1. What Is White Release Paper?

White release paper — also called a release liner or silicone paper — is a multi-layer sheet engineered to protect pressure-sensitive adhesives (PSA) and allow clean, controlled separation at the point of use. The term "white" refers to the most commercially widespread surface color, though liners are also produced in yellow, brown, blue, and transparent variants to support color-coded inventory systems or process identification requirements.

At its most basic, a release liner consists of three functional zones: a base substrate (the structural carrier), an intermediate barrier or PE coating (to control porosity and surface energy), and a silicone release layer (the functional non-stick surface). Understanding each zone is essential for specifying the right product for your process.

2. Substrate Types & Their Properties

The choice of base substrate fundamentally determines the mechanical strength, dimensional stability, moisture resistance, and processing behavior of the finished liner. Wanbaolong's PE Coated Paper & Silicon Paper Series covers the most widely used substrate families:

Table 1 — Common release liner substrate types and their primary characteristics.

3. The Role of PE Coating in Release Liners

Polyethylene (PE) coating is applied between the paper substrate and the silicone layer for two critical reasons. First, it seals the porous fiber network of the paper, preventing silicone from "sinking" into the substrate — a phenomenon that would cause inconsistent release values and silicone waste. Second, PE provides a uniform, chemically inert surface to which the silicone will bond predictably.

PE coatings are applied by extrusion at thicknesses typically ranging from 10 µm to 30 µm. LDPE (Low-Density Polyethylene) remains the most common grade due to its flexibility and adhesion to paper, while HDPE is occasionally used where higher stiffness is required. The PE layer also meaningfully improves the moisture barrier of the liner, which is especially important in humid storage and tropical shipping conditions — a critical consideration for Wanbaolong's global customer network.

One-Side vs. Two-Side PE Coating

Standard release liners use one-side PE coating (PE applied to the face that receives silicone). In certain high-performance applications — particularly where the liner must also serve as a moisture barrier on both surfaces, or where back-side printability on a PE surface is required — two-side PE coating is specified. Two-side coated liners cost approximately 15–25% more but offer superior flatness and reduced curl in humid environments.

4. Silicone Release Coatings: Chemistry & Cure Systems

The silicone layer is the functional heart of the release liner. It creates a low-energy surface that allows adhesives to wet out fully during lamination, yet separate cleanly during dispensing. The chemistry of the silicone system determines release force, anchorage to the substrate, migration resistance, and compatibility with different adhesive chemistries.

Table 2 — Silicone cure systems used in release liner manufacturing.

Modern high-performance liners — including those produced at Wanbaolong's manufacturing base — predominantly use platinum-catalyzed thermal cure systems, which deliver ultra-thin, precisely controlled coat weights and the cleanest possible release surface. This technology is critical for applications requiring zero silicone transfer (e.g., optical films and medical-grade adhesives).

5. Release Force: Specification, Measurement & Selection

Release force (measured in cN/cm or g/cm at a defined peel angle and speed) is perhaps the single most important performance parameter for a release liner. Too low a release force, and the liner may lift prematurely on roll stock or during converting. Too high, and the liner resists peeling and can damage delicate face materials or de-laminate the adhesive from the face stock.

Release force is tuned primarily through silicone formulation — specifically the ratio of reactive functional groups, the use of controlled-release additives (CRAs), and cure conditions. Wanbaolong's technical team supports customers in defining the correct release window through sample evaluation and application trials. Contact the team via wbl.fred@gmail.com or by phone at +86-19975380486.

6. Key Performance Properties of White Release Paper

Table 3 — Standard performance tests for white release paper evaluation.

7. Industry Applications & Product Selection Matrix

White release paper serves as a functional component across a remarkable breadth of industries. The full product range at Wanbaolong — spanning lightweight films, durable films, paper-based stocks, and specialty substrates — is designed to meet this cross-industry demand.

Printing & Labeling

In the label printing industry, glassine and semi-gloss release liners dominate. Paper series products provide the caliper uniformity and flatness needed for narrow-web flexo and digital inkjet presses. The liner's dimensional stability directly affects label registration accuracy — a critical factor for high-resolution barcodes and RFID inlays.

Packaging

Tamper-evident seals, resealable pouches, and lidding films all rely on release liners. Kraft-based PE-coated liners are favored for heavier-duty packaging applications due to their tear resistance, while specialty paper products address functional requirements such as anti-static or food-contact compliance.

Electronics

The electronics sector demands the highest liner precision. PET release films and CCK liners support die-cutting of tiny adhesive components for smartphones, tablets, and display assemblies. Key requirements include ultra-low silicone migration (to protect optical adhesives), tight caliper tolerances (±1 µm for film), and electrostatic dissipation (ESD). Durable film series products from Wanbaolong address these exacting specifications.

Automotive

Automotive assembly operations use release liners to protect structural adhesive tapes used for door panels, emblems, gaskets, and weatherstripping. These liners must withstand storage temperatures exceeding 60 °C, maintain release force stability over 12+ month shelf lives, and resist plasticizer migration from PVC substrates. PE-coated white kraft liners with tight or medium release profiles are the dominant specification here.

Medical Devices

Medical-grade release liners must meet biocompatibility standards (ISO 10993) and are produced under controlled contamination conditions. Silicone coat weight uniformity, absence of extractables, and sterilization compatibility (gamma, EtO, or autoclave) are mandatory. Variable information printing capability becomes important when each device liner must carry a unique serial number or lot code.

8. Customization Options

Off-the-shelf release paper covers the majority of standard applications, but many converting operations benefit from custom specifications. Wanbaolong's manufacturing capabilities support:

Table 4 — Customization parameters supported by Wanbaolong's production lines.

9. Sustainability Trends in Release Paper

Release liners have historically been a recycling challenge because the combination of silicone coating, PE layer, and paper fiber requires specialized separation. The industry is addressing this through several parallel initiatives:

Liner recycling programs now operate across North America and Europe, collecting post-use liners for pulping or energy recovery. Major brand owners in consumer goods and logistics are actively requiring their supply chains to quantify and reduce liner waste.

Liner-free label technology is gaining traction in high-volume FMCG applications, though it requires specialized presses and is unsuitable for all adhesive chemistries. For the foreseeable future, release liners remain the dominant delivery mechanism for PSA products.

Reduced-weight substrates cut both material cost and transportation carbon footprint. Thinner glassine and lightweight CCK at 60–70 g/m² are increasingly specified where mechanical requirements allow. Wanbaolong's commitment to providing eco-friendly liner options — including biodegradable and recyclable versions — reflects this market direction, as noted on the PE Coated & Silicon Paper product page.

10. Why Specify Wanbaolong White Release Paper

Zhejiang Wanbaolong Adhesive Products Co., Ltd. (formerly Shanghai Canglong), established in 2005, is a recognized manufacturer of innovative label and release materials. With a comprehensive product portfolio covering lightweight film, durable film, paper-based, specialty, and PE/silicon liner series, the company serves converting and end-user customers across a verified global distribution network.

Key reasons procurement teams specify Wanbaolong: