Products Description
Light-Blocking White PVC/PVDC Films: UV Protection Combined with High Moisture Barrier for Photosensitive Actives
White PVC/PVDC blister film that blocks >99% of UV light (200–400 nm) while providing high moisture protection – designed for drugs, supplements, and foods that degrade when exposed to light or humidity.
Product Basics – What You're Getting
| Parameter | Specification |
|---|---|
| Film structure | PVC (white pigmented) + PVDC barrier coating (clear) |
| Total thickness | 200–350 µm (most common: 250 µm) |
| Color | Matte white (titanium dioxide‑based, non‑yellowing) |
| Light blocking | UV transmission <1% at 200–400 nm; visible light transmission <5% (at 250 µm) |
| Barrier | OTR ≤5 cm³/m²·day, WVTR ≤2.0 g/m²·day (typical) |
| Width | 100–1200 mm, slit to order |
| Core | 76 mm (3″) or 152 mm (6″) |
| Thermoforming | Compatible with standard blister lines (Bosch, Uhlmann, Marchesini) |
Why White Instead of Amber or Clear?
Many photosensitive actives require protection from both UV/visible light and moisture. Common options have trade‑offs:
Amber PVC/PVDC – blocks UV well but allows some visible light (10–20% transmission). Also amber color makes visual inspection of fill level difficult.
Clear with UV‑block additive – often fails to block visible light (400–700 nm), which can also degrade certain molecules (e.g., riboflavin, amiodarone).
Foil – excellent barrier and light block, but opaque (no product visibility) and expensive.
Our white PVC/PVDC – titanium dioxide pigment scatters all wavelengths. No light passes through. Yet the white background offers high contrast for print and easy inspection of tablet presence (you see a silhouette). Cost is only 10–15% above clear, far below foil.
Key Features – Designed for Photosensitive Actives
Total light block – TiO₂ loading at 12% by weight. UV‑vis spectrophotometer shows <1% transmission from 200 nm to 700 nm at 250 µm thickness. Your drug sees zero photons.
Moisture barrier from PVDC – WVTR as low as 1.5 g/m²·day, protecting hygroscopic actives (e.g., ACE inhibitors, probiotics).
No pigment migration – TiO₂ is encapsulated in PVC matrix. No dusting or transfer to sealing tools.
High whiteness retention – Non‑yellowing formulation, even after accelerated aging (60°C / 75% RH for 6 months, ΔE <2).
Good print contrast – White background makes black or colored lot numbers highly readable. Barcode scanners read easily.
Same formability as clear PVC – No change in tooling or forming parameters. Draw depth up to 12 mm.
Performance Data – Light Block & Barrier
| Property | Value | Test method |
|---|---|---|
| UV transmission (200–400 nm) | <1% | UV‑Vis spectrophotometer |
| Visible light transmission (400–700 nm) | <5% | ASTM D1003 |
| Whiteness index (CIE) | ≥85 | ASTM E313 |
| OTR (23°C, 0% RH) | 4.2 cm³/m²·day | ASTM F1927 |
| WVTR (38°C, 90% RH) | 1.8 g/m²·day | ASTM F1249 |
| PVDC coat weight | 35–50 g/m² (adjustable) | XRF |
| Haze (post‑forming) | N/A (opaque) | – |
| Seal strength (PE sealant, 140°C) | 26 N/15mm | ASTM F88 |
Thicker options for extreme light sensitivity:
300 µm: UV transmission <0.5%, visible <2%
350 µm: UV transmission <0.2%, visible <1% (pharmacy amber substitute)
Applications – Which Products Need This?
| Category | Examples | Why white PVC/PVDC |
|---|---|---|
| Photosensitive drugs | Nifedipine, nitroglycerin, vitamin A, riboflavin, amiodarone, certain antibiotics | Light degrades potency – white blocks everything |
| Hygroscopic + light‑sensitive | Probiotics (light kills bacteria, moisture activates), some ACE inhibitors | Dual protection: moisture + light |
| Pediatric supplements | Liquid vitamin D drops (unit‑dose blisters) | Prevents photodegradation during shelf life |
| Veterinary tablets | Ivermectin, fenbendazole – often stored outdoors | UV protection for tropical climates |
| Medical food / nutraceuticals | Omega‑3 softgels (prone to oxidation from light) | White reflects heat as well (keeps cooler) |
| Diagnostic reagents | Glucose test strips, lateral flow assay cartridges | Light and humidity both affect enzyme activity |
Not recommended for:
Products that must be visually inspected through the blister (e.g., coated tablets with print). Use clear with UV block instead.
