UV Adhesives / UV Curing Equipments / UV LED Equipments / UV LED Spot Equipments

UV Glue for Polycarbonate: Selecting a Light-Cure Plastic Bonder

Polycarbonate is tough, clear, and impact-resistant, and it is unforgiving to bond. It stress-cracks in contact with the wrong solvent, it has a moderate surface energy that many adhesives cannot wet, and it moves a lot with temperature. A one-part light-cure adhesive, chosen and processed correctly, gives polycarbonate assemblies a fast, clear, durable joint. Incure's Uni-Weld™ plastic-bonder line is formulated for this work. Why Polycarbonate Fails at the Bond Line Three failure paths account for most bonded-PC problems: Environmental stress cracking. Polycarbonate under tensile stress crazes and cracks when exposed to incompatible chemicals, including some adhesive components, cleaners, and uncured monomers. A joint that is fine on assembly can craze weeks later. Interfacial adhesion loss. Untreated PC surfaces carry mold release and a low-energy skin. An adhesive that does not wet the surface peels cleanly under load. Thermal-expansion stress. Polycarbonate's coefficient of thermal expansion is several times that of glass or metal. A rigid bond to a dissimilar material builds shear stress on every temperature cycle, as described in how CTE mismatch causes adhesive bond failure. Matching a Uni-Weld™ Grade to the Joint The Uni-Weld™ plastic-bonder range spans grades tuned for different priorities. For polycarbonate work the relevant choices are: Flexible, high-elongation grades such as Uni-Weld™ 1417, which cures to a bond with elongation in the mid-300 percent range. High elongation lets the joint stretch with polycarbonate as it expands, which is the right property for PC bonded to a dissimilar, more rigid substrate. Moderate-elongation grades such as Uni-Weld™ 1435 for PC-to-PC joints that need more stiffness but still some give. Clarity-optimized grades for visible bond lines in lenses, light pipes, and display covers. Because published numbers differ by grade, confirm elongation, tensile, and viscosity for the specific grade against its current data sheet before you design the joint around a value. Surface Preparation Wipe with isopropyl alcohol only. Avoid acetone, MEK, and other aggressive solvents that attack polycarbonate. For structural joints, treat with plasma or corona to raise surface energy. Bond within the activation window. Verify with a dyne test on a sample coupon. Cure Process Polycarbonate transmits UV-A and visible light well, which helps light reach the bond line, though many PC grades are UV-stabilized and attenuate shorter wavelengths. Use a source matched to the adhesive's absorption band, confirm dose at the bond plane with a radiometer, and account for lamp output decline over time. Equipment selection is covered in Incure's L-Series UV LED flood lamp guide. Give the joint a full cure. Residual uncured monomer is itself a stress-cracking agent for polycarbonate, so an under-cured bond can seed the exact failure you are trying to avoid. Gap Filling and Bubbles Light-cure plastic bonders in this class typically bond gaps up to a few tenths of a millimeter. For fitted joints, apply to the assembled edge and let capillary action fill the line. Grades formulated to release entrained air reduce bubble defects in the cured bond; still, dispense with a technique that minimizes air pickup and let large…

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August 29, 2024
UV Adhesives / UV Curing Equipments / UV LED Equipments / UV LED Spot Equipments

