Scrap Metal Recycling Line Design: From Feed to Finished Bale
A recycling line is a chain, and every link decides what the next one can do. The most common design mistake we see is buying machines one at a time, then discovering the shredder wants feed the shear cannot produce, or the baler expects bales the shredder cannot deliver. This article lays out the sequence we walk through with buyers planning a line — the order of decisions, and where each machine family fits.
Start With the Material, End With the Buyer
Line design runs backwards from the sale, not forwards from the machine. Two documents decide everything: your material mix (what arrives, in what condition, how contaminated) and your buyer’s specification (what fraction, what density, what contamination limit). Everything between those two documents is logistics.
Write down your three biggest material streams by weight. A line optimized for light non-ferrous looks nothing like one built for heavy demolition steel, and a mixed yard needs deliberate sorting before any machine sees material.
The Standard Sequence
Most metal recycling lines follow the same skeleton:
- Intake and sorting — grapple, magnet and manual sort separate streams before processing.
- Pre-cutting / sizing — shears reduce oversize pieces to what downstream machines can accept.
- Shredding — shredders liberate mixed material into clean, sized fraction.
- Separation — magnetic, eddy-current and screening stations split the fraction.
- Densification — balers compress loose fraction into shippable bales.
- Load-out — weighing, tagging and truck loading.
Not every line needs every stage. A yard buying clean HMS and reselling it needs sizing and load-out only. A dismantler pulling cars apart needs shredding and separation as the core. The point of the sequence is knowing which stages your material actually requires — and which machines feed each other correctly.
Where Shears Fit
Shears are the sizing stage. Heavy material — HMS, plate, section steel — goes to a gantry shear, cut into pieces the downstream can handle. Light material, rebar and short offcuts belong on an alligator shear, which can sit at the sorting line without tying up the big machine.
Pre-sizing matters more than buyers expect. A shredder fed oversized structural steel will stall, wear and eventually fail; the same shredder fed consistent pre-cut pieces runs at its rated duty. Buying the smaller pre-cutter protects the bigger machine behind it.
Where Shredders Fit
The shredder is the liberation stage: it breaks mixed material into clean fraction where separation becomes possible. Its chamber size and motor rating should be selected against the sized feed the shear delivers, not against the raw intake. A deliberate mismatch — shredder sized for pre-cut feed receiving whole structural members — is the fastest way to destroy a machine.
Downstream of the shredder, plan separation early. Magnetic separation pulls ferrous; eddy-current separation pulls non-ferrous; screening handles fines. Each station is a conveyor interface away from the shredder discharge, and planning the interface at order is vastly cheaper than retrofitting it.
Where Balers Fit
The baler is the densification stage, and it is where your line makes its margin visible. Loose fraction ships as air; the same material baled ships at density. Match baler chamber and bale size to the buyer’s specification, and match baler throughput to the shredder’s output class — a baler that cannot keep up with the shredder becomes the line’s bottleneck within a month.
For light non-ferrous, the high-density baler family reaches the density UBC and aluminum buyers pay for. For ferrous fraction, standard classes produce the bale sizes mills accept.
Sizing the Line: Three Rules of Thumb
Feed consistency beats raw capacity. A line whose every stage receives consistent material will out-produce a line with one oversized machine and irregular feed.
The bottleneck is a person, not a machine. Tying, tagging, sorting and load-out are per-bale or per-piece labor. Size the crew and the staging floor for the count, not for the tonnage rating.
Leave the interface open. Buy machines whose discharge arrangements can accept the next stage’s conveyor later. Lines grow.
Line Design FAQ
Should I buy the shredder or the baler first?
Whichever stage creates value first for your current operation. If freight cost is your pain, the baler pays first. If mixed material is piling up unsaleable, the shredder does. Then size the second machine against the first, rather than both against a wish list.
Can one line handle both ferrous and non-ferrous?
Yes, with sorting before processing. The moment streams are separated at intake, each can take its own path — ferrous to shear and heavy baler, non-ferrous to high-density baler or shredder. Mixed streams through one machine always compromise one material or the other.
What power supply does a full line need?
Each machine’s rating is published on its product page, and machines are built for your confirmed supply — 380 V, 400 V or 415 V at 50 Hz, or 60 Hz to order. Have your electrician total the connected load, including conveyors and separation stations, before ordering any single machine.
How long does it take to build a complete line?
Single machines ship in 30 to 45 days after deposit, with non-standard configurations at 60 to 75 days. A multi-machine line is planned as one order so delivery dates and commissioning sequence line up.
Do you provide layout drawings?
Yes. For line orders we supply foundation drawings, electrical schematics and a suggested layout against your site dimensions. Send a site plan with your inquiry.
Plan the Line, Then the Machines
Send us your material mix, target fractions and site plan. We will come back with a stage-by-stage proposal — including the machines you should not buy yet — within two business days, factory direct. Explore the shear, shredder and baler ranges, or contact our team to start the conversation.