Gadget Guardian: Inside the secret science of packaging materials

Gadget Guardian: Inside the Secret Science of Packaging materials - Article by Alan Fackler - posted on Maximum Tech 9/16/2010

We gadget freaks obsess over consumer electronics gear, big and small: cameras, phones, notebooks, desktops, home theater speakers, HDTVs, and much, much more. But how often do we pay attention to the technology surrounding our gear, the packing material that keeps it safe?

Whether organic or man-made, squishy or rigid, there’s a deliberate method to every type of packing material madness. Why use cardboard inserts instead of polyurethane cushions? Why use those newfangled air pouches instead of traditional bubble wrap? Which packing peanuts are safe to eat, and why are some colored green or pink? All of these questions and more will be answered on the following pages. Behold! We submit 36 things you (probably) didn’t know about packing material.


Since its humble beginnings as a lab experiment in the late 1830s, polystyrene—you might be more familiar with its “foamed” format, aka Styrofoam—has emerged to become one of the world’s most useful man-made materials. And thanks to its form-fitting moldability, it’s a pretty good packaging medium to boot. Styrofoam isn’t great for the environment, but it will protect your gear on its journey through the currents and eddies of the global shipping infrastructure.

If you think these molded Styrofoam pieces look like modern art, then you haven't seen the amazing Styrofoam sculpture on

Humble German Origins

According to legend, Styrofoam’s path to greatness began in 1839. That year a German apothecary named Eduard Simon accidentally discovered polystyrene when he distilled an oily muck from storax, the resin of the sweetgum tree. The substance thickened, and a primordial version of Styrofoam’s base material had formed.

Early Military Applications

Spearheaded by Hermann Staudinger’s Nobel Prize-winning research on the elasticity of polymers, scientists at BASF were able to begin commercial manufacturing of polystyrene in 1930. By 1937, Dow Chemical jumped on board, and introduced this new material to the US market under the brand name Styrofoam. We can thank a Dow scientist named Ray McIntire for combining polystyrene with isobutylene, a highly flammable gas, in order to create the foamy version of polystyrene that we know and love today. McIntire’s goal was to create a flexible insulation material, but by 1942 the US military began studying Styrofoam—which resists moisture and is extremely buoyant—for use in life rafts.

How Modern Styrofoam Is Created

You ever notice that Styrofoam has a “grain” to it? That’s because molded Styrofoam is really the aggregation of multiple small, foamed polystyrene beads. The beads start out relatively miniscule, but include a hydrocarbon expanding agent. When the beads are hit with steam, the agent grows the beads to about 40 times their original size. Then the beads are tossed in a mold, where they’re steam-heated again. Here they expand some more—and also fuse together to create the shape of the mold’s negative space. Voila! You’ve got your Styrofoam cup. Or egg carton. Or the precision-molded packaging for whatever gadget you just purchased.

Why Styrofoam Is a Good Packing Material

As a packaging medium, Styrofoam can create strong, coddling, form-fitting shapes of amazing lightness. In fact, that piece of Styrofoam that forms a sandwich around your LCD display or photo printer is about 98 percent air. In the world of shipping, extra weight means extra charges, so Styrofoam’s merger of strength and lightness has its attractions.

Styrofoam also does extremely well as a hand-me-down material. Large blocks of Styrofoam can be cut and reshaped to fit around different sized objects, and Styrofoam packing peanuts ( Mic-Pac), which never really “age” (have you ever heard anyone complain about receiving “second-hand” peanuts?), can be re-stuffed into any box with an item in need of protection. Styrofoam and its polystyrene stablemates may not represent the cutting-edge of packing material science, but they get the job done. And they won’t cause any injury if you drop a palette of the stuff on your foot (though the wooden palette itself might hurt like a mother).

Styrofoam Drawbacks

Unfortunately, Styrofoam isn’t great for the environment. The substance can be recycled, but you have to bring it to a specific type of collection site. The biggest downside, however, is that Styrofoam isn’t bio-degradable—you can’t just toss it into landfill and expect it to quickly decay. Even worse, because of its lightness, Styrofoam pieces can blow away once they reach the dump. All it takes is a light wind.

Styrofoam By Any Other Name

If for some reason you’re not into brand name products, you can call Styrofoam by its generic trade name: expanded polystyrene plastic, or EPS. Also remember that Styrofoam is just what Dow Chemical calls this material. Owens Corning has its own version of EPS. It’s trademarked as PINK, and is marketed for construction insulation by none other than the Pink Panther.

Protective Foam

Protective foam—you might know it better as polyurethane or polyethylene. Don’t feel bad if you’ve ever confused these two substances for each other, or even gotten them mixed up with Styrofoam. All three materials can look, feel and even smell similar to one another. Nonetheless, if you really know your polys, you’ll know that urethane, ethylene and styrene are quite different animals on both an overtly physical and molecular level.

Left: Polyurethane is soft and squishy. Right: Polyethylene is rigid and hard.

Birth Story: Those Industrious Germans Are Back At It!

The story of protective foam begins with polyurethane in 1937, nearly a hundred years after Eduard Simon discovered the base material to make Styrofoam. This time around, another German scientist, Otto Bayer, was looking to create a truly flexible polymer. Bayer mixed liquid polyether with polyester diols, and—boom!—polyurethane was born. Unfortunately, World War II disrupted further research, and polyurethane foam wouldn’t become commercially available at reasonable prices until the late 1950s.

Why Polyurethane Excels as a Packing Material

Polyurethane foam is a cheap, flexible material that can be molded and trimmed into innumerable shapes and sizes to accommodate a wide range of packing tasks. It can be thinly sliced for use as a wrap, and molded or cut into form-fitting inserts like the gray ones you see above. Far softer than polyethylene (which we’ll get to soon), polyurethane can also be laminated onto other materials like pressure-sensitive adhesives. And let’s not limit ourselves to the world of packing and product protection. Chances are good that you’ve got polyurethane panels lining your walls for insulation, or stuffed in your car seats for padding. And, of course, we wouldn’t have modern Nerf warfare if Parker Brothers didn’t find success with the polyurethane Nerf ball in 1970.

Polyurethane Drawbacks

While polyurethane excels in flexibility and squishiness, it stands to suffer in protective power, especially when compared to polyethylene. Both materials are foams, but polyurethane is too spongy for some packing situations. Whether you bend it, ball it up, and or even use it to absorb water, polyurethane shifts back to its original shape. Polyethylene, on the other hand, feels and performs much more like Styrofoam. It’s quite rigid and can’t be bent or shaped without snapping into pieces. The softer, spongier protection of polyurethane could theoretically absorb more impact, but the stiff, armored shell of polyethylene could potentially help some products survive a longer drop.

Why Polyethylene Sometimes Trumps Polyurethane

Polyethylene differs from polyurethane on a molecular level—it’s a plastic-based foam that achieves extreme rigidity thanks to a complex, impenetrable cellular structure. It’s impossible for even water vapor to pass through the hardened material (in total contrast to polyurethane, which can actually absorb liquid). As such, polyethylene boasts a hardy resistance to damage from chemicals, solvents, and—most importantly, at least in the world of shipping—friction and collision.

Polyethylene Problemoes

Polyethylene is not without its faults. First, it isn’t impervious to ultraviolet light, so exposure to sunlight can cause warping and degradation. Second, because of polyethylene’s rigidity, extremely fragile, brittle items are better left to the softer polyurethane foams. Indeed, while polyethylene offers a thicker, harder coat of armor, so to speak, the impact of a fragile item against a hardened polyethylene shell can create enough force to shatter delicate pieces. For this reason, in the world of packaging, polyethylene is synonymous with protecting larger, bulkier items, while soft polyurethane is better suited for smaller, more fragile items.

The Two Polys: Not Earth Friendly

Like Styrofoam, neither of our foamy friends are biodegradable, so leaving them to dissolve au natural at the dump won’t work. And while polyethylene can actually be recycled (if entrusted to the right hands), polyurethane, sadly, cannot. If you’d like to safely recycle your polyethylene refuse, bring it to a local recycler that has the capacity to handle the substance. Your polyethylene will be fed into a large, heated barrel that melts the material into a soft, pliable foam that can be reshaped via a new mold cavity. Once a new shape has been cast, it needs only to cool down to garner its rigid, hardened shell again. Needless to say, this is not something that you can do yourself at home. So put down that butane torch, Chester.

