How to reduce the cost of using an injection molding machine by using high-quality lubricants?

How to reduce injection molding machine operating costs using high-quality lubricants

An injection molding machine is used to manufacture thermoplastic parts via injection molding. Today, more than one third of the world’s single-piece polymer products are produced using injection molding machines, and more than half of the equipment used in polymer processing is dedicated to injection molding. This technology is ideal for mass production of complex shapes that require repeatable, precise dimensions.

Key takeaways

✅ In practice, the biggest costs are not the oil price, but downtime, failures and productivity loss (TCO)

✅ High-quality hydraulic fluids can support system stability, component protection and repeatable cycles

✅ Oil condition monitoring helps you act before issues become expensive failures

What is an injection molding machine?

Traditionally, injection molding machines can be divided into manual machines, where the operator starts each cycle and removes each finished part, and controlled machines where processes run automatically. Cycle time can vary significantly—thin-wall products may be made in seconds, while very heavy castings can take minutes.

In general, an injection molding machine has two main units: a plasticizing/injection unit and a clamping unit with subsequent ejection. In some cases, the machine can be equipped with additional features such as mold heating, sensor sets, CNC unit, separate drives for key assemblies, etc.

Why is proper maintenance so important?

In the plastics industry, injection molding machines are among the most valuable assets. Proper lubrication can help keep the machine running 24/7. Reducing unplanned downtime significantly increases productivity.

Using the right lubricant is an important element of effective injection molding equipment maintenance. Hydraulic oil is critical for injection molding machines and plays a key role in extending equipment life and achieving the highest cycle speed.

Effective lubrication can help reduce total operating costs through lower maintenance costs, fewer unplanned stops and improved productivity. Although purchasing a high-quality hydraulic fluid may not be a priority for some manufacturers (often just 1–2% of total operating expenses), long-term savings can be substantial.

What does correct lubrication actually deliver?

• Wear protection – helps reduce wear and corrosion, lowering failure risk.
• Longer equipment life – higher oxidation resistance supports longer operation under higher loads.
• Energy efficiency – high-quality oil maintains lubricating properties longer, which can translate into lower energy consumption.

When calculating the value of higher-quality lubricants, it’s important to consider the total cost of ownership (TCO). This calculation includes acquisition and operating costs over the entire life cycle, plus production losses caused by downtime related to failures.

Oil condition monitoring

Monitoring the condition of lubricating oil and grease in injection molding machines helps estimate the remaining service life of hydraulic oil. Regular monitoring is necessary to know when to replace the lubricant and to prevent costly and unnecessary breakdowns and downtime. In fact, poor lubricant maintenance in injection molding machines can reduce productivity by 5–20%.

Across injection molding operations—whether producing large automotive components or small parts—the priorities are the same: high product quality at the highest possible cycle speed. Because machines often run continuously, any unplanned shutdown due to equipment failure is expensive and harmful to productivity.

Practical checklist (without complex diagnostics)

• Set a consistent oil check schedule (aligned with maintenance and operating conditions).
• React to symptoms: leaks, higher operating temperature, reduced cycle stability, valve/filter issues.
• Treat oil as a system component—its condition affects machine availability.

Lubrication is critical for these machines, especially in hydraulic fluid selection. In addition to protecting moving parts (helping extend equipment life), hydraulic fluid also transmits power through the hydraulic system. In a Shell Lubricants survey, more than half of respondents did not know how lubricant selection could affect delayed or lost production, equipment availability or unplanned downtime.

Consider the importance of oils and greases

Today’s injection molding machines face increasing operational challenges linked to heavier and longer duty cycles. Maintaining peak equipment performance is critical. Typical challenges include corrosion, contamination, leaks, wear, and the formation of sludge and varnish, which may lead to issues such as stuck valves, clogged filters and worn pumps.

These failures are often attributed to the equipment rather than the hydraulic fluid. However, numerous studies by hydraulic equipment manufacturers and industry organizations have shown that 50% to 70% of equipment failures are related to an “improper hydraulic fluid condition.” It’s easy to overlook fluid importance because it is estimated to represent less than 2% of total injection molding machine operating costs.

The reality is that high-performance lubrication can deliver significant long-term savings, because improved protection helps reduce failure risk and related costs. Hydraulic fluid is the driving force of a hydraulic injection molding machine. Besides transmitting mechanical power, it should also extend machine life, reduce downtime and increase productivity and repeatable precision.

An example of an oil that improves injection molding performance is SHELL TELLUS S4 ME, which is stated to have up to 10× longer life compared to standard oils used in injection molding machines.

Hydraulic systems are expected to deliver peak performance under high pressure, temperature fluctuations and often harsh conditions. Under such demands, it pays to choose products with advanced protection and stability. Prioritizing lubrication as part of a sustainable maintenance strategy can reduce TCO—for example through shorter start-up times, lower energy use and optimized cycle times.

Fast start-up matters because it means the injection molding machine reaches optimal operating conditions sooner. If you want to see the full product group, check: TELLUS HYDRAULIC OILS.

See also: lubricants and maintenance products

If you want to move from theory to selecting specific products (industrial oils, greases, sprays, coolants, accessories, oil analysis), see:

➡️ LUBRICANTS – product categories

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Recommended examples (hydraulic oil category / reference products)

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FAQ

Can a “more expensive oil” really reduce injection molding costs?

Yes—if it improves system stability and reduces failures and downtime. In TCO, production losses and service costs often matter more than the oil purchase price.

What matters more: the oil type or condition monitoring?

Both. Product selection is the foundation, but without regular monitoring and response to oil deterioration, it’s easy to miss the moment when failure risk increases.

Which issues can be linked to oil condition?

The text highlights risks such as stuck valves and filters, worn pumps, sludge/varnish formation, leaks and contamination.

Sources

Optimize today to accelerate tomorrow – Shell Lubricants brochure.