How disposable ware is made

The trade calls it single usage plasticware but that is just industry speak for throw away plastic dishes, plastic plates, bowls, drink ware and cutlery. They come in many styles and colours so for your next party you can go for the recycled option even with champagne flutes. Factories make pottery by injecting plastic into moulds; however they make cups, plates and bowls using a different process called thermoforming.

Before the forming phase can begin, an automated system loads polystyrene pellets into a machine called an extruder. The extruder heats the pallets until they melt, then it forces the molten plastic through a die to shape a hard plastic sheet about two millimeters thick. The factory uses moulds to form this continuous sheet into plastic cups. First, the sheet passes through a three-metre long oven that heats the hard plastic until it becomes malleable. Then it enters the thermoforming machine which simultaneously pushes and vacuums the sheet into the mould cavities, forming row after row of cups.

The entire process takes just three seconds. The cops then travel to the trimmer, which uses a dye to cut them off the sheet and the machine grinds up the leftover plastic and melts it into new sheets so there’s no loss of material whatsoever.

The trimmer feeds the cups directly to a machine that stacks them, then feeds them to a conveyor belt in one long line. The conveyor transports them to a machine called the lip roller which reheats the cups just enough to make the plastic flexible. It folds the rim over forming a rounded lip.

Cutlery can also be made from melted polystyrene pellets as well as from polypropylene, a lighter more flexible and less expensive type of plastic. The cutlery moulds consist of two halves. In one half the utensil cavities are the right side up and in the other half the cavities are upside down. A plastic injection machine melts the pellets and injects the molten plastic into the mould. A built-in cooling system solidifies the form in about 10 seconds and the extracted cutlery drops to a conveyor belt that leads directly to the automated packaging equipment for certain customers such as fast food restaurants. A factory packages utensils individually; the automated wrapping machine cuts polythene film to size, heat sealing the ends.

A factory can also use polypropylene pellets to make straws. The black beads are pickles to colour the plastic. An extruder melts the pellets, then forces the molten plastic through a circle shaped dime. As the long continuous straw leaves the extruder, it cools and hardens in a tank of chilled water. The giant straw is then cut with a knife into individual straws, which fall onto a conveyer belt which transports them to the packaging line. Just like the forks, these straws will also be individually wrapped but in paper and not plastic film.

The wrapper machine feeds them one by one into a paper sleeve. Gears mesh the edges together, creating a crimped seal. The dyes on this machine turn ordinary straws into flexible ones by forming a corrugated section that allows for bending at the top of the straw. The machine compresses the corrugation to preserve the shape. A factory can print customised designs in up to six colours applied simultaneously. Ultraviolet lamps built into the printing press dry the ink instantly. And when you are using disposable party ware, remember to never overfill a plastic plate at a party as it could prove to be embarrassing!

Just how exactly was the the Universe created again?

In 1966 Time magazine ran a cover story asking: “Is God Dead?” The cover reflected the fact that many people had accepted the cultural narrative that God is obsolete — that, as science progresses there is less need for a “God” to explain the universe. It turns out, though, that the rumors of God’s death were premature. In fact, perhaps the best arguments for his existence come from — of all places — science itself.

Here’s the story: The same year Time featured its now-famous headline, the astronomer Carl Sagan announced that there were two necessary criteria for a planet to support life: The right kind of star, and a planet the right distance from that star. Given the roughly octillion planets in the universe — that’s 1 followed by 24 zeros — there should have been about septillion planets — that’s 1 followed by 21 zeros — capable of supporting life. With such spectacular odds, scientists were optimistic that the Search for Extraterrestrial Intelligence, known by its initials, SETI, an ambitious project launched in the 1960’s, was sure to turn up something soon.

With a vast radio telescopic network, scientists listened for signals that resembled coded intelligence. But as the years passed, the silence from the universe was deafening.

As of 2014, researchers have discovered precisely bubkis, nada, zilch, which is to say zero followed by an infinite number of zeros. What happened? As our knowledge of the universe increased, it became clear that there were, in fact, far more factors necessary for life — let alone intelligent life — than Sagan supposed. His two parameters grew to 10, then 20, and then 50, which meant that the number of potentially life-supporting planets decreased accordingly. The number dropped to a few thousand planets and kept on plummeting. Even SETI proponents acknowledged the problem. Peter Schenkel wrote in a 2006 piece for Skeptical Inquirer, a magazine that strongly affirms atheism: “In light of new findings and insights . . . . We should quietly admit that the early estimates . . . may no longer be tenable.”

Today there are more than 200 known parameters necessary for a planet to support life — every single one of which must be perfectly met, or the whole thing falls apart. For example, without a massive, gravity-rich planet like Jupiter nearby to draw away asteroids, Earth would be more like an interstellar dartboard than the verdant orb that it is. Simply put, the odds against life in the universe are astonishing. Yet here we are, not only existing, but talking about existing. What can account for it? Can every one of those many parameters have been perfectly met by accident?