Polythene Pam

Folks in the United Kingdom shorten the word polyethylene to “polythene.” So when John Lennon sang about an obnoxious fan named “Polythene Pam,” dressed in her “polythene bag,” he was really commenting on her inappropriate choice of packing material.


Packing Peanuts

Nearly 30 years after introducing Styrofoam, the Dow Chemical Company threw the dice on a daring innovation. What if, someone posited, we took our beloved miracle substance, and split it into a plethora of tiny pieces for the unique protection and damage-absorption properties that “loose fill” particles provide? It would be like a big hunk of Styrofoam gave birth to millions of intelligent, self-adjusting babies! That fateful year was 1965. Someone greenlit this bold escapade, and packing peanuts were born.

Why Peanuts Form a Formidable Filling

Whether they’re made from polystyrene (Mic-Pac)  or one of the biodegradable (Bio-Fill), more eco-friendly materials in vogue today, packing peanuts have the uncanny ability to “loose fill pack” when added to an enclosed box. In effect, when peanuts are used in bulk, they act as a self-correcting packing material that can shift and tumble to fill air gaps. This is quite an advantage if your hardware item has a bunch of corners or easily damaged edges. While Styrofoam panels can’t shift or move within the confines of a shipping container, peanuts have the ability to alter their aggregate arrangement and density in order to take on the many shapes needed to fill loose spaces.

When Good Peanuts Go Bad

The “adjust as needed” quality of peanuts garners mixed reactions among packaging aficionados. Dissenters point out that while peanuts can conveniently alter their arrangement within the confines of a box, simply not having enough peanuts can cause a product to migrate to one side of a container—resulting in a damaged piece of gear should, heaven forbid, the inevitable occur.

This may be true, but running into a shortage of packing peanuts shouldn’t be much of a problem. Peanuts don’t age, so you can re-use accumulated peanuts, stuffing them into any sufficiently sized box, along with your gadget that’s in need of protection. Also be aware that if you find yourself with simply way too many peanuts after unpacking your recently purchased display, espresso machine, Tesla coil or what have you, the fakey legumes can be taken to any local packaging company (Fed EX, UPS, MailBoxes Etc and so on) for re-use in other shipping endeavors.

Yes, These Peanuts Are Edible

Polystyrene isn’t good for the environment, and Polystyrene peanuts are no different. Luckily, many modern packing peanuts such as Bio- Fill are made of cornstarch, which is biodegradable and eco-friendly. Additionally, packing peanuts made from corn starch have no electrostatic charge, making them a great alternative for safe-guarding electronics in transit. The cornstarch peanuts are also non-toxic, addressing many pet owners’ fears of poisoning their beloved pooches. Nonetheless, all these benefits aside, dissenters point out that public knowledge of recyclable peanuts is limited.

Peanut Disposal—Just Add Water (Sometimes)

Bio-Fill starch-based packing peanuts can be dissolved with just a little bit of water—so you could literally “hose away” any excess peanuts in your own backyard. However, attempting to dissolve Polystyrene peanuts (or Polystyrene of any kind) could prove hazardous to your health. The material is only soluble in acetone (the active ingredient in nail polish) and the resulting fumes emitted from performing such a task could be toxic. Even fatal.

The Packing Peanut Cubicle Prank

Imagine you’re the unsuspecting dude in the photo below. It’s your last day at work, and your send-off includes a cubicle stuffed to the brim with packing peanuts ...
Photo Credit: Noah Jacobs

While the cubicle stunt is impressive, the packing peanut office prank is far tougher to pull off, though the pay-off—seeing some poor schmuck open his office door only to be buried in an avalanche of peanuts—is well worth the trouble. It’s also can be an expensive prank.

Air Protection ( Bubble Wrap)

You can’t discuss the origin of Bubble Wrap—or any air-based protection, for that matter—without first mentioning Sealed Air, perhaps the largest player in the rough-and-tumble, hard-knock world of product packaging.

How Bubble Wrap Was Invented: The IBM Connection

The Sealed Air story arch begins in 1951 when two engineers, Alfred Fielding and Marc Chavannes, bonded together two plastic shower curtains in a zany attempt to develop a new type of wallpaper. Air became trapped in pockets between the sheets, and thus begat wacky idea number two: greenhouse insulation. Makes sense, right? The sealed air pockets could theoretically be used as heat traps.

But, alas, no one was interested.

