Contents
1. What a PE Mulch Film Recycling Washing Line Is
A PE agricultural mulch film recycling washing line is a complete plant that takes used polyethylene film lifted from farm fields and turns it into clean, dry flake or finished pellets suitable for making new products. Mulch film is spread over soil to conserve moisture, suppress weeds and raise crop temperature, and after harvest it is thin, torn, loaded with earth and often partly degraded by sunlight. A washing line removes that soil, separates stones and plant matter, strips agrochemical residues, dries the material and feeds a pelletizing step. The output is a secondary raw material rather than waste, and its value depends almost entirely on how well the washing stages perform.
The difference between flake and pellet output
Some operators stop at clean flake, which can be sold to compounders or fed directly into a film blowing line with a suitable melt filter. Others add an extruder and pelletizer so the material becomes uniform granules that are easier to store, meter and sell at a higher price. A line that produces pellets typically costs 60,000 to 180,000 US dollars more than one ending at dried flake, but the product commands a stronger margin and reaches a wider group of buyers. The decision depends on local customers rather than on the machine itself.
Where the line sits in the recycling chain
The washing line is the middle of a three-part chain. Collection and baling happen in the field and at aggregation yards, washing and drying happen at the plant, and conversion into new film, pipe, injection molded parts or crates happens downstream. A well-sized washing line protects the conversion equipment by delivering consistent flake, which is why converters frequently specify the washing quality their suppliers must meet. Wanplas supplies the washing and pelletizing equipment that forms this middle stage.
2. Why Farm Used Film Needs a Dedicated Line
Used mulch film is the most difficult polyethylene film to recycle. Unlike post-industrial trim or clean post-consumer bags, it carries a very high mineral load, is exposed to weather for months, and is often contaminated with fertilizer, pesticide and crop residue. A line built for bottle flake or woven bags will not reach an acceptable ash content on this feedstock, and a line built for clean factory scrap will clog within hours. A dedicated line is engineered around the soil load rather than around the plastic.
Soil load drives every design choice
Field collected mulch film can carry 30 to 60 percent of its incoming weight as soil, sand and stones, and in dry seasons even higher. That single number determines the size of the pre-washing tanks, the capacity of the sand removal equipment, the volume of water treatment needed and the wear rate of the cutting blades. Designing for a 15 percent load when the real figure is 45 percent produces a line that is permanently overloaded. Buyers should measure their own bales before fixing the specification.
UV degradation and polymer quality
Mulch film is deliberately thin, often 10 to 30 micrometers, and is exposed to sunlight for a full growing season. Ultraviolet radiation reduces molecular weight and raises melt flow rate, so the recycled resin is stiffer and more brittle than virgin linear low density polyethylene. A dedicated line minimizes further damage by avoiding excessive thermal and mechanical stress, and the pelletizing step can add stabilizer or blend with virgin resin. Understanding the incoming polymer quality is as important as cleaning it.
Collection and baling economics
The cost of the plastic begins in the field. Lifting, gathering and baling used mulch film is labor intensive, and the material is bulky, so transport often costs more per metric ton of recoverable resin than the washing itself. A realistic budget for collection and delivery to the plant gate is 60 to 180 US dollars per metric ton of incoming bales, rising sharply when the collection radius exceeds roughly 100 kilometers. Bales also carry moisture that the buyer pays for by weight, which is why many processors specify a maximum moisture content in their purchase agreement and sample each delivery. Some operators install a simple baler and wire removal station at the aggregation yard for 20,000 to 55,000 US dollars, reducing volume before transport and cutting freight cost enough to repay the unit within two seasons. Because harvest is seasonal, a plant may need to buy most of its annual feedstock in a few months and store it under cover, which ties up working capital. Planning the collection chain together with the washing line avoids the common mistake of building a plant that is technically sound but short of material for half the year.
