Fire resistance Imerys minerals - cost-effective fire retardants and insulation additives
Imerys talc, mica, and wollastonite are successfully used in many halogenated, halogen-free, and intumescent flame retardant (FR) formulations as FR synergists and/or for improving mechanical, thermal, rheological and aesthetic properties of fire resistant plastics.
Imerys minerals in intumescent flame retardant PA 6
Imerys talc, mica and wollastonite products demonstrate synergistic flame retardant (FR) performance allowing manufacturers to reduce FR additive loading or FR specimen thickness when used for partial replacement of chopped glass fiber (GF) in polyamide 6.
Replacing 10% of glass fiber with any of the above minerals improves rheology of 30% GF-filled FR PA which is a known weakness of glass fiber reinforced PA6.
For example, partial replacement of GF with high aspect ratio talc or mica allows compounders to achieve UL94 V0 or V1 rating at decreased loading levels of organic phosphinate-based intumescent FR additives in a 30% GF-filled PA6 formulation at 1/8” or 1/16” specimen thickness.
Talc for MDH and ATH replacement
Imerys talc can be used effectively for partial replacement of magnesium hydroxide (MDH) and aluminum tri-hydrates (ATH) to reduce compound costs without affecting flame retardant properties.
- Reduce the combustible content of the compound
- Reduce combustion rate
- Contribute to char formation
We recommend our HAR® product for maximizing FR performance in MDH and ATH due to its high aspect ratio.
Mica for APP replacement
Imerys mica grades make cost-effective replacements for ammonium polyphosphate (APP) commonly used to meet UL94 V0 requirements in halogen-free flame retardant formulations for polyolefins.
APP is not only expensive it also diminishes physical properties such as tensile strength.
Imerys micas can be used as a synergist to replace up to one third of APP flame retardants where they:
- Boost flexural modulus
- Improve HDT
- Reduce shrinkage and warping
- Promote char formation
We recommend our Suzorite® range for APP replacement in polyolefins.
UL94 ratings at 1/8” specimen thickness
UL94 ratings at 1/32” specimen thickness
We offer a full range of bespoke formulation and technical and process support services to help you match the right mineral grade to your application requirement.