By 1960, messers Fielding and Chavannes had officially launched Sealed Air Corporation, but it wasn’t until a few years later that they found a willing evangelist for the madness they had concocted. The man’s name was Frederick Bowers. IBM was launching the IBM 1401, the world’s first commercially manufactured business computer, and needed a way to protect all those delicate computer components whilst the machines were in transit. IBM knew Bowers; Bowers knew Sealed Air.

Suddenly, the engineers’ previously fruitless endeavor had a purpose. Suddenly, the bubble wrap that fascinates us today was born.

How Modern Bubble Wrap Is Made

Modern bubble wrap manufacturing involves complex machinery, a relatively small amount of polyethylene, and lots and lots of plastic sheets. Pea-sized polyethylene pellets are fed into an extruder—a long, rotating cylinder that’s heated to 200 degrees Celsius. The resin produced from this process is then melted into a liquid, and formed into flat sheets of plastic. One layer of plastic sheeting is wrapped around a rotating drum whose surface is full of holes. Via a nifty suction process, the sheet is sucked into the holes—creating air pockets—and then another sheet of plastic is laid on top. The two polyethylene surfaces bond to each other, trapping air inside the pockets.

And then, some many months later, some dude in an office park annoys his co-workers by popping the air bubbles at the most annoying moment possible.

Why Use Bubble Wrap In the First Place?

Bubble wrap offers some distinct advantages over other materials used to safeguard our precious commodities.

Does Bubble Size Matter?

As pretty much anyone who’s ever opened a box already knows, bubble wrap comes in various sizes. So which size bubble gauge is appropriate for your packing project? Luckily, the formula to help you pick a bubble size (and also a bubble count) is relatively simple: The more air in any given bubble, the more protection it offers. Respecting this simple rule brings us to a staggeringly simple conclusion: The larger the item—and thus the greater potential collision impact if your item is dropped from the back of a truck—the larger the bubble you’ll need to protect it. Wrist watches? They get wrapped in 10mm baby bubbles. Audio speakers? Those deserve the respect of big-daddy bubbles, say, 10mm – 20mm wide.

Air Pillows: A Modern Innovation

If a bubble gauge larger than this is available, it certainly wasn’t manifest in the Maximum Tech Lab at the time of this writing. But air pillows or Fill Air, which can be found protecting some of the larger components shipped around the world, are a different story. Seems like the bigger your air chamber, the fancier it has to be named. Sealed Air makes a number of pillows—you’ve probably already seen its Fill-Air bags in action.

Air pillows are inflated “on demand,” saving warehouse space as a result.

These larger air receptacles (some of them up to eight inches long) provide a higher damage-absorption rate. And because the pillows are filled with air “on demand,” right on the warehouse floor, their raw material take up less warehouse space (because what’s the alternative—setting aside hundreds of square feet of floor space for pre-filled bubble wrap?).

Why Bubble Wrap is an "Uncontrolled Packaging Approach"

On the downside, filled air pillows and bubble wrap take up loads of room inside a box, especially compared to form-fitting Styrofoam and cardboard. From a manufacturing standpoint, this translates into larger packaging dimensions—as well as higher costs because fewer units can be delivered in a single shipment. Oliver Campbell, Dell’s Senior Manager of Global Packaging, says, “We try to avoid bubble wrap, because when we optimize a package for a notebook, we want it to be as small as possible. Bubble wrap is a much more uncontrolled packaging approach. When the packaging box is way too large, that drives up shipping costs, and also creates problems for customers because they have more packaging to dispose of.”

Bubble Wrap: Could It Save Your Life?

If you were buried alive with a diminishing air supply, but had a bounteous supply of bubble wrap with you, could you pop the air bubbles for more oxygen? The answer, technically, is yes. The oxygen in the pouches could be used as breathable air. Not for long, though. You see, every healthy breath you take leads to the exhalation of CO2, a poisonous gas. So even if you had all the bubble wrap in the world, you wouldn’t die from a lack of oxygen, you’d die from an overabundance of CO2 in your enclosed space. Our advice? Just try not to be buried alive.


Foam in Place Packaging

“Foam in place”: It’s a term that minces no words. You’ve got your foam, and it goes in a place. Simple. But it’s also a devilishly effective strategy for taking a time-tested packing material—polyurethane foam—and making sure it fills every nook and cranny between your delicate product and the cardboard box in which it’s packed.

