The Saint-Gobain CHR 2300-5R is a single-coated pressure-sensitive tape in which a skived or extruded ultra-high-molecular-weight polyethylene film backing is combined with a natural rubber pressure-sensitive adhesive. The “-5R” suffix identifies a nominal backing thickness of 0.127 mm (5 mil) and a rubber-based adhesive system; the same 2300-series film may be offered with other adhesive chemistries for different thermal, UV, and chemical exposures. UHMWPE backings of this gauge are characterized by molecular weights commonly above 3 × 10⁶ g/mol. The backing contributes low sliding friction, high abrasion resistance, and negligible moisture uptake, while the rubber adhesive provides high initial tack on stainless steel, epoxy-powder-coated surfaces, and some polar metals. The trade-off is that the natural rubber layer limits continuous service temperature and exhibits lower resistance to ozone, ultraviolet radiation, and nonpolar oils than acrylic or silicone alternatives.

In service, the adhesive layer is the limiting component. Natural rubber pressure-sensitive adhesives are resin-modified cis-1,4-polyisoprene compounds that show high loop tack and peel on polar surfaces at ambient temperature. They can be applied at lower surface temperatures than many acrylic dispersion adhesives, but continuous service above 65 °C accelerates oxidative chain scission, yellowing, and tack loss. The backing alone can tolerate short-term excursions above 80 °C; the total laminate should be qualified at the assembly level when process temperatures exceed 60 °C. Ultraviolet exposure, ozone-generating equipment, and contact with nonpolar solvents all reduce rubber PSA performance and are addressed later in this document.

Because exact lot-specific coat weight, peel adhesion, and shear values are influenced by release liner and slitting history, users should obtain the certificate of analysis from Saint-Gobain before setting incoming inspection limits. Published data for this specific adhesive-backing configuration is limited; the property windows below are therefore presented as representative ranges for unfilled UHMWPE film backings and natural rubber PSAs of the product class, not as batch-specific product guarantees.

Backing, Adhesive, and Dimensional Stack-Up

The UHMWPE backing is available in roll widths from 25 mm to 1,250 mm for sheet and roll conversion, with typical slitting tolerances of ±0.4 mm on widths below 100 mm and ±0.8 mm on wider formats. The nominal backing thickness is 0.127 mm; total tape thickness depends on adhesive coating weight and liner construction and cannot be reliably inferred from backing thickness alone. Die-cut parts are usually produced from master rolls with a silicone-coated release liner to preserve adhesive transfer and prevent roll blocking during storage at 15–25 °C.

No single backing property should be used to qualify the tape for service. The low coefficient of friction under ASTM D1894 is measured against a smooth stainless-steel sled; field conditions involving cardboard, glass, or abraded aluminum can produce different slip behavior. UHMWPE is also sensitive to creep under sustained compressive load, so the tape should not be used as a load-bearing wear layer where point pressure exceeds the polymer yield strength. For abrasive sliding contact, UHMWPE film typically outperforms PTFE-coated glass cloth in mass loss measured by ASTM D4060, especially when the counterface is rough or particulate-laden. However, PTFE may exhibit lower friction in clean dry sliding conditions. The selection between UHMWPE and PTFE therefore depends on whether the primary objective is abrasion resistance or the lowest possible sliding friction.

The adhesive layer is a natural rubber PSA, which is generally tackified with hydrocarbon or rosin ester resins and protected with antioxidants. At room temperature, rubber PSAs of this class may display a storage modulus in the rubbery plateau around 0.05–0.3 MPa at 1 Hz; below 10 °C, the modulus increases and conformability decreases. High-pressure pneumatic rollers exceeding 0.4 MPa should be avoided because they can thin the adhesive layer and create starved bond lines at the edges. A soft 60–70 Shore A rubber roller at 0.2–0.3 MPa, applied in both machine and transverse directions, is typically adequate for wet-out.

Peel adhesion values measured under ASTM D3330/D3330-04 depend strongly on dwell time and backing stiffness. For an elastomeric PSA on a stiff metallic substrate, the failure mode is likely adhesive if the substrate is clean and the adhesive is crosslinked; if the adhesive exhibits cohesive split, plasticizer migration or excessive coating thickness is a likely cause. Users evaluating incoming material should specify a 20-min dwell after lamination and a 300 mm/min jaw speed; variations in peel rate can shift the measured value by more than 15%.

