Saint-Gobain CHR SG36-10(R) Industrial Glass-PTFE Backing Silicone Adhesive Pressure Sensitive Tape is a woven fiberglass carrier coated with polytetrafluoroethylene on one surface and furnished with a silicone pressure-sensitive adhesive on the opposite face. The 10 in the model designation corresponds to a nominal total construction thickness of 0.010 in (0.254 mm), including the glass-PTFE backing and the silicone adhesive layer. The suffixed (R) is part of the manufacturer’s product configuration code, typically associated with liner format or roll build; because the suffix may affect the liner structure, procurement documentation should reference the complete Saint-Gobain technical data sheet rather than a shortened part number. Published data for this specific suffix configuration is limited, and the liner side should be confirmed when the tape is destined for rotary die-cutting or automated placement.

The product is specified for release, friction reduction, and high-temperature masking where dimensional stability of the backing is more important than conformability. The glass-PTFE backing provides a low-energy release face with continuous service temperature capability above that of polyester, polypropylene, or polyethylene carrier tapes. The silicone adhesive is selected for elevated-temperature adhesion and low-temperature flexibility. The tape is not a direct substitute for acrylic adhesive tapes in all operations because silicone adhesives create a contamination risk in painting, coating, and certain optical or semiconductor processes. Those operational boundaries are identified in the application and regulatory sections that follow.

Construction of the 10 Mil Glass-PTFE Backing

The backing combines a filament glass cloth with a PTFE coating, creating a structure that resists tearing and elongation under web tension. Thickness is controlled according to ASTM D3652/D3652M, while breaking strength and elongation are evaluated under ASTM D3759/D3759M. The woven carrier gives the product higher tensile strength and lower elongation than a skived PTFE film of comparable thickness. The exact warp and fill values depend on the glass style and the coating add-on weight; published comparative data for this exact configuration is limited, and lot-specific breaking strength should be obtained from the manufacturer certificate of analysis before the tape is run on high-tension slitting equipment.

The silicone adhesive is not a topcoating release layer. It is a pressure-sensitive layer on the opposite face of the glass-PTFE backing, and its cohesive strength is controlled by the degree of siloxane crosslinking. The PTFE face acts as the release surface. The adhesive thickness is part of the 0.010 in nominal total and may vary within the manufacturer’s tolerance. In converting operations, liner-side kiss-cutting is preferred because the woven glass fibers accelerate rotary die wear when cutting from the backing side. Slitting requires reduced web tension relative to polymeric film tapes because excessive tension can fracture the glass cloth at the slit edge and create a feathered, unstable edge.

The PTFE surface has a low critical surface tension and resists wetting by most process films, release liners, and polymer melts. It is chemically inert in most acid and alkali environments within the practical pH range at room temperature. The backing is not resistant to molten alkali metals or elemental fluorine and fluorine-based oxidizers under aggressive conditions. The silicone adhesive is sensitive to aggressive aromatic and ketone solvents such as toluene and methyl ethyl ketone; these solvents plasticize or swell the adhesive and lower its shear holding power. The glass-PTFE backing itself does not absorb solvent, but solvent exposure on the adhesive side must be avoided after application.

How Does the Silicone Adhesive Wet Out on Cold Rolled Steel and Anodized Aluminum?

Peel adhesion of the silicone pressure-sensitive adhesive is measured according to ASTM D3330/D3330M Method A after conditioning at 23 ± 2 °C and 50 ± 5 % RH. Silicone pressure-sensitive adhesives typically show lower initial peel to polished steel than acrylic adhesives of equivalent coating thickness, but they retain a larger share of peel strength at 200–260 °C. The exact peel value for this configuration is not stated here because the manufacturer’s published value may vary by lot, backing treatment, and substrate; the certificate of analysis should be requested for critical applications. Adhesion build on low-energy surfaces such as polypropylene or PTFE is slower than on steel, and final adhesion may not stabilize for 24 h or longer.

A surface energy of at least 38 mN/m is recommended for reliable silicone adhesive wet-out. Cold rolled steel and anodized aluminum should be cleaned with isopropyl alcohol and dried with a lint-free wipe before application. A water break-free surface is checked by ASTM F22; if water beading persists, the surface must be recleaned or a different surface preparation is required. Silicone adhesive does not wet well over hydrocarbon oils, plasticizer residues, or mold-release agents. The adhesive surface must not be solvent-cleaned after the liner is removed because solvent incursion into the adhesive reduces initial tack and can cause edge lifting under thermal load.

The adhesive is also sensitive to plasticizer migration from adjacent films and gaskets. When the tape is stored against plasticized vinyl or strips, plasticizer transfer into the silicone adhesive lowers peel and shear. Roll stock should be stored in the original packaging at 10–27 °C and 30–60 % RH. High-humidity storage does not degrade the glass-PTFE backing, but condensation on the adhesive surface can interfere with initial wet-out and should be avoided before application.

