How to Choose Plastic Whitening Agent?
1) How to Choose Optical Brightener for Polyolefins
2) How to Choose Optical Brightener for PVC
It is worth noting that same optical brightener gain different whitening effect in rigid PVC (RPVC) and flexible PVC (FPVC). Bisbenzoxazole or phenyl coumarin group are often used in PVC. When PVC powder, heat stabilizer, fluorescent brightener agent dry mixed together, optical brighteners were evenly dispensed. For flexible PVC, OBAs were dissolved or dispersed into plasticizer. It is better to add FWAs in masterbatch form. For transport PVC, optical brightener plus plasticizer masterbatch or OBAs plus PVC masterbatch were used.
normally,50mg to 100 mg per kg is enough. To meet the requirement of extreme white with filler inside, 500mg/kg optical brightener agent is added. In rutile titanium dioxide PVC system,1000mg/kg OBAs is suggested. in most cases, the plasticizer in PVC had little effect on OBAs, the process temperature is normally 100 to 200 degree which means optical brightener heat stability shall meet. We shall pay attention to solubility and immigration which is important to flexible PVC
3) How to Choose Optical Brightener for Polyurethane?
4) How to Choose Optical Brightener for Engineering Plastics?
5) How to Choose Optical Brightener for Styrenics?
6) How to Choose Optical Brightener for Rubber
How to Add Whitening Agent Into Plastics?
Optical brighteners are added during the thermoplastic molding process, rather than added in liquid form afterward, that’s the word “mass-whitening” come from. Generally, OBAs were mixed with powder or granules plastic for flexible PVC, OBAs were added in solution form or dispensed into plasticizer. OBAs were used in masterbatch form to gain a better dispense effect in plastic. For PET fiber, some OBAs could be added during polymerization process which in monomer form. In this way, stable heat resistance and low volatility is required for OBAs