Transparent APET (amorphous polyethylene terephthalate) sheet is one of the most widely used rigid films for clamshells, trays, blister packs, display covers and electronic carriers. It looks simple on a spec sheet, yet most complaints we hear from converters are not about the resin itself.
What Makes APET Sheet Transparent
PET can exist in an amorphous or a crystalline state. In APET the polymer chains stay disordered, so light passes through with very little scattering. That is why a clean APET sheet reads as glass-clear, while crystallized grades such as C-PET plastic sheet turn opaque or hazy in exchange for higher heat resistance.
This has a practical consequence. Clarity is a property of the molecular structure and of how the sheet is handled. Overheating during forming, long dwell times in the oven, or a contaminated surface can all reduce the clarity of a sheet that was perfectly clear when it left the extrusion line.
Standard Specifications of Our APET Plastic Sheet
The figures below are taken from our APET plastic sheets product page. Custom specifications are available for bulk orders.
| Parameter | Value | Why it matters |
|---|---|---|
| Density | 1.35 g/cm³ (±0.02) | Consistent material mass and predictable forming behavior |
| Thickness | 0.2 mm to 1.3 mm (±0.015 mm) | Tight tolerance keeps wall thickness uniform after forming |
| Width | 300 mm to 1000 mm (±1.0 mm) | Allows better nesting of cavities and less edge trim waste |
| Maximum roll weight | 550 kg (±0.5 kg) | Fewer roll changes on automatic thermoforming lines |
Choosing the Right Functional Grade: Surface Resistance Explained
A common mistake is to treat "antistatic" and "conductive" as interchangeable. They are different electrical categories, defined by surface resistance, and the right choice depends on what the sheet will carry.
| Grade | Surface resistance (Ω) | Typical use |
|---|---|---|
| Normal | ≥10¹² | Food, cosmetics, stationery, retail and tool packaging |
| Antistatic | 10⁹ to 10¹¹ | General electronic components, dust-sensitive parts |
| Conductive | 10⁴ to 10⁸ | ESD-sensitive components, ICs, circuit boards, carrier tape |
An insight that saves rework: electrical performance and optical clarity usually pull in opposite directions. A normal-grade APET sheet gives the clearest view of the product. Conductive grades rely on additives that generally reduce transparency, so if you need both full visibility and static control, discuss the trade-off with your supplier before tooling is cut. For electronics packaging, our guides on APET antistatic plastic trays and APET conductive carrier tape material go deeper into this selection.
How to Choose Sheet Thickness
Thickness is the biggest cost lever. Sheet is bought by weight, so every extra 0.1 mm adds material cost across the whole run. The key point is that the finished wall is always thinner than the sheet. Deep draws stretch the material, and corners and sidewalls can end up at a fraction of the starting gauge. Work backwards from the thinnest acceptable wall in your part, not forwards from the flat sheet.
| Application | Typical starting gauge | Main consideration |
|---|---|---|
| Carrier tape and small component pockets | 0.2 to 0.5 mm | Pocket accuracy and flatness on the reel |
| Food clamshells and shallow trays | 0.2 to 0.6 mm | Hinge and lid-snap performance, stacking strength |
| Cosmetics and retail blister packs | 0.3 to 0.8 mm | Clarity, edge appearance, sealing surface |
| Electronic component trays | 0.5 to 1.0 mm | Rigidity under load, surface resistance grade |
| Tool packaging and protective covers | 0.6 to 1.3 mm | Impact resistance and corner thickness |
These are starting points drawn from common practice, not guarantees. Confirm with a sample run on your own mold and machine.
