Saint-Gobain CHR 2302-5R UHMW Film Backing Acrylic Adhesive Pressure Sensitive Tape is a roll-applied wear-surface product assembled from a nominal 0.127 mm (5 mil) ultra-high-molecular-weight polyethylene film backing and an acrylic pressure-sensitive adhesive. The 5R suffix identifies the backing thickness class in the manufacturer’s coding system; it does not define total tape thickness. The tape is specified where dry sliding contact, impact abrasion, release, and replaceable wear surfaces are required on chutes, guide rails, and conveyor transfer points. The acrylic adhesive layer is selected for oxidation resistance and long-term aging stability relative to natural-rubber pressure-sensitive adhesive systems. Published data for this specific configuration is limited beyond the manufacturer’s current technical data sheet, and acceptance limits should be verified against the latest revision of Saint-Gobain documentation before installation.

As a backing layer, UHMW-PE is a linear polyolefin with molecular weight typically above 3.1 × 10⁶ g·mol⁻¹. That molecular-weight regime reduces chain mobility, producing elevated abrasion resistance and a low dry coefficient of friction, but it also lowers surface energy and complicates adhesive anchorage. The backing surface is therefore corona-treated or chemically primed in tape conversion to allow the acrylic pressure-sensitive adhesive to wet out at the backing interface. Without that treatment, adhesive transfer and liner-side delamination become failure modes during die-cutting or exposure to cyclic shear. The acrylic adhesive is a high-molecular-weight acrylate copolymer coated over the film and protected by a silicone-coated release liner. The liner prevents adhesive blocking and excludes particulate contamination before application.

What Constitutes the Backing and Adhesive System in CHR 2302-5R?

The tape construction consists of a UHMW-PE film, a thin adhesive-coating layer, and a release liner. Backing thickness is measured according to ASTM D3652/D3652M. Adhesive coat weight is not a tightly controlled buyer-level specification; the finished-tape thickness is the relevant dimensional parameter. Slitting tolerances, core dimensions, and roll length are application-specific. For automated dispensing, liner release force and tape unwind force should be specified because variations in liner release can cause tearing, telescoping, or misplacement in high-speed applicators. The acrylic adhesive is supplied in a pressure-sensitive form that builds peel strength with time and temperature after lamination. Surface preparation before application influences bond formation because the adhesive requires direct contact with a clean, high-energy substrate.

Roll lengths and slitting tolerances are not universal across distributors. Standard log rolls may be converted to narrow-width spools with widths from 12.7 mm (0.5 in) up to 914 mm (36 in), but exact availability must be confirmed. The tape is frequently die-cut into custom wear pads for packaging-machine change parts. Clean cutting of the UHMW backing requires sharp dies and low cutting speeds; edge burr and liner fragmentation have been observed when tooling temperature exceeds ambient by more than 20°C. The acrylic layer may flow during die-cutting if the roll is held above 32°C, producing exposed adhesive edges.

Dimensional, Peel, and Friction Test Values

Nominal values reported for UHMW film tapes of this class are obtained under controlled conditions and should not be treated as batch-certified specifications. The table below summarizes representative values commonly cited in tape specification literature for the 5 mil acrylic-adhesive configuration. Acceptance limits for any production lot must be taken from the current Saint-Gobain certificate of analysis.

Peel adhesion is tested after a dwell period and roller pressure using a 2.04 kg (4.5 lb) rubber-covered roller per ASTM D3330/D3330M. The quoted 60 N/100 mm value reflects wet-out to stainless steel, not to low-surface-energy plastics. On low-density polyethylene or powder-coated substrates, initial wet-out is reduced and bond development may require 24–72 h at 20°C–25°C. Friction testing per ASTM D1894 is performed against a polished steel sled; values for product-laden packaging materials can vary because contact surface roughness, humidity, and dust mass affect the sliding interface.

In dry particulate-handling systems, the UHMW surface reduces the boundary lubrication requirement and prevents product sticking. The tape is not a release coating in the silicone sense, but its low surface energy reduces adhesion of many food powders, adhesive residues, and polymer pellets. When the tape is laminated over a stainless-steel chute, the backing’s impact resistance and low friction allow granular material to slide without metallic galling or cavitation. Production-scale behavior depends on line speed, particle angularity, and bed depth. Published data for this specific configuration is limited, so wear life must be established through site-specific trials.

When Replacing Lubricated Metal Guide Rails with Pressure-Sensitive UHMW Tape

Installation on carbon steel, stainless steel, or anodized aluminum begins with solvent cleaning using isopropyl alcohol or methyl ethyl ketone. Oils, mold-release agents, and oxide dust reduce adhesive contact. For porous or low-energy substrates, corona treatment to 38–42 dyn/cm or use of a thin primer can improve bond strength. The tape is applied with firm roller pressure to eliminate entrapped air. Overlap joints should be oriented so that product flow does not continuously lift the leading edge. Edges exposed to high-pressure washdown may require sealing or edge dressing to prevent moisture ingress.

