Bundling folding cartons of Suave and Pond’s moisturizing lotions into multipacks is going a lot smoother for Unilever these days. That’s due to a shrink-wrapping system from Packaging Machines Intl. (Elk Grove Village, IL).
The PMI Model SIRD-15 SS bundler was started up in March 2002 at the company’s Clinton, CT, facility. The dual-lane machine collates and wraps cartons that contain a 4-oz plastic bottle into three- and six-count packs. It also includes an integrated dual-lane heat tunnel. The system unitizes 60 to 100 cartons/min over two to three shifts.
“The reason for purchasing this machine was to eliminate ‘crash bottom packers,’” says Steve Martinik, senior maintenance engineer. “The benefits were based on changing from distributor packers to shrink wrap. The cost savings were significant—film is much less expensive.” Martinik explains that a “crash bottom packer” is a five-sided chipboard sleeve with an open top. It opens from flat to accept the cartons when opposite corners are pressed together at the same time.
The per-unit material cost savings using film amounts to about a 90% reduction compared with the chipboard carton. Those had been packed manually, so the plant also realized notable labor savings. The SBS bottle cartons, which measure 2¾’’ x 47/8’’ x 1½’’, remain unchanged.
For marketing, the wrapper allows Unilever to configure the products in a 1 x 3 three-pack or a 2 x 3 six-pack. Suave Lotion is bundled as a three-pack; Pond’s Lotion is bundled as a six-pack. Martinik points out that they could easily run a 1 x 6 configuration, although they have no plans to do so. For Suave three-packs, the film width is 5’’; for Pond’s six-packs, the film width is 8’’. The shrink film is removed by the retailer so that the cartons may be sold individually.
Collated and shuttled
The cartoned bottles are conveyed upright to the machine in single file with the package front leading. The cartons are then collated into groups by a shuttle arm that transfers the group to the right and then to the left, three cartons at a time. Six-packs require two cycles of the cross-pushing shuttle.
Once the group is collated and in position, a pneumatic arm pushes it straight ahead through a curtain of unprinted, 1.5-mil polyethylene film. The curtain is formed from top and bottom film rolls that are heat-sealed together to form a single web of film. After the group moves forward, the two trailing edges of film are sealed together and cut. The seam appears about one-third up the upright packs, and results in a bulls-eye on each side. Using top and bottom rolls of film is said to be a more efficient method than using a single roll for slower speed applications of 20-25 bundled packs/min, Martinik claims.
Two parallel rows of bundles are then conveyed through the 5’-long electrically heated shrink tunnel. The two-lane, dual-chamber tunnel is mounted on the same frame as the wrapping machine.
Following the heat tunnel, the side-by-side bundles are brought into single file by converging side guides and a combiner.
“The PMI bundler provides production with a machine that is very reliable and extremely quick to change over—in under 15 minutes,” states Martinik. “The quality of the wrapped packs has been excellent.”
The bundler is run by programmable logic controller and has a touchscreen operator interface that enables operator-selectable changeovers. The change of films is also easy, according to Martinik, and is done in a few minutes using slide-out trays. The new film roll is spliced to the old using tape.
Martinik terms the machine start-up as “excellent. It is the latest of four PMI shrink wrappers that our plant now operates. We believe that the bundlers are a very good value for the dollar and perform very well in a three-shift environment.”
