What is mineral fibre?

Per GB/T 4132-1996, man-made mineral fibres are the general term for inorganic fibres made from rock, slag, glass, metal oxides or porcelain clay. Boer products are made mainly from natural rocks such as diabase, basalt and dolomite, processed by melting, wet-process purification and surface treatment.

What does Boer's wet process mean?

Raw materials are melted in a cupola furnace and fibreised by a four-roll centrifugal spinner. Fibres are separated from shot in the settling chamber, then collected by hub collectors, purified, dried and packaged. The water medium eliminates electrostatic attraction between fibres and shot, and separates them by their different gravity and drag in motion.

What is shot content and how is it controlled?

Shot refers to non-fibrous material in the fibre (usually counted above 125 μm). Boer separates fibre from shot in the settling chamber through the wet process; some models control non-fibrous content below 1%. Specific values are subject to the batch test report.

Melting point and heat resistance?

Standard models have a melting point above 1000 ℃; the white-fibre series (e.g. BE-B03, BE-B07, BE-C08) has a melting point above 1600 ℃. Specific values are subject to the batch test report.

Dispersibility and resin bonding?

The wet process gives a more uniform surface treatment; the fibre is hydrophilic and easy to disperse, bonding well with phenolic resin, and is suitable for friction and sealing material formulations.

Does Boer fibre contain asbestos?

No. Boer products are asbestos-free man-made mineral fibres and have passed SGS asbestos testing (report CANEC25025290506, 2025-10-22); all 6 asbestos types, including chrysotile, were not detected (XRD/PLM, detection limit 0.1%).

Is Boer fibre RoHS/SVHC compliant?

Yes. Products have passed RoHS 10-substance testing (CANEC25025290502) and SVHC 250-substance testing (CANEC25025290504), complying with applicable REACH requirements.

Is an MSDS/SDS available?

Yes. Boer can provide MSDS/SDS prepared in accordance with REACH Annex II (e.g. EECSSDS2605060802), and the batch test report is delivered with each shipment.

What are the packaging and storage requirements?

Normally moisture-proof laminated bags or eco-friendly paper bags, with custom packaging on request. Store in a dry, ventilated place away from moisture, open flame and strong oxidizers.

How can I select a product and contact Boer?

Call the national sales hotline 4006-0763-82 or email info@boerfibre.com. Boer provides selection advice, samples and batch test reports.

Vermiculite (expanded vermiculite)

Category Raw Materials Published 2026-03-31 Source www.boerfibre.com

Abstract

Vermiculite is a hydrated aluminium silicate mineral (approx. (Mg,Fe,Al)[(Si,Al)₄(OH)₂]·4H₂O), monoclinic, brown/yellow-brown/bronze, Mohs hardness 1–1.5, specific gravity 2.4–2.7, melting point about 1320–1350 ℃. It is named for its worm-like expansion when roasted; the useful product is expanded vermiculite. Roasting at 800–1000 ℃ for 0.5–1 minute expands the volume 8–15 times (up to 30 times), giving a bulk density of about 100–130 kg/m³ and insulation, sound-absorption, water-absorption and fire-resistance properties.

Expanded vermiculite is used as lightweight building, insulation and sound-absorbing material, and more recently in friction materials — exploiting its light weight, wear resistance, sound absorption, high temperature resistance and high porosity to improve high-temperature performance and damping for smoother braking. Its flaky structure also gives some reinforcement; the suitable fineness for friction materials is 40–120 mesh, often used in non-asbestos inorganic-fibre formulations for passenger-disc and truck drum brake pads.

Key facts

Mineral: hydrated aluminium silicate, monoclinic; Mohs 1–1.5; SG 2.4–2.7; mp ~1320–1350 ℃
Expansion: roast 800–1000 ℃ for 0.5–1 min → volume ×8–15 (up to ×30)
Expanded product: bulk density 60–200 kg/m³; heat resistance 1000–1100 ℃; melting point 1370–1400 ℃
Reported composition: SiO₂ 37–42%; Al₂O₃ 9–17%; Fe₂O₃ 5–18%; MgO 11–23%; H₂O 5–11%
Friction-material use: improves high-temperature performance and damping; flaky structure gives some reinforcement
Suitable fineness: 40–120 mesh; used in non-asbestos inorganic-fibre formulations

The original article is in Chinese; see the Chinese version for the full text. This page provides the English title, abstract and key facts only — translated and compiled from the original, without full verbatim translation.

Vermiculite (expanded vermiculite)

Abstract

Key facts

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