{"id":3549,"date":"2026-10-08T10:18:53","date_gmt":"2026-10-08T02:18:53","guid":{"rendered":"http:\/\/www.intacthair.com\/blog\/?p=3549"},"modified":"2026-10-08T10:18:53","modified_gmt":"2026-10-08T02:18:53","slug":"how-does-a-bag-on-valve-aerosol-filling-machine-deal-with-the-filling-of-viscous-product-4357-d9a1a9","status":"publish","type":"post","link":"http:\/\/www.intacthair.com\/blog\/2026\/10\/08\/how-does-a-bag-on-valve-aerosol-filling-machine-deal-with-the-filling-of-viscous-product-4357-d9a1a9\/","title":{"rendered":"How does a Bag – on – Valve Aerosol Filling Machine deal with the filling of viscous products?"},"content":{"rendered":"

Hey everyone, it\u2019s Jake from the Bag-on-Valve aerosol filling machine team here, and today we\u2019re diving into something I get asked about all the time: how do we actually fill super viscous products with Bag-on-Valve (BoV) equipment? Let\u2019s be real\u2014you\u2019ve probably got a product you\u2019re working with that\u2019s thick, gloopy, hard to move: maybe a hair gel that\u2019s so good it\u2019s like pumping liquid sunshine, a thick lotion that feels like silk but won\u2019t pour, or even a high-viscosity adhesive that\u2019s way too thick for regular aerosols. Regular aerosol machines struggle with this big time\u2014they clog, they underfill, the product doesn\u2019t spray right, it\u2019s a mess. But BoV machines? We built them to handle exactly this. Let\u2019s break it down like we\u2019re chatting over a coffee, no stuffy jargon here. Bag-on-Valve Aerosol Filling Machine<\/a><\/p>\n

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First off, let\u2019s remember what makes BoV different from regular aerosols. Regular ones mix product and propellant in one can, so if your product\u2019s super thick, it has to move through a tiny dip tube that\u2019s prone to getting clogged. BoV splits it up: the product goes into a flexible bag inside the can, and propellant is outside the bag, pushing the product out. That separation is the game-changer for viscous stuff, but we still have to design the filling process to work with that bag and the thick product. Let\u2019s start with the core part: the feeding system for the viscous product. If you\u2019ve got something that\u2019s like honey mixed with glue, just pumping it with a regular pump isn\u2019t going to cut it\u2014you\u2019d get air bubbles, or the pump would seize up, or you\u2019d get inconsistent fills.<\/p>\n

What do we do here? We use positive displacement pumps, but not just any\u2014we size the chamber and the internals specifically for viscosity. For low-viscosity products, a regular peristaltic pump works, but for stuff that\u2019s over, say, 10,000 cP (that\u2019s centipoise, the unit we use for viscosity\u2014think toothpaste is around 10,000, hair gel might hit 50,000), we switch to gear pumps or lobe pumps. Why? Positive displacement pumps move a fixed amount of fluid per cycle, so we can dial in the exact fill volume we need, no matter how thick the product is. Gear pumps work by using interlocking gears to push product through the chamber, and we can adjust the speed to match the viscosity\u2014slow enough so the thick product doesn\u2019t shear, fast enough so it doesn\u2019t hang up. Lobe pumps are even gentler for shear-sensitive viscous products\u2014shear is when you apply too much force and the product\u2019s structure breaks down, which is bad if you\u2019re filling lotion or food-grade thick syrups. We tune the pump\u2019s torque settings too; if the product gets too thick mid-fill (like if the temperature drops a little, which makes it thicker), the pump\u2019s smart sensors pick up the increased torque and adjust the speed automatically. No more underfills because the pump couldn\u2019t push the product through.<\/p>\n

Next, we have to handle the bag. BoV bags are usually made of laminated plastic or aluminum, designed to stretch as the product is filled and shrink as it\u2019s dispensed. But if you\u2019re filling something super viscous, the bag material and the fill nozzle have to work together. If the nozzle is too small, the viscous product gets stuck and can\u2019t flow into the bag evenly, which causes air gaps or inconsistent fill weights. So we size the fill nozzle diameter based on the viscosity\u2014for thick products, we use wider nozzles, maybe with a tapered end to help the product flow into the bag without splashing or getting trapped at the top. We also do a pre-fill evacuation step, which is key. If you fill a thick viscous product into a bag with air, that air gets stuck in the product or the bag, and when you put the valve on, the air expands and can mess up the spray, or even push the product out of the wrong place. We pull a mild vacuum on the bag before filling\u2014enough to suck out any loose air, but not so strong that it collapses the bag or deforms the product. For really high-viscosity stuff, we might even heat the product slightly before filling, but only just enough to lower the viscosity a little, not enough to change the product\u2019s properties. Wait, I know what some of you are thinking\u2014heating would ruin things like natural lotions or certain adhesives, so we only use that when the product is heat-stable, and we\u2019ve got temperature controls that are super precise, like within 1 degree Fahrenheit, so no hot spots.<\/p>\n

