Extrusion Blow Molding

What IS 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.

What Are Typical Extrusion Qualities?

•    Bottles & Jars: Healthcare OTC, Household & Industrial Chemical, Personal Care and Food  ½ oz up to 2.5 gallon
•    Typical Resins: LDPE, HDPE, PP, PVC, extrudable PET(ePET), PETG, “soft touch” resins.
•    Standard Machinery: Bekum, Sabmann, Baker, Sig, R&B Plastics, B&W
•    Monolayer & multi-layer capable
•    Often multiple extruders for multiple bottle layers

What are Silgan Plastics’ Extrusion Processes?

Shuttle
•    This is the most popular type of machinery for blow molding high density polyethylene (HDPE) and Polypropylene Plastic (PP) containers around the world.
•    A shuttle machine consists of either single or dual molds that shuttle (or slide) from under the die head to a blow pin station.
•    The machines come in all sizes and configurations from single cavity to as many as 24 and bottle sizes from a ½ ounce up to a 2.5 Gallon.

Shuttle Capabilities:
•    In Mold Labeling (IML)
•    View stripe on colored bottles
•    Handleware
•    Angled and offset necks
•    Retractable bases for deep pushups
•    Multiple necks
•    Dosing chambers

BDS – “Blow Direct Screw”
•    Proprietary to Silgan
•    Horizontally Mounted Rotary Shuttle

BDS Capabilities:
•    ½  oz – ½  gallon bottles
•    Max height of a bottle is 13.8”. Max bottle diameter is 6.250” for rounds.  
•    Max bottle width for ovals is 6.700”.
•    Non-flashed / Non-handleware
•    Non-calibrated neck
•    Mono-layer or multi-layer (up to 3 layers)