Incure Uni-Weld™ 1013: Polyetherimide Bonding Adhesive

Polyetherimide, sold most widely as ULTEM, is chosen for parts that have to stay dimensionally stable at temperature, resist hydrolysis, and carry load. Bonding it reliably is harder than bonding commodity plastics, because PEI's smooth, chemically resistant surface gives an adhesive little to grip. Incure Uni-Weld™ 1013, a low-viscosity light-cure acrylate, is a practical answer for PEI assemblies that need fast, clear, structural joints. Why PEI Is Difficult to Bond PEI is an amorphous, high-glass-transition thermoplastic with a moderately low surface energy and excellent solvent resistance. Those same properties that make it a good engineering material also make it hard to wet and hard to chemically couple to. An adhesive placed on untreated PEI often forms a bond that looks fine but peels at the interface under modest stress. Successful PEI bonding depends on doing three things well: cleaning, treating, and curing fully. Surface Preparation for PEI Clean. Wipe with isopropyl alcohol to remove mold release, plasticizer bloom, and handling oils. Let it flash off completely. Treat. Raise surface energy with plasma, corona, or flame treatment. Plasma is the most controllable and typically lifts PEI well above the threshold needed for a durable acrylate bond. Treated surfaces lose activation over hours to days, so bond soon after treatment. Verify. Check dyne level or water-break behavior on a sample before committing a production lot. Light abrasion followed by a solvent wipe is a lower-cost fallback that improves mechanical keying, though it is less consistent than plasma for structural work. How Uni-Weld™ 1013 Performs At roughly 550–1,100 cP, 1013 flows into fitted PEI joints and can be wicked into telescoping or lap geometries after assembly. Cured tensile strength on plastics reaches about 7,100 psi, and elongation near 50 percent lets the joint absorb vibration and small thermal movements rather than fracturing. It cures in seconds under UV, visible, or LED light and offers high optical clarity, which matters when PEI is used in sensor windows or lighting components. Because PEI parts often run warm in service, the bonded joint should be qualified at the real maximum temperature. Differential expansion between PEI and any bonded metal component is a common long-term failure driver; the mechanism is explained in how CTE mismatch causes adhesive bond failure. Cure Process for PEI Assemblies Light path: PEI is often translucent amber rather than water-clear. Confirm enough light reaches the bond line through the part, or expose the joint edge directly. Measure dose at the bond plane with a radiometer. Wavelength match: Use a source whose output overlaps the adhesive's absorption band; 365–405 nm LED systems are typical. See Incure's L-Series UV LED flood lamp guide for matching lamp to part. Oxygen inhibition: Air-exposed acrylate surfaces can stay tacky. Increase dose or cover the joint during cure. Applications Electronics: Bonding PEI connector bodies, bobbins, and insulators where heat resistance is required. Aerospace interiors: Joining PEI ducting, brackets, and panels that must meet flammability and smoke requirements. Industrial sensors: Sealing PEI housings and windows used in high-temperature or chemically…

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August 29, 2024
UV Adhesives / UV Curing Equipments / UV LED Equipments / UV LED Spot Equipments

UV Light Cure Adhesive for Plastics – Incure Uni-Weld™ 1013

Bonding engineering plastics on a production line means fighting two things at once: short cycle time and low surface energy. A one-part adhesive that cures in seconds under UV, visible, or LED light and wicks into a tight joint by capillary action addresses both. Incure Uni-Weld™ 1013 is a low-viscosity, light-cure acrylate built for precision plastic assembly. What Makes 1013 Different Uni-Weld™ 1013 runs at roughly 550–1,100 cP, low enough to flow into narrow bond gaps and along fitted joints without pooling. Once positioned, exposure to a matched light source fixtures it in seconds and reaches full cure shortly after. Tensile strength on plastics reaches about 7,100 psi, with roughly 4,100 psi on metal-to-glass joints, and elongation near 50 percent gives the cured bond enough give to survive vibration and mild thermal cycling. The low viscosity is the design lever. Where a paste adhesive must be metered onto a surface and then clamped, 1013 can be applied to the outside of an assembled joint and drawn in by capillary flow, which is how optical fiber splices and small telescoping plastic parts are bonded without fixturing every piece. Substrates and Surface Preparation The adhesive bonds a broad range of plastics, along with metals, glass, and ceramics. Bond performance still depends on surface energy: High-energy plastics such as polycarbonate, acrylic, ABS, and PETG bond well after a solvent wipe to remove mold release and handling oils. Low-energy plastics such as polyethylene and polypropylene need surface treatment, typically flame, plasma, or corona, to raise wettability before bonding. Without it, the adhesive beads up and the joint peels cleanly. Metals and glass benefit from degreasing and, for structural joints, light abrasion. Measure water-break behavior or dyne level after prep if the joint is critical. A surface that fails a water-break test will fail the bond. Cure Process Control Light-cure adhesives are only as consistent as the delivered dose. Three parameters govern the outcome: Irradiance and dose. Confirm both with a radiometer at the bond plane. An under-dosed joint may feel hard on the surface while the depth stays weak. Spectral match. The lamp's output must overlap the adhesive's absorption. LED sources at 365–405 nm are common; verify the adhesive is rated for the wavelength you run. Equipment selection is covered in Incure's L-Series UV LED flood lamp guide. Oxygen inhibition. Acrylate surfaces exposed to air can stay slightly tacky. Higher dose, an inert blanket, or a top film resolves it. Shadowed joints are the classic problem. If part geometry blocks light from the full bond line, either redesign for a light path, use a clear substrate as the light entry, or switch to a dual-cure chemistry. Where It Is Used Electronics: Bonding flexible circuits, connectors, and small housings where clarity and fast fixturing matter. Optical assembly: Wicking into fiber splices and lens mounts that need dimensional stability. Automotive: Securing interior trim clips, sensor lenses, and small bonded sub-assemblies. Consumer products and wearables: Joining small plastic components without visible fasteners. Failure Modes to Watch The…

