Choosing the right shrink wrap machine for your bindery or shipping department
The five Preferred Pack machines on this page cover three very different operations: a manual chamber sealer, two semi-automatic L-sealer and tunnel combos, and two fully automatic combos built for continuous runs. Picking the wrong one usually shows up within the first year, either as a bottleneck in front of your shipping dock or as a machine that never earns back what it cost.
Match the machine to your actual peak, not your average week
Most print shops don't shrink wrap evenly across the month. Volume spikes around statement mailings, catalog drops, or seasonal runs, and that peak is what should size the machine, not the Tuesday-afternoon average. The 48ST chamber unit handles one package per cycle and fits shops doing short runs or irregular bundling where a few seconds per piece doesn't matter. Once you're running recurring bindery jobs that need a steady pace rather than a stop-and-start cycle, the PreCombo 1519 or the 1622MK Combo make more sense. If your peak days are pushing well past what a semi-automatic line can clear in a shift, that's the point to look at the Excel 5300 or 5600 Combo, which are rated for continuous production rather than batch runs.
Don't buy automation you can't keep fed
The jump from a semi-automatic combo to a fully automatic one changes how your floor operates. An automatic L-sealer and tunnel needs a consistent feed of product to actually hit its rated output, and we've seen shops install a high-speed combo expecting it to solve a bottleneck that was actually upstream, in finishing or packing, not in the shrink wrap step itself. If your current volume doesn't require a steady, mechanized feed into the sealer, the semi-automatic PreCombo 1519 or 1622MK will run close to full capacity with a lot less complexity and a lower repair bill when something goes wrong.
Floor space and clearance get underestimated every time
Shops measure the machine footprint and forget the rest: infeed table space ahead of the sealer, discharge conveyor length after the tunnel, and clearance on the sides for film changeovers and routine maintenance. The compact combos are built with this in mind, but the automatic 5300 and 5600 units need real staging room on both ends to work the way they're designed to. Before ordering either automatic combo, walk the actual floor space with a tape measure, not the brochure footprint, and account for the discharge path to wherever packages go next, whether that's a table, a cart, or a conveyor into packing.
Operator skill varies more than people expect
A manual chamber machine like the 48ST runs fine with rotating staff since there's little to set wrong beyond seal time and temperature. The semi-automatic combos take a bit more training on film tracking, pinwheel perforation, and tension, but a shop can cross-train a bindery operator on one in a shift or two. The automatic combos are a different commitment. The programming and touch-screen controls mean there's real setup involved, and the shops that get the most out of these machines have one or two people who actually own the programming and troubleshooting rather than whoever's free that day. If you don't have that person on staff, the semi-automatic equipment will be more reliable in practice even if the spec sheet says the automatic unit is faster.
Film type and seal technology affect your consumables, not just your throughput
Shops running older wire-seal equipment call us for wire replacement more than almost any other maintenance item, which is why the Micro Knife sealing on the 48ST and PreCombo 1519 shows up in our service history less often. Both machines run PVC and polyolefin film, so if you're not locked into one film type, that flexibility is worth having.
Package size dictates the model more than speed does
Run length and throughput get the attention, but package dimensions eliminate options faster. The 5300 Combo tops out at a smaller maximum package than the 5600, and if your product mix includes taller cartons or bundled sets that run close to that ceiling, the extra headroom on the 5600 is the difference between a machine that handles your full catalog and one that needs a manual workaround for your largest items. Pull your actual package dimensions, including the tallest and widest item you run regularly, before comparing these two, not just your typical piece.
Total cost over three to five years
The manual and semi-automatic machines cost less upfront and less to maintain, and for shops under a few thousand packages a week, they rarely get outgrown fast enough to justify the automatic combos. Where we see money wasted is the opposite mistake: a shop buys a fully automatic combo for a volume they hit twice a year, then runs it at a fraction of capacity the rest of the time while absorbing the higher service and parts cost of the more complex machine. If your peak volume genuinely requires 40 packages a minute on a sustained basis, the automatic combos pay for themselves. If that peak is occasional, you're better off with the 1622MK and a plan for overtime during the two busy months, not a machine sized for a demand you don't have most of the year. As an authorized dealer for Preferred Pack equipment, we install and service all five of these lines across the Western U.S., and that service history is exactly how we know which class of machine a given shop's volume actually supports.
Common shrink wrap machine problems and how to fix them
The seal splits open or peels apart before the package reaches the end of the line This is the single most common call we get across the 48ST, PreCombo 1519, 1622MK, and the automatic 5300 and 5600 combos. The seal looked fine coming off the machine, then it opens in the box or on the truck. The usual cause is seal temperature or dwell time that's set for a different film gauge than what's actually loaded, so the film never fully fuses along the seal line. The next most common cause is contamination on the sealing surface, film dust, adhesive residue, or melted film buildup on the Micro Knife or hot-knife bar that keeps it from making clean, even contact. Less often, it's seal bar pressure that's drifted out of adjustment or film tension that's too tight and stressing the seal as it cools.
