APET (amorphous polyethylene terephthalate) sheet is a widely used thermoforming substrate for pharmaceutical blister packs, unit-dose trays, and tamper-evident closures, valued for its clarity, formability, and food/pharma-grade safety profile. This guide covers how APET is engineered for pharmaceutical use, how blister forming affects moisture-barrier performance, and what regulatory references apply.
What Is APET, and Why Pharmaceutical Packaging Uses It
APET is the amorphous (non-crystallized) form of PET sheet, produced by extruding and rapidly cooling the polymer so it stays clear and thermoformable rather than crystallizing into an opaque, heat-resistant state — that crystallized version is C-PET, used instead for oven-ready trays. For pharmaceutical packaging, the amorphous structure is exactly what's needed: APET sheet forms cleanly into blister cavities under vacuum or pressure at moderate temperatures, holds a sharp cavity shape without excessive thinning, and stays optically clear so tablets or capsules remain visible for inspection.
Compared to PVC, the material long associated with blister packaging, APET offers better chemical resistance, easier recyclability as a single-polymer structure, and no chlorine content to manage in disposal. Compared to PVdC-coated or ACLAR-laminated barrier films, standard APET has a higher moisture vapor transmission rate — a trade-off addressed either by increasing sheet thickness, laminating a foil lid, or moving to a coated APET variant for moisture-sensitive formulations.
Haining Hongkai Technology produces APET sheet on two dedicated production lines at 700 tons of monthly output, supplying food-grade, anti-static, and functional-coated variants through its APET Plastic product line.
Key Material Properties for Pharma Applications
| Property | Why It Matters for Pharmaceutical Packaging |
|---|---|
| Optical Clarity | Allows visual inspection of tablets/capsules through the blister cavity without opening the pack |
| Thermoformability | Forms sharp, uniform cavities at moderate temperatures without excessive material thinning at cavity walls |
| Moisture Vapor Barrier | Determines shelf-life protection for hygroscopic or moisture-sensitive active ingredients |
| Chemical Inertness | Prevents leaching or interaction with the packaged drug product |
| Sealability | Must heat-seal reliably to foil or paper-backed lidding to form a tamper-evident closure |
| Recyclability | Single-polymer PET structure is easier to recycle than multilayer PVC/PVdC laminates |
Interactive Thermoforming Diagram & Barrier Calculator
Blister forming heats the APET sheet, draws it into a mold cavity under vacuum, then cools and trims it before sealing lidding material over the filled cavities. Adjust the settings below to see how sheet thickness and lidding choice affect estimated moisture barrier performance, then press Form to run the cycle.
Draw ratio (cavity depth ÷ cavity opening width) above roughly 0.8–1.0 risks excessive wall thinning at the cavity base; formulations with strict moisture-sensitivity limits should be verified against WVTR data measured to ASTM F1249 or USP <671> — see Sources below.
APET Variants Suited to Pharmaceutical Use
| Variant | Best Suited For | Product Page |
|---|---|---|
| Standard APET Plastic Sheet | General tablet/capsule blister cavities with standard moisture requirements | View sheet → |
| High/Low-Temperature Resistant PET Sheet | Blister packs exposed to extreme storage or transport conditions | View sheet → |
| R-PET Plastic Sheet | Sustainability-focused packaging programs using recycled PET content | View sheet → |
| BIO-PET Plastic Sheet | Bio-based feedstock programs for reduced-footprint packaging | View sheet → |
| C-PET Plastic Sheet | Rigid trays for medical devices or kits requiring heat-set dimensional stability | View sheet → |
For a full technical primer on crystallized PET as a related packaging substrate, see the site's guide on C-PET Plastic Film.
Regulatory & Testing References
Pharmaceutical packaging materials sit under a different compliance framework than general food packaging, with specific test methods for moisture barrier performance and resin food/drug contact status.
- ASTM F1249 is the standard test method for measuring water vapor transmission rate (WVTR) through plastic film and sheeting using a modulated infrared sensor, the most common method for characterizing blister-film moisture barrier.
- USP General Chapter <671> (Containers — Permeation) sets the pharmacopeial weight-gain method used to classify container moisture permeability for solid oral dosage forms.
- 21 CFR 177.1630 governs polyethylene terephthalate polymers used in articles intended for food and, by extension, pharmaceutical contact in the United States.
Haining Hongkai Technology's APET production is carried out under ISO 9001 and ISO 14001 certified quality and environmental management systems, with SGS-verified products for safety and compliance — see the About Us page for certification background.
Manufacturing Capabilities
| Metric | Figure |
|---|---|
| Founded | 2018, Jianshan New District, Haining City, Zhejiang |
| Monthly Output | 700 tons across two production lines |
| Factory Area | 24,000 m² |
| Certifications | ISO 9001, ISO 14001, SGS-verified products |
| Global Sales Reach | 60+ markets |
Custom functional films — conductive, anti-static, anti-fog, and UV-resistant — are available alongside standard APET sheet. See the full Product range, including ABS Plastic and HIPS Plastic sheet for packaging applications outside pharma.
Frequently Asked Questions
Food-grade APET sheet is manufactured to meet food-contact resin requirements such as 21 CFR 177.1630, and SGS-verified batches provide third-party confirmation of safety and compliance for packaging solid oral dosage forms.
APET generally offers better chemical resistance and easier single-polymer recyclability than PVC, though standard APET has a higher moisture vapor transmission rate than PVdC-coated PVC — a gap that's closed with thicker gauge, foil lidding, or a coated APET variant for moisture-sensitive formulations.
Yes. Conductive, anti-static, anti-fog, and UV-resistant APET variants are available, and thickness, width, and coating can be specified to match a particular blister-forming line and drug formulation.
Most solid oral dosage blister packs use APET in roughly the 250–500 micron range, with thicker gauges chosen when moisture protection or cavity depth requirements are greater.
Sources & Further Reading
- ASTM F1249 — Standard Test Method for Water Vapor Transmission Rate Through Plastic Film and Sheeting Using a Modulated Infrared Sensor
- USP General Chapter <671> Containers — Permeation, United States Pharmacopeia
- 21 CFR 177.1630 — Polyethylene Phthalate Polymers, U.S. FDA / eCFR
- About Haining Hongkai Technology Co., Ltd.