The natural rubber PSA is most reliable when substrate temperature is between 15 °C and 35 °C during application. Below 10 °C, the adhesive cannot flow quickly enough into the microscopic roughness of a stainless-steel rail; press-out with a 4.5–6.8 kg laminating roller is insufficient to compensate for a cold substrate. Pre-warming the metal to 20 °C and wiping with 70% isopropanol/30% deionized water removes drawing oils and increases consistent peel adhesion under ASTM D3330/D3330-04. Low-energy substrates such as polypropylene and untreated polyethylene require corona or flame treatment to raise surface energy from approximately 29–32 mN/m to above 38 mN/m; otherwise the natural rubber adhesive will show intermittent wet-out and edge lift within the first 24–72 h of service.

Surface roughness is another process variable. On bright chrome-plated rails with Ra below 0.1 µm, the surface is clean but may have low surface energy; adhesion can be lower than expected. On 304 stainless steel with Ra 0.8–1.6 µm, the rubber adhesive can mechanically key into the surface and provide longer bond life under intermittent shear. However, if roughness is too high, air entrapment and uneven film contact reduce peel values. The optimum condition is a clean, dry, lightly abraded surface with an average roughness between 0.4 µm and 1.2 µm; this range is routinely achievable with a fine nonwoven abrasive pad.

On plasticized PVC, LDPE, or EPDM foam substrates, the rubber adhesive can absorb ester plasticizers, leading to tack loss, adhesive softening, and visible edge bleed. This failure mode is accelerated at 40–60 °C and is generally not reversible. If the application requires adhesion to plasticized materials, a crosslinked acrylic PSA is preferable. Natural rubber is also incompatible with ketone-based cleaning agents, aromatic hydrocarbons, and ozone, which attack the unsaturated backbone of polyisoprene. Repeated washdown with oxidizing agents such as hydrogen peroxide or peracetic acid is outside the intended operating envelope.

In production-scale bottling and form-fill-seal line trials, edge lift is most often observed at exposed leading edges subjected to repeated package impact. The failure propagates from the cut edge because the stiff backing concentrates peel stress at the adhesive-substrate interface. To reduce this failure mode, tape edges are located outside direct product-impact zones or protected by a mechanical stainless-steel clamp. When flush edge-to-edge application is required, gap spacing should be maintained at 0.5–1.0 mm to allow for thermal expansion of the UHMWPE film and prevent buckling under heat from adjacent motors or sealing jaws.

Static shear performance under ASTM D3654/D3654-82 is not the primary selection criterion for this adhesive class; natural rubber PSAs can exhibit cohesive failure at 70 °C under a 1 kg static load in less than 24 h. The tape should not be used in overhead or vertical load-bearing applications where the backing or adhesive carries more than the weight of the film itself for extended periods. At 23 °C and 50% RH, static shear is more stable, but the adhesive is still selected for tack and peel rather than shear resistance.

Application equipment in automotive and packaging plants commonly uses pneumatic nip rollers with 0.2–0.4 MPa contact pressure and 2–4 m/min line speeds. The rubber adhesive can be applied at these speeds without preheating when the metal substrate is above 18 °C. On curved rails with radius below 50 mm, the 0.127 mm backing may bridge or buckle; slitting narrow widths or using a heated forming step reduces stress. The tape should not be post-stretched during application because tension above the yield point induces residual stress and eventual edge lift.

When Abrasive Sliding Contact, Impact, and Chemical Washdown Determine Service Life

The product is used primarily as a low-friction face stock on metal guide rails, chute liners, and packaging-machine transition plates where plastic bottles, cartons, or pouches slide at high speed. UHMWPE backing provides a low kinetic coefficient against stainless steel and glass, reducing package jams and particulate generation. Compared with a PTFE-coated glass cloth tape, the UHMWPE construction offers higher tensile strength and better impact resistance but a lower continuous-temperature ceiling. PTFE backings typically survive processes above 200 °C, whereas the natural rubber adhesive on CHR 2300-5R limits the laminate to roughly 60–65 °C. PTFE may also exhibit lower friction in clean dry conditions, but UHMWPE generally shows lower abrasion loss against abrasive particles under ASTM D4060.

