Egg Tray Machine Sizing: Mold Count, Cycle Time and Drying Cost

Most first-time buyers start with "how much for a 48-mold machine?" — and that is the wrong first question. Price follows output, and output is decided by three numbers working together: cavities per mold, cycle time, and how fast you can dry the wet tray. Get those three right and the quote makes sense. Get them wrong and you buy a machine that either sits idle or runs your dryer crew into overtime.

1. Mold count alone tells you almost nothing

A 32-cavity reciprocating machine and a 32-cavity rotary machine do not produce the same tonnage. The difference is cycle time — forming, transfer and demolding in one pass. On a semi-automatic reciprocating unit we normally see 45–70 seconds per cycle; on a rotary multi-mold machine with PLC control, a station pass runs 25–40 seconds. Same mold, roughly double the output.

So when a supplier quotes you "48 molds, 6000 pcs/h", the honest follow-up is: at what cycle time, with what pulp consistency, and counting rejects or not.

2. Run this calculation before you contact anyone

Output (pcs/h) = cavities * 3600 ÷ cycle time in seconds.

Example: 4 cavities, 60-second cycle → 4 * 3600 ÷ 60 = 240 pcs/h, about 1,900 trays in an 8-hour shift after changeover and cleaning. That number, not the mold count, is what you sell to your egg farmers every morning.

Compare that against our paper egg tray making machine range and the numbers line up: the small units are genuinely small — do not let anyone sell you a 1,000 pcs/h machine as a 3,000 pcs/h machine by quoting a cheerful wet-tray weight.

3. Drying is where the money actually goes

A freshly formed tray leaves the mold at 70–75 g with roughly 55% moisture. Sell it like that and it collapses in the stack; you need it down to about 10%. Three ways to do it:

• Sun drying — cheapest on paper, 24–48 hours, 3–5% breakage, and one week of monsoon rain means your line stops while your orders keep coming.
• Drying room with hot air — 4–6 hours, moderate fuel cost, good compromise for 1,000–2,000 pcs/h plants.
• Tunnel / multi-layer dryer with boiler — 2–3 hours, breakage typically under 1%, and the only option that keeps a 3,000+ pcs/h line honest through the rainy season.

Budget the dryer as part of the machine, not as an accessory. In most projects the energy bill over three years is bigger than the difference in purchase price between a cheap dryer and a properly insulated one.

4. Pulp preparation: the numbers buyers forget

For a 6,000 pcs/h line you are chewing through roughly 450 kg of waste paper and 1.35 tonnes of water per hour at 1–1.5% pulp consistency. Two practical consequences:

• Return-water recycling should recover around 80%. Without a settling tank and a clean return line, you will be buying water and paying for effluent.
• Paper quality matters more than brand names. Mixed office waste forms faster; heavily printed newsprint needs longer pulping and gives a softer tray. Send us 20 kg of your local waste paper and we will run a forming test on it before you commit to a mold design.

5. Floor space and shipping reality check

A 48-mold line with a 28–35 m dryer loads into about seven 40ft containers and needs a workshop of at least 1,000 m² with 200 kW available at the panel. Check your transformer before you check the price list — upgrading a site supply costs more than the machine in some countries. If you are tight on space, the small egg tray making machine range fits a 150–200 m² shed and still produces saleable trays from day one.

6. Five questions to ask before you wire a deposit

1. What is the guaranteed output at 1.2% consistency, measured over a 4-hour run — not the theoretical maximum?
2. Which parts are cast iron, which are aluminium, and what is the mold life in cycles? (Mold replacement is your largest recurring cost.)
3. What fuel does the dryer burn locally, and what is the consumption per 1,000 trays at that calorific value?
4. How is the PLC wired for your voltage — 380V/50Hz, 415V/50Hz or 440V/60Hz — and who supplies the transformer?
5. What is the commissioning plan: who pays for the engineer's flight, visa and how many days of training are included?

A supplier who answers these with numbers has built machines before. One who answers with adjectives has not.

FAQ

How many trays per hour can a 4-mold machine really make?

Around 700–1,000 pcs/h at a 50–60 second cycle, with one operator feeding pulp and two stacking. Anything above 1,200 pcs/h from four cavities means the cycle claim is optimistic.

Can I add molds later instead of buying a bigger machine?

On reciprocating frames, usually yes — the frame and mold plate are designed with spare stations. On rotary machines, adding cavities changes the vacuum and drive balance, so it is better to choose the right size up front.

Egg trays only, or can the same machine run fruit trays and cup trays?

Same machine, different mold. Buyers in apple and mango regions often start with egg trays and add a fruit tray mold in year two; the production line pulley and drying racks stay unchanged.

How long does installation take?

A semi-automatic line: 5–7 days including pulp system and trial run. A 48-mold line with tunnel dryer: 20–30 days with a two-man team, plus foundation curing time before that.

What warranty do you actually honour?

Two years on the frame and drive, one year on electricals, with spare molds and vacuum pumps held in stock for shipment within 72 hours. Jinan Wanyou has been building pulp molding machines since 2003 and exports 70–80% of its output — the machines you see in our factory videos are the same ones we ship.

Written by the engineering team at Jinan Wanyou Packing Machinery Factory. If you send us your daily tray target, local waste paper type and the fuel available on site, we will size the line and send a capacity table rather than a price list.