Window profiles

From Lead to Calcium/Zinc stabilisers
Although the demand for Calcium/Zinc stabilisers is vastly growing, Lead stabilisers are still used because of their large processing latitude and outstanding heat stability.
Baerlocher has continuously developed Calcium/Zinc systems to produce stabilisers which are not just equivalent but in some respects even superior to Lead formulations.
The product development for Calcium/Zinc systems also involves the choice of sustainable raw material sources and the compliance of all raw materials with current and future chemical legislations.
The latest-generation Calcium/Zinc stabilisers offer good performance at considerably lower addition levels than Lead stabilisers or previous Calcium/Zinc systems. In addition, the 2% lower density of a Calcium/Zinc-stabilised dryblend is a key consideration in the comparison of overall dryblend costs.

After introducing melt products of Lead stabilisers some time ago, Baerlocher’s efforts have lead to the first melt products of Calcium/Zinc stabiliser for PVC profile applications. The pastilles, formed by a melt process, are well approved for their various advantages.
The production process of the so called TX products ensures highly homogeneous one-packs which can even include processing aid. The pastilles are not prone to abrasion during transport and conveyance, thus there are virtually no fines. The good flowability of the TX products facilitates dosage and handling of the stabilisers. Moreover, the pastilles possess superior silo storage ability. Baerlocher TX products are tailor-made for each customer and serve in white as well as coloured profile applications.

Weathering resistance
Weathering resistance is a key requirement of profiles, especially window profiles. Over the last decades, Lead-stabilised window profiles have proven their outstanding durability under different climatic conditions. They maintain their mechanical properties, such as impact strength or dimensional stability, even when exposed to strong temperature changes, alternate periods of humid and dry weather and solar radiation. Calcium/Zinc stabilisers exhibit better colour hold than traditional Lead systems both in artificial and natural weathering.

   Processing aid is included in stabilisers

Processing properties
Baerlocher has further improved the modern Calcium/Zinc formulations in terms of dosage, which now is below 4 phr in most cases. Generally the processing aid is included in the one-packs. Cacium/Zinc Stabilisers provide good early colour and excellent colour hold under mechanical and thermal stress. It is thus possible to produce profiles of consistently high quality even with a variety of machinery and tools. When processed with suitable lubricant systems, Calcium/Zinc-stabilised profiles compare equally with Lead-stabilised profiles in terms of surface gloss.

   MC = powder; R = granules; TX = pellets