At what point is it fair to admit that it is science itself that suggests that we cannot be the result of random forces? Doesn’t assuming that an intelligence created these perfect conditions in fact require far less faith than believing that a life-sustaining Earth just happened to beat the inconceivable odds?

But wait, there’s more. The fine-tuning necessary for life to exist on a planet is nothing compared with the fine-tuning required for the universe to exist at all. For example, astrophysicists now know that the values of the four fundamental forces — gravity, the electromagnetic force, and the “strong” and “weak” nuclear forces — were determined less than one millionth of a second after the big bang. Alter any one of these four values ever so slightly and the universe as we know it could not exist.

For instance, if the ratio between the strong nuclear force and the electromagnetic force had been off by the tiniest fraction of the tiniest, inconceivable fraction then no stars could have formed at all. Multiply that single parameter by all the other necessary conditions, and the odds against the universe existing are so heart-stoppingly astronomical that the notion that it all “just happened” defies common sense. It would be like tossing a coin and having it come up heads 10 quintillion times in a row. I don’t think so.

Fred Hoyle, the astronomer who coined the term “big bang,” said that his atheism was “greatly shaken” by these developments. One of the world’s most renowned theoretical physicists, Paul Davies, has said that “the appearance of design is overwhelming”. Even the late Christopher Hitchens, one of atheism’s most aggressive proponents, conceded that “without question the fine-tuning argument was the most powerful argument of the other side.” Oxford University professor of Mathematics Dr. John Lennox has said “the more we get to know about our universe, the more the hypothesis that there is a Creator . . . gains in credibility as the best explanation of why we are here.”

The greatest miracle of all time is the universe. It is the miracle of all miracles, one that inescapably points to something — or Someone — beyond itself.

The science behind the common can

Every year nearly a half trillion of cans are manufactured—that’s about 15,000 per second — so many that we overlook the can’s superb engineering.
Let’s start with why the can is shaped like it is. Why a cylinder? An engineer might like to make a spherical can: it has the smallest surface area for a given volume and so it uses the least amount of material. And it also has no corners and so no weak points because the pressure in the can uniformly stresses the walls.

But a sphere is not practical to manufacture. And, of course, it’ll roll off the table. Also, when packed as closely as possible only 74% of the total volume is taken up by the product. The other 26% is void space, which goes unused when transporting the cans or in a store display.

An engineer could solve this problem by making a cuboid-shaped can. It sits on a table, but it’s uncomfortable to hold and awkward to drink from. And while easier to manufacture than a sphere, these edges are weak points and require very thick walls.
But the cuboid surpasses the sphere in packing efficiently: it has almost no wasted space, although at the sacrifice of using more surface area to contain the same volume as the sphere.

So, to create a can engineers use a cylinder, which has elements of both shapes. From the top, it’s like a sphere, and from the side, it’s like a cuboid. A cylinder has a maximum packing factor of about 91% — not as good as the cuboid, but better than the sphere. Most important of all: the cylinder can be rapidly manufactured.

The can begins as this disk —called a “blank”— punched from an aluminum sheet about three-tenths of a mm thick. The first step starts with a “drawing die,” on which sits the blank and then a “blank holder” that rests on top. A cylindrical punch presses down on the die, forming the blank into a cup. This process is called “drawing.” The cup is about 88 mm in diameter—larger than the final can — so it’s re-drawn. That process starts with this wide cup, and uses another cylindrical punch, and a “redrawing die.” The punch presses the cup through the redrawing die and transforms it into a cup with a narrower diameter, which is a bit taller. This redrawn cup is now the final diameter of the can—65 mm—but it’s not yet tall enough. A punch pushes this redrawn cup through an ironing ring. The cup stays the same diameter, as it becomes taller and the walls thinner.

You we watch this process again up close, you see the initial thick wall, and then the thinner wall after it’s ironed. Ironing occurs in three stages, each progressively making the walls thinner and the can taller. After the cup is ironed, the dome on the bottom is formed. This requires a convex doming tool and a punch with a matching concave indentation. As the punch presses the cup downward onto the doming tool: the cup bottom then deforms into a dome. That dome reduces the amount of metal needed to manufacture the can. The dome bottom uses less material than if the bottom were flat.

A dome is an arch, revolved around its center. The curvature of the arch distributes some of the vertical load into horizontal forces, allowing a dome to withstand greater pressure than a flat beam. On the dome you might notice two large numbers.
The debossed numbers are engraved on the doming tool. The first number signifies the production line in the factory, and the second number signifies the bodymaker number — the bodymaker is the machine that performs the redrawing, ironing and doming processes. These numbers help troubleshoot production problems in the factory.

