Design Guide for HDPE 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.

This guide is written for engineers, purchasers and project managers who need a practical answer, not a resin data sheet.

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 gauge 1.5 to 8.0 mm; custom cavity layouts; stack and nest geometry. 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 under body shields, line side trays, interior panels.

Key Material Properties

Typical values for a general purpose grade are listed below; filled, stabilised and speciality compounds will differ.

High Density Polyethylene is frequently the default selection here: HDPE combines toughness with chemical inertness, which is why it dominates pipe and tank markets.

Design Rules for Thermoformed Parts

Thermoforming rewards designs that respect how the sheet stretches. These rules prevent most tooling rework.

• Leave a flat sealing flange of at least 6 mm when the pack has to be heat sealed or lidded.
• Make corner radii at least equal to the sheet thickness; sharp corners are where holes start.
• Use a draft angle of at least 3 degrees per side so the part releases without vacuum locks.
• Design uniform wall thickness by avoiding abrupt depth changes in the same cavity.
• Confirm the trim method early: steel rule die, CNC router or press tool each have different tolerances.
• Keep the draw ratio moderate: deep cavities thin the sheet and force you to start with a thicker gauge.

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

• Polypropylene based: lowest density among commodity plastics
• Acrylonitrile Butadiene Styrene based: high impact toughness
• Polyethylene Terephthalate based: excellent barrier to CO2 and moisture
• High Density Polyethylene based: high impact strength even at low temperature

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.

• Cnc trimming
• Assembly
• Twin sheet forming
• 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

These are the criteria that actually predict whether the part will perform in service.

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

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

Frequently Asked Questions

Can you produce industrial dunnage and handling trays in High Density Polyethylene?

Yes. {mat1} is one of our regular materials for this item, and we can supply virgin, modified and certified grades with full traceability. Material certificates and test reports are issued per batch.

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.

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.

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.

Conclusion

If you are planning a new automotive and mobility project, send us your drawing, annual volume and target properties, and we will come back with a material proposal, a tooling plan and a budget quotation.