Direct answer: A one-cavity crate production line molds one plastic crate per cycle on a 650–1,000 t machine with a single-cavity hot-runner mold. It fits 400×300 mm to 600×400 mm turnover boxes, runs 18–35 s cycles and produces 180 crates an hour gross at a 20 s cycle.

What the line includes

One machine, one mold, and the periphery that protects the cycle. A complete cell pairs a 650–1,000 t fast-speed injection molding machine with a single-cavity hot-runner mold, a 3-axis take-out robot, a cooling conveyor, a beside-the-press granulator, a check scale and packing. Output is set by the slowest link — usually take-out, cooling or packing, not the machine itself.

The format is growing: the plastic pallets, crates and boxes market is forecast to reach USD 37.3 billion by 2033, a 5.8% annual growth rate, according to Grand View Research.

Why one cavity beats two for crates

Clamp force scales with projected area. DKM’s rule of thumb — projected area × 250–300 bar × 1.15 — puts a 600×400 mm crate at 690–830 tf, so 650 t is the floor and 850 t is comfortable. A second cavity doubles the projected area and the mold base (to about 1,600×1,000 mm), needs a 1,300–1,450 t machine and roughly 90% more capital, for about 75% more output.

That trade only pays above roughly 1.2–1.5 million crates a year; below it, single-cavity tooling wins on capex, changeover and maintenance. The same logic carries over to foldable crate lines and pallet box lines, where mechanisms and part size limit multi-cavity tooling anyway.

The machine and the mold

The DKM-650 Victor delivers 6,500 kN of clamp, 900×900 mm tie-bar spacing, 185 mm/s injection speed and a 1,920–3,631 g shot. DKM reports cycles 25–50% shorter than standard machines, with three parallel actions — slide, closing, and mold opening with ejection — that keep non-molding movements out of the cycle.

The mold decides the rest. Crate tools use 718H or 738H pre-hardened steel, a valve-gated hot runner and directed core cooling, because cooling takes 60% or more of a crate cycle. SinoMould builds crate tools from 650 to 1,800 t with 15–20 s cycles at 2.5–3.5 mm wall, 800,000–1,000,000 cycles of mold life and about 60 working days of lead time. The reference tool on the one-cavity line molds a 50×30×25 cm turnover box in 20 seconds.

What it produces and what it costs

At 20 seconds, one cavity produces 180 crates an hour gross, 153 at 85% OEE — 3,672 per 24-hour day and about 918,000 a year. Cycle time rises with crate height: DKM’s 2017 field data shows a 600×400×350 mm crate at 35–40 s on a 650 t machine, about 2,100 crates a day.

Unit cost for a 1.6 kg PP crate is about USD 2.75, of which resin is roughly 72%. A 10% resin price move therefore changes crate cost by about 7%, while a 10% machine discount changes it by about 0.2% — which is why buyers should negotiate cycle time, OEE and scrap, not just machine price. A 650 t line with one mold, robot and auxiliaries budgets at roughly USD 210,000–360,000 factory-direct, excluding building and utilities.

Compliance: PPWR and recycled content

The EU Packaging and Packaging Waste Regulation (EU) 2025/40 applies from 12 August 2026. Article 29 requires 40% of listed transport packaging — plastic crates are named — to be reusable by 1 January 2030, and 100% on own-site and same-Member-State routes. Article 7 sets recycled content at 10% by 2030 for food-contact non-PET packaging and 35% for other plastic packaging — not the 30% beverage-bottle figure often quoted for all packaging. Food-contact crates also need an EU 10/2011 declaration of compliance, as on the beverage crate line.

FAQ

One cavity or two? One for most crates: a two-cavity 600×400 tool needs 1,300–1,450 t for about 75% more output at roughly 90% more capital.

How many crates per hour? 180 gross at a 20 s cycle, 153 at 85% OEE — about 918,000 a year.

What tonnage do I need for a 600×400 mm crate? 650 t minimum and 850 t usual for one cavity; 1,300–1,450 t for two cavities.

What does the PPWR require for plastic crates? From 1 January 2030, 40% of listed transport packaging — plastic crates are named — must be reusable within a reuse system, and 100% on own-site and same-Member-State routes. Recycled content starts at 10% by 2030 for food-contact non-PET packaging and 35% for other plastic packaging.

About DKM (Sino Group)

DKM (Zhejiang Dekumar Machinery Co., Ltd.) is a Sino Group brand based in Taizhou, Zhejiang, China. It builds fast-speed injection molding machines from 90 to 4,000 t and turnkey crate lines, with 24+ years in crate production, 1,500+ crate molds and machines, SinoMould tooling, UL 508A-certified machines and 1,600+ customers in 150+ countries. See the one-cavity crate production line and turnkey production solutions.