Proper application of lubricant, reuse of net savings

Overapplication is easily seen in the form of puddles of lubricant on the floor, a mess on equipment, and clouds of fog in the air.

Die lubricants and other process fluids are often the last things to consider in stamping manufacturing operations. Yet they can make or break your chances of producing good coins profitably. How you use lubricants and other metalworking fluids significantly affects your housekeeping activities and can become a health, safety and environmental (HSE) concern while driving up costs in a way that many stampers do not take this into account.

By planning a proactive strategy for your lubrication process and making a few simple changes in advance, you can save money and improve your HSE program.

Supplier’s role in cost savings and HSE upgrades

So where do you find the cost savings and HSE improvements?

It starts with engagement and communication between all relevant departments, including your lubricant supplier, who can provide guidance from the earliest stages of operation. Lines of communication should be open and active with internal and external partners to ensure everyone is on the same page with respect to desired goals and budget.

Your lubricant supplier can advise you not only on the optimum lubricant for the part and operation, but also on how to eliminate excessive fluid consumption when mixing. The supplier may report improper application of lubricant; insufficient lubricant can lead to tool wear and corrosion, while too much lubricant can create slip hazards and maintenance issues. They can also explain impact costs for waste hauling or internal disposal and advise on recovery options and best practices for reuse.

Over-, under-application

Cost savings and HSE improvements typically begin when the fluid is first used in the shop. Even in today’s Industry 4.0 world, it is still common to see a press operator manually mixing lubricant on the press, resulting in over or under application. Often the practice of hand mixing can result in variations in water stretch lubricant blends up to 50% less or up to double the specified blend. What does that mean ? Beyond that, do you have a lubricant cost and process out of control? The impacts can add up quickly.

Insufficient lubricant. If you use less lubricant than specified, you will lose tool performance and corrosion protection for your parts, both costly failures. Insufficient lubrication on the tool equates to tool wear or excessive application of lubricant to compensate. A close inspection of the cost of failing corrosion protection shows the associated costs in terms of quality. Sorting and reshuffling parts also comes with a lot of hidden costs. These costs include transportation to re-deliver parts, internal meetings, and perhaps the most significant cost: lost customers.

Excessive lubrication. When it comes to applying lubricant, more is not always better. Overapplication is a huge unnecessary expense, and one that can be obvious because it’s visual as you walk around the store.

Overapplication is easily seen as puddles of lubricant on the floor, a mess on equipment, or clouds of mist in the air. This can lead to the need for additional housekeeping activities, additional cleaning of parts, wasted lubricant disposal costs, dermatitis, and other overexposure issues. All of these are a financial drain but offer no value.

To deal with excessive lube application, start by assessing why it is happening. Sometimes problems with tooling or part geometry are the underlying cause. You may be able to modify a tool that will reduce the use of lubricant and other tool maintenance. A one-time tool change can significantly reduce lubricant costs. For example, if the modification changes the lubricant mix from 20% to 10%, the cost of the lubricant is cut in half.


To the left is a properly mixed lubricant in the correct order of addition (oil last, thoroughly mixed). On the right is an improperly mixed fluid in the wrong order of addition (oil first, inadequate agitation while mixing).

There are four common reasons for overapplication:


  1. Coaching. Have the tooling and engineering groups worked with the production team to optimize lubricant application, volume, and the correct lubricant for the process? Do they apply lubricant where required by the construction of the tooling and the behavior of the part?

  2. Equipment failures. Are the mechanics of the lubrication system in good working order? Excess lubricant may indicate that application equipment needs repair. For example, it is not uncommon to see lubricant dripping from nozzles and onto the floor due to lack of check valves or too much pressure to apply it. In these cases, a significant amount of lubrication may be used to make the part, but an equal amount comes out the back of the press and onto the floor.

  3. Application material. Do you have the best application equipment for the operations to be performed? There are many choices in the application equipment market. Usually the only limit is your budget.

  4. Inattention. Sometimes the operator just doesn’t pay attention to the amount of lubricant applied, whether through lack of knowledge or a “we’ve always done it this way” attitude.

Mixing systems provide optimum dilution for application

The most effective solution for inaccurate mixing is to purchase a good quality lubricant mixing system that will provide you with years of accurate service.

Mixing systems come in many variations, but can be categorized into two common styles: the venturi, which is acceptable for thin, low-viscosity fluids, or a positive-displacement pump, for thicker, more robust fluids.

With positive displacement pump units, results tend to be much more consistent, especially with heavy duty fluids.

When you bring excessive lubricant consumption into the right range, there is no need to do complicated calculations to justify a mixer’s return on investment.

Recovery, reuse

Another area where you can save money is in refurbishment. Can you recover or recycle used metalworking fluids? These are great ways to lubricate, cool and flush a tool while reducing costs and being environmentally friendly.

However, you should not go ahead with these processes without clearly understanding the management and maintenance of the lubricants they will require. Questions you need to discuss with your lubricant supplier may include:


  • Is the product I am using suitable for recovery and reuse?

  • What filtration and clarification methods are recommended?

  • Should I use additives to control biological activity or restore corrosion protection?

  • What monitoring and testing should I follow as part of my regular program to ensure the fluid remains fit for purpose and the operators using it?

  • What is my budget to achieve this?

Keep in mind that filtration equipment can range from a simple system costing a few thousand dollars to elaborate systems costing tens of thousands of dollars. Which one you use depends on your needs and budget.

It is especially important that you have a designated person with the time, training and resources to manage your recovery/recirculation system. If not maintained properly, bioactivity can cause problems such as dermatitis and corrosion, not to mention foul odors that will make the workplace unpleasant.

Security

Finally, and perhaps most importantly, make sure you have created an effective and efficient workplace that takes into account the safety of the teams you work with and the environment. Have you done your best to minimize or eliminate the use of hazardous chemicals, such as replacing flammable solvents containing volatile organic compounds (VOCs) with non-flammable, VOC-free alternatives?

Environmental issues with metalworking fluids go beyond the handling and disposal of pure oils or water-soluble oils and synthetics. In some cases, the use of solvent-based lubricants is still necessary to efficiently produce clean, dry parts with minimal residue. When using these lubricants, reduction methods are particularly important.