3M™ Glass Bubbles S38

Chemical Resistance:

• In general, the chemical properties of 3M™ Glass Bubbles S38 resemble those of a soda-lime-borosilicate glass.
• Conductivity increases with temperature and product density.
• The thermal conductivity of a composite will depend on the matrix material and volume loading of 3M™ Glass Bubbles S38.

Thermal Stability:

• Appreciable changes in bubble properties may occur above 1112°F (600°C) depending on temperature and duration of exposure.

pH:

• Because 3M glass bubbles are a dry powder, pH is not defined.
• The pH effect will be determined by the alkalinity as indicated above.
• When 3M glass bubbles are mixed with deionized water at 5% volume loading, the resulting pH of the slurry is typically 9.1 to 9.9, as measured by a pH meter.

Hard Particles:

• No hard particles (e.g. glass slag, flow agent, etc.) greater thanU.S. number 40 (420 microns) standard sieve will exist.

Oversize Particles:

• Using a 10 gram sample on a U.S. number 140 standard sieve (105 microns), a maximum of three (3) percent by weight glass bubbles will be retained on the sieve.

Flow:

• 3M™ Glass Bubbles S38 remain free flowing for at least one year from the date of shipment if stored in the original, unopened container in the minimum storage conditions of an unheated warehouse.

Small Box (10 Cubic ft.):

• A single corrugated box with a plastic liner. All boxes are banded together and to the wooden pallet. 4 boxes per pallet. Each box inside diameter is 22 in. × 19 in. × 39 in. Pallet size is 42 in. × 48 in.

Large Box (50 Cubic ft.)*: 

• A single corrugated box with a plastic liner.
• Top enclosed with interlocking double cover banded.
• Bottom is normal box closure, entire box banded to wooden pallet.
• Each box inside diameter is 48 in. × 42 in. × 44 in. Overall load size is 48³/⁴ in. × 42³/⁴ in. × 50 in. including pallet. Pallet size is 42 in. × 48 in.

Box Weights:

• Small Box: 100 lb.
• Large Box: 680 lb.
• Truckload Large Box 44 Pallets: 29,920 lb.

• To help ensure ease of storage and handling while maintaining free flowing properties, 3M™ Glass Bubbles S22 have been made from a chemically stable glass and are packaged in a heavy-duty polyethylene bag within a cardboard container.
• Minimum storage conditions should be unopened cartons in an unheated warehouse.
• Under high humidity conditions with an ambient temperature cycling over a wide range, moisture can be drawn into the bag as the temperature drops and the air contracts.
• The result may be moisture condensation within the bag.
• Extended exposure to these conditions may result in “caking” of the 3M glass bubbles to various degrees.

To minimize the potential for “caking” and prolong the storage life, the following suggestions are made:

1. Carefully re-tie open bags after use.
2. If the polyethylene bag is punctured during shipping or handling, use this bag as soon as possible, patch the hole, or insert the contents into an undamaged bag.
3. During humid summer months, store in the driest, coolest space available.
4. If good storage conditions are unavailable, carry a minimum inventory, and process on a first in/first out basis.

Dusting problems that may occur while handling and processing can be minimized by the following procedures:

1.  For eye protection wear chemical safety goggles. For respiratory system protection wear an appropriate NIOSH/ MSHA approved respirator. 
2. Use appropriate ventilation in the work area.
3. Pneumatic conveyor systems have been used successfully to transport 3M glass bubbles without dusting from shipping containers to batch mixing equipment.

• Static eliminators should be used to help prevent static charges.
• Diaphragm pumps have been used to successfully convey 3M glass bubbles.
• Vendors should be consulted for specific recommendations.
• 3M glass bubble breakage may occur if the product is improperly processed.
• To minimize breakage, avoid high shear processes such as high speed Cowles Dissolvers, point contact shear such as gear pumps or 3-roll mills, and processing pressures above the strength test pressure for each product.