To confirm the cause, pull a sealed package and flex the seal by hand before it's boxed. A seal that separates in a clean line usually points to temperature or dwell time. A seal that looks scorched, uneven, or has visible debris embedded in it points to a dirty sealing surface. Wipe down the Micro Knife or seal bar with the cleaning method in your operator manual and run a test package before changing any temperature settings, since a clean sealer fixes more of these calls than a temperature adjustment does. If the surface is clean and the seal still fails, adjust seal temperature or dwell time in small increments and retest rather than jumping to a large change.
Prevention is a wipe-down of the sealing surface every shift on any of these machines, since film residue builds up fast on recurring runs. This is a straightforward in-house fix. Call us only if the seal bar or Micro Knife shows physical wear, pitting, or won't hold a consistent temperature after cleaning and adjustment, since that points to a heating element or sensor issue.
Packages come out of the tunnel pillowed or ballooned instead of shrunk tight The film shrank around the package but trapped air kept it from pulling down tight, usually most visible on irregular or multi-item bundles. The leading cause is the perforating pinwheel not cutting enough vent holes, either because the pinwheel needles have dulled or because pinwheel pressure against the film has backed off. The next most common cause is tunnel airflow or recirculation settings that are too low for the film gauge, which doesn't let trapped air escape before the film sets.
Confirm it by checking the film itself for perforation marks before it enters the tunnel. If the holes are faint, widely spaced, or missing on one side, the pinwheel is the problem. If perforation looks normal and packages still balloon, move to tunnel airflow and conveyor speed settings. The fix is usually a pinwheel adjustment or replacement, which is a routine in-house task on the PreCombo 1519 and 1622MK, both of which use a pinwheel perforator. If airflow is the issue, check the tunnel's recirculating air setting against the film manufacturer's recommendation for that gauge and adjust in small steps.
Inspect the pinwheel weekly on machines running daily production, more often if you're running heavier or textured film that dulls the needles faster. This is operator-level maintenance. A service call is only needed if the pinwheel drive itself isn't engaging or the tunnel's blower motor isn't cycling.
Film tracks off to one side or packages come out wrinkled going into the tunnel This shows up first as a package that enters the tunnel slightly crooked, then gets worse as a run continues. The most common cause is film roll tension that isn't balanced side to side, often from a roll that wasn't seated squarely in the cradle. The second most common cause is a buildup of paper dust or adhesive on the film rollers, which creates uneven drag across the web. Less frequently, it's a roller that's gone out of alignment from a jam that wasn't fully cleared.
Confirm by watching the film path from the roll to the sealer during a slow test run. If the film visibly pulls to one side before it reaches the sealer, check the roll seating and tension first. If the film runs straight off the roll but drags or hesitates partway through, the rollers likely need cleaning. Reseat the roll and rebalance tension as the first fix, since that resolves most of these calls without touching anything else. If rollers are the cause, clean them with the solvent and method specified in your operator manual, not a generic cleaner that could leave residue.
Wipe down film rollers weekly, or more often on shops running a lot of coated or glossy stock bundles where dust transfers to the film path. This is operator maintenance. Call us if a roller shows physical wear or won't turn freely by hand after cleaning, since that's a bearing issue, not a cleaning issue.
The magnetic hold-down isn't gripping the product squarely during the seal cycle On the 48ST, PreCombo 1519, and 1622MK, the dual magnetic hold-down is what keeps the product from shifting as the seal bar comes down. When it's not holding, the seal comes out crooked or the package shifts mid-cycle. The most common cause is debris, usually dried film residue or paper dust, sitting on the magnet contact surface and breaking full contact. The second cause is a product that's too light or too rigid for the magnet strength to seat properly, which is a setup issue rather than a machine fault.
Confirm by wiping the magnet surface clean and running the same package again. If the hold-down is solid after cleaning, that was the cause. If it's still inconsistent on the same product that ran fine last week, check whether the product mix or packaging weight has changed, since that changes how the magnets seat even when the machine hasn't changed at all.
Clean the magnetic contact surfaces daily on machines in regular production, since this is a fast wipe-down that prevents most of these calls. This is entirely an operator task. A service call is only warranted if the magnets have measurably weakened, which shows up as inconsistent hold-down even on a clean surface with a known-good product.
The automatic combo (5300 or 5600) stops mid-cycle or misfeeds instead of running continuously This is specific to the fully automatic L-sealer and tunnel combos, where product staging and the photoeye sensors control the automatic product adjustment. The most common cause is a photoeye lens that's picked up dust or film residue and is no longer reading product position reliably, which the machine reads as a fault and stops. The second cause is product staging that's inconsistent, meaning product isn't arriving at the infeed in the spacing or orientation the program expects, which looks like a machine fault but is actually an upstream feed problem.
Confirm by checking the photoeye lenses for visible film haze or dust first, since that's the fastest thing to rule out. If the lenses are clean and the machine still faults on product that's staged consistently, check the touch screen's diagnostic log. Both the 5300 and 5600 use a self-diagnosing PLC, and the fault log will usually point to which sensor or station triggered the stop rather than leaving you guessing.
Wipe photoeye lenses daily on machines running full shifts. This is operator maintenance and takes a minute. If the diagnostic log points to a sensor, drive, or PLC fault rather than a feed or cleaning issue, that's a service call, since these are factory-calibrated systems and resetting values incorrectly can throw off the automatic product adjustment across every program stored on the machine.