August 22, 2007 | General

What's New? Baggers And Blenders

BioCycle August 2007, Vol. 48, No. 8, p. 45
Product blending and packaging equipment can be an essential part of multiple product offerings at a composting facility.
Craig Coker

COMPOSTERS understand that offering multiple compost-based products is an important tactic in establishing reliable and expanding product market share. Multiple product offerings expand sales to new customers, increase brand loyalty by widening the choices available to existing customers, and can dampen the seasonal fluctuations in straight compost sales. Compost-based products now in the marketplace include: Potting soils and container mixes for horticultural production; Growing media for green roofs, bioretention storm water ponds, constructed wetlands and sports turf; Erosion and sediment control filters; Vegetated support layer soils for sanitary landfill closures; and Tailored soil mixtures for specific landscaping plants. Each of these products is a blend of different ingredients. Most are sold in bulk, but some – particularly horticultural and landscaping products – are sold in bags.
For the most part, these are large-volume markets with high repeat sales potential. These markets demand consistent quality over time and across large volumes, arguing against the time-tested method of blending soil ingredients with a bucket loader or a trommel screen. Supplying bagged products to markets is always a trade-off between manual and automated processing.
This month’s What’s New? series looks at new developments in soil blending and product bagging equipment, as reported by manufacturers responding to a survey sent out by BioCycle editors. The comparisons that follow are presented for general information only and are based entirely on information supplied by each manufacturer. Claims and information presented have not been independently verified. Contact information for manufacturers of equipment described are in the accompanying Baggers and Blenders Directory.
Methods of soil blending frequently used by composting facilities include (in order of increasing consistent product quality): bucket blending with a front-end loader, alternating ingredients in the hopper of a trommel screen (and then reblending the layered fines that fall out), and layering the ingredients on the pad and using a windrow turner to mix the ingredients together. While these methods work, the materials handling nature of blending makes it difficult to ensure each mix has the right proportions of ingredients and that all ingredients are thoroughly commingled and mixed.
As with other types of equipment used in composting, technologies are available, at a cost, to deal with these shortcomings of traditional blending techniques. Soil blending equipment is similar to compost feedstock mixing equipment (see sidebar), in that it is based on some form of rotating machinery (i.e. augers, rotary drum with paddles, etc.) to mix. Blenders can be either stationary or mobile equipment. Unlike feedstock mixing equipment, some soil blending equipment comes with individual hoppers for storing and metering ingredients into the mix.
Some types of raw material mixers, such as the equipment featured in What’s New? Mixers (July 2007), have been used for soil blending. Both Roto-Mix and Kuhn Knight mixers have been used for this application, according to the manufacturers. Steps need to be taken to eliminate the potential for cross-contamination of finished product with raw waste. As soil blends are generally heavier than feedstocks (on the order of 200-600 lbs/cy heavier), there are limits on how much can be blended at a given time, and the unit must have enough horsepower to move heavier material. The manufacturer of the mixer should be consulted before using it to blend soils to be sure the machine is loaded and operated properly within its design limits.
Dakota Blenders, Inc.’s Model 2250 Hydro 3-hopper mobile blender is a five-stage homogeneous blender with a 300 RPM paddle mixer run by an 80 horsepower diesel engine and two 10 cubic yard (cy) separate metering ingredient hoppers. (A third hopper for ingredients in 1-2 ton totes is also available.) Depending on the ingredients being blended, the machine can process 150 to 275 tons/hour (for soil blends tons per hour and cubic yards per hour are roughly equivalent). The machine comes with a stacking conveyor that can pile mixed ingredients to 12 feet. There is a pintle hitch for transport with a smaller truck capable of towing 18,000 lbs. In addition to manufacturing blending equipment, Dakota also offers custom on-site blending (for approximately $3.50/ton), has an accredited soils lab that can test ingredient mixes, and manufactures a line of turf topdressing equipment. “Dakota Blenders builds and maintains their own blenders,” says Robin Dufault, Blending Manager. “We are backed by our own manufacturing capabilities, which greatly reduces equipment downtime.”
