Why Bottles Tip Over on Conveyors - Tips to Prevent Tips

Bottles tipping on a conveyor can be the first step of a packaging line nightmare. In most cases, the fix is not as simple as picking the bottles up. Tipping bottles can lead to machine jams, bottlenecks, spilled product, and even damaged machinery. Bottle instability can result from several different factors, often working together, that may include the container design, the conveyor speed, the conveyor guide rails, product fill levels, and equipment integration. Understanding these variables, and how they affect performance, is essential to ensuring and maintaining an efficient packaging line with minimal downtime.

At Liquid Packaging Solutions, Inc., we understand that a well-designed conveyor system is about more than moving bottles from one machine to the next. Whenever possible, our conveyors are engineered as a part of the complete packaging solution to keep products flowing through rinsing machines, liquid fillers, capping machinery, and more. In our experience, some of the more common reasons for bottles tipping are discussed below:

Lightweight or Unstable Containers

With an emphasis on sustainability and reducing product waste, one way many businesses reduce costs and waste is by using thinner plastic containers. Lightweight bottles can offer economic and environmental benefits but also become less stable during the packaging process. In addition to lightweight bottles, tall, narrow, or uniquely shaped containers are also susceptible to tipping when guiderails are not configured to offer support, contacting too high or too low. Properly configured guiderails, or even extra guiderails to provide more support, can help these bottles remain upright.

Conveyor Speed Changes

The speed of all the conveyors on a packaging line should be synced to provide a continually flow along the packaging system. One of the most common causes of bottle tipping occurs when bottles accelerate or decelerate when moving from one conveyor to another. For example, if the conveyor for a filling machine discharges bottles faster than the downstream capping machine can accept them, backpressure can cause bottles to lean or tip. Or if the conveyor is simply moving faster for the filler than the capper, the bottles may tip when moving from one conveyor to another. Though some exceptions do apply, packagers typically need to find a single speed for the entire conveyor system to keep bottles flowing smoothly through all machines to help avoid leaning and tipping bottles.

Improper Guide Rail Adjustments

Guiderails adjustments should provide support for bottles without squeezing them or restricting their movement. For companies with many daily changeovers involving multiple container sizes, this can be an important adjustment to avoid bottle tipping. If guiderails are too wide, containers can wobble, lean, tip, or cause spills. If they are too tight, they can cause bottle blockages or squeeze product onto the conveyor. Rails must also find the bottles center of gravity to provide proper support as they move down the packaging line. Too high or too low and bottles can easily become unstable. Always doublechecking guiderail width and height for proper support will avoid downtime from tips and spills.

Product Fill Levels

Bottles behave differently when their weight changes, as alluded to earlier when talking about thinner plastic containers. The same is true of empty bottles versus filled bottles; the weight will change and they will act differently on the conveyor system. The center of gravity for some bottles may change when filled, especially if the containers are not completely filled or have an odd shape. Guide rails may need to be positioned differently before and after the fill to avoid bottle tipping along the packaging line.

Conveyor Layout

Though a conveyor might simply be a straight line from loading bottles through rinsing, filling and capping, right on to accumulation, many systems will include turns or curves, elevation changes, transition plates, or areas of accumulation for quality control checks. Engineering a conveyor system with all the turns, curves, and other transitions in mind will help to avoid poor transitions or jams in accumulation areas that can lead to lost time from tipped or leaning containers.

Reducing bottle instability and preventing tips begins with the proper conveyor system design for the project at hand. Evaluating container shapes, container materials, conveyor speeds, guide rail positioning, and other factors help to create a packaging line that runs efficiently through minimizing downtime and product loss. Contact Liquid Packaging Solutions to work with the engineering team at LPS to design an optimal conveyor system that works for your own unique packaging line.