Deep drawn (>14 mm) cavities – white PVC may thin at corners, reducing light block. We recommend increasing base thickness.
Quality Assurance – Light Block Consistency
In‑line spectrophotometer:
Every master roll passes through a dual‑beam UV‑vis scanner. We measure transmission at 365 nm (UVA), 450 nm (blue visible), and 650 nm (red visible).
Acceptance criteria:
A365 <1.5%
A450 <6%
A650 <6%
If any roll exceeds, it is rejected or downgraded to "industrial grade."
Pigment dispersion test:
We take cross‑sections of each batch and examine under microscope (400x). TiO₂ agglomerates >10 µm cause pinholes and uneven whiteness. Our specification: >95% of particles <5 µm.
WVTR verification for white film:
Pigment can sometimes create micro‑voids that increase moisture transmission. We test every batch on MOCON. If WVTR exceeds 2.5 g/m²·day, we recoat with additional PVDC.
Retain sample program:
We keep a 1 m² sample from each lot in a dark cabinet. You can request it for long‑term light stability correlation.
Factory & Manufacturing – White Grade Specifics
Dedicated white compounding line – No color cross‑contamination with clear or amber grades.
Titanium dioxide source – Rutile grade (not anatase), FDA‑listed, from a single supplier (Kronos or Chemours) for batch consistency.
PVDC coating on white substrate – White PVC has slightly higher surface energy; we adjust corona treatment to 48 dynes/cm for adhesion.
Cleanroom slitting – ISO 7. White films show dust easily; we use ionized air knives to remove particles before winding.
Certifications – ISO 15378 (pharma primary packaging), FDA 21 CFR 175.300 (PVC) and 177.1520 (PE sealant, if present).
Recent investment: A X‑ray fluorescence (XRF) line that measures TiO₂ concentration in real time. The control system adjusts feeder speed if whiteness drifts.
FAQ – Light‑Blocking White Film
Q1: Is the white pigment safe for direct drug contact?
A: Yes. Titanium dioxide (TiO₂) is listed in FDA 21 CFR 178.3297 (colorants for polymers). It does not migrate; particle size is >100 nm, no nanotoxicity concern. We provide a certificate of compliance with EU 10/2011 Annex I.
Q2: Can I see through the blister to check if a tablet is missing?
A: Not directly. However, the white background creates a silhouette – you see the shadow of the tablet against the white surface. For automated vision systems, we recommend backlighting. We have a white paper on vision system settings for white blisters.
Q3: Does white PVC/PVDC cost more than clear?
A: Approximately 12–18% higher due to TiO₂ and tighter QC. Much lower than amber PVC/PVDC (which uses expensive dyes) and far below foil.
Q4: How does it compare to amber film for UV protection?
A: Amber typically blocks UV (200–400 nm) but transmits 10–20% of visible light (400–700 nm). White blocks >95% of visible light as well. Some drugs degrade under visible light (e.g., riboflavin, methylene blue). Use white for complete protection.
Q5: Does the white film become brittle over time?
A: No – TiO₂ does not affect PVC flexibility. After 2 years of ambient storage, elongation remains >180%. Accelerated aging shows no embrittlement.
Q6: Can you print on the white side?
A: Yes. White is the outer layer (reverse print). We can print up to 8 colors with UV‑cured inks. The printed surface is then laminated to PVDC (or PVDC coated on the opposite side). Ask for our "print‑ready white" grade.
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