On impulse and constant-heat sealing equipment, the tape is applied over the sealing element or the opposing silicone pad. The PTFE face prevents molten polyethylene or polypropylene film from sticking to the sealing bar, and the silicone adhesive holds the tape in place during repeated thermal cycling. The continuous service temperature is normally 260 °C, which is the upper threshold for the adhesive and backing. Above 260 °C, PTFE begins measurable decomposition, and the release surface degrades by discoloration and embrittlement. Local exhaust ventilation is required if the tape is exposed to overheated sealing bars or hot-air impingement because PTFE decomposition products are hazardous. Heat-seal process validation should include a dwell-time study because the glass fabric adds thermal mass and slows heat transfer compared with a thin skived PTFE film tape.

In roll-to-roll packaging lines, edge lifting is the dominant failure mode. It occurs when the adhesive is subjected to uneven pressure distribution, textured steel, or high cycle rates without mechanical edge fastening. When line speed exceeds approximately 60 cycles/min, the silicone adhesive may not provide sufficient shear holding power on a hot sealing jaw, and mechanical clamps or high-temperature edge fasteners are sometimes used. Published data for this specific configuration is limited, and a short production trial is advisable before full implementation on high-cycle sealers.

When Acrylic Adhesives Lose Peel Strength Below -40°C

Acrylic and rubber pressure-sensitive adhesives become brittle at low temperatures and lose peel strength; silicone adhesive remains flexible below -40 °C and is specified for cold-environment applications where acrylic tapes delaminate. At the upper end of the service window, silicone adhesives retain cohesion and peel after exposure to 200–260 °C, while acrylic adhesives soften, oxidize, or leave residue. Hot-melt adhesives are not rated for continuous service above 80–120 °C in most industrial tape constructions and are excluded from heat-sealing and high-temperature release applications. Polyimide tapes provide higher mechanical strength and electrical performance in thin form, but they do not provide the same low-friction PTFE release surface or the same broad chemical resistance of the glass-PTFE backing.

Compared with skived PTFE film tapes using silicone adhesive, the glass-PTFE backing of this product has lower elongation and higher tensile strength. The glass carrier resists edge-initiated tearing in cyclic heat-seal applications and on guide rails. The tradeoff is lower conformability and higher thickness, which can reduce fit in close-tolerance roller gaps or applications requiring tight wrapping around small diameters. The backing is also stiffer than an unsupported PTFE film, so adhesion on curved surfaces depends on adhesive wet-out rather than backing conformability.

The product differs from ultrahigh-molecular-weight polyethylene pressure-sensitive tapes in temperature resistance and release chemistry. Polyethylene tapes offer lower friction and lower cost but are limited to lower continuous temperatures and are not suitable for direct contact with high-temperature sealing bars. Glass-PTFE tape is specified when the release surface must survive repeated contact with molten polymer film at sealing temperatures above 150 °C. The glass-PTFE backing also provides better resistance to cutoff knives and sharp film edges than polyethylene or polyester film carriers.

What Does the 2011/65/EU RoHS Recast Require for a Multi-Layer Tape Article?

RoHS recast 2011/65/EU operates at the level of the homogeneous material, not the finished tape article. The glass fiber, PTFE coating, silicone adhesive, and release liner must therefore be assessed as separate homogeneous layers. REACH 1907/2006/EC requires article-level reporting when substances of very high concern exceed 0.1 % w/w in an article as supplied. For a multi-layer tape, the article-level declaration depends on the exact liner and roll configuration, so the (R) suffix can affect the compliance statement if the liner contains a different material from the standard configuration.

Food-contact approval is not automatic. The PTFE component may be manufactured from resins evaluated under 21 CFR 177.1550, but the silicone adhesive is a separate layer that must be assessed for the intended food-contact use under the applicable FDA section. The user must request the manufacturer’s food-contact statement for the complete construction. Use in vacuum or cleanroom environments should be preceded by outgassing testing under ASTM E595 because silicone adhesives can release low-molecular-weight siloxane species. Those siloxanes can contaminate optics, semiconductor wafers, and paint surfaces. In painting operations, even trace silicon transfer can produce cratering; the tape should not be used in areas where painted surfaces are prepared or cured.

For slitting and die-cutting, the liner-side kiss-cut configuration is used because the glass fibers cause rapid blade wear from the backing side. Hardened steel rules and low web tension are typical. The slitting threshold should be established by measuring edge quality and elongation on a short lot sample rather than by using a fixed tension value from a different tape construction. After processing the silicone adhesive, converting equipment should be cleaned before running acrylic or rubber adhesive products because silicone transfer from anilox rolls, die shoulders, or idler rolls can interfere with downstream coating and laminating.

In high-temperature masking and protective applications, the tape should not be stretched beyond the point at which the glass cloth fabric begins to distort. Distorted glass cloth changes the release surface geometry and can open gaps along the edge of a sealing bar. The adhesive layer has limited shear holding power at 260 °C; continuous shear loads near the upper temperature limit can cause adhesive transfer to the substrate. Mechanical fastening at the tape edges reduces this failure mode. The product is not intended for use as a structural bond or as a permanent insulation barrier where an adhesive failure would create a safety hazard. For electrical applications, recognition status under UL 510 is configuration-specific and should be confirmed with the manufacturer before the tape is listed in an end-product insulation system.