- December 01, 2000, Claudia Hine, Senior Editor
The materials used to make pouches are changing. We are seeing specialty films that are thinner, stretchier, multilayered. While multiple thin layers of film will reduce the weight of the pouch and increase the barrier, they can cause problems in production.
Terry Rego, sales manager at GN Packaging Equipment, Mississauga, Ont., Canada, explains: "Thinner film has a smaller temperature sealing window, so the equipment has to be more accurate with sealing time. We put in servos on sealing bars, for example, to get a very precise, accurate sealing time."
The same is true for nonwoven materials, which are becoming more and more sophisticated. As new chemistries are developed, pouchmaking equipment must adapt. Bruce Butler, VP of Independent Machine Co., Fairfield, NJ, says, "The material is becoming more delicate; tension control is more of a factor. As the materials change, handling those materials becomes the challenge."
Rego says devices such as clamp stackers are available that maintain control of the product throughout the whole process to hold the film, cut the film, and then stack the film, all mechanically, with multiple servo drives. "If you don't have the system in place," he adds, "you just don't get a good quality stack, so you either slow down or you put more people on the machine. Both are a negative on the efficiency side."
Because these materials are expensive, converters have to find ways to reduce scrap, says Mike Greely, Totani product manager at Amplas Inc., Green Bay, WI. "Servo drives combined with computer controls make it easier to add features to the machine to make it operator-friendly and more efficient. For example, a splice detection feature makes it easier to remove and discard bad product."
When specifying a new machine for a converter, Rego adds, "We always hammer them to make sure they list the pouches they want to make in order of importance and quantity. Sometimes a converter will say they want to make four types of pouches, but the fourth one might cause a problem in upping the price of the machine. If they're going to make only a few thousand a year, then take it off the list. Either buy it and resell it or do it down the road when the quantities go up."
Butler says converters need flexibility. "They may be making one type of pouch today, but they don't want to get locked in for next week," he explains. "The size of the pouch or how it's actually constructed may change, so we try to build a little flexibility into the operation of the machinery. Everybody wants more and more flexibility, mostly in terms of the size of the pouch."
Greely agrees. "Converters want [to be able to produce] these hot trendy jobs but also be flexible enough so that when those are gone, their equipment will do the standard stuff. There are some companies that offer versatile machines so that it's common to be able to run three-side seal, stand-up, and a zipper pouch, or a stand-up zipper pouch, all on the same machine. On the downstream end, automatic stack assist equipment has been developed in the last few years. This equipment tends to start dedicating the machine to specific sizes or longer-term runs, but as the volume of these runs becomes greater and greater, that becomes more important."
Rego notes, "Converters are looking for some sort of validation system that the machine is running consistently; to know that your piece of equipment is repeating itself accurately—every cycle—is very important." Manufacturers have responded to this need by adding data collection systems to capture this information, he says.
What's coming down the road? According to Rego, "Machine speeds are already where they're supposed to be. Our efforts are all on the delivery side and handling the specialty films. In fact, we're putting together what we're calling an R&D machine, because customers have a need to know whether their films will be able to be converted. It also gives us a platform to try new web control devices or delivery systems."