A 4' x' 4' x 4' box filled with pucks at the rate of 131 pounds per cubic foot will yield a weight of 8,384 pounds per box.

Again, the maximum weight is 40,000 pounds, the usable volume is 2,025 cubic feet.  Given that pucks fill a given volume at the rate of 75% of that of solid (which we’ve already established as 131 pounds per cubic foot), a 40,000 pound load demands a volume of 305 cubic feet, which is only 15% – that's right, only 15% – of the available volume of a 2,025 cubic-foot sea container.

66.7 pounds per minute and 3.8 pounds per puck.

The 4" diameter x 4" long puck with a volume of 50.3 cubic inches, equal to 2.9% of a cubic foot, equals 75% of solid aluminum or 131 pounds per cubic foot. That puck weighs 3.8 pounds (131 x 2.9% = 3.8).
Loose wet chips at 4000 pounds per hour at 20 pounds per cubic foot in chip form yields 200 cubic feet of chips to handle per hour, which equals 66.7 pounds per minute or 3.33 cubic feet per minute.
Compared to Other Methods

While we’re not an unbiased source, our hundreds of extremely satisfied customers and hundreds of installations around the world support our position that there’s really only one way to efficiently and effectively manage machining byproducts – with Inter-Source.

We’d appreciate the opportunity to discuss your specific application requirements and share our knowledge.  We can be reached at 1-800-334-1470.

Until that discussion, here are some things to consider about other approaches.

Batch Processors, Spinners, Slingers

These devices only remove fluid.  Thus, either significant labor (and the associated cost) is required to sort, size and move the scrap, or components must be added to do so. Those components are generally one-size-fits-all and not optimized for the installation, thus compromising performance.  The case against batch spinners is well explained in the September, 1999 issue of Automatic Machining.

Pucking

There are two major reasons not to puck:

  • It has substantial fluid removal limitations among other problems.
  • Even if puckers are used simply for chip consolidation, pucking is an inefficient material handling method, as explained below.

Do the Math: An Inter-Source Case Study

When weighing the value of pucking versus Dynamic Chip Management, it’s important to understand the savings offered by an Inter-Source solution.  Let’s take a look at the following example:

The Problem

1 Loose wet chips at 4000 pounds per hour at 20 pounds per cubic foot '\n' in chip form yields 200 cubic feet of chips to handle per hour, which equals 66.7 pounds per minute or 3.33 cubic feet per minute.
Assume your facility generates 4000 pounds of aluminum chips per hour.  This is 3.33 cubic feet per minute1, the approximate volume equivalent of half of a fifty-five gallon drum – every minute.  Picture having to fill 30 fifty-five gallon drums of chips every hour; that's the process requirement.  In a typical single shift operation that means handling 240 fifty-five gallon drums of chips, every day.

The problem is the volume of chips being generated.

Pucking: One Approach
One method for handling 3.33 cubic feet per minute is to employ pucking equipment to compress those chips into pucks.  Here are some factors that will be used in determining the pucking equipment capacity required to handle the volume:

  • Pucking equipment creating a 4" diameter x 4" long puck (which is equal to 50.3 cubic inches, 2.9% of a cubic foot).
  • A solid cubic foot of aluminum weighs 175 pounds.
  • A high quality puck is equal to 80% of solid by weight.
2 The 4" diameter x 4" long puck with a volume of 50.3 cubic inches, equal to 2.9% of a cubic foot, equals 75% of solid aluminum or 131 pounds per cubic foot. That puck weighs 3.8 pounds (131 x 2.9% = 3.8).

Thus, a cubic foot of pucks has to weigh something less than 140 pounds, less because 140 pounds is actually 80% of 175 pounds of aluminum, but the weight per cubic foot will be less because the shape of the pucks prevents even and accurate filling of a cubic foot of space.  (Remember, it's a round puck filling a square space).  So, optimistically, a puck can really only yield 75% of solid, or 131 pounds per cubic foot2.

The bottom line is the pucker will have to make 18 pucks every minute3 – or one puck every 3.3 seconds.

3 66.7 pounds per minute and 3.8 pounds per puck.

The best cycle time on any pucker is about 10 seconds. In a perfect world that's only 6 pucks per minute out of a good pucker, which means at least 3 puckers operating at 100% efficiency just to keep up with the base demand.  Budgetary quotes from sales representatives suggest that one machine to puck 4,000 pounds of aluminum chips per hour could be as much as $750,000 (or multiple machines that would end up costing that much anyway).

Storage and Shipping: Another Dilemma

4 Again, the maximum weight is 40,000 pounds, the usable volume is 2,025 cubic feet. Given that pucks fill a given volume at the rate of 75% of that of solid (which we've already established as 131 pounds per cubic foot), a 40,000 pound load demands a volume of 305 cubic feet, which is only 15% - that's right, only 15% - of the available volume of a 2,025 cubic-foot sea container.

Assume someone in Asia wants those pucks (rapidly becoming the standard solution).  According to international shipping standards, regulations and requirements, the maximum amount of weight for any of the three standard size sea containers is 40,000 pounds.

If the sea container is the standard 8' x 8' x 39', a 40,000 pound load uses only 15% of the available volume4.

The same holds true if gaylord boxes are loaded into a sea container. Only 4.7 gaylord boxes will fit in a sea container before weight is made5. 

So what does this mean?

It means that pucking will cost a lot of shipping containers with a lot of empty space.

5 A 4' x' 4' x 4' box filled with pucks at the rate of 131 pounds per cubic foot will yield a weight of 8,384 pounds per box.

And because the pucks still contain some level of encapsulated fluids, some portion of the weight being shipped is retained fluids – fluids that could have been reclaimed with efficient chip processing and reused, but are now adding shipping costs and going to a vendor who doesn’t want them and is paying less for pucks because of the fluid content.

Inter-Source Dynamic Chip Management: The Best Solution

For a third of the cost of your $750,000 pucking investment, Inter-Source can provide a 40" wringer system that will handle 4,000 pounds per hour, get the chips stone dry, and load any type of container, bag or box.  This includes a shredder, wringer, a solids separator, a coolant collection/filtration tank, a transfer pump, and additional options such as:

  • a load cell/scale platform to weigh the box as it fills
  • a shrink wrap station to secure and protect the contents in the gaylord box after filling
  • a printed weight ticket to attach to each box
  • an automatic shuttle conveyor to move the full box to shrink wrapping station and then move an empty box into place.

Typically, with processing, an Inter-Source chip management solution will increase the density of the chips by at least 25%, so after processing your chips will weigh 25 pounds per cubic foot and they will be dry.

And what about shipping?

In that same sea container, 40,000 pounds of dry chips at 25 pounds per cubic foot requires 1,600 cubic feet of space, or only 79% of the volume of a 2,025 cubic foot sea container.  An Inter-Source system will make weight in a sea container that is no more than 80% full and there will never, without exception, ever be a drop of coolant left in the container.  The system will ship more volume per container and get the best value out of chip shipping costs.

When considering the most economical way to handle your chips, do the math, and it will be apparent the only solution is Inter-Source.