Four products dominate halogen-free and low-halogen flame retardancy: aluminium trihydroxide, magnesium hydroxide, zinc borate and antimony trioxide. They are not competitors – they do different jobs at different dose levels – but purchasing departments routinely put them in one comparison table, and that is where bad decisions start. This article puts them side by side

Zinc borate is the most misunderstood product in the flame-retardant toolbox. It is not a flame retardant in the way aluminium trihydroxide is – you cannot load a compound with 50% zinc borate and expect it to work. It is a synergist and smoke suppressant, dosed at a few parts per hundred, whose value is

Si-69 and Si-75 differ by two sulfur atoms, and that difference decides which of them your mixer can run. The tetrasulfide gives more coupling per kilogram but punishes a hot mix; the disulfide gives slightly less coupling but keeps its composure when the rotor speed climbs. Buyers who treat them as interchangeable end up either

Silane coupling is often described as if it were a single reaction. It is three, in sequence, and each one has its own temperature requirement and its own failure mode. Most “the silane did not work” problems trace back to one of the three steps being starved of what it needed – usually water, temperature,

Every tyre compound is a compromise between rolling resistance, wet grip and wear – the three corners of the “magic triangle” that conventional carbon black cannot escape. Silica filled compounds break the compromise, but only because a sulfur silane couples the silica to the rubber. Get the silane wrong and the compound is worse than