3. Feedstock Characteristics and Contamination Profile
Before sizing equipment, a processor should characterize the bales it will actually receive. The main variables are mineral content, moisture, film thickness, polymer type, non-film plastics, organic matter and chemical residues. Each one affects a different stage of the line, and several interact. A bale with high clay content behaves very differently from one with coarse sand, because clay stays suspended and loads the water circuit while sand settles and abrades the machinery.
| Contaminant | Typical share | Removal stage |
|---|---|---|
| Soil, sand and stones | 30 to 60 percent | Dry screening, pre-wash, sink separation |
| Crop stalks and leaves | 3 to 12 percent | Manual sorting, float separation |
| Other plastics and twine | 2 to 8 percent | Sorting, sink and float, melt filtration |
| Moisture | 5 to 25 percent | Dewatering and thermal drying |
| Agrochemical residue | Trace to 1 percent | Hot wash with detergent |
Seasonal and regional variation
Feedstock changes with harvest season, soil type and local farming practice. Bales collected after rain are heavier and carry more clay, while bales from sandy regions are cleaner but more abrasive. Lines should be sized for the worst expected bale rather than the average, and the water treatment system should handle peak clay loading. A supplier that understands this variability will propose adjustable retention times and generous settling capacity instead of a fixed nominal throughput.
Testing a bale before purchase
A simple bench test – weighing a sample, washing it by hand, drying it and weighing the recovered plastic – gives the yield figure that all the economics depend on. A representative test costs very little, perhaps 200 to 600 US dollars in labor and lab time, yet it prevents a costly mismatch between the rated line capacity and the real output. Wanplas encourages buyers to run such a test and to share the results before the line layout is finalized.
4. Line Architecture and Equipment Price List
A complete mulch film line follows a fixed logical order: bale opening and metering, dry pre-sorting, size reduction, pre-washing with sand removal, friction washing, hot washing, rinsing, mechanical dewatering, thermal drying, and optionally melt filtration with pelletizing. Each stage removes a particular class of contamination, and skipping one simply shifts the burden downstream. Water flows counter-current, so the cleanest water meets the cleanest film and the most contaminated water leaves at the first washing stage.
| Line section | Main function | Typical price |
|---|---|---|
| Bale opener and metering feeder | Breaks bales, evens out flow | 18,000 to 45,000 US dollars |
| Trommel and sorting belt | Dry soil removal, manual picking | 12,000 to 35,000 US dollars |
| Wet granulator or shredder | Cuts film to 20 to 60 millimeter flake | 20,000 to 55,000 US dollars |
| Pre-wash tank with sand discharge | Removes the bulk mineral load | 25,000 to 60,000 US dollars |
| Friction washer and hot washer | Scrubs off adhered soil and chemicals | 30,000 to 85,000 US dollars |
| Rinse, dewatering and drying | Clean water wash, moisture to low single digits | 28,000 to 75,000 US dollars |
| Water treatment circuit | Settling, filtration, recirculation | 35,000 to 110,000 US dollars |
| Pelletizing line with melt filter | Filtration, devolatilization, granules | 60,000 to 180,000 US dollars |
Throughput classes and total investment
A small 500 kilogram per hour line with basic water treatment typically costs 180,000 to 320,000 US dollars. A mid-range 1,000 kilogram per hour line with hot washing and pelletizing runs 350,000 to 700,000 US dollars. A large 2,000 kilogram per hour plant with full water recycling and automation can reach 800,000 to 1,600,000 US dollars. These figures cover equipment; buildings, site works and working capital are separate.
Layout and material flow
The line is long and mostly linear, so a straight bay of 60 to 120 meters is typical for a mid-size plant. Wet sections need drainage, containment and service access, while dry sections need dust control. Planning the flow so dirty bales enter at one end and clean pellets leave at the other prevents cross contamination and simplifies the water circuit. Wanplas provides layout guidance as part of a complete line proposal.
5. Bale Opening, Pre-Sorting and Size Reduction
Field film usually arrives as compressed bales held with wire or twine, sometimes weighing several hundred kilograms. A bale opener breaks these apart and a metering feeder delivers a steady, controlled rate to the rest of the line. Without this buffering, a granulator alternates between overload and starvation, which raises blade wear and produces uneven flake. Consistent feed is the cheapest way to improve everything downstream.
