Optibloc® clarity antiblocks exhibit high clarity, low haze, low coefficient of friction (COF), and low blocking force. Additionally, Optibloc® clarity antiblocks have a low affinity for other film additives, including antioxidants, slip agents, and polymer process aids (PPA).
Reducing PPA Interaction With Optibloc® Talc Antiblocks
Interaction with PPA is measured by melt-fracture elimination rate or the time-to-zero percent melt fracture. Melt fracture is a film surface imperfection that results from slip-skip of polymer melt against the film die. The effect seems to be more prevalent in the so-called fractional melt index polymers. Specific process aids are used to reduce this phenomenon in these low melt index resins. A shorter time-to-zero percent melt fracture indicates a reduction in slip-skip behavior and overall better extrusion performance.
Optibloc® clarity antiblocks allow for fast elimination of melt fracture—equal to synthetic silica and diatomaceous earth. Two examples of this improvement are shown below.
Melt Fracture Elimination in 1 MI Butene LLDPE With Optibloc® 10 Antiblock
Melt Fracture Elimination in 1 MI Hexene LLDPE With Optibloc® 25 Antiblock
Click here to download an introduction to antiblocks and Specialty Minerals Inc. talc-based antiblocks in LLDPE films.
Learn more:
- Specialty Minerals antiblocks
- What is an antiblock?
- Selecting a talc-based antiblock
- Formulating High Performance LLDPE Blown Films With Optibloc® High Clarity Antiblocks – Introduction to antiblocks – a downloadable Specialty Minerals publication.
- Replacing diatomaceous earth with SMI talc-based antiblocks
- Diatomaceous earth replacement study
- Replacing synthetic silica with Specialty Minerals talc-based antiblocks
- Economical SMI talc antiblocks
- Reduced coefficent of friction with surface-treated talc antiblocks
- Blown Film Basics
- Cast Film Basics
- Specialty Minerals Antiblock Technical Service Support
- What is Talc? A mineral introductory page
- Download technical data sheets for SMI products
- Request a sample
- SMI Publications on talc-based antiblocks: Downloadable papers by Specialty Minerals on talc-based antiblocks and their applications.
- About Specialty Minerals Inc.
- Specialty Minerals Plant Locations and Profiles
- Quality and ISO at Specialty Minerals




