PET extrusion coating - taking extrusion coating to a new level Mr. - PowerPoint PPT Presentation

PET extrusion coating - taking extrusion coating to a new level Mr. Mikko Peltovuori 10, 7630

PET Extrusion coating • Polymer comparison PE vs. PET • Equipment • Processing • Applications 7030 10,1 Mikko Peltovuori 2

Polymer comparison PE vs. PET

Chemical properties PE vs. PET PET Synthesis 7030 10,1 Mikko Peltovuori 4

Chemical properties PE vs. PET PET Polyethylene • some natural polarity • non-polar • not branched • branched • narrow MWD • broad MWD 7030 10,1 Mikko Peltovuori 5

Physical properties PE vs. PET PET Polyethylene • density about 1.37 • density about 0.91 • melting point 245 °C • melting point 110 °C • tough/hard • soft 7030 10,1 Mikko Peltovuori 6

Equipment

Equipment • Drying • Motors and extruders • Laminator and nip 7030 10,1 Mikko Peltovuori 8

Drying • PET has to be dry before processing – water reverses esterification reaction • Water level from 5 000 ppm to 50 ppm • Drying – Temperature 140 °C – Dry air, dew point below -30 °C – Time min 6 hours 7030 10,1 Mikko Peltovuori 9

Drying • Transfer dryer to extruder with dry air • Transfer piping temperature resistance • Hopper design – Short residence time – Sealed from ambient air 7030 10,1 Mikko Peltovuori 10

Motors and extruders • Motors – PET properties → More torque needed → High motor loads 7030 10,1 Mikko Peltovuori 11

Motors and extruders • Extruders – Low friction screw design – Gentle and quick conveying after melting • Screw design PET vs. PE – Problems? – Solution: multiple extruders 7030 10,1 Mikko Peltovuori 12

Laminator and nip • Aim of the design minimal air gap – Why? Adhesion • Melted PET polymer pressed into paperboard fiber matrix – Mechanical locking • High nip pressure 7030 10,1 Mikko Peltovuori 13

Processing

Processing • Temperature • Adhesion • Neck-in • Other 7030 10,1 Mikko Peltovuori 15

Temperature • Very narrow temperature window KEEP YOUR PROCESS IN CONTROL!! • Ensure drying • Screw design • Rpm • Temperature setting – Extremely dependant on equipment 7030 10,1 Mikko Peltovuori 16

Adhesion • Laminator and nip design important – MINIMIZE YOUR AIR GAP!! • Flame pretreatment • Melt temperature control • Extra equipment for low coat weight 7030 10,1 Mikko Peltovuori 17

Neck-in • High Neck-in & strong edge waving • Minimize your air gap – short unsupported area • Air pins • Edge encapsulation • Coextrusion 7030 10,1 Mikko Peltovuori 18

Colors • Research and testing – Covering? – Dispersion? – Processing? – Additives? 7030 10,1 Mikko Peltovuori 19

Applications

Applications • Temperature 7030 10,1 Mikko Peltovuori 21

Applications • Strength 7030 10,1 Mikko Peltovuori 22