New or Used Blow Molding Machine? How to Decide

A used blow molding machine can cost much less than a new one, and for some projects that is the right choice. But the purchase price is only part of the cost of making containers. This guide compares new and used extrusion blow molding machines and gives a checklist for inspecting a used one.

New vs used at a glance

	Used machine	New machine
Purchase price	Lower	Higher
Condition	Depends on age, hours and maintenance history	Known, built for your product
Molds	Existing molds may not fit your containers	Molds made for your product
Parison and wall thickness control	Often an older controller with fewer points	Current controller, matched to the container
Energy use	Older hydraulic drives without energy saving	Choice of hydraulic, servo or fully electric
Spare parts and support	Depends on whether the maker still supports the model	Supplied by the manufacturer
Installation and training	Usually arranged by the buyer	Commissioning and operator training by the manufacturer

What wears out on a blow molding machine

• Screw and barrel. Wear lowers plasticizing output and makes melt temperature less stable, which shows up as uneven walls and higher scrap.
• Die head. Scored or worn die parts cause streaks and uneven parisons; parison control depends on a die head in good condition.
• Hydraulic system. Leaks, worn pumps and tired valves slow the cycle and make clamping and blowing less repeatable.
• Electrical and control system. Old controllers, heaters and sensors fail more often, and replacement parts for discontinued models can be hard to find.
• Molds. Molds wear at the pinch-off and cooling channels, and a mold for someone else’s container rarely matches your product.

Energy use over the machine’s life

Electricity is a large part of the cost of every container. Among the energy-saving options for blow molding machines, servo drives give the largest saving, and the saving grows with machine size, as explained in how to choose the right extrusion blow molding machine. Many older used machines have none of these options, so compare the energy use per hour for your own container, not only the price. See the servo and fully electric series.

Checklist for inspecting a used machine

1. Ask for the year of manufacture, running hours and maintenance records.
2. See it running with your material, or a similar container, and weigh the parts for consistency.
3. Check the screw, barrel and die head for wear, and the heaters for faults.
4. Look for hydraulic leaks and listen to the pump under load.
5. Confirm the controller works and that spare parts are still available.
6. Check that the platen size, clamping force and die head suit your container.
7. Agree who will dismantle, ship, install and commission the machine.

When each choice makes sense

A used machine can suit a short-term project, a product you are testing on the market, or a buyer with experienced technicians who can rebuild worn parts.

A new machine suits long-term production, containers that need precise wall thickness such as jerry cans and chemical drums, clean production, and buyers who want molds, commissioning and spare parts from one supplier.

Compare new machines

Browse Tongda blow molding machines by container size, read what drives blow molding machine price, or see the 12 checks before buying a blow molding machine from China.