Getting Value from Your Machining Scrap

Last Word

Metalworking is a subtractive process. Machinists have been generating scrap metal for decades. Chips, turnings, bushy wads and contaminated coolants have been a by-product of production from belt-driven lathes to NC tape equipment in the 1970s to today’s most complex Swiss machining centers. As machine tool equipment has evolved, spindle speeds and multi-axis work have increased, causing part production to reach unprecedented efficiencies.

But how we handle our scrap stream has not changed as fast. The days of using pitch forks and simply dumping our spent coolant on the ground outside or down the drain, untreated, are gone. 

We see the trend of handling and processing these scrap streams becoming increasingly sophisticated and finding its way into smaller shops. Many are taking advantage of today’s advancements in metal chip processing and filtration equipment to reduce their liability exposure, add value to their scrap and allow the reuse of expensive coolants and cutting fluids.

A centralized, dedicated chip processing area is still ideal, and there are some exciting concepts that have been designed and are occurring right now. As motivation, a centralized chip processing system, increased scrap value, a reduction in effluent to drain, and improved housekeeping can be realized by any sized operation.

Review each individual application, and then engineer, design and build to provide application-specific solutions. Pre-processing is often needed to reduce material to “shovel grade” size and remove solids to effectively remove coolants. Customers are looking to vendors who can provide a range of crushers and shredders to accomplish this task.

Further, our wringers can reduce the moisture content to 2 percent or less by weight. This level generally is considered dry and changes the classification of the chips to a non-hazardous status, dramatically reducing liability exposure. 

In addition to wringing out the moisture from machining scrap, a briquetter can also reduce moisture content and simplify handling. We’ve seen briquetters become popular in machine shops. 

Some briquetters have received less than ideal reviews because of their problematic issues with up-time. Many of these issues are related to the hydraulics and how they are applied. Violent cycling and high decibel levels have been included in these concerns.

Our company has addressed these issues with unique, advanced hydraulic systems that allow a conversation to be carried on while standing next to a dual, opposing ram unit that has a history of success, including one unit that has more than 3,500,000 cycles without issues.

Customers now are requiring their chosen vendor to be able to handle all aspects of volume reduction, fluid removal, coolant management and wastewater treatment. Vendors must be able to offer application specific solutions to all these areas and that requires a unique integration capability. This is a capability that does not occur overnight, but rather is developed over many years of successful installations.

Look for a company with valuable integration experience, such as dry briquetting, where plants will use efficient conveying to meter feed the product into both wringing and briquetting units, producing very low moisture content before introducing the briquettes into their on-site furnace. Find out its experience with pneumatic transfer-based systems with multiple pick-up points ending with dry chips being blown directly into the back of a trailer or storage silo.

For control, the ability to recycle coolants, waste waters and other fluids are being brought in-house. Coolant reclamation and reintroduction back into the system can cut spent coolant disposal costs up to 90 percent and address concentration and bacteria control as well. A central system such as PRAB’s Guardian removes suspended particles and tramp oils that shorten the useful life of the coolant. This increases tool life and product quality, including improved surface finish, fluid life and reduces maintenance costs.

The reality of tighter federal, state and local fluid discharge regulations requires companies to adopt procedures to meet these mandates. There is money in that scrap and we are about helping you retrieve as much as possible.