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August 28, 2024
Silicone

Silicone Compression Set: Understanding and Minimizing the Challenge

A silicone gasket that seals perfectly on day one can leak two years later without any visible damage. The usual culprit is compression set: the permanent deformation a rubber retains after a sustained compressive load is removed. When a gasket takes a set, it stops pushing back against its sealing surfaces, and the joint opens a path for fluid, gas, or contamination. What Compression Set Measures Compression set is expressed as the percentage of original deflection that a specimen fails to recover after a defined time, temperature, and compression, per test methods such as ASTM D395. A result of 0 percent means full recovery; 100 percent means the material stays exactly as compressed. Well-formulated silicones typically fall in the low tens of percent after 22 hours at elevated temperature, and lower is better for long-service seals. The number matters because sealing force is what keeps a joint tight. As set accumulates, the gasket's residual contact stress decays. Once that stress drops below the pressure the joint must contain, the seal fails, often intermittently as temperature cycles change the geometry. What Drives Compression Set in Silicone Crosslink density and network structure. A more completely cured, tightly crosslinked network recovers better. Incomplete cure, whether from a short bake, low catalyst level, or cure inhibition, leaves dangling chain ends that flow under load and never spring back. Cure system. Peroxide-cured silicones generally show higher set than addition (platinum) cured systems, partly because of residual cure byproducts. A post-cure bake drives off volatiles and completes the network, and it is one of the most effective single steps for lowering set. Filler type and loading. Reinforcing fumed silica improves strength but interacts with the polymer network; excessive or poorly dispersed filler can raise set. Extending fillers added only to reduce cost usually make set worse. Temperature. Set rises sharply with service temperature. A gasket rated comfortably at 100°C may take an unacceptable set at 200°C. Always qualify at the real maximum continuous temperature, not an average. Time and strain level. Set accumulates with dwell under load, and running a gasket at high compression accelerates it. Designing for moderate compression extends sealing life. Design and Process Strategies Specify the set limit. Put a maximum compression set value, with the test temperature and duration, directly in the material specification. A generic "silicone rubber" callout does not control this property. Design compression into the mid range. Target roughly 15–30 percent compression on the cured gasket cross-section. Enough to develop sealing force, not so much that the material is overstrained. Use a groove that limits over-compression. A defined groove depth and land width caps deflection during assembly and stops installers from crushing the seal. Complete the cure. For molded parts, hold the specified post-cure. For dispensed form-in-place silicones, confirm the cure mechanism has finished throughout the section before the part enters service. Control temperature exposure. If the seal sees a hot spot, either move the material selection up a temperature class or shield the gasket. Related Failure Modes Compression…

