What Thickness for Thermoforming Trays? A Practical Guide for Packaging Buyers

Selecting the correct thickness for thermoforming trays is one of the most critical decisions in packaging design. The thickness of a plastic sheet directly affects tray rigidity, cost efficiency, forming performance, and product protection.

For manufacturers working with PET, PP, or PS sheets, even a small change in thickness—such as from 0.45 mm to 0.55 mm—can significantly impact the final tray quality and production yield.

This guide explains how to determine the ideal thickness for thermoforming trays, based on real-world packaging applications, material behavior, and manufacturing constraints.

Quick Answer: Typical Thickness for Thermoforming Trays

Most thermoformed packaging trays fall within the following thickness range:

Application	Typical Thickness
Fruit & vegetable trays	0.25–0.45 mm
Fresh food trays	0.35–0.60 mm
Bakery packaging trays	0.30–0.50 mm
Takeaway food trays	0.50–0.80 mm
Ready-meal trays	0.60–1.00 mm
Electronics blister trays	0.40–0.80 mm

In general:

0.35 mm – 0.60 mm is the most common thickness range for thermoforming trays.

However, choosing the correct thickness requires evaluating multiple factors.

Key Factors That Determine Tray Thickness

1. Product Weight

The weight of the packaged product is the primary factor influencing tray thickness.

Product Weight	Recommended Thickness
Under 200 g	0.25–0.35 mm
200–500 g	0.35–0.50 mm
500–1000 g	0.45–0.70 mm
Over 1 kg	0.70–1.00 mm

Heavier products require thicker sheets to maintain structural rigidity and stacking strength.

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2. Tray Design Depth

Deeper trays require thicker sheets because the thermoforming process stretches the plastic material.

For example:

• shallow trays → 0.35 mm may be sufficient
• deep trays → may require 0.50 mm or more

A deep draw ratio often reduces final wall thickness by 30–40%.

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3. Material Type

Different plastics behave differently during thermoforming.

PET Sheet

• Excellent rigidity
• Good clarity
• Often used at 0.35–0.60 mm

PP Sheet

• Higher heat resistance
• Lower stiffness than PET
• Often requires slightly thicker material

PS Sheet

• Good forming ability
• Lower impact resistance

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4. Machine Capability

Thermoforming machines have different heating zones and forming pressures.

Older machines may require thicker sheets to prevent forming defects such as:

• tearing
• uneven walls
• deformation

Recommended Thickness by Application

Fresh Produce Packaging

Typical trays for fruits and vegetables use 0.30–0.45 mm PET sheet.

Advantages:

• lightweight
• cost-efficient
• good transparency

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Ready-Meal Packaging

Ready-meal trays must withstand heating, transportation, and stacking.

Typical thickness:

0.60–0.80 mm

Common materials:

• CPET
• PP

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Bakery Packaging

Bakery trays prioritize clarity and appearance.

Typical thickness:

0.30–0.50 mm PET

Cost vs Thickness Optimization

Thickness directly affects packaging cost.

Example:

Thickness	Cost Impact
0.35 mm	baseline
0.45 mm	+20% material
0.60 mm	+40% material

However, reducing thickness too much can cause:

• tray collapse
• product damage
• transportation losses

The optimal approach is engineering-based thickness selection, balancing strength and material cost.

Decision Framework: How Buyers Choose Thickness

Professional packaging buyers usually follow three steps:

Step 1 – Define product weight

Step 2 – Evaluate tray depth

Step 3 – Select material

Then choose the thickness accordingly.

Common Mistakes When Selecting Thickness

Choosing thickness based only on price

Cheaper thin sheets may increase:

• rejection rates
• machine downtime

Ignoring thermoforming stretch

Final tray walls are always thinner than the sheet thickness.

FAQ

Q1. What is the most common PET thickness for thermoforming trays?

Most PET thermoforming trays use 0.35 mm to 0.50 mm sheets.

Q2. How much thickness is lost during thermoforming?

Typically 20–40% depending on tray design.

Q3. Can thinner sheets reduce packaging cost?

Yes, but excessive reduction can lead to structural weakness and higher defect rates.

Q4. What thickness is used for ready-meal trays?

Usually 0.60–0.80 mm, especially for microwaveable packaging.