Dry screening before any water is used
Removing loose soil while the film is still dry is far cheaper than removing it from water. A rotating trommel or vibrating screen shakes out a large share of the sand and stones before washing, reducing both the water treatment load and the abrasion on wet machinery. A trommel with a screening belt costs 12,000 to 35,000 US dollars and often pays for itself within a year through lower sludge disposal and longer blade life.
Cutting strategy and blade wear
Film is cut wet or dry to a flake size of roughly 20 to 60 millimeters. Smaller flake washes more thoroughly but is harder to dewater and creates more fines that are lost in the water circuit. Because soil is abrasive, granulator knives on mulch film wear several times faster than on clean industrial scrap. Budgeting 3,000 to 9,000 US dollars a year for replacement knives and sharpening is realistic for a mid-size line, and Wanplas supplies wear parts as standard spares.
6. Pre-Washing and Sand Removal
The pre-washing stage carries the heaviest burden in a mulch film line. Its job is to detach and remove the bulk of the mineral load before the film reaches the more expensive friction and hot washing equipment. A typical pre-wash tank uses paddles or a rotating drum to agitate the flake in water, allowing stones and sand to sink to a collection cone while polyethylene floats and is skimmed forward.
Sink and float separation
Polyethylene has a density below that of water, while soil, stones and most other plastics sink. This simple difference is the backbone of the whole washing process. A well-designed tank provides enough residence time for heavy particles to settle but enough agitation to keep the film moving. Retention of 3 to 8 minutes is common, and the tank should include an automatic bottom discharge so settled grit does not accumulate and recirculate.
Handling clay and fine silt
Fine clay does not settle quickly and instead stays suspended, turning the water into a slurry that redeposits on the film. Managing it requires generous settling area, lamella clarifiers or a dissolved air flotation unit, plus a bleed stream to the water treatment circuit. A pre-wash tank with sand discharge costs 25,000 to 60,000 US dollars, while a clarifier sized for a mid-size line adds 20,000 to 55,000 US dollars. Under-sizing this step is the most common cause of a line that never reaches its ash target.
7. Friction and Hot Washing
After the bulk soil is gone, a thin layer of adhered clay, organic matter and agrochemical residue remains on the film surface. Friction washers use high-speed rotors to scrub the flake against itself and against a screen, mechanically dislodging that layer. Most lines use two friction stages in series, with a rinse between them, so loosened contamination is carried away rather than redeposited.
Hot wash chemistry and temperature
A hot washing tank typically runs at 70 to 90 degrees Celsius with a mild alkaline detergent, held for 10 to 20 minutes. Heat softens greasy residues and improves the removal of pesticide films and sticky labels. The chemical dose is modest, often 0.5 to 2 percent by water volume, and the main operating cost is the energy needed to heat and hold the bath. A combined friction and hot washing package costs 30,000 to 85,000 US dollars, with heating and insulation included.
Protecting the polymer during washing
Washing should clean the film without further damaging the already UV-weakened polymer. Excessive rotor speed or long high-temperature exposure can create fines and raise melt flow rate beyond the target range. Wanplas sets rotor speed, retention and bath temperature to match the incoming film quality, and its control system logs these values so a processor can prove the process stayed within its validated window during a production run.
8. Rinsing, Dewatering and Drying
The final wet stages remove detergent and suspended dirt, then take the flake down to a moisture level that a pelletizer can accept. A counter-current rinse uses the cleanest water last, so the film leaving the line carries almost no dissolved contamination. From there a centrifugal dewatering unit spins off free water, and a thermal dryer removes the remaining bound moisture.
Moisture targets and their cost
Centrifugal dewatering alone typically leaves 8 to 15 percent moisture, which is acceptable for some direct applications but too wet for extrusion. Thermal drying brings the figure to 1 to 3 percent at an energy cost that depends on the incoming moisture and the dryer design. Every percentage point of moisture that mechanical dewatering removes is cheaper than the same point removed by heat, so a strong centrifuge is a sound investment. A rinse, dewatering and drying package costs 28,000 to 75,000 US dollars.
