Clarified PP fights way into high-end cosmetics application

In its search for the best package to market a new line of bath oils, one European cosmetics brand owner opted for bottles that are extrusion blowmolded of clarified polypropylene (c-PP). More established materials including PVC and glycol-modified PET also were considered but lost out in the materials specifying race.

Clarified PP got the call for exrusion blowmolded bottles for these high-end bath oils.

Natural cosmetics company Bielenda (Krakow, Poland) has begun marketing this new range of bath oils throughout Europe and overseas in the c-PP bottles. PP has some natural advantages over PVC and PET. Its lower density allows for weight savings of about 20% less than comparable PVC bottles and up to 10% less than PET ones. PVC can be harsh (abrasive) to head tooling, screws and barrels, while PET requires pre-drying.

Problematic has been its clarity, especially in extrusion blow melded applications, since these are processed at lower pressures. An extrusion blowmolded (EBM) bottle's clarity depends in large part on the quality of its wall surface. Normally, the low pressures and the mold surface finish used in EBM don't yield the best wall surfaces with PP.

But according to Bernard Vermeersch, senior development engineer at Milliken, the supplier of the Millad NX8000 clarifier used in the PP specified by Bielenda, says this has changed. "New grades containing (our clarifier) can yield EBM bottles with opticals on a par with PVC. Processors can achieve gloss levels of 120 at an angle of 60 degrees, clarity levels of 95% and haze as low as 6%. These values have never been achieved before with PP in EBM," he said. —[email protected]