What is Compression Blow Forming and How Does it Work?

As demand for high-quality plastic packaging rises, new innovations in materials science are stepping up to the plate. One of those recent innovations is Compression Blow Forming (CBF), a patented technique that blends features of compression molding and blow molding together to achieve precise results while optimizing plastic usage.
 

What is Compression Blow Molding?
CBF is a single-stage, resin-to-bottle process that can produce containers and bottles directly from pellets. It has become a sought-after method in the pharmaceutical and CPG space because it combines multiple advantages from other techniques.

The CBF process is highly controlled for quality, yet flexible enough to work with a wide variety of resins, making it a practical and efficient way to meet a range of packaging needs. 
 

The Compression Blow Forming Process
CBF is a continuous plastic extrusion process that produces a more consistent part quality when compared to traditional injection molding. Resin is continuously fed through an extruder, and as that resin overflows, it’s cut into precise pellets, which are then placed into an open compression mold. This single large pellet process uses 100% of the pellet, reducing waste throughout the process. Additionally, with no gate needed, meaning there are no gate marks on the final product, leaving a clean bottom surface.

Once a mold is filled, the plastic inside is compressed into a preform, then thermo-regulated to a temperature that allows for immediate blow-molding. After achieving the desired shape, the container is extracted, and the process continues.  
 

Why Choose Compression Blow Forming for Your Bottles?
When compared to other bottle manufacturing methods, Compression Blow Forming offers several advantages, including:

Superior Bottle Quality: Containers made with Compression Blow Forming can achieve very tight neck dimensions with precision. Additionally, due to a more uniform wall thickness, CBF bottles also have a 30-40% stronger moisture barrier (MVTR) and an improved Oxygen Transmission rate on average. This barrier improvement makes them ideal for pharmaceutical and food packaging.

Sustainability: Compression Blow Forming’s flexibility also extends to sustainability. With CBF, manufacturers looking to reduce raw material usage can easily adjust bottle weight and reduce material consumption by up to 10%.

Customization: HDPE Compression Blow Formed bottles are available from 45cc-500cc as well as a variety of color options in addition to custom solutions to meet individual needs and projects. 

Redefining What’s Possible in Packaging
Alltrista is proud to offer Compression Blow Forming for pharmaceutical bottles. Whether you are looking for world-class precision, or a way to further your sustainability goals (or both), our manufacturing experts are ready to help your team explore Compression Blow Forming. Reach out to our team to learn more.