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August 28, 2024
Silicone

UV Dual-Cure Silicone Adhesive Sealant for Electronics

A silicone sealant that gels in about ten seconds under UV light and still cures fully in the areas light never touches solves two problems at once: line speed and shadow cure. Incure's Pyra-Sil™ silicone line includes one-part UV/moisture dual-cure grades built for form-in-place gaskets, conformal coating, and enclosure sealing in electronics manufacturing. The Case for Dual-Cure Silicone Single-mechanism UV silicones cure only where photons land. In real assemblies, that leaves liquid resin under bead overhangs, beneath mating flanges, and in the shadow of tall components. Uncured silicone can creep onto contacts, outgas into a sealed enclosure, or wash away in a later cleaning step. A dual-cure grade fixes this. UV or UV-LED exposure gels the surface in seconds for immediate handling. A slower room-temperature moisture cure then finishes crosslinking in every shadowed pocket, typically over about 72 hours depending on section thickness and humidity. The result is a fully cured elastomer with no trapped liquid and no oven step. Elastomeric Behavior Under Thermal Cycling Cured silicone is a low-modulus rubber, not a glassy film. On a board that swings through temperature, that compliance lets the sealant stretch and relax with the substrate instead of cracking at solder fillets and lead exits. Rigid coatings on mixed-material assemblies can instead transfer expansion strain into solder joints; the mechanism is explained in how CTE mismatch causes adhesive bond failure. Silicone also holds up outdoors. It resists ozone, UV weathering, and elevated temperature, and stays dielectrically stable when wet, which is why it is a default choice for suppressing arcing across high-voltage traces in equipment that operates at altitude. Application Methods The material is formulated for manual brushing and for automated selective-coat, spray, and dispense systems, so a process scales from prototype to production without changing chemistry. Form-in-place gasket: Dispense a bead onto one enclosure half, UV-fix so the profile holds and the part can be inverted, then assemble. Design the groove so the cured gasket is compressed 15–30 percent. Under-compression leaks; over-compression drives long-term compression set. Conformal coating: Apply a uniform 75–200 micron wet film. Thin spots at board edges and component shoulders are where moisture first reaches a biased conductor. Sealing and potting shallow cavities: Fill, UV-skin the exposed surface, and let the moisture cure complete the depth. Where It Is Used Industrial and consumer electronics: Enclosure sealing and board protection on high-throughput lines. Automotive electronics: Sealing control modules and sensor housings against heat, vibration, and road salt. Renewable energy: Gasketing inverter and charge-controller enclosures exposed to weathering and marine air. Outdoor lighting and signage: Sealing luminaire and driver compartments. Process Control and Failure Modes Measure UV dose. Use a radiometer at the work surface. LED lamp output declines over thousands of hours, and an under-dosed skin stays tacky and collects debris. Matching the material to a documented lamp output, as in Incure's L-Series flood lamp guide, keeps the fixture step stable. Allow the moisture cure to finish. Do not seal parts in a dry barrier bag before shadowed silicone has…

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August 28, 2024
Silicone

Dual-Cure Silicone: Incure Pyra-Sil™ 915

On a high-mix electronics line, the slowest step is often waiting for a sealant to set before the assembly can move. A silicone that fixtures in roughly ten seconds under UV light, then finishes curing on its own in hidden areas, removes that bottleneck. Incure Pyra-Sil™ 915 is a one-part, UV/moisture dual-cure silicone designed for form-in-place gaskets, conformal coating, and general sealing. Two Cure Mechanisms, One Material The primary mechanism is UV or UV-LED photopolymerization. Exposed resin gels in about ten seconds, giving immediate handling strength and a tack-free surface. The secondary mechanism is a room-temperature moisture cure that completes crosslinking in shadowed regions, typically over about 72 hours depending on section thickness and ambient humidity. That combination matters because pure UV silicones leave liquid resin wherever light cannot reach: under a bead's overhang, beneath a mating flange, or in the shadow of a tall component. Uncured silicone can migrate, contaminate contacts, or outgas into an enclosure. The moisture-cure backstop converts those pockets to fully crosslinked elastomer without a secondary bake. Form-in-Place Gasket Use As an FIPG material, Pyra-Sil™ 915 is dispensed as a bead directly onto one half of an enclosure, UV-fixed so the bead holds its profile and the housing can be handled or inverted immediately, then assembled. The moisture cure finishes the compressed cross-section over the following days. Key process controls for FIPG work: Bead cross-section: Keep the dispensed bead consistent. Under-filled sections lose sealing force after compression set; over-filled beads squeeze out and can bridge to nearby features. Compression: Design the groove and land so the cured gasket is compressed 15–30 percent. Too little compression leaks; too much accelerates long-term set. UV dose: Verify surface dose with a radiometer. An under-cured skin stays soft and distorts during assembly. Conformal Coating and Sealing The same material brushes or sprays as a conformal coating on populated boards, protecting against condensing humidity, dust, and corrosion, and suppressing arcing across high-voltage traces at altitude. Because the cured film is a low-modulus elastomer, it flexes with the board through thermal cycling rather than cracking at solder joints. The stress mechanism that makes rigid coatings risky on mixed-material boards is covered in how CTE mismatch causes adhesive bond failure. Where 915 Is Used Consumer and industrial electronics: Enclosure sealing and board protection where cycle time drives cost. Automotive modules: Sealing control units and sensor housings against underhood heat and moisture. Renewable energy hardware: Gasketing inverter and combiner enclosures exposed to outdoor weathering and ozone. Lighting and signage: Sealing outdoor luminaire housings and driver compartments. Durability and Environmental Resistance Cured Pyra-Sil™ 915 resists ozone, UV weathering, and elevated temperature, and stays dielectrically stable when damp. Silicone's weak point is mechanical: it is not abrasion-resistant and offers modest tensile and tear strength compared with a rigid structural adhesive. Use it where sealing, dielectric protection, and stress relief matter, and use a structural adhesive where load transfer matters. The trade-offs between fast light-cure chemistries and higher-strength systems are laid out in UV glue versus epoxy…