Then there\u2019s the filling process itself, which is automated, obviously, but the automation is tailored for viscous products. Regular filling machines might just shoot product in fast, but with thick stuff, that leads to product building up in the nozzle or on the bag walls, and not getting a uniform fill. We use a slow-start, fast-in, slow-stop fill profile. So the pump starts at a low speed to get the product flowing into the bag without splashing or pushing air, then speeds up to the set volume rate for most of the fill, then slows down again at the end to avoid overfilling the bag or dripping product from the nozzle when it retracts. We also have a drip-free nozzle design\u2014because if you\u2019re filling something thick, a little drip at the end can get on the valve or the outside of the can, which is a waste and a mess. The nozzle retracts quickly and seals itself once the fill is done, so no drips. We test this with every product we work with\u2014last month we had a customer filling a 70,000 cP heavy-duty lubricant, and the standard nozzle they were using was leaving 2-3 grams of product dripping, which added up to thousands of dollars in waste. We swapped them to a tapered nozzle with a spring-loaded seal, and that drip was gone entirely.<\/p>\n

Wait, another big thing: pressure control. When you\u2019re dealing with BoV, after filling the product into the bag, we have to add propellant into the space between the bag and the can wall. For viscous products, the pressure when adding propellant matters because the bag is already full of thick product\u2014too much pressure and you can rupture the bag, too little and the product won\u2019t dispense properly. We use digital pressure regulators that are linked to the fill system, so once the product fill is done, the regulator measures the bag\u2019s internal pressure (wait, no, the bag is inside the can, so we measure the headspace between bag and can) and adjusts the propellant pressure accordingly. For thick products, we add a little more propellant pressure than we would for thin ones, because it takes more force to push the thick product out of the bag through the valve. We also make sure the valve itself is sized right for viscous products\u2014valves with larger orifices let the thick product flow easier, instead of getting stuck in a tiny opening. I\u2019ve had customers come to us with BoV fill machines that weren\u2019t made for their viscous stuff, and their valve orifices were too small, so they\u2019d get inconsistent spray\u2014some times nothing, some times a glob of product. We swap out the valves for larger ones, and that fixes 90% of the problem right there.<\/p>\n

What about common issues we actually run into with viscous products? Clogging is the big one. When thick product dries or thickens in the fill line or nozzle, that\u2019s a headache. We designed our machines with quick-disconnect parts for the product path\u2014pump, lines, nozzle\u2014so you can take them apart and clean them in minutes, not hours. We also have a solvent flush cycle that\u2019s automated for product changes. If you\u2019re switching from filling a thick lotion to a thick hairspray, you can run a small amount of cleaning solvent through the lines and pump, and the machine\u2019s sensors make sure all the old product is gone, no cross-contamination. For really stubborn viscous products, like epoxy, we even have heated lines that keep the product at a consistent temperature so it doesn\u2019t thicken and clog mid-fill. But again, we only use heating when the product can handle it\u2014no hot chocolate or heat-sensitive foods, obviously.<\/p>\n

I should also mention that we test every single machine we build for viscous product fills. When a customer orders a BoV machine, we ask them to send us a small sample of their product\u2014no need to send gallons, just a pint or so\u2014and we run test fills in our lab. We adjust the pump speed, nozzle size, pressure settings, even the bag material to make sure the fill is consistent, no clogs, no air bubbles, exactly the volume they need. Last quarter we had a customer who made a thick, natural sunscreen that was 45,000 cP, and their old machine was getting 10% underfills because the product wouldn\u2019t flow. We tested their product, tweaked the lobe pump speed, used a wider nozzle, and cut their underfills to less than 1%, way below industry standards. That\u2019s the stuff we\u2019re good at\u2014customizing the machine to their product, not just using a one-size-fits-all.<\/p>\n

Wait, let\u2019s talk about why this matters for your business, not just the tech. If you\u2019re filling viscous products, downtime is money. If your machine is always clogging, or getting fills that are too inconsistent, you\u2019re wasting product, missing deadlines, and annoying your customers. Our BoV machines for viscous stuff have been running 24\/7 for some of our customers, with only 15 minutes of clean-up per production run, that\u2019s it. No more spending hours unclogging lines, no more throwing away cans that are underfilled. And because BoV separates product and propellant, the shelf life of viscous products is way longer too\u2014no propellant mixing in, no product breaking down, which is another win for your bottom line.<\/p>\n

I know there\u2019s a lot of small details here, but that\u2019s the thing about viscous products\u2014they don\u2019t follow the same rules as thin ones, so you need a machine that\u2019s built to adapt, not just a regular BoV machine that\u2019s been repurposed. We don\u2019t just sell machines; we work with you to figure out what your product needs, whether it\u2019s a super thick grease, a high-viscosity serum, a food-grade thick syrup, whatever. We\u2019ve tested with everything from 5,000 cP to 100,000 cP products, so we know what works.<\/p>\n

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At the end of the day, the biggest advantage BoV has over regular aerosols for viscous products is that we don\u2019t force the product to flow through a dip tube with propellant mixed in. We let the product stay in a flexible bag, only moving it when we need to fill, and use positive pressure from propellant outside the bag to push it out when dispensing. The filling process is all about making sure that product moves smoothly, no clogs, no air, consistent volume, and that\u2019s what our machines are designed to do.<\/p>\n

Aerosol Filling Line<\/a> If you\u2019re dealing with a viscous product that\u2019s giving you headaches with your current filling setup, we can help. We don\u2019t do hard sell tactics\u2014just honest advice, test fills with your product, and a machine that\u2019s built to work for your specific needs. Reach out to our team to chat through your requirements. We\u2019re here to make filling viscous aerosols easy, not complicated.<\/p>\n

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