How Does a ROPP Capper Work?

Roll-On Pilfer-Proof capping machines, also known as ROPP Cappers, are perhaps most commonly associated with sealing wine bottles and distilled spirits. However. these bottle cappers are becoming more and more popular across a range of industries as a means to keep both products and consumers safe via a tamper evident seal with an aluminum cap. So how does the ROPP capper work? To better understand, let's take a look at the different components of ROPP capping machines manufactured by Liquid Packaging Solutions and the unique sealing process used by the machine to achieve a tamper-evident seal for a range of products.

Most people, whether in the packaging industry or not, have seen a screw-on type cap - such as those found on bottled water and other popular beverages. The threads on screw caps complement the threads found on the bottles that they seal, allowing the consumer to simply screw the lid on or off, as needed. ROPP caps, however, are typically blank aluminum sleeves prior to being placed on a bottle and sealed. Instead, the ROPP capping heads create threads on the aluminum closure to match the threads on the bottle as the capping is taking place.

First, caps must be placed on the bottle before the machine can create the tamper-evident seal. Depending on the automation level of the ROPP capper, this task may be completed in several different machines. Semi-automatic models may require manual placement of the aluminum blank on the bottle prior to sealing, while other semi-automatic models might let an operator load a chute with multiple caps for quicker and easier placement. Automatic ROPP cappers include an automatic delivery system that will deliver and place the aluminum blanks on the bottle just prior to positioning the bottles under the capping heads.

Next, the bottles must not only be properly positioned under the ROPP heads but must be stabilized to ensure consistent and reliable sealing. Both automatic and semi-automatic bottle cappers may use different indexing methods depending on the speed desired, the bottles, the closures, and other factors. Some may use a bottle nest to properly place individual bottles, while others could use pin indexing, screw indexing, or even a star wheel to position and hold bottles steady as the threads are created.

Once in place on the bottle, the smooth aluminum blank closures, absent threads, are ready to be applied to the bottles. The capping head, using specialized rollers or knives, rotate around the bottle cap and neck, shaping the aluminum blank to match the threads on the container and applying pressure to create a secure, tamper-evident seal that protects both the product and the end user.

ROPP Capping Machines Manufactured by Liquid Packaging Solutions

At LPS, we build both automatic and semi-automatic ROPP cappers. Semi-automatic machines typically seal a single bottle at a time, and require an operator to interact with the machine for each cycle run. Operators may place the cap, position the cap and bottle, activate the capping process, or perform a combination of these and other tasks.
Automatic ROPP capping machines will likely include multiple capping heads, a cap delivery system and an indexing system as described above. While operators will set up the machine and use the PLC to store and recall recipes for certain cap and bottle combinations, once production begins, they will not need to interact with each sealing cycle. Instead, the operator a line using an automatic ROPP capper will monitor the machine and provide bulk closures when necessary, freeing up time to perform other tasks for the business.

The versatility of the ROPP capping equipment allows the machine to serve the needs of packagers with both large-scale and small-scale production processes by providing consistent, secure and tamper-evident seals with every cycle. To learn more about LPS ROPP cappers or for more information on any of the capping equipment built in our Indiana plant, browse the Bottle Capper section of our website, or contact LPS with help finding the right capping solution for your own packaging project.