How to Choose a PU Pultrusion Injection Machine?

How to Choose a PU Pultrusion Injection Machine?

When choosing equipment, price isn’t everything. Here are four key areas you need to pay close attention to.

PU pultrusion injection machines can cost anywhere from a hundred thousand to over a million yuan. So how do you decide?

First, metering accuracy and stability. A ratio accuracy of ±1% is the baseline. Don’t just take the manufacturer’s word for it—go to their site and check the actual operating data. Servo-driven precision pumps, ideally imported, are a reliable configuration.

Second, the reliability of the temperature control system. Polyurethane is sensitive to temperature changes. The resin tanks, pipelines, and mixing head all need consistent temperature control. If the temperature fluctuates, the viscosity will vary, and so will the output volume—leading to unstable shots.

Third, ease of cleaning and maintenance. PU cures quickly; if you shut down without cleaning, the system will clog up. An automatic cleaning function is a must—high-pressure atomized cleaning is far more dependable than manual cleaning.

Fourth, the manufacturer’s depth of understanding of the pultrusion process. The injection machine isn’t a standalone piece of equipment; it has to work with the pulling line and the die. Whether the manufacturer truly understands pultrusion—and whether they can help you optimise the injection box design and adjust the injection parameters—matters more than the machine’s own specifications.

The PU pultrusion sector is growing fast, but many manufacturers are still making do with equipment meant for epoxy resins, or using old-style open dipping tanks. The result? Unstable product quality, high scrap rates, and low production efficiency.

If you’re currently running or planning to set up a PU pultrusion line, my advice is to think carefully about the injection machine first—it’s not an auxiliary device; it’s the heart of the operation. Watching the actual injection results and continuous running stability is much more useful than reading spec sheets.

There are no shortcuts in this industry. Choose the right equipment, and everything else will fall into place much more smoothly. Feel free to reach out if you have any specific questions—I’m happy to discuss.