An assembly with three or four bond points poses a throughput question: cure them one at a time, or all at once? UV spot lamps that drive several lightguides from one controller answer it, but only if each point receives the dose it needs. Q: How Do You Cure Several Bond Points at Once With One UV Spot Lamp? A: Use a Multi-Pole or Multi-Guide Configuration, Then Measure and Balance the Output at Every Point Incure offers two paths. The S20™ arc spot lamp splits one mercury arc across a 1-, 2-, 3-, or 4-pole liquid lightguide. The L9000™ LED spot lamp runs up to four independent lightguides from one controller. In both cases, each point must be verified on its own, because a single reading at one tip says nothing about the others. How Pole Splitting Works on the S20™ On the S20™, each additional pole splits the same mercury arc output across another simultaneous cure point. A 200W arc drives peak output above 21 W/cm² (up to 23 W/cm²) at the lightguide tip, across 275–650 nm. Because the source is shared, adding poles spreads that output across more tips rather than multiplying it. Pole count should follow the fixture: S20-1P suits a single joint, such as one connector or small component. S20-2P fits symmetrical assemblies and dual-joint fixtures. S20-3P fits triangular layouts and connector potting with three points. S20-4P serves high-volume lines with four bond positions per fixture. The S20™ lightguide configuration guide details these options. How Four Guides Work on the L9000™ The L9000™ supports up to four independent lightguides running simultaneously, so one unit can cure four points on one fixture or feed four separate stations. Each unit is set at the factory to one wavelength (365, 375, 385, 395, or 405 nm), so all four guides share it. Choose multi-point LED curing when every point uses the same adhesive or adhesives that cure at the same wavelength. Guide geometry can differ by position. The Cool Guide (83 mm, fan-cooled), Short Guide (66 mm), and Long Guide (118 mm) suit different reach requirements, so a fixture may mix lengths to reach points at different depths. The L9000™ reach and working-distance guide covers that choice. Why Points Rarely Receive Identical Dose Even with a shared source, several factors make one point differ from another: Working distance at each tip. On the L9000™, moving from 9 mm to 10 mm drops irradiance from 7,500 to 5,000 mW/cm², a one-third loss. A fixture with four holders has four standoffs to hold. Guide condition. Guides of different ages or histories can transmit differently. Guide routing. A run with tighter bends or a damaged section can deliver less. Bond size. A larger bead may need more dose than a smaller one on the same part. Email Us with your fixture layout and bond sizes, and Incure's team can help plan a balanced multi-point configuration. Balancing the Points Balancing means making each point deliver the dose its bond needs within one shared…

More irradiance is not always a faster route to a good bond. A UV spot lamp focused tightly on a small joint can deliver more energy than the adhesive or the part handles well, and the result can look cured while carrying hidden problems. Q: Can a UV Spot Lamp Deliver Too Much Intensity for a Bond? A: Yes — Excess Irradiance Can Heat Sensitive Parts, Raise Cure Stress, and Cure the Surface Before the Depth The fix is rarely a different lamp. It is usually a different balance of intensity, distance, and exposure time that delivers the same dose more gently. Incure's spot lamps include the controls needed to make that adjustment. How Concentrated a Spot Lamp Really Is Spot lamps concentrate their output into a few millimeters. Incure's L9000™ UV LED spot lamp reaches 7,500 mW/cm² at a 9 mm focal point at 365 nm, with a spot as small as 3 mm. Incure's S20™ mercury arc spot lamp delivers more than 21 W/cm² (up to 23 W/cm²) at the lightguide tip. Those figures are useful for speed, but they also mean a large amount of energy lands on a very small area. On a thin plastic housing, a small dark component, or a thick adhesive bead, that concentration can work against you. Symptom 1: Heat at Sensitive Parts Light energy absorbed by the part rather than the adhesive can show up as heat. A broadband source carries visible light alongside ultraviolet; the S20™ emits across 275–650 nm. An LED emits a narrower band, but a concentrated beam on an absorbing surface can still warm it. Watch for these signs: Warping or gloss change on thin plastic near the bond. Discoloration of labels, inks, or nearby