Saint-Gobain CHR SG23-10(R) is a pressure-sensitive adhesive tape constructed from a primary woven fiberglass fabric coated with polytetrafluoroethylene and combined with a crosslinked acrylic adhesive. The parenthetical R in the commercial designation identifies the release-liner-supplied roll format; the underlying SG23-10 backing and adhesive construction remains unchanged. This construction is specified where a dimensionally stable, electrically insulative, non-stick release surface is required on heated platens, heat-sealing bars, and wire-harness separation points. The woven glass phase limits elongation under tension, while the PTFE surface resists wetting by molten polymers. The crosslinked acrylic adhesive is intended for adhesion to polar substrates including stainless steel, aluminum, and epoxy-coated machine frames without primer application.

The release liner protects the adhesive during slitting and die-cutting. Liner removal must be controlled to avoid transferring silicone from the liner surface to the adhesive, because surface transfer of silicone can interfere with subsequent painting or bonding. Rolls should remain in the original packaging with the release liner intact and should be handled with low-lint gloves in clean converting cells. The tape is not a conformable unsupported film, and the glass fabric produces a relatively stiff wrap profile that requires attention to minimum radius limits in automated application.

Nominal Construction and Physical Property Data

Typical values for the SG23-10(R) product family are summarized in Table 1 as reported in North American industrial distribution literature. These values are not release-controlled and should be confirmed against the current Saint-Gobain certificate of analysis for lot-specific acceptance testing.

Thickness is measured under a dead-weight micrometer according to ASTM D3652. Peel adhesion values are determined after 24 h conditioning at 23 °C and 50% RH; values on cold-rolled steel or aluminum may differ from stainless-steel data. The reported tensile strength is a machine-direction value. The woven glass fabric produces orthotropic properties, and transverse tensile behavior should be separately characterized when the tape is loaded across its width in wrapping or bundling applications. The short-time dielectric strength is not a safety clearance or creepage rating; it is a flat-sample breakdown measurement only.

The acrylic adhesive is the thermal rate-limiting layer, not the PTFE-glass backing. The backing tolerates continuous exposure to +260 °C, but the adhesive loses cohesive strength under shear as temperature approaches +177 °C. For short-term contact with hot tooling, the backing side may be exposed to temperatures above +177 °C provided the adhesive-side temperature is monitored with a thermocouple and remains below the recommended continuous-use limit. In hot-press applications above +200 °C, adhesive-side temperature measurement should be collected on the first production cycle because thermal equilibration across the tape thickness occurs rapidly when the backing is compressed against a heated metal surface.

In flat-platen impulse and direct-heat sealing equipment used for polyethylene and polypropylene film, the sealing-bar surface is commonly maintained between 150 °C and 220 °C for dwell times of 0.5 s to 2.0 s. The SG23-10(R) tape is applied to the steel or aluminum jaw as a replaceable release cover. The glass reinforcement prevents the tape from necking or telescoping under cyclic jaw closure, and the PTFE surface prevents polymer melt from wetting the metal. Where the adhesive interface remains below +177 °C, acrylic creep is not the dominant failure mode; above that temperature, edge lifting and adhesive transfer to the platen are observed within repeated cycles.

On continuously heated rotary sealing drums operating above +200 °C, silicone-adhesive PTFE-glass constructions are preferred. The SG23-10(R) may be used only if the drum is intermittently rotated or if the adhesive-side temperature is verified below +177 °C with an embedded thermocouple. Failure to maintain this boundary results in tape movement, adhesive ooze, and loss of bar release. This is an operational limit, not a storage limit. For sealing-bar retrofit, the metal surface should be cleaned with isopropanol and dried before tape application; surface oil contamination reduces peel adhesion even when the initial hand-tack appears acceptable.

For electrical insulation, the tape functions as a supplementary barrier rather than a certified primary insulation system. A single layer of 0.254 mm thickness exhibits a short-time dielectric strength of approximately 7.5 kV; however, creased or abraded tape can fail at lower voltage. End-use qualification under IEC 60335-1 or UL 499 is required before the tape is used in line-voltage appliances. The PTFE phase has a volume resistivity on the order of 10¹⁵ Ω·cm, but the woven glass reinforcement and adhesive interface can reduce tracking resistance compared with unsupported PTFE film.

In aerospace harness assemblies, the tape is used as a chafe barrier and bundle separator. The glass fabric resists cut-through from cable lacing cord and provides a low-friction outer layer that reduces abrasion against airframe structure. For moisture sealing, the tape is not a replacement for self-amalgamating silicone tape or heat-shrinkable polyolefin boot systems, because the acrylic adhesive and butt joints do not form a continuous environmental seal. In harness routing through bulkheads, edge fraying at slit edges can release glass filaments; edge-sealed slit rolls or secondary edge coating should be specified for cleanroom or electronics integration.

In autoclave and press cure of carbon-fiber-reinforced epoxy laminates, the tape is used as a release cover for caul plates and tooling pins at cure temperatures not exceeding +177 °C. The non-wetting PTFE surface prevents cured resin transfer to the tool. For cure cycles above +180 °C, the acrylic adhesive can outgas and contaminate the bondline; either a non-adhesive PTFE-coated glass fabric or a silicone-adhesive high-temperature tape should be substituted. When the tape is used as a flash-breaker on a vacuum bag, the adhesive side must not contact the prepreg edge because adhesive residue can create void sites in the laminate.