Dryer types and energy use
Most mulch film lines use a hot air tube dryer or a fluidized bed dryer with a steam or electric heater and a cyclone to collect the flake. The dryer is one of the largest energy consumers in the plant, commonly 40 to 120 kilowatts on a mid-size line. Insulating ductwork, recovering heat from the exhaust and avoiding over-drying can cut this load noticeably. Energy here is a real part of the per-ton cost and should be measured rather than estimated.
Fines control and safe dryer operation
Thin mulch film breaks down more easily than rigid plastic, and every cutting, friction and conveying stage creates fine particles that can be lost with the water or the drying air. A line that ignores this can quietly lose 3 to 8 percent of its recoverable yield as fines, which directly reduces revenue. Cyclones and bag filters on the dryer exhaust recover much of this material, at a cost of 8,000 to 22,000 US dollars for a mid-size plant, and they also keep the working area free of dust. Dryer temperature should be high enough to reach the moisture target but not so high that the light film softens, agglomerates or sticks to duct walls; most lines hold inlet air well below the softening point of the resin and rely on residence time rather than extreme heat. Good housekeeping matters as much as the equipment, because accumulated polyethylene dust is combustible and should be removed on a fixed schedule. Wanplas includes dust collection and accessible clean-out points in its drying packages so that routine cleaning does not require dismantling the ductwork or stopping the line for a full shift.
9. Wastewater Treatment and Water Recycling
Washing one metric ton of dirty mulch film can consume several cubic meters of water if the circuit is open. Recirculating that water is both an environmental requirement in most jurisdictions and an economic necessity, because fresh water and discharge fees quickly dominate operating cost. A closed or semi-closed circuit treats the water, returns it to the early washing stages and discharges only a concentrated sludge stream.
Treatment stages and equipment
A practical circuit includes coarse screening, a settling or lamella clarifier, dissolved air flotation for fine suspended solids, a filter press for sludge dewatering, and clean water storage with pumps. Chemicals such as flocculant are dosed to speed settling. A complete water treatment circuit for a mid-size line costs 35,000 to 110,000 US dollars, and with good design can return 80 to 90 percent of the process water to the line.
Sludge handling and disposal cost
The soil removed from the film becomes sludge that must be dewatered and handled as a controlled waste, particularly when agrochemical residues are present. A filter press reduces volume and disposal cost, typically 15,000 to 45,000 US dollars for the unit itself. Disposal can run 20 to 80 US dollars per metric ton of sludge depending on local rules, so a processor should calculate the sludge mass arising from the expected soil load before signing a supply contract.
10. Melt Filtration and Pelletizing
Clean dried flake can be sold as a product, but pelletizing gives a more uniform, higher value material. The flake is fed to an extruder where it melts, passes through a melt filter that removes remaining fine contamination, is devolatilized to strip moisture and volatile residues, and is cut into granules. Fine filtration is what allows recycled mulch film to return to demanding applications such as film blowing or pipe extrusion.
Filtration fineness and pressure
Mulch film recycled resin needs finer filtration than bottle flake because mineral fines are small and persistent. A continuous or backflush screen changer with filtration in the range of 80 to 150 micrometers is common for general grade pellets, while film grade material may need finer screens and a larger filter area. A melt filtration and pelletizing package costs 60,000 to 180,000 US dollars, with the filter and screen changer alone at 12,000 to 40,000 US dollars.
Compounding to restore properties
Because UV exposure lowers molecular weight, many producers blend the recycled resin with virgin linear low density polyethylene or add stabilizer, antioxidant and a small amount of compatibilizer. A twin-screw compounding step with gravimetric feeders allows this to be done precisely, adding 80,000 to 220,000 US dollars to the plant. Wanplas supplies both single-screw pelletizing lines and parallel twin-screw compounding extruders, so a processor can choose a simple wash-and-pelletize layout or a full upgrading line.