components. Dimensional shift in parts that were aligned before cure. Measure the part's temperature during a full-length exposure with a thermocouple or thermal camera rather than assuming. If the result is a concern, reduce peak irradiance and extend time, as described below. Symptom 2: Shrinkage Stress in the Bond UV-curable adhesives shrink as they cure; Optik™ 7613, for example, documents a cure shrinkage of 2.21%. That shrinkage, together with any stiffness mismatch between adhesive and part, leaves residual stress in the joint and the substrate. When stress is a concern, it is worth comparing parts cured at full intensity against parts cured at a lower intensity for a longer time, then choosing the profile that tests better. On optical parts, residual stress can show up as birefringence. On rigid assemblies, it can load a brittle substrate or a solder joint. Lower-modulus adhesives help: Optik™ 7213 has 573% elongation and a D25–D35 durometer, a formulation designed to flex rather than pass stress into the glass. A gentler cure profile helps too. Email Us with your adhesive and part materials, and Incure's team can suggest an intensity and exposure balance for stress-sensitive joints. Symptom 3: Surface Skinning Over a Soft Interior A very intense exposure can cure the top layer of a thick bead…

In high-stakes manufacturing, the performance of an adhesive, coating, or ink is only as reliable as its cure. With the widespread adoption of UV LED curing systems, manufacturers are frequently confronted with a critical choice: which UV wavelength — 365 nm or 395 nm — is genuinely better suited for their resin? The answer isn't universal. It depends entirely on the chemistry of the resin and the physics of the application. Understanding the differences between these two common UVA LED wavelengths is paramount for achieving a consistent, high-quality, cost-efficient cure. The Wavelength Debate: Energy vs. Efficiency Both 365 nm and 395 nm fall within the UVA spectrum (roughly 315–400 nm), the primary region for industrial curing. Their 30 nm difference, however, has significant implications for the curing outcome. 1. 365 nm: The Deep Penetrator The 365 nm wavelength sits "deeper" in the UV spectrum, meaning its photons carry slightly higher energy. This higher energy is a key advantage for specialized applications: Deep Curing of Pigmented or Filled Resins: Shorter wavelengths like 365 nm are less susceptible to scattering and surface absorption by common pigments, such as titanium dioxide in white formulations, and by mineral fillers. That allows energy to penetrate opaque or thick materials more effectively. If you're working with thick potting compounds, highly filled epoxies, or a deep-section resin, 365 nm is often the stronger choice for ensuring a complete cure at the bond line or substrate interface, preventing partial curing and bond failure. Photoinitiator Affinity: Many traditional, high-performance photoinitiators were originally designed to peak near 365 nm, mimicking the strongest emission band from traditional mercury arc lamps. 2. 395 nm: The High-Efficiency Workhorse The 395 nm wavelength sits closer to the visible-light spectrum, and that position grants it two significant manufacturing benefits: higher LED chip efficiency and cost-effectiveness. Higher Output and Efficiency: LED chips manufactured for 395 nm and longer wavelengths are generally more energy-efficient and can achieve higher output intensities per dollar compared to 365 nm chips. Higher intensity often translates directly into faster line speeds and greater throughput. For high-volume applications involving clear coatings, varnishes, or standard inks where speed is the dominant factor, a high-intensity 395 nm system will often provide the quickest overall cure time. Visible Alignment: 395 nm light emits a noticeable violet-blue glow, which operators find useful for visually confirming light alignment and coverage on the substrate — a practical benefit on a busy production floor. The Critical Factor: Photoinitiator Absorption The single most important rule in UV curing is that the wavelength of the UV light must match the absorption spectrum of the resin's photoinitiator. Many older adhesive datasheets specify 365 nm because they were tested using traditional mercury lamps that peak at that wavelength — but modern resin chemistry often uses newer photoinitiators that absorb better at 385 nm, 395 nm, or even 405 nm. The optimal wavelength for any given project is defined by the resin supplier's data: a high-quality cure at 395 nm with an optimized photoinitiator will…