Why Use Foam? Why Put it in a Place?

Instapak being the progeny of the ever-innovating Sealed Air Corporation. Instapak products can create a perfectly form-fitting foam sandwich around the contours and edges of whatever gadget (or glass vase or Roman antiquity) you need to ship. Bearing the eerie imprints of recognizable objects, foam in place pieces can look sort of creepy. But you know what? Deal with it. Foam in place provides excellent protection by completely filling void spaces with a known, effective cushioning agent. And because foam in place starts off in a liquid form, its base materials take up much less warehouse space than, say, packing peanuts. Instapak foam, for example, can expand up to 280 times its liquid volume, drastically cutting storage and handling costs.

A Dynamic Chemical Duo

So how do get the liquid to expand into foam? It all involves a chemical reaction between two chemical agents: polymeric isocyanate and polyurethane resin. As soon as the two substances are mixed together, they turn into a foam that continues to expand until the chemical sources are spent, or the expansion is stymied by opposing pressure. While researching this article, we can tell you that Sealed Air Corporation has many different contraptions to help you mix up your foamy mojo.

How Foam In Place Is, Umm, "Made"

So how exactly do you pack your precious cargo in a foam-in-place sandwich? We’ll describe the process in the context of using the Instapak 900 system. First you grab your box or carton, and line the bottom with a generous sheet of Instamate film—the piece you use should be about double the size of your box’s bottom. Now grab your foam dispenser gun, and press the trigger over the Instamate. The dispenser sucks the key chemical agents from two separate drums (coyly labeled Component A and Component B), mixes them in real time, and shoots the goop on to the film.

The liquid wastes no time expanding into a puffy piece of foam, so take your excess film and fold it over the foam to keep it all enclosed. Now nestle your product into the rapidly expanding cushion. It should sink into the Instapak as the foam creates a perfect form-fitting nest. To complete your packing escapade, repeat the same process with a piece of Instamate sitting on top of your product. Now close and seal the top of your cardboard box. Congrats! Your cargo is now entombed in the middle of a polyurethane ravioli.

Variations of a Foamy Concept

Sealed Air makes a daunting variety of other Instapak equipment, and all rely on catalyzing various formulations of Component A and Component B to create the expandable foam. For example, Instapak FlowRite if your formulation choice if you’re looking for “extended rise, flowable foam-in-bag foam,” whereas GFlex QS is perfect for “high-performance, high load-bearing foam with rapid de-mold capability.” Instapak machinery can cost up to $26,500, which is a lot of money, even accounting for the fact that Instapak cuts down on warehouse space, and may be the most cost-efficient packing method for some companies in the long run.

Mixing Foam By Hand

Even regular folk can now work with Instapak in the form of the Quick Room Temperature (QRT Bags) Quick Start Kit—essentially a box full of pre-goopified Instamate bags that require no machinery whatsoever for inflation and use. To inflate your bag with foam, you press two “buttons” at its base (and, yes, the buttons are labeled A and B). As you alternate between the two buttons, you can feel Instapak’s famous liquid agents begin to mix below your fingertips, then drastically increase in temperature. After a final “pop” emanates from the base, the bag begins inflating with hot, quick-drying foam. Stuff the bag in a box, and then quickly put your product on top of the bag. That’s step one in creating your custom-fit Instapak sandwich. Now place another expanding bag on top, and close the box. The system is duly protective, if not close to air tight.

Foam in Place: Another Environmental Challenge

Whether their source materials are labeled A, B or Z, Instapak packaging is full of polyurethane chemicals, which isn’t easy to dispose of. The easiest way, according to Sealed Air’s website, is to take your used material to the nearest waste-to-energy combustion facility (your grandpappy might have called this place “the incinerator”). You can also return the foam to one of the 20 “foam return locations” around the world. Twenty locations? Really? We think there are more Burger Kings within a 5-mile radius of our office.

Instapaking Prehistory On a Ginormous Scale

On July 27, 2000, a startling find was made in Malta, Montana. It was the most complete, reticulated dinosaur fossil ever unearthed, and it needed to be transported 2,000 miles across the country to Houston, Texas. Enter Bill Armstrong, Sealed Air’s Technical Development Manager. He led a team of experts in developing strategies to safely transport the ancient fossil. The team assembled a base for the artifact to ride on, and shrink-wrapped the fossil in CorTuff film, a material typically used for industrial applications. The fossil was then braced on the base using Instapak foam, and reinforced with Stratocell H polyethylene foam, a high-density foam for extra resistance to shock and transport vibrations. 