Pellet testing, packaging and storage
Once granules leave the pelletizer, a short set of checks confirms that the batch meets the promised grade. Melt flow rate, ash content, moisture, bulk density and visible black specks are the usual measures, and a small laboratory setup with a furnace, a balance and a melt flow tester costs 12,000 to 35,000 US dollars to equip. Running the checks on each production lot adds roughly 40 to 120 US dollars in labor and consumables, a modest cost compared with a rejected shipment or a lost customer. Pellets are normally packed in 25 kilogram bags or 1,000 kilogram bulk bags, with an automatic bagging and weighing unit at 15,000 to 45,000 US dollars. Storage should be dry, covered and organized by lot so that a customer can be supplied with a consistent material and any question about a delivery can be answered from the production record. Because recycled resin can pick up moisture from humid air, bags are kept sealed until use and older stock is rotated forward. These simple disciplines turn a variable recycled product into a material that converters can buy repeatedly with confidence.
11. Process Parameters and Quality Targets
A washing line is controlled by a small set of measurable parameters, and the quality of the output is judged by an equally small set of targets. Holding the parameters steady is the whole job of the control system. The most useful targets are ash content, moisture, melt flow rate, bulk density and visible contamination, each of which maps back to a specific stage of the line.
| Parameter or target | Typical value | Controlled at |
|---|---|---|
| Pre-wash retention | 3 to 8 minutes | Pre-wash tank |
| Hot wash temperature | 70 to 90 degrees Celsius | Hot wash bath |
| Detergent dose | 0.5 to 2 percent | Dosing pump |
| Flake moisture after drying | 1 to 3 percent | Thermal dryer |
| Ash content of clean flake | Below 3 to 5 percent | Washing train |
| Water recirculation rate | 80 to 90 percent | Treatment circuit |
Testing the output
Ash content is measured by burning a weighed sample and weighing the residue, a test that takes a few hours and needs only a small furnace. Moisture is checked with a balance or a rapid meter. Melt flow rate requires a simple extrusion plastometer. Running these tests on each production lot costs perhaps 30 to 100 US dollars in labor and consumables, and the resulting record is what lets a processor sell into higher value applications with confidence.
Control and record keeping
A modern line records bath temperature, motor load, water flow, chemical dosing and throughput so any drift can be traced to a time and a batch. Alarm limits hold the process within its window, and the log is proof that a given lot was produced under control. Wanplas builds this logging into its line control system because traceability has become a commercial requirement as well as a technical one.
12. Output Quality, Applications and Market Value
The value of the recycled material rises steeply with cleanliness and consistency. Clean flake with low ash can be sold to compounders, while filtered and pelletized resin with controlled melt flow can go back into film, pipe or molded goods. Understanding the grades and their price bands is essential before choosing how far to take the line, because each additional stage must be justified by the price uplift it delivers.
| Output grade | Typical use | Indicative price per metric ton |
|---|---|---|
| Washed flake, basic grade | Thick sheet, pallet parts | 320 to 480 US dollars |
| Hot washed, low ash flake | Pipe, crates, injection parts | 450 to 620 US dollars |
| Filtered pellets, general grade | Bags, industrial film, profiles | 620 to 850 US dollars |
| Blended upgraded pellets | Blown film, higher value goods | 780 to 1,050 US dollars |
Matching the grade to the buyer
The best grade is not always the most profitable one. Upgrading consumes energy, additives and capital, and the price premium must cover all three. A processor with a reliable local buyer for pipe grade flake may earn more from a simple line than from a complex one chasing film grade pellets. Wanplas advises customers to confirm the target grade and the offtake before fixing the line configuration.
Common applications for recycled mulch film resin
Recycled polyethylene from mulch film is widely used in garbage bags, agricultural pipe, crates, pallets, drainage fittings and non-critical molded parts. With fine filtration and blending it can re-enter film production, often at a controlled percentage rather than as a full replacement for virgin resin. Because UV exposure has shortened the polymer chains, the material is usually blended rather than used alone in demanding applications.