For professionals in manufacturing, electronics, and printing, ultraviolet light is not a single tool — it's a spectrum of distinct energies, and understanding the differences between them is essential for selecting the right curing equipment, optimizing material adhesion, and ensuring product integrity. The UV Spectrum: A Breakdown for Industrial Use The three primary classifications of UV light are UVA, UVB, and UVC. They're distinguished by wavelength, measured in nanometers, which dictates photon energy, penetration depth, and — critically — their industrial application. 1. UV-A (Long-Wave UV): The Curing Workhorse UVA covers the 315–400nm range, carrying the lowest energy of the three but the highest penetration, sitting closest to the visible light spectrum. Its industrial role is deep curing and adhesion. UVA's longer wavelength allows it to penetrate deeper into adhesives, coatings, and inks, ensuring a thorough cure all the way to the substrate. The majority of modern UV LED curing systems, including Incure's, focus on the UVA range — typically 365nm, 385nm, or 405nm — because it effectively matches the absorption profile of most photoinitiators used in industrial resins, ensuring strong cross-linking and reliable final bond strength. If an adhesive is thick or pigmented, maximizing UVA intensity is essential for a full, through-depth cure. 2. UV-B (Medium-Wave UV): The Cross-Linking Support UVB spans 280–315nm, carrying medium energy and moderate penetration, and its industrial role centers on coating toughness and mid-range cure. In broad-spectrum lamps — traditional mercury vapor or metal halide systems — UVB contributes to overall cross-linking density in the cured material, often improving mechanical properties like flexibility and toughness in coatings and inks. It's less common in dedicated LED systems, but some specialized chemical formulations are designed to react specifically within the UVB range to achieve a particular curing outcome. 3. UV-C (Short-Wave UV): The Surface Specialist UVC covers 200–280nm, carrying the highest energy but the shallowest penetration of the three. Its industrial role spans surface cure, abrasion resistance, and germicidal disinfection. UVC light is the most biologically active of the three bands, making it highly effective at damaging the DNA and RNA of microorganisms — though its high energy means it's quickly absorbed by oxygen in the air and can't penetrate far into material layers. In curing applications, UVC is crucial for achieving a tack-free, hard surface finish with strong scratch and abrasion resistance on coatings; a lack of UVC energy in a cure profile often results in a sticky or soft surface. UVC is also the wavelength of choice — typically 254nm or 265nm — for industrial disinfection systems used in water treatment, air purification, and semiconductor cleanroom surface decontamination. Dose Consistency Matters as Much as Wavelength Selection Choosing the right band is only half the equation — delivering a consistent dose within that band over time is what actually determines whether a production line stays in spec. Both LED and arc-lamp UV output decline gradually over the service life of the source, and a cure schedule validated when equipment was new can silently under-dose material…

Guide length is often treated as a convenience, ordered long "just in case" and coiled behind the lamp. That habit costs delivered UV on every cure and adds a bend that the guide has to survive for its whole service life. Q: Does a Longer Light Guide Reduce UV Intensity at the Part? A: Yes — Specify Length From Required Reach, Not From Spare Slack Light intensity drops with distance along a lightguide, so every extra length of guide between the lamp port and the tip removes some of the energy the lamp produced. The practical rule is to measure the real routing path, add only what the fixture's motion and service access require, and order that length. Then confirm delivered output at the tip, because the guide, not the lamp, is the last component to affect dose before the bond line. Length and Working Distance Are Two Different Losses Engineers sometimes merge two separate effects. The first is loss along the guide itself, which grows with guide length. The second is falloff in air between the tip and the part, which depends on working distance. Incure's data for the L9000™ UV LED spot lamp illustrates how steep the second effect is: 7,500 mW/cm² at a 9 mm focal point falls to 2,300 mW/cm² at 17 mm and to 223 