What Operational Boundaries Apply to the Acrylic Adhesive Under Continuous Thermal Load?

Continuous static shear testing according to ASTM D3654/D3654M with a 25 mm × 25 mm bonded area on stainless steel and a 1 kg dead weight typically survives more than 100 h at +177 °C. At +204 °C, cohesive creep failure commonly occurs within 24 h, especially when the bonded surface is polished or contains low-surface-energy contaminants. The practical maximum for continuous adhesive-side temperature is therefore +177 °C. The PTFE-glass backing can tolerate +260 °C, but thermal conduction across the tape during press dwell means the adhesive layer may approach the backing temperature within a few seconds. Thin films and high contact-force presses accelerate this equilibration.

The crosslinked acrylic adhesive has limited solvent resistance. Ketones, esters, and aromatic hydrocarbons soften the adhesive and reduce peel adhesion; cleaning should be limited to isopropanol or aliphatic hydrocarbon solvents such as heptane. Prolonged immersion in methyl ethyl ketone or toluene causes irreversible adhesion loss and edge lifting. For vacuum environments, outgassing should be evaluated by ASTM E595; acrylic adhesives may exceed 1.0% total mass loss without bakeout. Applications requiring low outgassing in semiconductor or photovoltaic chambers should qualify a cleaned and baked alternative.

Humidity and storage conditions affect converting performance. Above 60% RH, the adhesive can absorb moisture, plasticize, and show reduced shear holding power. Rolls should be stored at 10 °C to 27 °C and below 50% RH, and should be conditioned at room temperature for 24 h before slitting if condensation is suspected. Shelf life is typically 18 months from date of manufacture under these conditions, after which liner release and adhesive peel should be retested. Adhesion to low-energy plastics such as polypropylene, polyethylene, and PTFE is lower than adhesion to stainless steel. On these substrates, surface treatment by corona or plasma may be required to raise surface energy above 38 dyn/cm before application. Without treatment, peel adhesion can fall below 2 N/10 mm and the tape may lift during thermal cycling.

When the lined format is processed on rotary or flatbed die-cutting equipment, the cut depth is controlled so that the adhesive is severed without cutting through the glass-PTFE backing into the anvil. A kiss-cut depth leaving approximately 0.02 mm of liner intact is typical for part transfer; through-cutting the liner can induce curl and cause dispensing failure in automation. Liner release values must remain stable across the lot. Release values below approximately 0.05 N/10 mm may allow premature liner separation during slitting, while release values above 0.25 N/10 mm may slow robotic pick-and-place cycling. These values are process-specific and should be measured according to ASTM D5375 or an equivalent flexographic liner-release procedure.

Laser converting is not recommended for PTFE-glass constructions without local exhaust and acid-gas scrubbing. Thermal decomposition of PTFE above 260 °C generates hydrogen fluoride and carbonyl fluoride, which are hazardous to personnel and corrosive to equipment. Rotary die-cutting or kiss cutting should be used instead. For lamination to metal or plastic carriers, nip pressures above 0.35 MPa can force the acrylic adhesive through the glass weave and produce visible strike-through, which degrades the non-stick surface and increases adhesive transfer. Slitting the product requires sharp rotary knives and adequate blade overlap to avoid fraying the woven glass edge. Fiberglass fraying generates airborne glass filaments that can contaminate electrical assemblies; a vacuum extraction system and edge sealing by heat or adhesive are required when slit rolls are used in cleanrooms.

When the SG23-10(R) Is Compared with Skived PTFE and Silicone-Adhesive PTFE-Glass Tapes

The principal mechanical difference lies in the woven glass reinforcement. SG23-10(R) exhibits elongation at break near 5%, while unsupported skived PTFE film of comparable thickness can elongate 300% to 500% before break. This dimensional stability makes the SG23-10(R) preferred for heated platens and reciprocating sealing jaws where the tape must not distort under load. The same reinforcement reduces conformability around small diameters; unsupported skived PTFE tape is easier to wrap around radii below approximately 25 mm and around irregular contours, but offers lower cut-through resistance and lower machine-direction tensile strength.

Compared with silicone-adhesive PTFE-glass tapes, the acrylic version provides higher room-temperature peel adhesion to stainless steel and is less likely to leave adhesive-derived silicone contamination on surfaces that will subsequently be painted or bonded. However, silicone-adhesive products are rated for continuous service to +260 °C, whereas the acrylic system is limited to +177 °C under shear. For hot-tool applications above +200 °C, the silicone version is therefore the lower-risk construction. The acrylic adhesive is generally more resistant to plasticizer migration from vinyl substrates than rubber-based tapes, but heavily plasticized PVC can still reduce peel over time.

Skived PTFE film tapes provide higher dielectric strength per unit thickness because they contain no woven-glass interface and fewer void initiation sites. The PTFE-glass construction in SG23-10(R) trades a portion of dielectric performance for mechanical reinforcement, cut-through resistance, and dimensional stability. In high-frequency RF dielectric barrier applications where partial discharge is the limiting criterion, unsupported PTFE film is usually evaluated first; in mechanical chafe and heat-seal release applications, the glass-reinforced construction is the default baseline. Static charge generated during liner removal can exceed 5 kV in dry conditions below 30% RH, which may damage electronic components. Ionizing bars or controlled humidification above 40% RH are used to control static discharge during automated assembly.