13. Capacity, Utilities and Per-Ton Cost
Capacity is quoted as input of dirty bales or as output of clean flake, and the difference between the two is large because soil can account for half the incoming weight. A line rated at 1,000 kilograms per hour of input may deliver only 400 to 600 kilograms per hour of clean product. Any financial model must use the output figure and the measured yield, otherwise the projected revenue will be badly overstated.
| Cost element | Basis | Per metric ton of output |
|---|---|---|
| Collected bales | Including transport and yield loss | 120 to 260 US dollars |
| Electricity and heat | 150 to 350 kilowatt hours | 25 to 70 US dollars |
| Water, chemicals, sludge disposal | Closed circuit operation | 20 to 60 US dollars |
| Labor and maintenance | Blades, screens, wear parts | 35 to 85 US dollars |
| Equipment amortization | Over 7 to 10 years | 40 to 110 US dollars |
Payback and the variables that matter
With a selling price of 600 to 850 US dollars per metric ton and a total cost near 240 to 580 US dollars, a well-run mid-size line can reach payback in roughly two to four years. The three variables that dominate the result are the purchase price of dirty bales, the measured yield, and the grade the plant can consistently achieve. Small improvements in yield or grade are worth far more than small savings on equipment, which is why process design deserves more attention than the initial quote.
Spare parts and service budget
Wet, abrasive duty makes a planned spare parts budget essential. Knives, screens, pump seals, bearings and filter meshes are consumables, and unplanned downtime during a supply contract is expensive. Wanplas includes an annual free spare parts allowance valued at around 500 US dollars with its complete lines and keeps wear parts in stock, which helps keep the plant running through peak collection season.
Working capital and seasonal planning
Recycling farm film is a seasonal business with year-round fixed costs, so cash planning is as important as equipment selection. A mid-size plant that processes 4,000 metric tons of bales a year may need to hold three to six months of feedstock, and at 120 to 260 US dollars per metric ton that inventory can tie up 120,000 to 500,000 US dollars at peak. Covered storage with drainage and fire separation typically costs 15,000 to 50,000 US dollars to prepare, depending on whether an existing building is available. Operators also budget for electricity demand charges, insurance, water discharge permits and a maintenance reserve, which together can add 20,000 to 60,000 US dollars a year. Running the line during off-peak electricity hours, where local tariffs allow it, can trim the energy bill meaningfully because drying is a large and flexible load. A realistic financial model uses the measured yield, the seasonal purchase schedule and the confirmed selling price rather than nameplate capacity, and it is the best way to decide whether to begin with a wash-and-flake layout or invest immediately in pelletizing.
14. Wanplas Equipment Recommendations
Wanplas recommends a complete washing and pelletizing line rather than separate machines, because the value of a mulch film plant lies in how well the stages are matched. The main brand supplies each element of the chain with consistent engineering and a single point of accountability, which simplifies commissioning, spare parts and process tuning for the processor.
For the front end, Wanplas offers bale openers, metering feeders, trommels and sorting belts sized to the measured soil load. For size reduction, Wanplas wet granulators and shredders use wear-resistant knives suited to abrasive film. For the washing train, Wanplas supplies pre-wash tanks with automatic sand discharge, friction washers, hot wash baths, counter-current rinse tanks and centrifugal dewatering units, all matched to one throughput.
For drying and water management, Wanplas provides thermal dryers, settling and flotation equipment, filter presses and recirculation packages that bring fresh water demand down sharply. For the back end, Wanplas offers single-screw pelletizing lines with continuous melt filters, plus parallel twin-screw compounding extruders and gravimetric feeders when the recycled resin needs blending or upgrading.
Service and support commitments
Wanplas backs its recycling lines with commissioning support aimed at bringing a plant into stable production within about seventy-two hours of installation, remote diagnostics for fast fault finding, an annual free spare parts allowance near 500 US dollars, and an open factory where customers can witness trials using their own bales. These commitments reduce the risk that matters most when a plant depends on a seasonal supply of dirty film.
Choosing the right configuration
The practical path is to test a representative bale, fix the target output grade, confirm the offtake, and only then size the line. Wanplas works through that sequence with customers and proposes either a wash-and-flake layout or a full wash-and-pelletize plant, with water recycling scaled to local discharge rules. A single accountable partner across the whole line shortens the route from purchase to saleable output.
Frequently Asked Questions
How much soil is typical in field collected mulch film?
Soil, sand and stones commonly make up 30 to 60 percent of incoming bale weight, and can be higher in dry seasons or clay soils. This figure drives the size of the pre-wash tank, the sand discharge system and the water treatment circuit. A simple hand-wash test on a weighed sample gives the real number before equipment is ordered.
