Design Guide for PET Slide Blister and Sleeve Packaging in electronics and electrical: 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 slide blister and sleeve 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 sleeve and tray combinations; friction fit and locked designs; hanging hole options. Materials most often specified are Polyvinyl Chloride, Polyethylene Terephthalate, Polystyrene, Recycled PET, and the choice between them changes stiffness, temperature resistance, chemical behaviour and price.

In the electronics and electrical sector the decision is usually driven by ESD protection and dimensional accuracy, with cleanliness as a secondary requirement. Typical end uses include device inserts, connector carriers, battery packs.

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

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

• 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.
• Add ribs, steps or kiss-offs instead of increasing overall gauge to gain stiffness.
• 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.

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
• Polyethylene Terephthalate based: excellent barrier to CO2 and moisture
• Polystyrene based: rigid and glossy
• Polyvinyl Chloride based: inherently flame retardant

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.

• Sleeve forming
• Printing
• Vacuum forming
• Die cutting

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 Slide blister and sleeve packaging Correctly

Use this checklist when comparing two or three supplier quotations.

1. avoid over-tight fits that split the sleeve
2. check the fit tolerance between sleeve and blister
3. test the pack after vibration and drop
4. validate hanging strength for retail
5. confirm the sleeve board grade and coating

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

Frequently Asked Questions

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.

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.

What is the minimum order quantity for slide blister and sleeve packaging?

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 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.

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.

Conclusion

Share your specification and quantity with us and we will recommend the most cost effective material, tooling route and packing method for your market.