Bouldin & Lawson offers both batch and continuous soil blending equipment. The batch mixers, Twister I and Twister II, are ribbon blenders with 2 cy hoppers. Twister I has either 3 hp or 5 hp single- or three-phase motors, whereas Twister II has a 7.5 hp single- or three-phase motor. Both batch mixers can be outfitted for portability with either 8-inch casters or 14-inch tires and pintle hitch. Continuous blending products are the MixMaster 10 and MixMaster 25 mixing systems. The former can process 10 cy/hour while the latter can handle 25 cy/hour. These units are driven by 220V single- or three-phase electric motors. Options available with these systems are computer controls for fast recipe changes, extra hoppers, and lengthwise and crosswise agitators. Bouldin & Lawson also can customize a continuous mixing system for particular applications.
Several previous articles in BioCycle have discussed the issues and rationale behind decisions to start bagging compost-based products (see “Expanding Markets With Bagged Products,” March 2006, “Bagging And Blending Compost Products,” June 2005 and “Should We Make The Bagging Investment,” March 2003 – all available at Considerations that affect the decision whether or not to get into bagging include the size of the market being targeted (big box stores versus local lawn-and-garden centers), the flow character of the material to be bagged, and the value of those bagged products.
Once the decision has been made to get into bagging, the most frequent question posed is “Should it be a manual or automated system?” Besides the obvious difference in costs, other considerations are repetitive motion injuries by workers, automating downstream processes like palletizing and moving bagged material (automating only filling and bagging can overwhelm manually-operated downstream processes), and the number of different types of products being bagged (fewer numbers of different products favors automated production). “If you’re running more than 20 SKUs (stock keeping units), you should consider running manual or semiautomated versus automated,” says Fred Schumpert of Creative Packaging. “Mechanical and programming changes needed to deal with a lot of different bag sizes can defeat the benefits of automated bagging.” For the purposes of this article, “manual” systems are those that rely on labor to move bags through the filling and sealing cycle (even if motorized features are used to fill, seal or stack bags); “automatic” systems are completely machine-driven.
Amadas Industries offers both manual and automatic bagging systems. Manual bagging lines include: BF01 Bulk Feeder; 248 Infeed Conveyor; BG03 Bagger, BC02 Upright Bag Conveyor; Crown Machine’s MCT Hot Air Sealer; PL02 Palletizer; and Lantech Q300 Stretch Wrapper. Amadas automated bag lines use the same BF01 Bulk Feeder and 248 Infeed Conveyor, but substitute the Amadas BF04 Bagger (set up for customer’s choice of available Form, Fill, and Seal (FFS) machine and/or Automated Palletizer). Bag options vary from 4 quarts (5 lbs.) to 3 cubic feet. Average throughput on an Amadas manual bagging line will be between 18 and 22 bags/minute, depending on the product and how quickly the operator can hang the bags. On automated equipment, the average production rate will be about 22 to 24 bags/minute. Capital costs for a manual bagging system are on the order of $150,000 (not including delivery or set up), whereas for a fully automated system, costs will be $300,000 to $450,000.
“Manual bagging operations usually require three to five workers to operate,” notes Tiny Andrews with Amadas. “This includes one to hang the bag, one to shake the product down in the bag, one to seal the bag and one to stack the bags on a pallet. This will usually cover production rates up to 15 bags/minute (bpm). Once you pass the 15 bpm rate, you will probably need to add two employees to the number of people required to run the line. These two people would be one to either guide the bag through the sealer or shake the bags to settle the product. The second worker would assist in bag stacking at the palletizer. As for automated equipment, it usually requires one to two people to monitor the functions of the form, fill, and seal machine and the automated palletizer. In addition to the employees mentioned above, there also are an outside loader operator and forklift operator to consider.”