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August 28, 2024
Silicone

Incure Pyra-Sil™ 909: UV Curable Silicone Adhesive

Electronic assemblies fail in the field for predictable reasons: moisture ingress, salt-fog corrosion, dendritic growth across biased conductors, and high-altitude arcing. A conformal coating that cures in seconds and still reaches shadowed areas closes those failure paths without slowing the line. Incure Pyra-Sil™ 909 is a one-part, UV/moisture dual-cure silicone built for exactly that job. How Dual-Cure Silicone Chemistry Works Pyra-Sil™ 909 fixtures under UV or UV-LED light in seconds, locking parts in position and forming a tack-free skin. A slower secondary moisture-cure mechanism then completes crosslinking in regions the light never reached: under connectors, beneath tall capacitors, and inside blind vias. This two-stage approach solves the central weakness of single-mechanism UV coatings, which leave uncured liquid resin trapped in optically shadowed pockets where it can wick, outgas, or attract contamination. The cured film behaves like a silicone elastomer rather than a rigid glassy coating. Low modulus means the coating flexes with the board through thermal cycling instead of cracking at solder fillets and lead exits. Silicone also holds its mechanical properties across a wide service window, resists ozone and UV weathering, and stays dielectrically stable when wet. Where the Coating Fits Consumer and industrial electronics: Protecting populated PCBs against condensing humidity, dust, and handling damage. Avionics and high-altitude equipment: Suppressing corona and arcing across high-voltage traces where air density drops and dielectric spacing shrinks in effect. Automotive electronics: Sealing sensors, connectors, and control modules exposed to underhood heat, vibration, and road salt. Renewable energy systems: Coating inverter and charge-controller boards that see outdoor temperature swings and marine air. Application and Process Control Pyra-Sil™ 909 is formulated for both manual brushing and automated selective-coat or spray systems, so a process can scale from prototype to volume without a chemistry change. A few parameters drive coating quality: UV dose. Confirm the delivered dose at the board surface with a radiometer, not by lamp age or exposure time alone. LED flood systems lose output gradually, and an under-dosed skin stays tacky and picks up debris. Matching the coating to a documented lamp output, as covered in Incure's L-Series UV LED flood lamp guide, keeps the fixture step repeatable. Film thickness. Aim for a uniform wet film in the 75–200 micron range. Thin spots at board edges and component shoulders are the first places moisture breaks through; pooled resin in low areas cures slowly and can trap solvent from earlier flux operations. Surface preparation. Silicone adhesion depends on a clean, dry substrate. Remove no-clean flux residue, mold-release transfer, and hand oils before coating. Ionic residue left under the film is the most common root cause of electrochemical migration despite an intact coating. Moisture-cure window. Allow adequate ambient humidity and time for the secondary cure to finish before stacking or bagging boards. Sealing parts in a dry barrier bag too early stalls crosslinking in shadowed zones. Failure Modes to Design Against The dominant field failure for any conformal coating is a pinhole or thin edge that admits water to a biased conductor. Design reviews…

