Design Guide for PET Industrial Dunnage and Handling Trays in automotive and mobility: Draft, Radii and Draw Ratio

Thermoforming rewards designs that respect how a heated sheet stretches. These rules prevent most tooling rework and most thickness complaints.

The notes below come from day to day production and export work with overseas buyers.

Product Overview

This category covers a family of products rather than a single item. In practice a buyer defines industrial dunnage and handling trays by three things: the base resin, the format or dimension, and the performance or certification level it has to meet. Typical options in this category include stack and nest geometry; ESD and conductive grades; custom cavity layouts. Materials most often specified are Acrylonitrile Butadiene Styrene, High Density Polyethylene, Polyethylene Terephthalate, Polycarbonate, and the choice between them changes stiffness, temperature resistance, chemical behaviour and price.

In the automotive and mobility sector the decision is usually driven by dimensional stability and heat resistance, with impact strength as a secondary requirement. Typical end uses include line side trays, interior panels, dunnage trays.

Key Material Properties

These figures are typical for commercial grades and should be confirmed against the supplier's certificate for your specific lot.

Polyethylene Terephthalate is frequently the default selection here: High IV PET resin is the reason a 1.5 L bottle can be light yet hold carbonation pressure.

Design Rules for Thermoformed Parts

A few geometry decisions made on the drawing save weeks of tooling adjustment later.

• Confirm the trim method early: steel rule die, CNC router or press tool each have different tolerances.
• Design uniform wall thickness by avoiding abrupt depth changes in the same cavity.
• Avoid undercuts unless the tool has moving sections, which adds cost to every cycle.
• Leave a flat sealing flange of at least 6 mm when the pack has to be heat sealed or lidded.
• Use a draft angle of at least 3 degrees per side so the part releases without vacuum locks.
• Add ribs, steps or kiss-offs instead of increasing overall gauge to gain stiffness.

Send these rules to your designer together with the sheet gauge and the target cycle time; most tooling modifications come from ignoring draft and corner radii.

Common Grades and Variants

• High Density Polyethylene based: high impact strength even at low temperature
• Polycarbonate based: outstanding impact strength (250x glass)
• Polypropylene based: lowest density among commodity plastics
• Acrylonitrile Butadiene Styrene based: high impact toughness

Beyond the base resin, most suppliers offer UV stabilised, food contact, flame retardant, anti-static and recycled content versions of the same product. Ask which additive package is included, because it is often the difference between a part that lasts three years and one that lasts ten.

Processing and Finishing Options

Each step below has its own control points, and skipping one of them is where most defects start.

• Assembly
• Cnc trimming
• Thick gauge thermoforming
• Welding

Secondary operations such as printing, welding, machining and assembly are often cheaper to do in the same factory, and they reduce the risk of mismatch between components.

How to Specify Industrial dunnage and handling trays Correctly

Use this checklist when comparing two or three supplier quotations.

1. specify ESD grade if electronics are handled
2. check stack load and conveyor compatibility
3. define the number of returnable trips expected
4. validate washing and drying resistance
5. design locating features that survive repeated use

Send this list to your supplier with the drawing and you will receive comparable quotations from every factory you contact.

Frequently Asked Questions

What is the minimum order quantity for industrial dunnage and handling trays?

For standard sizes and colours the minimum is usually one pallet or one production run; for custom tooling the economic minimum depends on the tooling cost amortised over the expected volume. Send us your annual volume and we will calculate the break even point.

How long does tooling and sampling take?

A new tool typically takes 25 to 45 days depending on cavity count and complexity, followed by T1 samples within one week. Existing tools can usually start production within 10 to 15 days of order confirmation.

What packing and shipping options are available?

Standard packing is export cartons on fumigation-free pallets, with custom labelling, barcode and retail packing available. We also handle consolidated containers and door to door delivery.

Do you offer samples?

Yes. Standard samples are normally free of charge and shipped within three working days; custom samples are charged at cost and credited against the first production order.

Which certifications can you provide?

We can provide ISO 9001 quality system documentation, material certificates, RoHS and REACH statements, and where applicable food contact, flame retardancy or drinking water approvals. Tell us your target market and we will match the document set.

Conclusion

Our team supplies industrial dunnage and handling trays to automotive and mobility customers worldwide, with samples, material certificates and full inspection reports available before mass production.