Thermoforming Problems and Practical Fixes
APET forms at lower temperatures than many engineering plastics and has a narrow comfort zone: too cold and it stress-whitens or cracks, too hot and it sags, sticks or loses clarity. Because the glass transition of PET is only around 70 to 80 °C, finished parts also soften if stored in hot warehouses or vehicles.
| Symptom | Likely cause | What to try |
|---|---|---|
| White stress marks in corners | Sheet too cool or draw too aggressive | Raise heating slightly, increase corner radii, use plug assist |
| Hazy or dull part | Overheating, dirty or marked mold surface | Shorten oven time, clean and polish the mold, check mold temperature |
| Excess sag in the oven | Heating too long or too hot on thin gauge | Balance zone heating and reduce dwell time |
| Cracking when trimming | Dull or misaligned trim tooling, cold parts | Sharpen tooling, check alignment, trim parts while still slightly warm |
| Part sticks in the mold | Insufficient draft angle or cooling | Add draft, extend cooling, check air-eject timing |
| Dust and lint on finished parts | Static charge on normal-grade sheet | Use ionizing air, or consider an antistatic grade |
Where Transparent APET Sheet Performs Best
Food packaging. APET suits fresh produce, bakery, deli and ready-meal packaging because buyers can see the product and the sheet resists moisture and many food oils. For refrigerated items that fog up, an APET anti-fog sheet keeps the view clear. For regulatory background, read our article APET Plastic for Food Packaging. Food-contact rules differ by market (for example, FDA requirements in the United States and the EU plastics regulation in Europe), so request the compliance documents for your target market.
Electronics. Clear APET trays and APET carrier tape sheets let operators inspect components without opening the package, while the resistance grade controls static risk.
Cosmetics, stationery and tools. Clarity, printability and impact resistance make APET a strong choice for retail-facing packaging, where the sheet is part of the brand presentation. Brand teams that need tinted packaging can look at APET colored sheets.
Light-sensitive or sustainability-driven products. For products that degrade under light, see the UV-resistant APET sheet. For recycled or bio-based content goals, compare R-PET plastic sheets and BIO-PET plastic sheets.
APET Compared With Alternative Sheet Materials
| Material | Clarity | Heat tolerance | Best fit |
|---|---|---|---|
| APET | Very high | Moderate | Transparent food, retail and electronic packaging |
| C-PET | Opaque or low | High | Ovenable and hot-fill trays |
| HIPS | Opaque | Moderate | Cost-sensitive, non-transparent parts |
| ABS | Opaque | Moderate to high | Rigid structural and mechanical parts |
If your part must survive temperatures beyond what standard APET handles, look at our high-temperature and low-temperature resistant PET sheets or read the C-PET technical guide before committing to a material.
Supplier Checklist: What to Ask Before You Order
Two suppliers can quote the same gauge at different prices and deliver very different results. These questions separate them quickly:
- What thickness and width tolerances do you guarantee, and can you show inspection records?
- Which quality and environmental certifications can you document?
- For antistatic or conductive grades, how is surface resistance tested, and is it consistent across the full roll width?
- Can you provide a test sample for a forming trial before the full order?
- What are your roll weight, core size and packing options for my line?
- Can you supply food-contact documentation for my target market?
About Haining Hongkai Technology
Haining Hongkai Technology Co., Ltd. was founded in 2018 in the Jianshan New District of Haining, Zhejiang Province. We research, produce and sell PET, ABS and PS thermoforming sheets, including conductive and anti-static functional materials. Two production lines deliver about 700 tons per month, and our quality and environmental systems are certified to ISO 9001 and ISO 14001. Our APET products are also SGS certified. You can learn more on our About Us page, browse the full APET plastic range, or read the broader overview in APET Plastic Sheet: A Versatile and Sustainable Material.
Frequently Asked Questions
Is APET sheet food safe?
APET is widely used for food contact, but compliance depends on the grade, additives and the market where the packaging is sold. Request the documentation for your target market. Do not assume that a functional grade such as conductive sheet is suitable for food.
Can APET sheet be recycled?
Yes, PET is one of the most commonly recycled plastics. Recycling outcomes depend on local collection systems and on whether labels, coatings and additives are compatible with PET streams.
What is the difference between APET and PETG?
PETG is a glycol-modified copolymer that forms over a wider temperature window and is often used for deeper or more complex parts, usually at a higher price. APET is a more economical choice for most standard packaging shapes.
Can I get a sample before ordering?
Sample and trial requests can be arranged through our sales team. Please tell us the application, gauge, width and grade you need.
