How to Select an Extrusion Blow Molding Machine

Begin with the product, not just its volume

Two containers with the same nominal volume can require different molds, heads, clamping arrangements and cooling. Define the part drawing, dimensions, target weight, neck, handle and intended use first. For technical hollow parts, include the critical dimensions, mounting features and service conditions.

1. Specify the material

Identify the actual resin grade and any permitted regrind, color or multilayer structure. Material selection influences plasticizing, die-head design, drying and process settings. Keep extrusion blow molding separate from other processes such as PET stretch blow molding when discussing equipment.

2. Define the mold and part envelope

Check the mold dimensions, opening requirement, product projected area and removal method. Compare these with platen spacing, maximum mold size and clamping force. The model name or volume rating alone does not establish that a particular mold will fit.

3. Review the head and station arrangement

The Tongda range includes continuous-extrusion bottle and container machines, plus accumulator-head machines for larger hollow products. Single- and double-station layouts and multiple heads are selected around the product and output requirement. Ask how the proposed arrangement affects cooling, trimming and changeover.

4. Define layers, view strips and finishing

Decide whether the application needs multiple layers or a view strip. Specify the neck finish and how flash will be removed. Include take-out, conveying, leak testing, labeling or filling interfaces in the discussion, so that these functions are designed as part of the line.

5. State the production target clearly

Describe required accepted parts per hour for a named product, weight, resin and cavity arrangement. Distinguish a dry-cycle rate from a production trial that includes extrusion, blowing, cooling and handling. Agree how rejects, stoppages and quality checks will be counted.

6. Match the factory utilities

Review the electrical supply, connected load, cooling-water requirements, compressed air, available space and material flow. Confirm the machine dimensions and maintenance access on the general arrangement drawing. Factory preparation is part of selection, not an afterthought.

7. Agree the trial and acceptance plan

Before ordering, define which product and material will be used for the trial and what evidence will be recorded. Typical project checks include product weight, dimensions, neck fit, appearance and the application’s agreed leak or load checks. The exact criteria belong in the project specification.

Where to start in the Tongda range

Your enquiry brief

Send your drawing or sample, material, volume, weight, output requirement, layer structure, neck and handle details, factory utilities and destination. Include your intended mold, auxiliary equipment and downstream line. This gives the supplier a concrete basis for the configuration and quotation.

Compare the whole project

Read the cost planning guide to compare machine, tooling, auxiliaries and services on the same basis.

Machine selection FAQ

How do I choose an extrusion blow molding machine?

Start from the product: drawing, volume, weight, resin, neck and handle. Then define the output, choose single or double station and the number of die heads, check that the mold fits the platen and clamping force, and agree the trial and acceptance plan.

What size machine do I need for a 5 L or 20 L container?

Containers up to 5 L usually run on HT, HTS or HS 5 L machines; 12–30 L containers on the 12 L, 18 L, 20 L and 30 L models; drums and large parts on TDB accumulator-head machines, from the TDB-50F (20–50 L) to the TDB-250F (200–220 L drums). The mold size and part weight decide the final choice.

Single station or double station?

A double-station machine alternates two molds under one extrusion head and suits higher output. A single-station machine suits lower volumes, larger molds and simpler projects.

When do I need an accumulator-head machine?

For large, heavy parts such as drums, tanks and panels. The accumulator stores melt and pushes out a heavy parison quickly so it does not sag before the mold closes.

What information should I send to a machine supplier?

The drawing or sample, material, volume, weight, output requirement, layer structure, neck and handle details, factory utilities and destination, plus any existing mold or downstream equipment.