Got Milk ... Cartons?
Some images from the 20th century are slowly disappearing. The corner market is vanishing as large supermarkets and big box stores like Wal-Mart are being built in what once were empty fields.
Also disappearing are the days of the milk bottle and home delivery.
There was a time when the local milkman delivered bottles to your doorstep each morning, and this still goes on in some places in the world. However, milk cartons made of paper have replaced the glass bottles of yesteryear, and now, just about every beverage – from milk to fruit juice to wine – can be found in paper cartons.
In 1915, the U.S. Patent Office granted John Van Wormer a patent for the first milk carton, which he called a paper bottle. But it wasn’t until 1937 that the familiar gable-top carton went into mass production under the name Pure-Pak. Glass bottles still dominated the market in the 1950s, but the paper milk carton became the choice of supermarkets because of its light weight and strength. The cartons remained the same until 1992, when the premium orange juice makers introduced the resealable cap to the familiar gable-top carton.
For Arthur J. Evers Corporation, the milk carton has become the key ingredient in their continuing success. The Riverton, New Jersey, machine shop sits just across the Delaware River from Philadelphia, and specializes in paper-converting machinery – more specifically, creating machines to score and cut milk cartons.
Evers began by making printing presses many years ago, but soon realized their niche was in manufacturing the machinery to create the fold lines and cut the paper for milk cartons. The paper comes off the printing press and rolls through the Evers machine – better known as a cutter creaser in the packaging industry. The first drum scores the paper, and then another roll cuts the paper into the familiar milk carton shape. The Evers cutter creasers are in use all over the world, including Asia, Europe, Africa and South America.
The key components of the cutter creasers are the rings mounted on the drums that score (create the folds on) a milk carton. The rings are made out of 4130 alloy steel and have a 15-inch outer diameter. To create cartons of various sizes, the rings can be placed on the shell of the drum in different positions. The ability to move the rings has been a big selling point for Evers around the world. “What used to take the customer two or three shifts, anywhere from 12 to 24 hours to make a size change, can now be made in less than four hours,” explains Warren Davis, plant superintendent at Evers.
While Evers was helping companies save time creating cartons, the company was also looking for a way to save time manufacturing the rings. “We were doing these on a vertical knee mill, and they were taking 75 to 80 hours per ring to machine,” says Davis. “We weren’t really pleased with the quality. It was acceptable, but we knew we could do better.”
In 1995, Davis was visiting a local trade show and saw the Haas HS-1RP horizontal machining center making ashtrays. He soon envisioned a Haas in his shop with a tombstone holding the rings. It took a little convincing of upper management, but soon Davis had his first Haas horizontal. “When it came in, I was the general foreman, and for the first eight months I ran the machine, because I wanted to find out what it could do and what it couldn’t do,” says Davis. “We did time studies on die parts, and a die part that used to take three or four hours in the vertical machine, we could do in an hour and a half on the horizontal, sometimes just an hour. Then I found I could run it unattended at night.”
It didn’t take long for Davis to realize Evers could use a second horizontal. “The savings were enough that we paid for the machine in six or seven months. We ran that machine 18 hours a day for a year and a half and then leased a second one. Now there are four of them,” he says.
The first horizontal took some time for others to get used to. “A lot of the operators, when they were watching me run it, were holding their heads, thinking it would crash,” laughs Davis, “but I knew where it was going. With the old machines, you could hit the start button and it might go where it is supposed to go, or it might go AWOL on you. Once they realized the reliability of the Haas, and that it was going to do what it was supposed to do, there was no problem training others to use the machine. Then they got to the point where they didn’t want to go back to the other machines, because they were slower and not dependable.”
Evers now has four HS-1RPs to manufacture the rings. “The ring is put up on a custom tombstone and roughed out. All the major material is removed from the part, and all the holes are drilled and tapped. Then it is taken off and goes to another machine where it is cut into sections, or quadrants. Then it goes back on the Haas to finish everything else,” says Davis. “All the roughing is done with half-inch carbide insert cutters, and then we go down to quarter-inch endmills, and then all the way down to ten-thousandths carbide endmills.”
The accuracy of the Haas horizontals allows Evers to make precise finishing cuts in the corners of the scores. “If you look into the corner, to the naked eye it looks like a sharp corner, but it’s a five-thousandths radius done with a ten-thousandths endmill,” says Davis. “The accuracy we have had is tremendous.”
Along with the high accuracy has come reduced cycle times: The time to machine a ring has gone from 85 hours down to 40 hours. “We had three machines running all the time. Now that we have four of them, we’ve been able to stop the second shift and still get everything done in one 12-hour shift.”
Evers has made some changes to the Haas horizontals to ease operation. One was taking off the doors to the pallet changers, because they found them unnecessary and in the way. Another change was moving the tool probe bracket to a position opposite the operator’s side of the machine. “For everything we do, the X axis stays on center, the Y axis is running up and down and then you have your A axis for your rotary. So we mounted the tool probe out of harm’s way,” says Davis, “because if you drop something on top of the tool probe, there goes your calibration. It has made a big difference.”
The shells, which the rings are mounted on, are also machined on the Haas. Using a custom drum, the shells of 4130 alloy steel look like Swiss cheese after being machined with all the holes to mount the rings. The shells need all the holes so that the customer can quickly move the rings to create different size cartons, whether liters in the metric system or pints, quarts and half gallons in the English system.
There were once up to 60 people working in the Evers shop, but with the Haas machines, there are now 35. “We were able to reduce our workforce by more than 25 percent and have moved people to other areas of the shop,” notes Davis.
And the Haas machines have been as reliable as advertised, he adds. “We ran the first one for four and a half years without any service calls. The reliability is excellent. If there was a problem, it was common things. The equipment we had before was very temperamental. You pushed the start button, waited and hoped it got to where it was supposed to go.”
Davis would like to replace some of the older machines in the shop to take advantage of the familiar Haas control. “My objective is to buy a vertical, probably a VF-2, and buy a Haas lathe. We have an older lathe that works fine, but the control is not user-friendly at all.”
In the meantime, Evers continues to build from two to four cutter creaser machines per year. The growth has been in making new rings for cutter creasers already in operation around the world. The quick-change tooling is popular, because if a score or blade gets damaged and needs to be replaced, a new ring can quickly be mounted to the shell. And the quick-change tooling allows customers to quickly change carton production from one size to another.
The gable-top milk carton can now be found in different aisles of the supermarket, from soups to laundry detergents, and students will continue to enjoy cartons of milk at schools around the world. So as the world’s population continues to grow, and with it, the world’s demand for inexpensive packaging, the Arthur J. Evers Corporation looks to continue producing cutter creasers and rings for packaging companies around the globe.