Destruction Done Right

Many information destruction companies assume that because they already shred paper their existing equipment can handle product destruction tasks, equipment providers say. However, this is not always the case. "Some paper shredders are suitable for product destruction that contains metals," according to Dave Wilson, technical sales, SSI Shredding Systems Inc., Wilsonville, Ore. "But processing metals such as hard drives can cause increased wear and, at worst, severe damage to the equipment."

Companies also can overlook the fact that the lifespan of a shredder and its components is directly related to the types of materials that are run through it, says Nick Wildrick, CEO of Total Product Destruction, Spartanburg, S.C. "The majority of product destruction jobs are for materials made from soft metals and plastics, both of which will wear machines’ cutting heads down at a faster rate than paper," Wildrick says.

Chris Hawn, director of business development, Vecoplan LLC, High Point, N.C., says the strip shredder that is sometimes used in document destruction applications is limited in the types of product destruction it can handle.

Wildrick adds that strip shredders tend to have the most trouble with non-paper items, particularly if the items are round. "These items tend to get stuck between the cutting heads and the conveyor, and the small plastic particles tend to damage the belts," he says.

To avoid encountering these problems, equipment providers suggest companies think ahead and purchase a system that is suitable for the range of materials they want to process. "They need to recognize that their need for today may not be their need for tomorrow and look for the most flexible machine that will do the job," Hawn says.

The type of shredder a company purchases depends on the type of destruction it wants to do, Hawn says.

For instance, Total Product Destruction shreds a variety of materials, including plastic products, hard drives, CD-ROMs, clothing, shoes, auto parts and small appliances. Total Product Destruction currently uses a Shred-Tech two-shaft machine for large items, a Shred-Tech custom-designed system for items that contain liquid and a Vecoplan single-shaft rotary grinder for small items such as toys, DVDs and CDs.

For companies that want to shred material to a specific size, equipment providers often recommend a single-shaft shredder, which contains a single rotor and a screen on the discharge side. "It is more prevalent to find a single-shaft shredder in a recycling plant," Hawn says. "The screen makes it easier for recyclers to change the parameters of destruction without having to change the whole machine." Equipment providers recommend using the single-shaft shredder when handing materials such as textiles, fiber and film.

Sean Richter, senior technical sales representative for Shred-Tech, Cambridge, Ontario, says a two-shaft shredder is more economical for product destruction because it has more cutting force and torque when compared to a single-shaft shredder. "The single-shaft does run at a much higher speed, but it doesn’t carry as much torque and is less tolerant to metals," Richter says.

Hawn says if a recycler is looking to do a rough shred, such as defacing material, a two-shaft shredder can do the job because it is also equipped with counter-rotating rotors.

When it comes to selecting shredding equipment, Steve Spence, director of operations, American Shredding, Reno, Nev., says recyclers should look for two things: versatility and horsepower. American Shredding uses 100-horsepower shredders because they can handle various types of material, including hard drives, floppy discs, magnetic tapes and cell phones.

Spence has learned from experience that, when it comes to shredders, bigger is better. "It’s better to buy a bigger shredder because its puts pressure on you to get the material you need to feed it," he says, adding that it also allows a company room to grow.

Hawn agrees that if a recycler is going to get into product destruction, it would be wise to go with a 100-horsepower shredder because it has enough muscle to process a wide variety of materials compared to a 40- or 75-horsepower shredder.

In addition to buying a bigger shredder, equipment providers suggest recyclers consider all of a system’s available options. "Some systems require special features, such as enclosed hoppers, infeed rams, video cameras, special feed and discharge systems," Wilson says. "For example, if a recycler is planning on shredding bottles with liquids, then he needs a special discharge system to separate the liquid from the shredded container," he adds.

"If a recycler thinks he may get into abrasive products one day, then he needs to look into purchasing hard-facing rotors now," Hawn says. For companies that are unsure of what they are going to do in the future, Hawn advises getting as many options as their budgets allow. "More options give recyclers more flexibility in the future," he says.

It is also not uncommon for equipment providers to custom design a shredder for a specific application. For instance, one of Shred-Tech’s customers needed a specific knife profile to destroy military and high-profile canvas uniforms into 4-to-6-inch long pieces. "So we created a knife with a chisel-tooth hook that would stab and take little bits of material at a time so as to not overload the shredder, cause a jam-up or draw in too much material at one time," Richter says. "This specialized knife design allowed the unit to be self feeding and self regulating," Richter adds.

The only downside to the custom designed knife, according to Richter, is that the client cannot really use it for other applications, as the low-profile hook won’t capture shapes or bulky items. "There are many cases where a shredder’s cutting chamber has been specifically designed for destroying or reducing one material stream, thus making its performance on other materials less acceptable," Richter says.

One of the most important aspects of product destruction is how recyclers feed their shredders, equipment providers say. Generally speaking, material can be loaded into a shredder two ways: using an automatic infeed system (dump and run) or a hand-feed system.

Recyclers generally prefer the freedom of an automatic infeed system. "Automatic infeed systems contain sensors that can tell when its time to add more material to the hopper, which makes everyone’s life easier," Wildrick says.

Using an automatic infeed system "employees can dump 4,000 to 5,000 pounds of material onto the conveyor and just walk away," Spence says. "With a hand-feed system, one or two employees have to physically feed the shredder," he adds.

Spence also says that an automatic infeed system enables the shredder to be fed at its maximum rate. With these systems, the operator also has control over the feed rate.

The additional equipment a company needs for its shredding system depends on whether the shredded material is going to landfill or will be recovered and recycled Shred-Tech’s Richter says. "After the shredding process, material going to the landfill is put into a compactor, while the material that is recyclable is sent to the baler," Richter says.

Balers can be used to compress plastics and aluminum as well as cardboard and paper. Recyclers suggest purchasing an auto-tie baler instead of a manual-tie unit. "You can’t shred and tie off the bale at the same time with a manual tie," Spence says. "An auto tie is so much more productive." American Shredding uses auto-tie balers exclusively at the end of its shredding systems.

Once in awhile Total Product Destruction will use its auto-tie baler for product destruction as well, Wildrick says. "Sometimes we will use a baler to destroy a product such as furniture," he says. "We started to get creative after a while."

Recyclers must consider many factors before investing in shredding equipment for product destruction. They have to take into account the products they want to destroy, the style of shredder they need as well as the necessary support equipment. Recyclers have to look at the whole picture when it comes to product destruction, because purchasing the wrong machine can be a very time-consuming and costly decision.