In that factory the manufacturing of a can takes place at a tremendous rate: these last three steps— re-drawing, ironing and doming—all happen in one continuous stroke and in only a seventh of a second. The punch moves at a maximum velocity of 11 meters per second and experiences a maximum acceleration of 45 Gs. This process runs continuously for 6 months or around 100 million cycles before the machine needs servicing. Now, if you look closely at the top of the can body, you see that the edges are wavy and uneven. These irregularities occur during the forming.

To get a nice even edge, about 6 mm is trimmed off of the top. With an even top the can can now be sealed. But before that sealing occurs a colorful design is printed on the outside—the term of art in the industry is “decoration.”

The inside also gets a treatment: a spray-coated epoxy lacquer separates the can’s contents from its aluminum walls. This prevents the drink from acquiring a metallic taste, and also keeps acids in the beverage from dissolving the aluminium.

The next step forms the can’s neck — the part of the can body that tapers inward. This “necking” requires eleven-stages. The forming starts with a straight-walled can. The top is brought slightly inward. And then this is repeated further up the can wall until the final diameter is reached. The change in neck size at each stage is so subtle that you can barely tell a difference between one stage and the next. Each one of these stages works by inserting an inner die into the can body, then pushing an outer die—called the necking sleeve—around the outside. The necking sleeve retracts, the inner die retracts, and the can moves to the next stage.

The necking is drawn out over many different stages to prevent wrinkling, or pleating, of the thin aluminum. Since the 1960’s, the diameter of the can end has become smaller by 6 mm — from 60 mm to 54 mm today. This seems a tiny amount, but the aluminum can industry produces over 100 billion cans a year, so that 6 mm reduction saves at least 90 million kilograms of aluminum annually. That amount would form a solid cube of aluminum 32 meters on a side—compare that to a 787 dreamliner with a 60 meter wingspan.

When the neck has been formed the top is flanged; that is, it flares out slightly and allows the end to be secured to the body, which brings us to the next brilliant design feature: the double seam. On older steel cans manufactures welded or soldered on the ends. This often contaminated the can’s contents. In contrast, today’s cans use a hygienic “double seam,” which can also be made faster. This can is cut in half so you can see the cross-section of the double seam.

To create this seam, a machine uses two basic operations. The first curls the end of the can cover around the flange of the can body. The second operation presses the folds of metal together to form an air-tight seal. While the operations themselves are simple, they require high precision. Parts misaligned by a small fraction of a millimeter cause the seam to fail. In addition to the clamping of the end and can body, a sealing compound ensures that no gas escapes through the double seam. The compound is applied as a liquid, then hardens to a form a gasket. The end, attached immediately after the cans is filled, traps gases inside the can to create pressures of about 30 psi or 2 times atmospheric pressure. In soda, carbon dioxide produces the pressure; in non-carbonated drinks, like juices, nitrogen is added.

So why is a beverage can pressurized? Because the internal pressure creates a strong can despite its thin walls. Squeeze a closed, pressurized can—it barely gives. Then squeeze an empty can—it flexes easily. The cans walls are thin—only 75 microns thick—and they are flimsy, but the internal pressure of a sealed can pushes outwards equally, and so keeps the wall in tension. This tension is key: the thin wall acts like a chain — in compression it has no strength, but in tension it’s very strong.

The internal pressure strengthens the cans so that they can be safely stacked —a pressurized can easily supports the weight of an average human adult. It also adds enough strength so that the can doesn’t need the corrugations like in this unpressurized steel food can. While initially pressurized to about 2 atmospheres, a can may experience up to 4 atmospheres of internal pressure in its lifetime due to elevated temperatures; and so the can is designed to withstand up to 6 atmospheres or 90 psi before the dome or the end will buckle.

Why is there a tab on the end of the can? It seems a silly question—how else would you open it? But originally cans didn’t have tabs. Very early steel cans were called flat tops, for pretty obvious reasons. You use a special opener to puncture a hole to drink from, and a hole to vent. In the 1960’s, the pull-tab was invented so that no opener was needed. The tab worked like this: you lift up this ring to vent the can, and pull the tab to create the opening. Easy enough, but now you’ve got this loose tab. The cans ask you to “Please don’t litter” but sadly, these pull tabs got tossed on the ground, where the sharp edges of the tabs cut the barefeet of beachgoers—or they harmed wildlife. So, the beverage can industry responded by inventing the modern stay-on tab.

This little tab involved clever engineering. The tab starts as a second class lever; this is like a wheelbarrow because tip of the tap is the fulcrum and the rivet the load — the effort is being applied on the end. But here’s the genius part: the moment the can vents the tab switches to a first class lever which is like a seesaw: where the load is now at the tip and the fulcrum is the rivet.