After unpacking the crate in a NASA hangar, scientists scanned the fossil to ensure nothing was displaced or damaged during the long journey across the country. It had arrived completely unscathed, leaving scientists with Leonardo one of only four existing brachylophosaurus (duck-billed dinosaur) specimens in the world.

Fiberboard ( Cardboard)

When’s the last time you received something in a wooden box? Yeah, that’s right: Wooden packaging has gone the way of steam-powered automobiles and handlebar mustaches. Today, everything comes in cardboard cartons or cardboard packaging and for good reason: cardboard is cheaper, lighter and doesn’t cause splinters. But cardboard and other pulp products aren’t just container materials, friends. They’re actually a packaging medium in and of itself, and one of the most environmentally friendly ones to boot.

How Cardboard Is Made

Cardboard isn’t a recent development—it’s been manufactured since the early 20th century using machines called corrugators, which separate hardwood and sapwood into individual fibers. These fibers are than treated with a heavy dose of high-pressure steam, and compressed by weights to form a straight, flattened panel that’s ready to join linerboards coated in starch-based adhesives. When the process is finished, you’ve got yourself a thick sheet of cardboard ready to be re-shaped and die-cut into a corrugated insert, or simply adhered to other pieces for a solid box that’ll ensure you cart home your 52-inch HDTV in complete safety.

Big Bamboo: The Perfect Packing Material?

The ancient alchemy of cardboard production hasn’t changed much over the years, but an industry-wide focus on green technology is making cardboard one of the more innovative packaging materials in the world of shipping today. Whether being used as custom-built inserts, fill packaging, or just good ol’ fashioned boxes, almost all the materials used to make these protective pieces are created with environmental sustainability in mind.

Take computer giants Dell and HP, which mass-produce their cardboard pieces using bamboo, which offers some clever benefits. As panda food, bamboo is nutritious—which is create news for all those pandas. But as a packing medium, it can be molded into any shape that typical cardboard can be, and is typically more cost-effective for manufacturers. More importantly, bamboo is a rapidly renewable resource that grows in heavy abundance and at a much hastier speed than tree bark. 


Fancy bamboo packaging – with a bamboo motifs pressed into each insert.

Why Big-Box Manufacturers Love Them Some Cardboard

Recyclability is a major benefit of cardboard. Virtually any “used” cardboard packaging material can be combined with other random cardboard piece to create a moldable pulp. The pulp can be reshaped into new cardboard-based flights of fancy, and because it’s made from trees and bamboo, it’s biodegradable.

“Cardboard is probably the most perfect sustainable packaging product, “ Salazar says. “People in the green community don’t agree very often, but we can all agree on that. It’s made with a high amount of recycled content. It’s compostable, re-pulp able, and comes from a renewable resource.”

Can Cardboard Really Offer Good Protection? Yes!

So cardboard takes the crown for environmental sustainability, but what about protective qualities? Oliver Campbell, Dell’s packaging guru, says, “If engineered correctly, a folded corrugated cushion can provide the same protective properties as Styrofoam or bubble wrap. The real question is whether it can be performed in the same amount of space, which translates more into a logistical cost.”

Unlike expansive foam or packing peanuts—which can either expand or fill to cushion empty spaces—the protective capabilities of cardboard are dependent on the amount of cuts or folds necessary to create the cushion. And the more folds necessary, the higher the manufacturing cost. This is an important consideration given the amount of folds found in the average corrugated insert, but it’s a smaller issue when using a cardboard mold, which typically uses form fitting dips and curves for protection rather than multiple folds.

And, Finally, It Often Comes Down to Saving Money

Lest you think cardboard is always chosen for its low environmental impact or even its protective capabilities, think again. Sometimes it’s used when shipping products to certain countries that heavily tax less sustainable packaging materials. That’s right: Even in the world of packaging, it’s not always about doing the right thing, whether that means helping the environment or making sure someone’s media streamer or notebook arrives safely. It often just comes down to which packaging solution costs less.



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