|
|
|
Kenplas Forum ==> Injection Molding (Machine) ==> Using rejected preforms mixed with virgin material to make PET preforms
|
|
|
|
|
| 1 |
My reply ...
1) You can use rejected preforms by grinding them to pellet size then mixing it with virgin using a gravimetric blender prior to enter the drier hopper.
2) Avoid PET dust or very very small particles post grinder. Use a kind of grinder that offer you a dust separator. Avoid to drive the PET dust to the hooper. If it enters the extruder it became into black specks. Use ground preforms (the outcome chips from the grinder) between 0% and 20% max. Stop dosing ground material once a week to grant the virgin resin can clean the system... otherwise you need to disassemble and clean... and I can ensure you that you will not want to do it...
3) Use from 0% to 20% max to retain virgin properties (Mechanical properties in special) as much as possible. (Today Preform IV is 0.80 ~ 0.82 dl/gr... -Resin is 0.84dl/gr- it is enough to reprocess.... final IV may be 0.78 dl/gr. IV drop must be 0.02 or 0.03 max. You can use 100% ground preforms....But don't do it at Home.. ok..!!??!!) Use 20% max. Use 5% to 10% as a preferred dossage. It depends on defects you can see on preforms... may be small size black specs.... If you find that... stop dossing or half the %.
4) PET doesn't need those additives at all. But even you want to use...you can.... Work with your additives supplier to find out a suitable one for your need or work with the supplier to develop a new additive... Colormatrix is a very good supplier (from USA, UK or Brazil...)
I am a process engineer from Argentina with 12+ years experience converting PET into preforms and bottles.
Sorry about my english...
I hope this can help.
Regards,
AV.
|
pl send the reply for
Please, can any one help me on the following:
1) How can we use rejected preforms by mixing with virgin to make fresh pet preforms.
2) What is the process and precautions that we need to take.
3) What is the maximum percentage of the rejected preforms that can be mixed with virgin to make pet preform for water application.
4) Are there any additives to improve the brightness/light/appearance of the pet preform.
|
Hi,
Please, can any one help me on the following:
1) How can we use rejected preforms by mixing with virgin to make fresh pet preforms.
2) What is the process and precautions that we need to take.
3) What is the maximum percentage of the rejected preforms that can be mixed with virgin to make pet preform for water application.
4) Are there any additives to improve the brightness/light/appearance of the pet preform.
Please help me on the above.
Thx,
Vikas
vikasaggie@gmail.com
|
| 1 |
|
|
|
|
|
|
This forum published since July 03, 2002.
Renewed on June 22, 2005. |
Discussion Forum