Metal Forming and Stamping Lubrication
Metal forming and stamping operations require proper stock, strip, or blank lubrication to ensure part quality and long die life. Lubrication protects tools and parts from wear, galling, scoring, and scratching. Metal formers and engineers often spend a lot of time ensuring that the lubricant selected for the job is effective. However, the method used to apply the lubricant in a production environment is just as critical for ensuring success in a metal forming or stamping operation.
Methods of Lubricant Application
There are two primary methods of lubricant application: contact and non-contact. Contact means the lubricant applicator makes physical contact with the strip being lubricated and non contact means no physical contact is made. For illustration, this can be thought of as the difference between a paint roller and a paint sprayer. Each of these methods has its place, and Unist provides solutions for both.
Our contact solution, the Uni-Roller® family of products, is designed to roll a thin layer of lubricant on the sheet metal. It has metered output, which amounts to less dripping, and no overspray or over-application. The Uni-Roller® features an internally-fed roller in which lubricant is spread evenly across the width of the inside the roller. The lubricant then soaks through the felt or foam of the roller cover. When the stock material is fed through a set of rollers, the roll coater spreads the lubricant evenly onto the material. Some roll coaters externally apply a drip feed of lubricant onto the outside of the roller, but this doesn't always soak in and can drip or pool in unwanted places. Similar to a paint roller, you don't just dip and go, you squeeze the excess out and make sure the paint is saturated into the roller. Internally fed rollers are saturated in this way to prevent runs, drips and pooling, etc.
Non-contact application is sometimes essential if you need to apply lubricant to something that is not flat or if there is a fear of scratches or marks from contact. An example of this might be an automotive body panel, or other materials that have a lot of value based on surface finish and appearance. Another reason for spray applicators of metal forming lubricant is for supplemental lubrication at stations far down a long progressive die. The original lubricant might not be sufficient for an aggressive operation towards the end of a long die. Unist offers a variety of spray nozzles in both air atomized and liquid only spray versions. There are also a wide variety of mounting arrangements that can suit almost any need.
Spray lubricant application can be less expensive than a roller system initially, but a roller provides more even, uniform application of the lubricant, and prevents overspray and over-application. Rollers tend to be a much cleaner method of application. Sprayed lubricant can get pooled up in any recesses or forms on a part. Overspray can cause concerns for safety, for waste, and for workers' health. We usually recommend a roller application for the majority of the lubricant required and supplement where needed with spray.
Just as important as the method of application of the lubricant is the way it is controlled. A programmable lubricant controller is the best way to ensure that the right amount of lubricant is consistently delivered to the material. Programmable lubricant controllers can incorporate a variety of sensors to ensure all systems are operating correctly and some can even monitor the amount of lubricant consumed. Other advantages of a programmable controller are saving and recalling jobs for easy changeover, interfacing with press line control systems, and precise timing and control of the fluid dispensed.
Metal Forming and Stamping Applications
Stamping and forming operations can take a wide variety of forms. Unist's 30 years of providing lubrication solutions have made us experts in the industry and we can help with a wide variety of applications.
Coil-fed stamping refers to a continuous coil of stock that is fed into a stamping press. The coil of material, or strip, is unwound by an uncoiler and moved through a feeder into the press. Coil-fed lines are great candidates for a Uni-Roller® applicator as the material feeds into the press.
Blank-fed or sheet-fed stamping lines are stamping presses fed by individual pieces of stock. Typically a destacker, robot, or conveyor will move the blank into the stamping press. If required, a roll coating lubricator can be powered such that the lubricating rollers also pull the sheet through for easy lubrication.
Roll forming is a specific type of metal forming. A flat piece of stock material comes into the roll forming machine and is formed into the desired shape with a series of rollers. Many architectural pieces and building products are roll formed: steel studs, garage doors, garage door tracks, aluminum soffit, fascia board, metal roofing, amongst others. Proper roll forming lubrication helps extend the tool life in these situations and keeps the machines run cleaner for longer. A mix of a roller applicator and spray nozzles can create an ideal solution for applying roll forming lubricants.
This refers to supplemental lubrication applied within the stamping die after stamping, rolling or forming steps have been completed and lubricant can no longer be applied with a roller due to the shape of the product. Automating lubrication with a programmable fluid controller allows metal formers to know how much is being applied and how often.
Unist has a history of great success in the can making industry. The can making process is demanding and features very tight margins. To maintain efficient production, lubricant application must be highly accurate and tightly controlled. There is a much smaller window for the correct amount of lubrication when producing aluminum beverage cans, aerosol cans, food cans, etc, than on other parts. Unist stock lubrication solutions provide the ability for consistent, neat, and uniform application. This results in less lubricant being consumed, and fewer scrap parts coming out of the process.
Thin stock lubrication refers to lubricating the ultra-thin stock commonly formed into heat exchanger fins for the HVAC industry. This material is so thin (barely thicker than aluminum foil) that applying lubricant with rollers, roller inertia can cause it to bend or buckle. For these types of applications, Unist developed thin stock lubrication solutions. The thin stock lubricator is a contact application, however it uses stationary felt pads saturated with lubricant to wipe the lubricant on, instead of rollers to roll it on. Other applications for the thin stock lubrication system include the manufacturing of disposable aluminum containers, cooking dishes, and pans. If you work with thin material, this potentially is the solution for you.
Metal stamping facilities often use a mixture of water and concentrate for their lubricants. Sometimes the processes of mixing and supplying the fluid to the plant are overlooked as a cost-saving opportunity. If the ratio of concentrate to water is too low or the fluid is poorly mixed, part quality and die life can suffer. Using too much concentrate is wasteful and can cause issues in downstream processing. Manually mixing batches of fluid is prone to human error. Manually distributing the mixed fluid across the facility is liable to cause fluid spills and waste. With an automated fluid mixing and supply system you can be sure that the correct ratio of water to concentrate is maintained and that it will be distributed across the facility through a central piping network.
Pipe and tube bending utilizes a specialized system and bending equipment. Since it is not feasible to roll lubricant onto tube or pipe, we suggest using a spray solution to lubricate the tube, wiper, die, and mandrel. Unist has a wide variety of spray lubrication systems available that can be figured for any tube bending operation.