PVC applications requiring enhanced stiffness or flexural modulus can benefit from the addition of Specialty Minerals Inc.'s (SMI's) ultrafine and fine talcs. Click here to read basic information on talc and its use for improvement of stiffness or flexural modulus.
The higher aspect ratio of talc versus either precipitated calcium carbonate (PCC) or ground calcium carbonate (GCC) is what gives talc this performance enhancement.
Formulators seeking to balance impact strength and stiffness may utilize both types of functional fillers for their formulation development efforts.
There is a trade-off between stiffness and impact strength. When talc is added to increase stiffness, impact strength decreases. This loss of impact strength is less severe when finer talc products are used but can still be significant and unacceptable. Impact strength can be recovered by raising the level of impact modifier in the formulation. Conversely, there is a drop in stiffness as this is done, but the trade-off is not as severe as it is with the addition of talc. The result, therefore, is a new compound with fine talc and high levels of impact modifier which exhibits an improved balance of properties.
SMI offers two downloadable publications with additional information on talcs. The brochure "Fillers in PVC - A Review of the Basics" offers a good introduction to the topic. Click here to download it. "Increasing the Flexural Modulus of Rigid PVC at Elevated Temperatures" summarizes a study on the use of talc in rigid PVC. Click here to download it.
- SMI minerals for plastics
- SMI minerals for rigid PVC
- SMI minerals for PVC window and door profiles
- SMI minerals for PVC fence and decking
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- SMI minerals for calendared and thermoformed rigid PVC
- SMI minerals for injected-molded PVC
- Talc in plastics uses
- What is Talc? A mineral introductory webpage
- Impact Fundamentals
- Flexural Modulus / Stiffness 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 Specialty Minerals products
- "Fillers in PVC - A Review of the Basics" - download brochure
- "Increasing the Flexural Modulus of Rigid PVC at Elevated Temperatures" - download publication
- Download brochure on Specialty Minerals Plastics Applications Laboratory
- Request a sample
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