mW/cm² at 30 mm. A longer guide that lets the tip sit closer to a recessed bond can therefore recover more dose than it loses along its length. Length is worth adding when it shortens working distance, and worth avoiding when it only adds slack. How Incure Defines Length on the L9000™ The L9000™ makes length an explicit selection rather than a free variable: Cool Guide (L9000-CG): 83 mm total length with a 24 mm cube head and integrated cooling fan, built for tight, confined fixtures where limiting heat transfer to a thermally sensitive assembly matters. Short Guide (L9000-SG): 66 mm fiber optic guide for standard bench-top curing and semi-automated dispensing lines. Long Guide (L9000-LG): 118 mm, for deep-reach positions inside complex fixtures that shorter guides cannot access. The Long Guide is 52 mm longer than the Short Guide (118 minus 66). That extra reach is justified only when the bond line actually sits that deep; on an open bench fixture, the Short Guide reaches the same part with less guide in the path. Email Us with a fixture drawing showing the lamp location and the bond line, and Incure can recommend a guide length and tip position for it. Bend Radius Sets a Floor on Practical Length Too short is also a problem. Every guide has a minimum bend radius, and exceeding it breaks glass fibers or kinks a liquid guide, both permanently. A guide cut so short that it must turn sharply to reach a fixture, or that pulls tight when a guard opens, will fail early. The right length includes a gentle service loop and enough slack for the full movement of any robot or slide it…

A spot-curing station rarely stops because the controller fails. It stops because a guide cracks, darkens, or gets crushed in a fixture change, and the spare that should have been on the shelf is either missing or the wrong part. Q: How Many Spare Light Guides Should a Spot-Curing Line Keep? A: Enough to Cover Each Distinct Guide Type Until a Replacement Can Arrive The count depends less on the number of stations than on the number of different guide specifications in use and how quickly each one approaches its replacement threshold. A line with five identical stations may need fewer spare part numbers than a line with three stations that all use different guides. Incure recommends building the spares list from a station inventory and a transmittance log rather than from a round number. This article covers how to build both, and what else belongs in the same spares kit. Step 1: Inventory Every Guide by Full Specification List each station with its lamp model, guide construction, core diameter, pole count, length, connector, and any terminator. Incure's own lines show why each field matters. The S20™ arc spot lamp pairs with 1-, 2-, 3-, or 4-pole liquid lightguides. The L9000™ UV LED spot lamp uses fiber-construction Cool Guide (83 mm total), Short Guide (66 mm), or Long Guide (118 mm) options. Core diameters for industrial spot curing run 3–12mm. Two guides that share a diameter but differ in pole count or construction are separate spare part numbers. Step 2: Group Stations Into Spare Families Once the inventory exists, collapse it into families of identical specifications. Each family needs at least one spare on the shelf. Where a family covers many stations, or where a station is a bottleneck whose downtime costs more than an idle spare, a second spare is a reasonable decision for the planner to make deliberately. Step 3: Use Transmittance Data to Predict Demand Guides do not fail on a calendar; they lose transmission through solarization, tip contamination, and handling damage. Incure's LS217™ Lightguide Simulator, which fits Standard D, Ø5mm ports on arc, xenon, and halogen spot lamps, provides readings that turn those losses into a trend. A widely used replacement threshold is 70–80% of a guide's original baseline. Plotting each guide's readings against its own threshold shows roughly when it will cross, which is when the spare should already be in stock. The routine for taking those readings is described in Incure's article on the LS217™ Lightguide Simulator. As a hypothetical example, if a guide family's log shows that its guides cross the threshold about twice a year across the stations that use it, and the replacement lead time is a few weeks, one spare covers most of the year with time to reorder after it is issued. Email Us with your station inventory, and Incure can help confirm part numbers for each guide family and the lead time to plan against. Step 4: Store Spares So They Are Usable When Needed A spare that…