0.02
For preform: 0.02 drop from pet resin
Effect:
If IV value is low in preform then polymeric bond will be weak which will
cause bursting issue in preform
In CSD bottle gas retention will be higher if IV is low
Cause:
If moisture content is high
Exposure to high temperature (thermal Degradation)
Corrective action:
Increase and monitor Dryer efficiency
IV Analysis :
IV
Tester
15. Range :
Not more than 0.2% (Both for resin & Crushed pre form)
Effect :
IV Drop may exceed more than 0.02dl/g
Haze Problem & gate crystallinity may observe in ready Pre form
AA a value may increase & IV value may decrease
Cause :
Lack of maintenance of temperature of blown air
Efficiency of subsidence of heaters of dryer
Break down of temperature sensor
Corrective Action :
Temperature has to be maintain from 170°C to 180°C in drying period
Cone temperature of hopper should be observed
Moisture Analysis :
Moisture
analzer
16. PREFORM DEFECTS & PREVENTATIVE ACTION
Defect Cause Prevention
Bubble If barrel screw rotation varies, if air bubble enter in screw
barrel
Screw barrel should totally be filled with melt, under hole should be used to take out melt in
case of maintaining air gap
Black specks Dirty resin It may cause in starting time. So, some shots should be wasted in starting. Also for continuous
manufacture of resins should be handle with care and clean.
Stretches Inside stretch: If core tubes in the mold become bent
Outside stretch: collision in conveyor
In case of inside stretch machine should be turned off and bent core in the mold should be
changed
Gate pin hole i. Gate bulb adjusted to the cavity doesn’t work properly
because of variation of temperature
ii. Required amount of material doesn’t inject to the mold
i. Screw pressure should be rise
ii. Temperature of nozzle tip adjust
iii. Temperature of mold should be adjust
Haze Improper drying Proper dry should be ensured
Short shot i. Material shortage
ii. If CSD resin is used in specification of AF resin
Proper amount and correct resin should be used
Gate Crystallinity Reduction of heat nozzle tip Nozzle tip heat should be increased
Neck crack( Neck
water ring)
If cooling water circulation somehow leaked in mold Cooling water pipes should be repaired
Long gate Gate bulb adjusted to the cavity doesn’t work properly
because of variation of temperature
Temperature of bulb should be increased
17. Defect type: Short Shots
Description: Neck finish not
completed
Cause: In-sufficient polymer
was packed during
the injection fill time
Concern: Poor bottle/closure
seal - High CO2 loss
Short Shots
Preform defects & preventative action :