Bouldin & Lawson offers bagging equipment in addition to the soil blending line described above. The Model 170 Soil Bagger is a manual bagging system. The Soil Bagger will fill bags from 8 quarts to 3 cubic feet. This system includes a 4 cy material hopper, lengthwise and crosswise agitators, a 5 hp hydraulic power unit, variable speed drive and PLC controls. The Model 18553 Mulch Bagger has a rotary drum that works like a water wheel. It combs the rough mulch into an even flow for bagging. The electric-drive system will allow the operator to fill as many as 18 bpm. Bouldin & Lawson also offers bulk soil feeders in 2.6, 4, and 10 cy capacities. Each unit can be used as feed hoppers for continuous soil mixing lines, potting machines, or flat fillers; bulk media is supplied at required levels. Units may be powered by hydraulic or electric controls. Each hopper features bed roller construction to reduce friction and extend the life of the belt and drive mechanism. The full skirting reduces excessive spillage and dust. An adjustable soil gate directs material flow. Optional pieces of equipment include: bag carrying conveyor, hot air sealer, bag kicker, bag flattening conveyor, elevating platform, and palletizing carousel.
Creative Packaging is marketing a new European-designed, automatic bagging system – the B&C Models CV-3080 and 3125. The vertical FFS systems can handle up to 1800 bags/hour (depending on volume), and can be integrated with automatic palletizing and pallet wrapping or stretch hooding systems. Form-fill-seal is a technique for making bags using poly films, either mono layer or laminates. In vertical FFS systems, the film is drawn around a forming tube and longitudinal and transversal heat seals are made after the product filling cycle. Unique features of this packaging system are minimization of product bridging, due to higher moisture composts, and the ability to handle side-gussetted bags for more uniform palletizing.
The B&C stationary soil mixing units, which can be interfaced directly with the B&C vertical FFS, consist of a rotary drum mixer with small shovels that mixes ingredients like composts, fertilizers, soils, perlites, etc. Three different soil recipes can be mixed simultaneously, with self-cleaning belts to wipe conveyor belts clean between each recipe delivered to in-line packaging systems, all of which are computer controlled. Each blending hopper features either screw or adjustable speed belt dosers, with reversible direction for rotation. The mixing line typically features three to five 8 to 12 cy volumetric hoppers, with two to three smaller electronically-weighed fertilizer/sand dispensers.
Hamer, LLC is the originator of automated horizontal FFS bagging. They introduced this technology almost 20 years ago as a more efficient, less costly system that also provides the highest throughput of any automated bagging systems. The Hamer product line includes the Model 60 10 cy live bottom bulk hopper; Model 3040 bulk in-feed conveyor; Model 300VF volumetric filler/manual bagger; Model 2080 horizontal FFS bagging machine; and Model 4200 transfer conveyors. For fully automated systems – including automatic palletizing and wrapping – Hamer offers the Fanuc M-410ib Series palletizing robot. For conventional palletizing, the Mollers line of fully automatic palletizers and stretch hooders is available. Cost of Hamer systems run from $70,000 to $150,000 for automatic bagging only to $400,000 to $500,000 for fully automated systems. The Model 2080 is capable of producing up to 1,800 bags/hour.
For manual bagging systems, the Hamer Model 300VF Manual bagger is among the newest innovations in bagging equipment. Introduced two years ago, the 300VF is designed to eliminate maintenance that causes bagging downtime. It uses a leveling wheel instead of chains, and has variable speed drives in place of clutch brakes, eliminating the potential for failures associated with brakes. The control package provided is UL-certified and features a solid state, low voltage design. When automating a manual line, the 300VF adapts for use with the Hamer Model 2080 FFS machine. Manual bagging systems run from $30,000 to $90,000, depending on the amount of equipment provided.
When considering manual or automated bagging, Dan Brown of Hamer notes that service support is critical to maximizing the purchaser’s investment. “While equipment cost is an important consideration, parts availability, easy access to field trained technicians and fast efficient start up are just as important.”
Premier Tech Systems can be a one-stop shop for a compost producer, from the bulk product to the wrapped pallet. Premier Tech makes a full line of mixing, fixed screening, feeding, bagging, palletizing and wrapping equipment. It also markets equipment previously sold by Les Machineries Verville. A bagging system might consist of a VF-2000 Volumetric Feeder, a FFS-200 Horizontal Form-Fill-Seal Bagger, an AP-400 High Level Bag Palletizer and a LW-400 Rotary Arm Stretch Wrapper. All of the equipment in this system is fully automated and can be operated by one person.
