New Taller Milk Carton Caps Are Easier to Open

Those short plastic caps on milk cartons that required superhuman strength to open? There's finally a better version hitting store shelves.

Shorter, thinner plastic caps showed up on milk, juice and other liquid cartons over the past few years. Better for the environment, terrible for actually opening the things first thing in the morning when you just want a little milk in your coffee.

A new version from Silgan Closures in Illinois is fixing that problem. Taller caps with better ridges that are actually possible to grip and twist.

"It's the knurling," said Fred Wolden, a Wisconsin resident who noticed the difference. "They're just easier to open."

Knurling is the textured pattern of lines along the cap. That plus being taller than the frustrating versions makes them way easier to twist.

"You can get a good grip," Wolden said. "It's being able to put your thumb and finger on the cap. And then when you turn it, the knurls help with the turn."

Why caps got so hard to open

Manufacturers faced pressure to design more environmentally sustainable containers. Over the past decade, companies reduced the amount of plastic used in packaging. That did good things—less plastic needed, lighter weight saved money on transportation, reduced carbon emissions.

But the tradeoffs were rough. The shorter, lighter caps required less plastic. They were about a third of an inch tall while older versions were almost half an inch. That difference made them significantly harder to unscrew.

"We've had to resort to using a pipe wrench to open them," said Wolden, a retired contracting officer with the Coast Guard. He and his wife keep pliers in their kitchen drawer specifically for wrestling with stubborn caps.

Americans consume about five million gallons of milk each year. About 17% is sold in traditional paper cartons. That's in addition to juice, non-dairy milks, broths and other liquids in gable top packages. Almost all of them now come with twist-off plastic caps. The closures got shorter and thinner and became harder to open.

The solution took years

It might not seem like a simple milk spout would require years of testing and design. But, it did.

Silgan started working on this several years ago. First, they tried designing a closure half as tall as previous versions. They weren't happy with the results.

After multiple iterations over several years, they hit on something that worked. A normal-height cap that was lighter due to thinner walls. The design with spaced-out ridges on the cap made them more prominent. That made it easier to grip.

"We put them in consumers' hands, had them open them, and tell us what they thought, and that helped us narrow down the designs that were good," said marketing director AJ Miller. "Then we had people use them at home and give feedback. All this took place over three years."

The result is the Silgan F15 cap.

Actually works better

"It looks good," said Alaster Yoxall, a professor of packaging ergonomics at Sheffield Hallam University in the UK. "If it's a lot easier and uses less plastic then it's a win-win."

The new caps are beginning to appear across the country but inconsistently. You can reach into the milk case at a supermarket and find several different types of caps, sometimes even on the same brand.

"We are excited about the positive customer and consumer response to the F15 Fitment," said Elizabeth Wiese, president of Silgan Closures.

What to look for

The new caps are taller than the frustrating short ones. They have more prominent ridges that are spaced out better. That gives your fingers something to actually grip when you twist.

They're showing up randomly in stores. If you grab a milk carton and the cap is taller with better ridges, that's probably the new design. If it's short and hard to grip, that's the old terrible version.

People are relieved

Fred Wolden in Wisconsin is just happy he doesn't need pliers as often.

"I know that sounds crazy, and I'm not a weak person," he said. "But when you grab the new cap, you can grip it a little better. And when you turn it, the knurls help with the turn."

That's the whole point. Opening a milk carton shouldn't be a test of strength or require keeping tools in the kitchen drawer. The new design fixes what the shorter caps broke.

Look for the taller caps with better ridges when you're buying milk or juice. Your fingers will thank you.

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