In dry-filling lines, the tape is used on side rails, transfer chutes, and reciprocating guides. It removes the need for wet lubricants and reduces audible stick-slip from corrugate, PET bottles, or metal cans. The acrylic adhesive shows better retention on high-energy metals after intermittent heat exposure than natural-rubber systems, but its quick-stick is lower at cold start. Below 10°C, application is not recommended unless the substrate and tape are warmed. After lamination, the bond continues to build as the adhesive wets substrate micro-roughness. A dwell period of 24–72 h at 20°C–25°C is typical before the line is placed into full service. Failure to observe dwell time can produce edge lifting under cyclic shear.

Compared with mechanical UHMW wear strips, the pressure-sensitive tape eliminates drilled fasteners and countersunk holes that collect product residue. It can be replaced during line maintenance without altering the substrate. However, it is not a structural bearing material. The product is intended for low-to-moderate normal loads and sliding speeds common to packaging and light assembly lines. In applications where continuous high-load sliding occurs, the backing may abrade, and adhesive shear strength may become the limiting factor rather than backing wear.

High-pH Cleaning Cycles and Cold-Start Peel Loss

Operating boundaries include thermal, chemical, and mechanical limits. Continuous exposure above 107°C softens the UHMW backing and may flow the acrylic adhesive, producing edge bleed and dimensional creep. Intermittent dry-heat exposure near the maximum should be evaluated with a load applied because the tape has a tendency to relax under tension. The backing is not inherently UV-stable for extended outdoor exposure unless a stabilized grade is specified. Long-term water immersion or high-pH cleaning cycles above pH 10 can plasticize the adhesive and reduce peel strength. Strong polar solvents, ketones, esters, and chlorinated organic compounds are not recommended for the acrylic adhesive. Plasticizer migration from flexible PVC substrates can also reduce adhesion.

Chemical compatibility of the UHMW backing is generally favorable in aliphatic hydrocarbons, dilute acids, and dilute alkaline solutions, but aromatic hydrocarbons can cause swelling over extended contact. The acrylic adhesive may be suitable for indirect food contact under 21 CFR 175.105 when used as a component of a food-contact article, while the polyolefin backing may be evaluated under 21 CFR 177.1520. Compliance must be confirmed with the manufacturer for the specific grade and use condition. Electrical insulation and surface burning characteristics should also be confirmed when the tape is used inside enclosed machine housings.

For vacuum-assisted placement or robotic dispensers, the tape is supplied with liner release levels matched to die-cut geometry and application speed. The liner must remain attached during transport and die-cutting but release cleanly at the point of application. In high-speed equipment, inconsistent liner release can interrupt automated cycles. If the roll is stored above 27°C or in direct sunlight, liner release may rise or fall depending on the release system. Storage in original packaging at 10°C–27°C and 40–60% relative humidity is typical for pressure-sensitive tapes of this class. Rotating inventory on a first-in, first-out basis prevents age-related loss of tack.

When a comparison is made against skived PTFE film tapes, the UHMW backing of CHR 2302-5R provides greater impact abrasion resistance in dry sliding contact but exhibits a higher dynamic coefficient of friction. PTFE tapes are preferred for continuous high-temperature service and for lower-friction release applications, whereas UHMW provides better impact toughness and often lower installed cost. Against UHMW tapes with rubber-based adhesives, the acrylic system shows better resistance to oxidation, UV exposure, and mineral oil but lower initial quick-stick on low-energy surfaces. Against silicone-adhesive UHMW tapes, the acrylic system offers lower outgassing and lower cost, but silicone adhesive provides better low-temperature adhesion and better adhesion to silicone-treated substrates. Selection between these products is therefore governed by substrate surface energy, washdown chemistry, temperature cycling, and the required wear-life window.

A further distinction arises in die-cutting and slitting. UHMW films with rubber adhesive are often less sensitive to die-cutting temperatures than acrylic-adhesive versions, because the acrylic layer can flow when tooling temperatures exceed 32°C. This is a known processing bottleneck on high-speed rotary die lines. If edge stringing or adhesive transfer is observed, reducing die temperature and increasing liner release liner caliper are typical corrective actions. Production experience indicates that sharp dies and controlled roll tension are more important for UHMW-backed tapes than for polyester-backed tapes because the UHMW film is softer and more extensible. The backing elongation of 300% allows conformity over curved rails but also requires tension control during lamination to prevent permanent stretch.