Self-Adhesive Constructions
How self-adhesive Flexstone is built, how the permanent PSA, removable WRA and air-release DPA adhesives differ, what the holding-power and rolling-ball figures mean, and the conditions for application and storage.
By Guangzhou Newlife New Material Co., Ltd. · Reviewed 2026-10-12
Anatomy of a self-adhesive Flexstone film
A self-adhesive Flexstone construction has three layers: the coated Flexstone face that carries the print, the adhesive, and a release liner that protects the adhesive until application. Specification sheets therefore list two thicknesses. Surface thickness is the Flexstone face alone; total thickness is the full construction. The pairing depends on the part number. In the wide-format grades, for example, a 0.22 mm S-coated face gives a 0.32 mm total and the K-coated PSA grades run 0.15 mm → 0.25 mm and 0.20 mm → 0.30 mm; in narrow-web label stock a 0.15 mm face gives a 0.23 mm total and a 0.20 mm face a 0.28 mm total. The same 0.15 mm face is therefore 0.25 mm in the wide-format grade and 0.23 mm in the label stock. All self-adhesive grades are printable on one side. The face film is chlorine-free and plasticizer-free, so there is no plasticizer to migrate into the adhesive over time.
- Three layers: coated face, adhesive, release liner
- Surface thickness = face only; total thickness = full construction
- Wide format, for example: 0.22 mm face → 0.32 mm total; K-coated PSA 0.15 / 0.20 mm → 0.25 / 0.30 mm
- Label stock: 0.15 / 0.20 mm face → 0.23 / 0.28 mm total
- One-side printable; chlorine-free, plasticizer-free face
PSA vs. WRA vs. DPA: which adhesive?
Flexstone uses three adhesives. PSA is a middle-tack permanent adhesive with medium initial adhesion and a non-carrier design; it adheres easily to mostly smooth surfaces and is not removable once fixed. WRA is a water-based, eco-friendly removable adhesive with medium tack, suitable for semi-rough and smooth surfaces. DPA is a high-tack acrylic removable adhesive applied in a dot pattern; its moderate initial tack allows repositioning, its air-release channels give bubble-free application, and it removes cleanly from smooth surfaces for up to 6 months indoors. Choose PSA when the graphic must stay, WRA for removable graphics on less-than-perfect surfaces, and DPA for large removable graphics on smooth surfaces.
- PSA — permanent, middle tack, mostly smooth surfaces
- WRA — water-based removable, medium tack, semi-rough and smooth surfaces
- DPA — dot-pattern acrylic removable, air-release, smooth surfaces
- DPA: clean removal for up to 6 months indoors
Reading the adhesion data: holding power and rolling ball
Flexstone specification sheets report two adhesion values. Static shearing, or holding power, shows resistance to a sustained load: for PSA, WRA and DPA alike, a 25 × 25 mm area hangs 0.5 kg for 24 hours without slide. Initial adhesion is measured by the rolling-ball method of GB/T 4852-2002, in which steel balls roll down an incline onto the adhesive and a larger ball number indicates higher initial tack. PSA and WRA are rated 8–10# steel ball within 100 mm; DPA is rated 6–8# steel ball within 100 mm. The lower initial tack of DPA is deliberate — it is what allows repositioning — while its holding power matches the other two.
- Holding power (all three): 25 × 25 mm hangs 0.5 kg, 24 h, no slide
- Initial adhesion, PSA and WRA: 8–10# steel ball, ≤100 mm
- Initial adhesion, DPA: 6–8# steel ball, ≤100 mm
- Test method: rolling ball, GB/T 4852-2002
Application and storage conditions
The working, application and storage conditions below are those printed on the specification sheets that list the self-adhesive grades: NMEQS-MACO 294, 295, 297, 298 and 303. Self-adhesive Flexstone should be printed and converted at 15℃ to 30℃ and 30% to 60% relative humidity. The application condition — for these grades, the environment after the material has been applied — is -20℃ to 60℃ at 20% to 80% relative humidity, with temperature variation within 30 minutes below 15℃. Apply to a clean, dry surface; PSA and DPA are intended for smooth surfaces, WRA also for semi-rough ones. Store the material in its original box, out of direct sunlight, at 10℃ to 35℃ and 20% to 70% relative humidity. Shelf life is 12 months; unfinished material should be seal-packed and used within one month. For an unfamiliar surface, test adhesion and removal on a small area first.
- Working condition (self-adhesive grades, NMEQS-MACO 294, 295, 297, 298, 303): 15–30℃, 30%–60% RH
- Application condition (after application; not a process limit): -20℃ to 60℃, 20%–80% RH, temperature change below 15℃ within 30 minutes
- Storage: 10–35℃, 20%–70% RH, original box, no direct sunlight
- Self-adhesive grades on those sheets: shelf life 12 months; seal-pack unfinished material and use it within 1 month
- Test unfamiliar surfaces on a small area first
Wide-format adhesive rolls vs. narrow-web label stock
The same part number can describe two different products. FS-K15-PSA-80G and FS-K20-PSA-80G appear both as wide-format rolls for wide-format UV inkjet (50 m × 1270 or 1370 mm, total thickness 0.25 and 0.30 mm) and as narrow-web label stock (210 to 510 mm wide, total thickness 0.23 and 0.28 mm) for offset, flexographic and UV label presses. Always state the width and the printing process when ordering. For sheet-fed digital label work, FG-I15-PSA and FG-I20-PSA are supplied in 460 × 320 mm and 480 × 330 mm. For large removable display graphics, the DPA Eco-Film grades are supplied in 1270, 1370 and 1524 mm widths.
- Wide-format K-PSA rolls: wide-format UV inkjet, 1270 / 1370 mm, total 0.25 / 0.30 mm
- Narrow-web label stock: offset / flexo / UV, 210–510 mm, total 0.23 / 0.28 mm
- Digital press PSA sheets: FG-I15-PSA, FG-I20-PSA
- State width and printing process when ordering