Design Guide for rPET Clamshell Blister Packaging in toys and games: 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 clamshell blister packaging 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 0.30 to 0.80 mm; hinged single piece designs; full colour printed inserts. Materials most often specified are Polypropylene, Recycled PET, Polystyrene, Polyvinyl Chloride, and the choice between them changes stiffness, temperature resistance, chemical behaviour and price.

In the toys and games sector the decision is usually driven by child safety and presentation, with durability as a secondary requirement. Typical end uses include model kit trays, collector windows, game inserts.

Key Material Properties

The table below summarises the values that usually decide the material choice.

Recycled PET is frequently the default selection here: Food-grade rPET requires a recognised recycling process plus solid-state polycondensation.

Design Rules for Thermoformed Parts

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

• Leave a flat sealing flange of at least 6 mm when the pack has to be heat sealed or lidded.
• Keep the draw ratio moderate: deep cavities thin the sheet and force you to start with a thicker gauge.
• Add ribs, steps or kiss-offs instead of increasing overall gauge to gain stiffness.
• Avoid undercuts unless the tool has moving sections, which adds cost to every cycle.
• Make corner radii at least equal to the sheet thickness; sharp corners are where holes start.
• Confirm the trim method early: steel rule die, CNC router or press tool each have different tolerances.

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

• Recycled PET based: lower carbon footprint than virgin resin
• Polyvinyl Chloride based: inherently flame retardant
• Polyethylene Terephthalate based: excellent barrier to CO2 and moisture
• Polystyrene based: rigid and glossy

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

Processing method drives both cost and performance, so it should be fixed early in the design.

• Rf sealing
• Pressure forming
• Die cutting
• Vacuum forming

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 Clamshell blister packaging Correctly

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

1. test the hinge for at least 20 open-close cycles
2. avoid sharp internal corners at the hinge
3. specify the closure type and tamper evidence level
4. check the pack passes the retail drop test
5. confirm the trim method to avoid sharp edges

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

Frequently Asked Questions

How do you control colour consistency?

Colour is controlled with a masterbatch reference approved by the customer, and every production lot is checked against the approved sample under standard lighting before shipment.

Can you produce clamshell blister packaging in Recycled PET?

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 tolerance can be achieved?

Standard production tolerance follows the relevant ISO or DIN tolerance class for the process; tighter tolerances are possible after machining or grinding, but they add cost. Define the tolerance only on the functional dimensions.

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.

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

Our team supplies clamshell blister packaging to toys and games customers worldwide, with samples, material certificates and full inspection reports available before mass production.