Chemical exposure must be evaluated separately for the backing and adhesive. UHMWPE resists dilute acids, alkalis, alcohols, and many aqueous detergent solutions. It is not recommended for continuous immersion in strong oxidizing acids, chlorinated solvents, or aromatic hydrocarbons because solvent uptake reduces tensile strength and increases creep. The natural rubber adhesive is the more chemically vulnerable layer; nonpolar cutting fluids, mineral oils, and ozone-generating motors can cause bond softening and tack loss. If the process includes regular washdown with hydrogen peroxide or peracetic acid, a silicone PSA may be suitable for chemical resistance but will have lower initial tack than the rubber system.

Moisture exposure is less critical for the backing than for some cellulosic or glass-cloth tapes. UHMWPE absorbs less than 0.01% water in 24 h under ASTM D570, so the film will not swell or support microbial growth. The adhesive-substrate interface, however, can degrade if water penetrates at exposed edges during repeated washdown. Edge-sealing is uncommon because it creates a ridge that disrupts package sliding; instead, the tape is placed to avoid direct high-pressure spray impingement. In dry packaging environments, moisture is rarely a root cause of field failure.

UHMWPE is an electrical insulator and can accumulate static charge when sliding plastic film or cartons generate triboelectric charge. If static discharge is a concern near sensors or flammable solvent vapor, an antistatic UHMWPE or a grounded metal rail treatment should be evaluated. The standard CHR 2300-5R is not an antistatic tape.

Compared with a UHMW tape using acrylic adhesive, the natural rubber version provides faster initial grab on low-temperature metal surfaces but lower shear strength at elevated temperature and lower UV/ozone resistance. If an application involves intermittent heat from sealing jaws or outdoor exposure, the acrylic adhesive version is preferred. If a high-speed packaging line requires immediate bond after roller application at 15 °C, the rubber adhesive may provide better first-pass edge hold.

The table is a selection guide, not a product-specific performance guarantee. Natural rubber PSA retains tack at low temperatures but loses strength at high temperatures; acrylic PSA provides a balance; silicone PSA provides high-temperature and chemical resistance but requires more preparation for acceptable adhesion on stainless steel. For CHR 2300-5R, the rubber PSA is therefore appropriate for indoor, low- to moderate-temperature applications requiring rapid initial grab on steel surfaces.

Regulatory status is application-specific. The UHMWPE backing may be evaluated under FDA 21 CFR 177.1520 for olefin polymer food-contact use, but the natural rubber adhesive is not considered a direct food-contact material and must be separated by a functional barrier or located outside the food-contact zone. Compliance with REACH Regulation EC 1907/2006 and the RoHS Directive 2011/65/EU should be confirmed through the product’s safety data sheet and supplier declaration. No halogens or heavy metals are intentionally added to the backing or adhesive according to typical product declarations, but raw-material traceability is batch-specific and a supplier certificate is required for quality systems.

Storage conditions affect tack and liner release. The product should be stored in the dark at 15–25 °C and 40–60% relative humidity. Roll stock should be used within the manufacturer-stated shelf life, commonly 12 months for natural rubber PSA, and should not be stacked under excessive weight because UHMWPE films can develop compression set and the liner can telescope. Cold storage below 5 °C should be avoided unless rolls are reconditioned for 24 h at room temperature before application.

For rotary die-cutting and laser-converted parts, the tape is typically kiss-cut through the backing and adhesive while leaving the release liner intact. UHMWPE film generates clean cut edges when the converter maintains blade depth within 10–20 µm of the liner surface. Laser cutting is possible but produces a narrow heat-affected zone that can reduce edge adhesion if the cut penetrates into the adhesive. Users should specify pull-tab liners and core sizes compatible with automated placement; core ID of 76 mm (3 in) is common for industrial rolls.

Before full-scale validation, a screening trial should measure peel adhesion after 24 h at process temperature and humidity, static shear under ASTM D3654/D3654-82, and dynamic friction against the actual package material. Standard peel testing on stainless steel does not reproduce the polymer surface or abrasive filler of many conveyor rails. A field trial should include at least 3 roll lots to capture batch-to-batch adhesive variation if the line operates above 50% relative humidity or below 20 °C.