Recycled PET (rPET) Injection Pallet Project: How to Size the Mould and Injection Machine (Practical Guide)

If you have recycled PET (rPET) feedstock and you are considering injection moulded pallets, the biggest challenge is not “can it be done”, but “how to size the mold + injection machine correctly befo

Many projects start with:

you have stable recycled material supply (tons per day)

you don’t have injection machines yet (or you are not sure what tonnage to choose)

you need a clear estimate for CAPEX, output/day, and the key technical risks (especially with recycled material)

This article is written for project owners, recyclers, and operations teams who want a practical path from rPET pellets to injection pallet production.

What we do:

We are a mold maker in China. For pallet projects using recycled material, we help you define the mold concept and size the injection machine together, so you can estimate investment and productivity clearly. If you need machines, we can also assist sourcing suitable injection machines in China.

Step 1: Decide the pallet direction (simple but critical) Most projects fall into one of these directions: A) Rackable pallet (for racking): higher strength requirement, usually heavier, more structural ribs, higher clamp force.

B) Nestable pallet (stacking only): lighter, space-saving, generally lower strength requirement than rackable.

If you are not sure, don’t worry. Start with your target application:

Will it be used on racking systems? If yes, treat it as rackable.

Is space saving (nesting) important? If yes, consider nestable.

Is it for export one-way logistics (single-trip)? That often targets lower weight.

Step 2: The 4 key inputs we need (to size mould + machine) To avoid guessing, the fastest way is to confirm these 4 items first:

Pallet size and type Typical sizes: 1100×1100, 1200×1000, 1200×1200 (but any size is possible). Type: rackable / nestable / hygienic (solid top) / mesh / legs structure.

Target pallet weight OR load rating If you already know target weight (kg), that is perfect. If not, tell us your load rating target: Static load / Dynamic load / Racking load (if applicable).

rPET material information (even partial is OK) If you have it: IV or MFI, moisture level, contamination level, any additives. If you don’t have data: tell us the feedstock source (bottle grade, mixed, flakes-to-pellet, etc.) and your filtering/cleaning process.

Target output/day How many pallets per day do you want to produce? (Or pallets per hour) Also helpful: shift hours per day (e.g., 16h/day, 24h/day).

With these 4 inputs, we can recommend:

Injection machine tonnage range + shot size range

Mold concept (cavity, gating, runner concept)

Estimated cycle time range + output estimate

A pilot line option vs. a scaled production option

Step 3: Quick output sense-check (so you can talk CAPEX internally) A simple way to translate “tons/day of material” into “pallets/day” is:

Pallets/day ≈ (Material kg/day) ÷ (Pallet weight kg)

Example: If you have 12 tons/day = 12,000 kg/day: If pallet is 15 kg → about 800 pallets/day If pallet is 20 kg → about 600 pallets/day

This is a rough reference only. Real output depends on:

cycle time (affected by design, cooling, rPET stability)

scrap rate (affected by contamination and process control)

actual run hours/day

But this quick math helps you and your team estimate project scale and ROI early.

Step 4: rPET-specific risks (and how to control them) rPET can be injection moulded, but large pallets are unforgiving products. The most common risks are:

Moisture causing hydrolysis (strength drops) If rPET is not dried properly, it can degrade during processing. For large parts, this becomes very noticeable in impact strength and long-term durability. Control: proper dehumidifying dryer, stable drying process, controlled moisture. Also keep material handling closed and clean.

Contamination (black specks, weak points, inconsistent flow) Mixed feedstock or insufficient filtration increases defects and weak spots. Control: better filtration, stable pellet quality, and clear incoming material standards.

Brittleness / low impact strength Some rPET can be brittle, especially if the chain length is degraded. Control: design reinforcement (ribs, structure), consider impact modification strategy if required, and validate by sample trials.

Warpage (large flat surfaces) Pallets are large. Cooling and shrinkage must be balanced. Control: mold cooling design, gate location strategy, uniform wall thickness, and process stabilization.

Practical note: For recycled material projects, a pilot validation step can save you a lot of cost. We often recommend starting with a pilot mould concept and sizing one machine first, then scaling after material + process is confirmed.

Step 5: Mould concept options (what changes investment and output) For pallets, the mould concept is usually driven by:

pallet size and weight

target output

your machine capacity

Common approaches: Option A: One cavity mold (most common for large pallets) Pros: lower complexity, easier process control, easier to validate rPET, stable quality. Cons: output depends heavily on cycle time.

Option B: Multi-cavity (less common for full-size pallets; more common for smaller trays) Pros: higher output per cycle. Cons: higher mould complexity, higher machine requirements, harder to balance with recycled material variability.

Gating and runner concept: For large pallets, gate strategy affects fill balance and warpage. The “best” option depends on design. We propose concept based on your pallet type and strength requirements.

Step 6: How to size injection machine for pallet moulding (simple rules) To recommend the injection machine, we look at:

clamp force requirement (tonnage)

shot size requirement (injection volume/weight)

machine configuration for rPET (drying, feeding, stable control)

What we need from you to size it quickly:

pallet weight target (or estimated weight)

pallet size and structure

your target cycle time expectation (if any)

If you don’t have a machine yet: We can provide a machine sizing range and a recommended configuration list. If you want, we can assist sourcing suitable machines in China. If you prefer buying locally in Australia, the sizing recommendation still helps you choose correctly.

Step 7: Recommended project workflow (fast and realistic) Here is a practical path from “idea” to “production”:

Confirm pallet type + size + load target

Choose mold concept and estimate pallet weight

Size injection machine range and auxiliary equipment (especially drying)

Pilot validation (material + process)

Finalize mold design and machine specification

Tooling build + trial + sample approval

Scale to production line

Two clear paths we offer (choose what fits your plan) Path A: Mold only If you already have machines or you plan to source machines locally, we focus on mold design, build, and trials.

Path B: Mold + assist sourcing injection machines in China If you need machines, we can support machine selection and sourcing in China, aligned with the mold and your recycled material conditions.

Call to action (WhatsApp) If you want us to size the mold and injection machine for your rPET pallet project, send the following 4 items on WhatsApp:

Pallet size (L×W×H) and type (rackable or nestable)

Target pallet weight OR load rating (static/dynamic/racking if applicable)

rPET info (IV/MFI if available, moisture/contamination level)

Target output/day (pallets/day, or tons/day with run hours)

Message us on WhatsApp: +86 139 5762 3391. Tip: You can simply send “CHECKLIST”, and we will reply with a 1-page quick sizing checklist you can share internally.

FAQ: Q1: Can rPET be used for injection pallets? Yes, but quality stability and drying/process control are critical. The feasibility depends on your rPET quality and the pallet performance requirement.

Q2: I have rPET supply but no injection machines. Where do I start? Start with pallet spec and load target, then size the mould concept and machine range to estimate CAPEX and output.

Q3: Can you only supply the mold? Yes. We can supply mould only, and we can also assist machine sourcing if you want.

Q4: What information do you need first? Pallet size/type, target weight or load, rPET info, and target output/day.

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