The VF-2000 Series is equipped with product level detectors and a 2-speed belt conveyor driven through a pneumatic clutch-brake. “The new VWF-3000 Feeder will increase the level of accuracy of products being fed to the bag,” notes David Lévesque of Premier Tech. “It is able to weigh and measure at the same time.” The FFS-200 Series baggers can fill bags of different sizes with a variety of products. It is designed to handle 30 to 32 bpm of 40-lb compost bags, 20 to 25 bpm for 3 cubic foot mulch bags, or 28 to 30 bpm for 1 cubic foot soils bags. The range of capital costs for a Premier Tech system is $100,000 to $150,000 for the bagging equipment only, and around $500,000 for a whole packaging line (feeder, bagger, palletizer, wrapper). These fully automated systems are feasible for production levels starting at 800,000 bags/year and can go up to 4.5 million bags/year and even higher if a plant is running two shifts/day, according to Lévesque.
Rotochopper has become well-known for producing high performance grinders for compost and mulch. In 2000, the company introduced its first mobile bagging machine, the Go Bagger 1000. The current models include the GoBagger 250, a manual bagging machine that is entirely mobile and self contained. It can be fed with a skid steer loader and includes a 5,000 lb. trailer, 2.5 cy hopper, bagging jaws, impulse bag sealer, and computerized controls for filling by volume or by weight. A positive feed conveyor at the bottom of the hopper delivers the material to the bagging head. Options include digital scales, diesel engines and continuous high-speed bag sealers. The GB250 can be set up to fill and seal plastic, burlap or nylon bags. Bagging speeds from 250 bags/hour up to 600/hour are possible. The unit enables a company to enter the bagged product market with a minimum level of effort or capital. It is being used most commonly to bag mulch, compost, sand, rock and small grains.
The Sandbagger Corp. offers two manual bagging machines: the Multibagger, for bagging compost, mulch, manure, sand, small stone, pea gravel and topsoil; and the Sandbagger, for sand, pea gravel and small stone. The 2,200-lb. Multibagger features a 2 cy steel hopper, an 11 hp gasoline engine and three filling stations that release the material into the bags by a foot control. The Multibagger can accommodate bag sizes from one to three cubic feet. The bag sits on a platform under the chute; the machine is designed to fill a bag every 10 seconds. With three employees at the filling stations, the unit can bag up to 1,000 bags/hour depending on the material being bagged and the bag size. Capital costs for the Multibagger are around $25,000; the smaller Sandbagger (which operates similarly) runs $5,000 to $18,000 depending on the number of feed chutes and an optional auger motor. Accessories include sealers, conveyors, bag stitcher, mechanical or electronic scales, safety shield, electric or hydraulic bag vibrator, and towing package. The Multibagger is also available from Morbark, Inc. in Winn, Minnesota.
Craig Coker is a Contributing Editor to BioCycle and a Principal in the firm of Coker Composting & Consulting in Roanoke, Virginia. He can be reached at (540) 904-2698 or by email at
Amadas Industries
1100 Holland Rd.
Suffolk, VA 23434
(757) 539-0231
Bouldin and Lawson LLC
P.O. Box 7117
McMinnville, TN 37111-7117
(800) 443-6398
Creative Packaging Inc.
820 Scenic Highway, Suite 500
Lookout Mountain, TN 37350
(423) 825-5311
Dakota Blenders, Inc.
P.O. Box 14088
Grand Forks, ND 58208
(701) 746-4300
Hamer, Inc.
14650 28th Ave. N
Plymouth, MN 55447-4821
(800) 927-4674
Kuhn Knight
1501 W. Seventh Ave.
Brodhead, WI 53520
(608) 897-2131
Les Machineries Verville
1835 Power
Drummondville, QC, J2C 5X4 Canada
(819) 477-3135
Morbark, Inc.
8507 S. Winn Road
P.O. Box 1000
Winn, MI 48896
(800) 831-0042
Roto-Mix LLC
2205 E. Wyatt Earp Blvd.
Dodge City, KS 67801
Premier Tech Systems
1, Avenue Premier
Rivière-du-Loup, QC G5R 6C1
(418) 868-8324
Rotochopper Inc.
217 West Street
P.O. Box 295
St. Martin, MN 56376
(608) 452-3651
The Sandbagger Corp.
P.O. Box 607
Wauconda, IL 60084
(815) 363-1400

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