how to make glass wool

Glass wool is made by spinning or drawing molten glass into fine fibers, then binding and forming those fibers into mats or rolls. The process is industrial, requiring high temperatures and specific machinery. Here's a simplified overview:

Raw Material Preparation

Main ingredients:

Recycled glass (cullet)

Silica sand

Limestone

Soda ash

Other minor additives (borates, alumina, etc.)

The materials are mixed and prepared for melting.

2. Melting

The raw mixture is fed into a glass furnace and melted at ~1,400–1,600°C (2,552–2,912°F).

This creates a homogeneous molten glass.

3. ��️ Fiberization

The molten glass is passed into a centrifugal spinning machine (like a cotton candy machine).

The high-speed spinners throw out thin glass threads by centrifugal force.

Cold air or steam jets help stretch and cool the fibers.

4. Binder Application

A thermosetting resin (usually phenol-formaldehyde) is sprayed onto the fibers.

This binds the fibers together, giving shape and mechanical strength.

5. Forming the Mat

6. The fiber mat passes through a conveyor system and is compressed to desired thickness and density.

Then it moves into a curing oven (200–250°C) where the binder hardens.

7. ✂️ Cutting and Packaging

The cured mat is cooled, trimmed to size (rolls, boards, or batts), and packed.

Often wrapped in plastic film for moisture protection.

Safety Note:

Making glass wool is not suitable for DIY due to:

High-temperature equipment

Toxic fumes from binders

Health hazards from inhaling fine fibers