5 replies to this topic

[Athula Saman]

Dear All,
I'm working in bottling water factory and I want to implement monitoring system for quality parameters of PET preforms and bottles. If someone is having detailed literature regarding the parameter to be checked of PET preform and bottles, please help me.

Athula

[George @ Safefood 360°]

Hi Athula

You do not say whether you buy in preforms / bottles or have your own in house injection / blow moulding facility. This is important since if you are buying them in you should not be spending too much time or money doing the job of your supplier. If you have in-house facilities then you need to monitor quality and safety. The nature of any in house facility will also determine the program you introduce. For example, if you are blow moulding direct to the filling line (and you do not produce stock) then many issues regarding performance and quality become immediately evident at filling/capping etc and you can take action at that time. If you produce to stock then your inspection program is important to ensure you don't produce large amounts of defective PET preforms and bottles.

Having said this there are a number of key areas that you need to control:

1. Starter Materials: You need to ensure that the PET resin used in preform manufacture is suitable and certified for contact purposes. Some customers will require analysis / certification of this including heavy metal content and migration levels.

2. AA Content: In water bottling the AA content is important since it can impart an off taste (citric) flavour from the plastic to the water. You may need to have a program for testing or certification of this parameter. This is essentially controlled at the injection moulding stage of preforms and relates to melting temperatures of the resin.

3. IV (Intrinsic Viscosity); This is a measure of the molecular length of the polymer and is important for producing consistent quality bottles capable of meeting performance requirements. If it too low you will see increase wastage, scrap and downtime. Also reduced shelflife for carbonated products. Certification from your preform supplier should be adequate or if moulded in house a testing program for IV is required backed up by process control of temperatures at moulding. The higher the moulding melt temperature the lower the IV due to thermal cleavage of the polymer.

4. Visual Attributes: The list here can be endless but the main ones include clarity, bubbles, haze, scratches, damage, flash on partting line (which can impact on cap torque), etc


5. Performance Attribures: Again a long list but the main ones include 1) Top Load - the pressure the bottle can withstand before collapsing 2) Height 3) Weight 4) Diameters 6) Perpendicularity 7) Thread finish 8) Short Shots 9) Weight Distibution etc.


George

[Dr Ajay Shah]

Hi Athula,

I totally agree with the comments made by George Hiowlett and they are all valid points

Kind regards

Ajay shah

Hi Athula

You do not say whether you buy in preforms / bottles or have your own in house injection / blow moulding facility. This is important since if you are buying them in you should not be spending too much time or money doing the job of your supplier. If you have in-house facilities then you need to monitor quality and safety. The nature of any in house facility will also determine the program you introduce. For example, if you are blow moulding direct to the filling line (and you do not produce stock) then many issues regarding performance and quality become immediately evident at filling/capping etc and you can take action at that time. If you produce to stock then your inspection program is important to ensure you don't produce large amounts of defective PET preforms and bottles.

Having said this there are a number of key areas that you need to control:

1. Starter Materials: You need to ensure that the PET resin used in preform manufacture is suitable and certified for contact purposes. Some customers will require analysis / certification of this including heavy metal content and migration levels.

2. AA Content: In water bottling the AA content is important since it can impart an off taste (citric) flavour from the plastic to the water. You may need to have a program for testing or certification of this parameter. This is essentially controlled at the injection moulding stage of preforms and relates to melting temperatures of the resin.

3. IV (Intrinsic Viscosity); This is a measure of the molecular length of the polymer and is important for producing consistent quality bottles capable of meeting performance requirements. If it too low you will see increase wastage, scrap and downtime. Also reduced shelflife for carbonated products. Certification from your preform supplier should be adequate or if moulded in house a testing program for IV is required backed up by process control of temperatures at moulding. The higher the moulding melt temperature the lower the IV due to thermal cleavage of the polymer.

4. Visual Attributes: The list here can be endless but the main ones include clarity, bubbles, haze, scratches, damage, flash on partting line (which can impact on cap torque), etc


5. Performance Attribures: Again a long list but the main ones include 1) Top Load - the pressure the bottle can withstand before collapsing 2) Height 3) Weight 4) Diameters 6) Perpendicularity 7) Thread finish 8) Short Shots 9) Weight Distibution etc.


George

[Athula Saman]

Thanks lot Mr. George and Dr. Ajay Shah. If you could send me a link or a web site from where I can get more information on manufacture of PET preforms and bottles would be much appreciated.

Athula

[George @ Safefood 360°]

I have many manuals on this but unfortunately they are in hard copy. However from a little browsing I came across this site where you can download some technical manuals on the subject e.g. blow moulding. You will need to copy and paste the URL links into your browser. I had a quick look at the content and it looks good.

Moulding Tech Manuals

Best of luck...


George

[azaam nafiz]

Hi Athula,

Please see below links,it got some literature which would helpful,



http://www.ptonline....ce-requirements

http://www.ptonline....regrind-quality

Thanks lot Mr. George and Dr. Ajay Shah. If you could send me a link or a web site from where I can get more information on manufacture of PET preforms and bottles would be much appreciated.

Athula