Shingle Recycling Challenges & the Rotochopper Advantage

As the only machines designed specifically for the challenges of asphalt shingle recycling, the Rotochopper RG-1 & RG-1 E (electric-powered) offer unmatched benefits:

• Consistent uptime

• Particle size control

• Ease of maintenance & operation

Why Purpose-Built Shingle Recycling Equipment?

Like asphalt contractors and other end users of recycled asphalt shingles, we never accept "close enough"—not in the design our equipment or the relationships we form with customers. We have been manufacturing horizontal wood waste grinders (the most common non-purpose-built machine used to grind shingles) for over 15 years. But in order to offer a complete solution for the challenges of shingle recycling, we designed the RG-1 from the ground up to ensure every component was suited to the unique challenges of shingle waste.

The RG-1 relies on some of the same time-tested technology as our horizontal grinders, yet every component that comes into contact with shingle waste is designed to minimize wear costs and maximize operating efficiency.

Challenges of Asphalt Shingle Recycling & the Rotochopper Advantage

Wear

The abrasiveness of shingle surfacing granules generates significant wear, particularly for equipment not designed to process asphalt shingle waste. Some non-purpose-built machines require weekly application of hardfacing welds within the grinding chamber, involving hours of downtime.  Some grinders have wear plates that need frequent replacement. Some grinders may require major overhauls or complete replacement every 2 to 4 years.

• The RG-1’s unique design limits major wear to easily replaceable parts—no routine hardfacing or wear plate replacement. In fact, no RG-1 put in service has ever experienced wear that required major repair.

Downtime

Besides the high cost of part replacement and maintenance, wear can result in several hours of maintenance downtime each week to keep up with wear if a grinder is ill suited to the abrasive properties of shingle waste.

• The RG-1’s clamshell screen makes tooth and screen changes fast and easy. With significantly less wear and faster maintenance, the RG-1 experiences a fraction of the downtime of other machines.

Heat

Grinding shingle waste quickly generates enough heat to cause asphalt cement to begin clumping together and sticking to surrounding surfaces, increasing wear.

The RG-1 injects water directly into the grinding chamber to effectively cool shingle waste as it is being processed.  Other machines spray water onto the infeed conveyor, which does not allow uniform water application.  By injecting water into the grinding chamber, the RG-1 is able to achieve the same level of cooling with less water than competitor models. Excess water must be removed from recycled shingle prior to utilization, increasing costs for asphalt paving mix producers and other end users.

Compaction

Tear-off or factory waste shingles sitting in stockpiles can clump together, especially in hot weather, reducing grinding efficiency. Tear-off shingles may be removed from roofs in long strips rather than neat sections.

• The RG-1 features a high-torque hopper agitator and load leveller that break apart compacted shingles into an even flow before the raw material reaches the grinding chamber.

Plugging

The pliability and cohesiveness of asphalt shingles, combined with the heat of the grinding process, can cause grinding chamber plugging. Compacted bundles may instantly plug a grinder.

• The RG-1’s high-torque agitator and load leveller maintain an even flow of loose material, decreasing the risk of plugging.

Size specs

Shingle waste must be processed to 1/2" minus for most end uses, such as asphalt paving mixes or cold patch asphalt mixes.  State DOTs (Departments of Transportation) set specifications for the maximum particle size of recycled asphalt shingles for use in public roadways. Specifications of 1/2" minus (12.5 mm sieve) or even smaller are common.  Use of 5% to 7% manufacturer’s waste in an asphalt paving mix is common.  Tear-off shingles are most commonly used in private paving projects, like driveways and parking lots. Some states allow use of tear-offs in state paving projects.

• With over 5,000 square inches of screen surface, the RG-1 can achieve these demanding specs more efficiently than any other grinder.

Cellophane tabs

Once shingles are ground up, the cellophane tabs from the underside of shingles can float through the air, creating a mess and liability.

• The RG-1’s enclosed grinding chamber allows for better containment and collection of cellophane tabs.