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August 28, 2024
Silicone

Incure Pyra-Sil™ 905: UV Cure Silicone Sealant

Electronics that operate at altitude face a problem sea-level designs ignore: as air pressure drops, its dielectric strength drops with it, and voltages that were safely separated on the ground can arc. Incure Pyra-Sil™ 905 is a UV-cure silicone sealant formulated to conformal-coat boards against moisture and against high-altitude arcing. The high-altitude arcing problem Air is an insulator, but a weak one, and its insulating ability falls with pressure. A circuit with high-voltage nodes, a power supply, an ignition driver, a sensor excitation rail, that is reliable at sea level can flash over between conductors at cruise altitude or in a depressurized bay. A dielectric conformal coating fills the space around and between those conductors with a solid insulator, raising the breakdown voltage well above what thin air provides. 905 is designed for that role: a silicone film that both seals against moisture and provides the dielectric barrier that suppresses corona and arcing at altitude. What Pyra-Sil™ 905 is 905 is a one-part UV/moisture-cure silicone adhesive sealant. It cures primarily under UV light, fixing exposed material in seconds, with a secondary moisture cure that completes shadowed regions within about 72 hours. The cured film is flexible and durable and resists ozone, weathering, and elevated temperature. It is specifically formulated for use as a conformal coating on printed circuit boards and components, and it also serves general bonding, sealing, and encapsulation. Where it is used Aerospace: avionics, power electronics, and instrumentation operating at altitude or in unpressurized zones. Consumer and industrial electronics: boards exposed to humidity that also carry higher-voltage nodes. Renewable energy: string inverters and combiner electronics with high DC bus voltages in outdoor enclosures. General industrial manufacturing: sealing and encapsulation where a flexible, dielectric silicone is needed. Application and cure control 905 is applied by manual brushing for repair and low volume, or by automated dispensing or spray for production. The UV step needs a measured dose, verified with a radiometer, with allowance for lamp aging. Batch fixturing under Incure L-Series UV LED flood lamps covers trays at a set intensity, and inline curing runs on an Incure CDM UV conveyor. For arcing suppression, coverage between high-voltage conductors has to be complete and of adequate thickness. A thin spot or a bubble at a critical gap is where flashover starts. Inspect under magnification, and if inspectability is required, ask about the Pyra-Sil™ grades that fluoresce under blacklight. For help matching Pyra-Sil™ 905 to a board's voltage map and altitude requirement, Email Us with the details. Failure modes to design against Voids or bubbles at a high-voltage gap: air pockets in the film defeat the dielectric barrier. Dispense to avoid entrapment and allow the film to wet out fully. Thin coverage between conductors: control film thickness where it matters most, not just overall. Assuming the UV fix is a full cure: shadowed material needs its moisture-cure time, up to about 72 hours, before the board is qualified. Contamination under the film: clean and dry the board; residue undermines both sealing…

