3M™ Glass Bubbles iM16K

  • Reduce final part weight by 15% or more without compromising mechanical integrity of finished product.
  • Extremely high strength-to-density ratio glass bubble survives high shear, high pressure processes like injection molding and extrusion.
  • Faster cooling times of melt processed polymers (injection molding and extrusion), typically 15-25% cycle time improvement.


3M™ Glass Bubbles iM16K will change the way you think about plastic parts. This product has a density of 0.46 g/cc and an excellent isostatic crush strength of 16,000 psi, providing an additive with a superior strength-to-density ratio for use in injection molding extrusion and sheet molding compounds. They can reduce final part weight by 15% or more without compromising the mechanical integrity.

Don’t Wait, Reduce Part Weight
From start to finish, 3M™ Glass Bubbles iM16K are about helping reduce weight while improving the production process and the quality of finished parts. Toward that end, weight reduction of 15% or more can be achieved in injection molded parts. Additionally, SMC manufacturers have created molded parts in the automotive industry with weight reductions up to 40% — a dramatic reduction that has revolutionized lightweighting in that industry. These substantial weight reductions don’t come at the expense of quality. In fact, parts maintain strength, surface aesthetics and mechanical integrity with the use of 3M glass bubbles iM16K.

Improving Throughput
Reduce cycle time by 15-25% or more without compromising critical mechanical properties of finished parts. The secret? Faster cooling. Typically, cooling takes up most of a mold cycle. By using glass bubbles to reduce thermal mass, parts cool faster from the melt and cycle times can be considerably shortened. Fillers like talc and calcium carbonate may cost less but can actually increase part weight. A reduction in part temperature of approximately 1.1°C per each weight % of 3M glass bubbles iM16K added to the formulation can be realized. Cycle time improvements allow customers to make more parts per minute, per hour, per day and per year.

Do More for Sustainability
Importantly, our 3M glass bubbles iM16K contribute to environmental sustainability. With a high strength-to-weight ratio, glass bubbles are ideal for lightweighting materials like plastics and composites. According to a single-site carbon footprint study conducted by 3M on one class of glass bubble popular for use in plastic manufacturing, the addition of 3M™ Glass Bubbles to injection molded parts had a neutral impact on the carbon footprint of the finished part. Additionally, lightweighting has known advantages such as improved fuel economy, easier handling of hand-held plastic parts and reduced shipping costs.

Automotive Injection Molded Plastics
3M glass bubbles iM16K can be used for many automotive injection molded parts. A typical automobile has 300 kg of plastic parts that contribute to vehicle weight. Using our glass bubbles can reduce the weight of these parts by up to 15% which can help improve fuel economy.

Class A Sheet Molding Compound
These bubbles are also used to reduce the density of SMC by up to 40% while maintaining physical properties and surface aesthetics. The narrow particle size distribution of 3M glass bubbles iM16K generate SMC with Class A paintable surfaces.

What are 3M™ Glass Bubbles?
Our 3M glass bubbles are engineered hollow glass microspheres that are alternatives to conventional fillers and additives such as silica, calcium carbonate, talc and clay. These low-density particles are used in a wide range of industries for many demanding applications to reduce part weight, lower costs and enhance product properties.

The spherical shape of 3M glass bubbles offers a number of important benefits, including: higher filler loading, lower viscosity/improved flow, and reduced shrinkage and warpage. Additionally, the spherical shape helps the glass bubbles readily blend into compounds, making them adaptable to a variety of production processes, including spraying, casting and molding. They also offer greater survivability under demanding processing conditions, such as extrusion, injection molding and other high shear mixing processes.

The chemically stable soda-lime-borosilicate glass composition of 3M glass bubbles provides excellent water resistance. These bubbles are non-combustible and non-porous, so they do not absorb resin; and their low alkalinity gives 3M glass bubbles compatibility with most resins, stable viscosity and long shelf life.

Typical Applications

  • Injection molded parts
  • Class A sheet molding compound
  • Automotive
  • Recreational vehicles
  • Heavy-duty trucks
  • Extrusion profiles
  • Electronics
  • Rubber parts
  • Sporting goods
  • Construction material
  • Concrete


Additional information

Appearance (Unaided Eye)

White Powder


Soda-lime Borosilicate Glass

Crush Strength (Imperial)

16000 psi (90% Minimum Fractional Survival)

Crush Strength (Metric)

110.32 MPa (90% Minimum Fractional Survival)

Density Range (g/cc)

0.40 – 0.49

Factory ISO Certification

No ISO Certification information available


Construction, Paints and Coatings, Rubber and Plastic, Transportation

Net Weight (Imperial)

2.2 lb, 99 lb, 100 lb, 775 lb, 781 lb, 798 lb

Net Weight (Metric)

0.5 kg, 44.906 kg, 45.4 kg, 351.534 kg, 354.256 kg, 361.967 kg

Product Usage

Cabin Components


Thin-walled Hollow Spheres

Typical Density

0.46 g/cc

Typical Median Particle Diameter

20 µm