VFFS Speed Considerations
Last week we kicked off our series on VFFS speed considerations, and discussed how package width and head space relate directly to the speed of your packaging. (If you missed it. You can view the post here.)
In part two, we are discussing product characteristics and how to maximize the efficiency of your food packaging machinery line for a wide variety of products.
In this post we're going to lay out each of these characteristics and how they will impact the speed of your packaging line:
Weight of your product
Shape of your product
Stickiness of product
Product Weight- Bricks or Feathers?
The packaging process of coffee is a great example of how differing product weights contribute to overall effectiveness of a VFFS solution.
Whole bean coffee is a speed-friendly product to work with. It essentially "falls like rocks" with near nonexistent downsides like dust or stickiness. Also, when comparing the packaging difficulty of light vs dark roasts, the whole bean varieties don't differ much in behavior when traveling down the line.
This cannot be said of ground coffee when comparing light and dark roasts. The variance in density between light roast coffee and french or dark roast coffee has a tendency to cause problems for the coffee industry, particularly with filling accuracy and seal integrity.
Ground dark roast coffee is incredibly airy and dusty because of how much more moisture is lost during the roasting process compared to lighter roasts. While the lower mass may not seem like a big deal, it can create issues while trying to run high speed coffee packaging equipment at 140 bags per minute. For more information on specific speed considerations for coffee packaging, click here for another resource.
For light weight products there are specific factors that need to be wisely addressed to achieve consistent high speeds. Ensuring that your package has enough head space to account for any kick-back of the product when it lands is imperative.
Another recommendation would be to utilize a static eliminator for high-friction products or even dry and cold climates is also helpful for low density products. Static build up will cause seal integrity issues as fine particles adhere to the film in the seal area.
For Rovema, the most effective solution to clean charges of very airy products, is the use of an adjustable column jack on our Auger filler. By reducing the drop height that the product has to fall, you can minimize the product kickback when it lands. The product also has less time to string out in the tube.
Product string out, in most contexts is considered a negative phenomenon, however for products that are awkwardly shaped, stringing out the of the product is precisely what drives the most effective results, especially for frozen food packaging.
Green beans for example, are a decent density for filling and don't have any dust or stickiness issues but their long shape brings other challenges. When charges are dropped all at once, their shape causes product bridging above and within the filling tube. These compact charges nearly eliminate free movement of the individual pieces.
To solve this issue, intentionally stringing out the product allows more movement of the pieces so that they can fall correctly.
While most sugary products don't have a sticky exterior at room temperature, since a coating of powdered sugar or wax or even an individual wrapper is added to keep the products free flowing, the real issues that effect overall speed and efficiency happen during the sealing process.
For candy packaging on a VFFS machine, if a piece strings out incorrectly and gets caught by the seal jaws, this can become a maintenance nightmare. Sugary products being mashed into the seal not only is going to create seal integrity issues caught either down the line or in the market just causes the waste of the rest of the package but also, the product as a tendency to get cooked onto the seal jaws, making clean up a time consuming process.
If the issue is not addressed immediately, the product build up with continue to result in reduced seal integrity and wear down the knife and the seal jaws at a faster pace.
Sense and Seal® technology has effectively eliminated the issue of product buildup in the seal area for Rovema customers allowing them to avoid costly unexpected down time and increase the useful life of their spare parts.
The technology is so sensitive when detecting a product at high speeds, that even a lightweight product, like a marshmallow, is detected and the seal process is halted. The Sense and Seal® process is shown below:
The Final Section: Complexity of Package Formation
For packaging trends like stand up pouches, the trade off of complexity and speed can seem like too much to overcome, however these changing consumer preferences can be met with easier-to-form bag styles that still have great merchandising presence.
In the final section of the speed considerations series we will be covering package complexity of different VFFS bag styles and how the overall speed of your packaging line can be impacted.
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