CDF Core Products
Drum & Pail Inside Sales
508.591.6700 • 888.593.2211
Smart Pail Inside Sales
508.591.6750
Intermediate Bulk Container
Inside Sales
508.591.6800 • 888.593.2212
Cheertainer Inside Sales
508.591.6732
Cheer Pack North America
888.593.2214
BLOW MOLDING
Blow molding technology provides extra performance in maintaining package integrity and durability.
Single-wall parts that are molded in one piece can be produced with CDF's unique large-part extrusion process, in the 30 to 55 gallon range.
Since wall thickness and lip design can be carefully controlled, we regularly produce designs that meet demanding DOT standards.
With this technology components are typically cylindrical, but square or rectangular shapes can be made.
Why choose CDF?
CDF has been providing blow-molded inserts since 1996. Our MACO 100-point advanced digital programmer provides precise control of material distribution and allows us to manipulate and control wall thickness and lip design more precisely than any of our competitors.
Additionally, CDF prides itself on our ability to work closely with our customers to provide cost-effective, custom packaging solutions.
Extrusion Blow-Molding
In Extrusion Blow Molding (EBM), plastic is melted and extruded into a hollow tube (a parison). This parison is then captured by closing it into a cooled metal mold. Air is then blown into the parison, inflating it into the shape of the hollow bottle, container or part. After the plastic has cooled sufficiently, the mold is opened and the part is ejected. EBM processes may be either continuous (constant extrusion of the parison) or intermittent.
Compared to injection molding, blow molding is a low pressure process, with typical blow air pressures of 25 to 150 psi. This low pressure process allows the production of economical low-force clamping stations, while parts can still be produced with textured surface finishes. The resulting low stresses in the molded parts also help make the containers resistant to strain and environmental stress cracking.
Injection Molding
Although Injection Molding is probably the most popular form of plastics processing, it is not conducive to liner manufacturing. In order to form a part as tall as a drum, the walls would have to be much thicker than is needed in thermoforming or blow molding, which would increase the part cost. Thicker parts also mean longer cycle times, also increasing costs. Injection molds are also typically more expensive and generally need more taper than thermoforming molds, so the liner will not fit the drum as well.
There are some technical issues with injection molding related to liners. There are inherent stress points at the sprue and gate (injection points), which may cause a fracture point and consequently a leak point.