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August 28, 2024
Silicone

Incure Pyra-Sil™ 904: UV Cure RTV Silicone Rubber

RTV silicone is the default when a joint has to flex, tolerate heat, and shrug off weather. What it has never been is fast. Incure Pyra-Sil™ 904 is a one-part RTV silicone rubber that cures primarily under UV light, with a secondary moisture cure for shadowed areas, so it fits a production takt time. RTV silicone with a fast fixture A conventional room-temperature-vulcanizing silicone develops strength over hours and days as atmospheric moisture works into the film. That is fine for a field seal and a problem for an assembly line, where the part has to be handled and moved within seconds of dispensing. 904 fixes under UV in seconds. The exposed silicone gels and holds parts in position immediately; the moisture cure then completes any material the light could not reach. The finished joint has the flexibility, ozone resistance, and temperature range of an RTV silicone without the line dwell. What Pyra-Sil™ 904 is 904 is a one-part UV/moisture-cure silicone adhesive usable as a form-in-place gasket, a conformal coating, or a sealant. The cured rubber resists ozone, harsh weather, and elevated temperature, making it a fit for outdoor and engine-bay environments. Bonding and sealing dissimilar substrates Because silicone stays compliant, 904 is useful where two materials with different expansion rates are joined, a metal bracket to a plastic housing, a glass window to a metal frame. A rigid adhesive concentrates thermal-cycling strain at the interface and eventually cracks; a silicone rubber joint stretches and relaxes with each cycle. The general mechanism is described in how CTE mismatch causes adhesive bond failure. Where it is used Consumer and industrial electronics: bonding and sealing components and enclosures. Automotive: securing sensors and connectors, sealing covers and housings against weather and vibration. Marine and offshore: sealing electrical enclosures and deck hardware against salt spray and UV. General industrial manufacturing: flexible bonding and sealing across a wide temperature range. Application and cure control 904 is applied by manual brushing for low volume, or by automated dispensing or spray for production. The UV step needs a measured dose; verify with a radiometer and allow for lamp aging. Batch work cures under Incure L-Series UV LED flood lamps at a set intensity, and inline work runs on an Incure CDM UV conveyor. For help matching Pyra-Sil™ 904 to a substrate pair, seal geometry, or environment, Email Us with the part details. Failure modes to design against Treating the UV fix as a full cure: shadowed silicone needs its moisture-cure time before the joint carries load or pressure. Low-humidity cure environments: the secondary cure slows in dry air, so fully shadowed sections take longer. Bead gaps in a FIPG seal: control the dispense path and inspect before closing the housing. Bonding an untreated low-energy plastic: clean the surface and, for difficult substrates, use a silicone primer. Surface preparation for dissimilar substrates A silicone joint between two different materials only lasts if both surfaces are properly prepared. Metals should be degreased and, for demanding service, lightly abraded to…

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August 28, 2024
Silicone

Incure Pyra-Sil™ 901: UV Cure Silicone Rubber

Silicone gives an assembly flexibility, a wide temperature range, and weather resistance. Its usual drawback is cure speed: a moisture cure can take hours and stalls in shadowed areas. Incure Pyra-Sil™ 901 is a one-part silicone rubber that cures primarily with UV light and finishes in shadow with a secondary moisture cure. The dual-cure advantage A UV-only silicone cannot cure where light does not reach, under an opaque part, inside a lap joint, or in the shadow of a standing component. A moisture-only silicone cures everywhere but slowly, and thick sections take a long time. 901 combines both. UV light fixes the exposed material in seconds, locking parts in position and letting the line index forward. The secondary moisture cure then completes hidden and shadowed regions over the following hours, so the final part is fully cured throughout without holding the assembly on the line. What Pyra-Sil™ 901 is 901 is a one-part UV/moisture-cure silicone adhesive that works as a form-in-place gasket (FIPG), a conformal coating, or a sealant. The cured rubber resists ozone, weathering, and elevated temperature, which suits it to outdoor and under-hood service. Where it is used Consumer and industrial electronics: bonding and sealing components in enclosures and modules. Automotive: securing sensors and connectors, and forming gaskets on housings and covers. Renewable energy: sealing inverter and combiner-box enclosures, and gasketing outdoor electrical housings against weather and UV. General industrial manufacturing: general-purpose bonding and sealing where a flexible, temperature-tolerant joint is needed. Form-in-place gasketing For FIPG use, 901 is dispensed as a bead along a sealing flange, given a UV pass to fix the bead so the housing can be closed and moved, and then left to complete its moisture cure. The result is a gasket shaped exactly to the flange with no die-cut part to inventory and no compression set from a pre-formed gasket sitting in storage. Dispense path control and bead consistency matter more than for a bonding application, because a gap in the bead is a leak path. An automated dispense head and a fixed UV station give repeatable results. Application and cure control 901 is applied by manual brushing for repair and low volume, or by automated dispensing or spray for production. The UV step needs a measured dose; verify it with a radiometer and account for lamp aging. Batch fixturing under Incure L-Series UV LED flood lamps covers trays at a set intensity, and inline work runs on an Incure CDM UV conveyor. For help matching Pyra-Sil™ 901 to a gasket flange, seal geometry, or bonding application, Email Us with the part details. Failure modes to design against Assuming the UV fix is a full cure: shadowed material still needs its moisture-cure time before the part sees load or pressure. Bead gaps in a FIPG seal: control dispense path and flow rate; inspect the bead before closing the housing. Curing in very dry air: the secondary moisture cure slows when humidity is low; deep or fully shadowed sections may need more time. Expansion…

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August 28, 2024