Specialty Minerals Inc. (SMI) ground calcium carbonate (GCC) (Hi-Pflex^® 100 GCC) and talc (MicroTalc^® MP 30-36 and 15-38 talc) products are used in foamed PVC formulations. Their primary function is as nucleating agents. They can also act as fillers, extending the resin. Loading levels can range from 5 phr to as high as 30 phr. Filler size typically ranges from 1 to 4 microns (median particle size) for medium to coarse cell-sized foams.

Ultrafine Minerals For PVC Strength and Small Foam Cell Size
Finer fillers improve melt elasticity, an important factor when blowing foam. They are also more efficient in that they contain more particles per unit weight—providing many more sites for bubble nucleation—and will produce foams with smaller cells. One micron appears to be an optimum size at a loading level of about 10-15 phr. Ultrafine fillers: precipitated calcium carbonates (PCCs) below 0.5 micron, Ultra-Pflex^®, Calofort^® S and Tuffgard^® PCCs and 1 micron or smaller talcs, UltraTalc^® 609 and FlexTalc^® 610 talcs, are not typically used but have shown some promise in foamed core pipe and similar applications. A key application for foamed core pipe is DWV piping for residential building.

Foamed PVC applications typically include decorative profile, pipe, and sheets used as coring material in composites such as boat hulls and decking to replace balsa wood and plywood.

Click on a product name on the chart to download the technical data sheet for that product. More on nucleation by fine fillers can be read by clicking here.

Learn more:

• SMI minerals for plastics
• SMI minerals for rigid PVC
• SMI precipitated and ground calcium carbonates for rigid PVC
• SMI talcs for rigid PVC
  
  
• Ground calcium carbonate (GCC) in plastics uses
• Precipitated Calcium Carbonate (PCC) in plastics uses
• Talc in plastics uses
  
  
• What is Ground Calcium Carbonate (GCC)/Limestone? A minerals introductory webpage
• What is Precipitated Calcium Carbonate? A minerals introductory webpage
• What is Nano Precipitated Calcium Carbonate (PCC)? A minerals introductory webpage
• What is Talc? A minerals introductory webpage
  
  
• Impact Fundamentals
• Nucleation Fundamentals
• PVC Compounding Technology Fundamentals
  
  
• SMI minerals in automotive products. See the parts of your car that are made with Specialty Minerals products.
• SMI minerals in housing. See the places Specialty Minerals products are used around your house.
  
  
• Download technical data sheets for SMI products
• “Fillers in PVC – A Review of the Basics” - download brochure  
• “Increasing the Flexural Modulus of Rigid PVC at Elevated Temperatures” - download publication
  
  
• Request a sample
  
  
• About Specialty Minerals Inc.
• Quality and ISO at Specialty Minerals