An effortless balance between tradition and innovation characterizes the Mexican Coca-Cola bottler Sistema Argos of Juarez. Its introduction of Coke's "true-contour" 600-mL bottle of polyethylene terephthalate is one shapely example of this balance.
The true contour bottle replicates the shape of the glass bottle traditionally associated with Coca-Cola throughout the decades. With this innovative use of PET and the Endura(TM) shrink labeling system from B&H Labeling System (Ceres CA) Coke in Mexico has created a new dynamic shelf presence.
Coke bottlers in the U.S. resisted the "true contour" and produce what's called a "straight-wall contour" (see photo). Coca-Cola de Mexico chose to adopt the Coke-preferred shape. Industry sources contend that new labeling equipment would have been required for U.S. bottlers or blow molders to handle the true contour because of the convex label panel. Argos began manufacturing the traditional shape in August 1994 when its growth forced the construction of a new blow-molding facility.
"We designed our new blow-molding facility to accommodate the true contour from the beginning" says Luis Fernandez project manager at Sistema Argos. "The result is a cost-effective innovation that differentiates our product on the shelf." Argos is a holding company made up of six Coca-Cola franchises in Mexico that operate seven bottling plants and two bottle molding plants. Each molding plant labels freshly made PET bottles in-line whether the new contour style or the generic plastic bottle. The Fernandez family and Coca-Cola go back 56 years when Luis Fernandez' grandfather ran a brewery and bottling operation that pioneered new territories for Coke.
Molding round the clock
The blow-molding side of the business Promotora Industrial engages both in captive manufacturing and in merchant sale of PET bottles. Coke franchises receive 70% of the bottles produced; the balance is sold to independent soft drink and bottled water manufacturers. Along with the contour Promotora also makes 2-L 1.5-L 500-mL and 600-mL generic PET nonreturnable bottles and it also molds plastic beverage crates.
In Juarez Promotora molds bottles around the clock seven days a week producing four million bottles each month. Since customers prefer to purchase prelabeled bottles a Model 2300 roll-fed labeler and Model 700 shrink tunnel both from B&H immediately follow the blow-molder an SB06/10 six-mold machine from Sidel (Doraville GA) that makes 110 bpm.
Sistema Argos first worked with B&H four years ago when it was looking for cost-cutting image-enhancing changes for its popular Jarritos soft drink that was packaged in glass bottles decorated with ACL ceramic labels. "At that time shrink labels hadn't been used on filled glass bottles but B&H worked with us to find the right film and converter to make the system work at speeds of 400 bpm" noted Fernandez.
Argos' satisfaction with B&H for Jarritos did not preclude consideration of competitive technologies when the time came to choose a shrink label system for the new contour line. "We prepared a comparative analysis of shrink label systems which evaluated five major criteria" explained Enrique Montenegro assistant manager of operations for Promotora. "We compared the cost of the machine changeover time maintenance requirements availability of spare parts and training. The B&H system came out ahead on each of the five points.
"Changeover time was the single biggest factor for us" Montenegro adds. "Running at full capacity and averaging eight changes per month the downtime during a changeover has a significant impact on productivity." The B&H 2300/700 system is equipped with programmable limit switches that accommodate the multiple bottle sizes and help reduce changeover to as little as 30 minutes.
The B&H equipment is designed for continuous use with accurate registration precise cutting and consistent glue application. "We choose to prevent registration problems rather than correct them through our regular maintenance of the blades photo cell and drum" says Montenegro.
The registration photocell detects the registration mark on the film. Proportional correction of label registration gradually returns the labels to the optimum registration and reduces the likelihood that labels will be outside the window of correction.
Promotora's labeler employs what B&H calls a Theta cutting system that is engineered to require minimum adjustments. Promotora has recently ordered optional carbide blades that will run in excess of one year in a round-the-clock operation.
The shrink tunnel employs six individually-controlled heat applicators to gently warm the label area as bottles rotate in front of each heater while being conveyed through the system.
The 2-mil label is a lamination of special biaxially-oriented polypropylene films the high-shrink Vision series from AET Packaging Films (Wilmington DE). The label is a ply of 1.2-mil high-whiteness BOPP that's printed and laminated to an 85-ga clear BOPP. The white color on the PP label is much brighter than the white on other types of film Fernandez says with satisfaction.
While he loves the look of the label Fernandez would prefer more sources of the film. "We're somewhat restricted in purchasing the label stock because there are only one or two companies that make shrinkable polypropylenes" he states.
Since these shrink labels are glued to the bottles there's little chance the label will slip out of position. For generic bottles customers cannot slip labels off bottles on the shelf as they can with stretch labels so retailers benefit. Additionally the cost of shrink labels is significantly less than the cost of ACL decorating. Because the contour bottles use smaller labels they cost less than the large panel labels typically used on generic bottles. However Fernandez says the limited availability of the film probably makes Promotora labels a bit more expensive than the nonshrink labels used on U.S. contour bottles.
For Promotora the decorating savings help offset the increased costs of the heavier preforms. The contour bottle weighs 0.6 g more than a generic bottle of the same capacity. However the cost of 1 labels falls from $5.87 for generic to $5.09 for contours.
At the bottling plants the true contour bottles haven't created any extra costs. While the 600-mL contour requires air conveyors on the filling lines to reach speeds up to 400 bpm so do the 600-mL generic bottles. While some consumers in Mexico remain cost-sensitive the contour bottle was not introduced at a price premium above other single serve nonreturnable bottles.
"People like the Coke contour. The bottle has a much higher quality image and an improved shelf presence" concludes Fernandez. "We consider the introduction of the true contour to be a huge success and we plan to increase our production capacity to accommodate the growing demand."