You can see clearly how the tab, when working as a wheelbarrow, lifts the rivet. In fact, part of the reason this clever design works is because the pressure inside the can helps to force the rivet up, which in turn depresses the outer edge of the top until it vents the can and then the tab changes to a seesaw lever. Looking from the inside of the can, you can see how the tab first opens near the rivet.

If you tried to simply force the scored metal section into the can using the tab as a first class lever with the rivet as the fulcrum throughout you’d be fighting the pressure inside the can: the tab would be enormous, and expensive.

A typical aluminum can today contains about 70% recycled material. The aluminum beverage can is so ubiquitous that it’s easy to take for granted. But the next time you take a sip from one, consider the decades of ingenious design required to create this modern engineering marvel.

Making chilli con carne

Chilli con carne is one of the nation’s favourites. It’s very simple and very quick to make. You need mince beef, kidney beans, paprika, a little cumin, cayenne pepper and a rich beef stock pot and then we have our tomato base which is all very easy. If you don’t have tomato sauce then what you’ll have to do is fry your onions, your garlic and then add 50% passata and 50% tin chopped tomatoes – it’s as simple as that.

What I do is I make very easy tomato sauce. It’s my base to many things from my Bolognese to my chili con carne. I make a very big batch and then I break it down into four or five pots and I freeze it so when I want to make some chili con carne it comes out of the freezer so it’s easy and peasy.

Now start chopping onions and then chopping garlic. Add a little olive oil, then we take our mince beef and seal it. Be sure to do this properly. It’s quite a long and slow process but the results pay off at the end and there’s nothing worse than when you get mince with those big lumps in it almost like meatballs.

Next I take a little cayenne pepper, a bit of cumin, (but again you make it as spicy as you wish) and take a little paprika. They all work fantastically well together. Then we add it to our base tomato sauce. When it comes to the boil simmer very gently for about 1 hour with a lid on. Keep on stirring and then finish with a little more fresh coriander just to make it look pretty and there we have it: chili con carne. It’s fantastic with baked potatoes, sour cream and rice. It’s your choice, just not cheese!

How erasers are made

Make no mistake about it: an eraser is a student’s best friend. Whether it’s attached to the top of a pencil or on its own, only an eraser can quickly rub out an error. White erasers are made of flexible vinyl while pink erasers are made of synthetic rubber.

In 1736 a French explorer observed South American native Indians using a certain tree resin to make bouncing balls. He brought this resin back home and before long Europeans discovered it could rub out pencil marks, hence the term rubber. There was just one problem after a while: rubber would rot. That dilemma was solved a century later by one Charles Goodyear, who developed a curing process to prevent rubber from rotting.

A lot of ingredients go into making a simple pink eraser. Carefully measured fillers, accelerators, curing agents, oils, colouring and the main ingredient – synthetic rubber. They start by putting a batch of rubber into a mill. The rubber passes repeatedly between large heated rollers. Then throw in any defective erasers from the last production run, recycling them into this new batch, then add sulphur as a curing agent.

Accelerators to help the sulphur do its job. Add red colouring then blend everything for five to ten minutes, until the mixture is the consistency of heavy dough. Next add vulcanized vegetable oil (that’s vegetable oil treated with sulphur). Following that regular vegetable oil is added, then calcium carbonate – this acts as a filler when the colour and thickness are just right. In a factory, workers remove the rubber, which by now is hot and soft as a result of all that milling, and leave it to cool and harden at room temperature for about half a day. When the rubber is ready, they cut out large squares, each weighing between 5 and 8 kilograms depending on the thickness of eraser the client has ordered. The squares go into a steam heated press to cure for about 20 minutes at 163 degrees Celsius and the pressure compacts the rubber while the intense heat hardens it. They trim off the excess then submerge the hot rubber squares in cold water to stop the curing process.

To make erasers that erase both lead and ink, they cut beveled strips from two batches of rubber; one pink and one blue. The blue contains pumice which gives it that extra abrasiveness to erase ink. They pair up each pink with a blue to form a two colour strip, then it’s into the steam press. After twelve minutes, workers remove the trays, trim off the excess and submerge the strips and cold water to stop the curing process. Then an automated machine chops the strip’s into pieces the size of erasers.

And back to the all pink erasers – the rubber squares come out of their cold water bath, and go through a machine that cuts strips with beveled edges, then chops the strip’s into erasers. From there the erasers drop into a giant barrel. Workers throw in some talcum powder to prevent them from sticking together, then they set the barrel spinning for three to five hours as the erasers tumble against each other. The abrasion rounds off their edges.

The last step is printing a machine stamps each eraser with the company name and the model number. It’s not the rubber that gives the eraser the ability to erase but rather the vulcanized vegetable oil that’s in it – that’s what makes the eraser crumble when rubbed on paper taking away the pencil marks with it.