Can a bottle flake washing line process mulch film?
Generally no. Bottle lines are designed for rigid, relatively clean feedstock with low mineral load, while mulch film is thin, tangled and heavily loaded with soil. Using a bottle line leads to clogging, rapid blade wear and ash content well above target. A dedicated line with dry screening and strong sand removal is required.
What ash content can a good line achieve?
A well-designed line with dry screening, pre-washing, friction washing and hot washing typically delivers clean flake with ash below 3 to 5 percent. Reaching lower figures usually needs additional washing stages and finer water treatment, which raises both capital and operating cost. The target should match the intended application.
Is pelletizing always worth the extra investment?
Not always. Pelletizing adds 60,000 to 180,000 US dollars but raises the selling price and widens the buyer pool. If a reliable local customer pays well for clean flake, a simpler line can be more profitable. The decision depends on the offtake and the price premium, not on the equipment alone.
How much water does the line consume?
With a closed or semi-closed circuit, 80 to 90 percent of process water can be returned to the line. Consumption then becomes mostly evaporation, water leaving with sludge and occasional bleed. A complete treatment circuit for a mid-size line costs 35,000 to 110,000 US dollars and sharply reduces fresh water and discharge fees.
Why is the recycled resin more brittle than virgin material?
A full growing season of ultraviolet exposure shortens the polymer chains and raises melt flow rate. Washing cannot reverse this. Producers commonly blend the recycled resin with virgin linear low density polyethylene or add stabilizer and antioxidant during compounding to restore the properties needed for the target application.
What does a complete mid-size line cost?
A 1,000 kilogram per hour line with hot washing, water recycling and pelletizing typically runs 350,000 to 700,000 US dollars for equipment. A smaller 500 kilogram per hour line starts near 180,000 to 320,000 US dollars, while a large 2,000 kilogram per hour plant can reach 800,000 to 1,600,000 US dollars. Buildings and site works are separate.
How long is the payback period?
With selling prices of 600 to 850 US dollars per metric ton and total cost near 240 to 580 US dollars, a well-run mid-size plant often reaches payback in two to four years. The dominant variables are the price of dirty bales, the measured yield and the grade the plant can consistently achieve.
What moisture level is needed before pelletizing?
Centrifugal dewatering leaves roughly 8 to 15 percent moisture, which is too wet for extrusion. Thermal drying brings the flake to 1 to 3 percent, the usual target before feeding a pelletizer. Removing water mechanically is cheaper than removing it with heat, so a strong centrifuge is a sound investment.
Does Wanplas supply a complete line?
Wanplas supplies bale openers, trommels, wet granulators, pre-wash tanks, friction and hot washers, rinsing and dewatering units, thermal dryers, water treatment circuits, melt filters and pelletizing or compounding extruders. The main brand offers commissioning, remote diagnostics, an annual free spare parts allowance near 500 US dollars and an open factory for trials with customer bales.
Conclusion
A PE agricultural mulch film recycling washing line is a plant built around one stubborn fact: the plastic may be less than half of what arrives at the gate. Success depends on removing soil early, protecting the weakened polymer through the washing stages, treating and recirculating water, and then choosing how far to upgrade the output. Every stage has a measurable target, and every target maps to a price the material can command.
The practical approach is to characterize the bales, fix the output grade, confirm the buyer, and size the line from the measured yield rather than the nameplate input. Dry screening, generous sand removal, controlled friction and hot washing, strong mechanical dewatering and a properly sized water circuit do more for profitability than shaving the initial equipment quote. Fine melt filtration and blending then decide whether the resin returns to molded parts or to film.
Wanplas, as the main brand of a group with deep experience across plastic machinery, recommends a complete matched line rather than separate machines, because integration is where a recycling plant earns its margin. From bale opening and wet granulation through washing, drying, water treatment and pelletizing or compounding, Wanplas supports the full chain with commissioning, remote diagnostics, spare parts and an open factory. For a processor planning to turn farm used film into saleable material, a single accountable partner shortens the path from purchase to consistent, inspectable output.
