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A continuous blow molding machine extrudes a nonstop parison while mold stations move in to catch and inflate it. The extruder never stops, which makes this the fastest route for HDPE and PP containers from about 0.5 to 30 liters. Three variables set your output: station count, die head cavities, and cycle time. Three more set your cost: energy per part, maintenance, and scrap. This guide covers both sides, with real specs from our own machines.

Blow molding inflates a tube of molten plastic against a mold in seconds to minutes. It costs more in tooling and wins at volume. Rotational molding tumbles plastic powder inside a heated, slow-turning mold. Its cycles run tens of minutes, but the tooling is cheap and the parts come out seamless. Annual volume usually decides it: low volumes favor rotomolding's cheap molds; production volumes favor blow molding's speed. For tanks, IBCs, floats, and barriers, a 250-liter blow molding machine runs 300 pieces per hour dry cycle, while a rotomolding cycle makes one part in the same span.

The three main types of blow molding machines are extrusion blow molding (EBM), injection blow molding (IBM), and injection stretch blow molding (ISBM). EBM covers the widest range — from small bottles to 2000-liter tanks — and splits into continuous machines for small parts and accumulator machines for large ones. IBM makes small bottles with precise necks. ISBM makes clear PET bottles. Your product decides the type. Find it in the table below.

To choose a blow molding machine, work from the container outward. Your part's volume sets the machine size. Your target output decides single or double station. Three specs settle the rest: clamping force, accumulator size, and melting capacity. As anchors: a 2 L bottle needs about 40 kN of clamping, a 30 L drum about 215 kN, and a 1000 L IBC about 1000 kN. Fix the container and the output first, and the model picks itself.

An IBC tank is the big roughly 1000-litre plastic bottle you've seen strapped inside a steel cage on a pallet, used to ship and store bulk liquids. That bottle is blow molded — and because it's so large, it needs the biggest accumulator machines made: three-cylinder storage heads, clamping forces around 1000 kN, and high-molecular-weight HDPE strong enough to hold a tonne of liquid without sagging or cracking. Kinggle's KGS1000L-IBC machine is built for exactly this: 1000 L capacity, 1000 kN clamping, twin 100 mm screws, and a 33 L accumulator on a 55-tonne frame.

Multi-layer blow molding builds a container wall from two or more plastic layers, each doing a different job — a barrier layer to block oxygen or fuel vapour, a recycled core to cut cost, virgin skins for a clean surface. They're co-extruded together through one die head, so the wall comes out seamless and fused. You need it when one material can't do everything: a fuel tank that mustn't leak vapour, a juice bottle that has to keep oxygen out for a year, a container that has to hit recycled-content targets without contaminating what's inside. Kinggle's KGH curved-arm machines run 1 to 6 layers on containers from 5 to 30 litres.