Packages and closures for packaging

A little bit of "know-how" - What kind of tube should be used in packaging?

Proper selection of closures in packaging plays a very important role in the process of its use. If each piece fits together, the packaging is airtight and functional, it will certainly give the consumer almost a 100% product consumption. One of the most important aspects of completing the package is the proper selection of the length of the closure tube (dispenser, atomizer, washer, etc.) relative to the bottle. To do this, measure the inside height of the bottle from the edge of the neck to its bottom, using the depth gauge, and read the result in millimetres. The length obtained is optimal for the tube to be placed directly in the bottle. Measure the length of the tube by measuring its length from the gasket in the closure nut (visible deepest from where the tube goes out) until it is completed. In case we want the tube to be slightly bent and in contact with the bottom edge of the bottle and its bottom, we can add a few millimetres (depending on bottle parameters) to the above described measurement and check whether the length is correct or if it should be corrected. In case the bottle is not transparent, it is possible to cut a small window into the bottle wall, just above its bottom and organoleptically evaluate the correctness of the measurement to facilitate this process.

The tube should also match the shape and height of the bottle. There are two most popular options: straight down to the bottom or diagonal to the bottle’s corner. In some instances one option is better than the second one. The shorter and rounder the bottle, the higher the probability of forming polymer surface stresses if we point the tube to the edge of the bottle’s bottom. It also causes the risk of breaking or bending the tube which would block the product’s application. Therefore, for short bottles we recommend tubes which are perpendicular to the bottom’s surface.
In case of higher bottles it is safer to choose a tube which is diagonally directed to the corner of the bottle’s bottom. This solution enables accurate dosage of the product.
Let’s remember: the devil is in the detail!

Another very important point in the selection of the tube is the proper shape of the cut of its end. A tube cut at right angles to the bottom of the bottle is definitely the wrong solution. In this case, it contacts the bottom of the bottle with its entire surface, which can lead to the application being blocked. The tube can also be cut under the slant. This method is safer, but there is still the risk that when the tube moves, it can come into contact with the wall of the bottle in such a way that it will seal the tube and stop the dosing. The third most popular and safest type of termination is the so-called 'dovetail'. The end of the tube looks like the letter 'V', whose two ends only point in contact with the bottom of the bottle, which guarantees a free intake of the medium during use. It should be noted that the tubes can also be colour-coded so that they can be matched to the individual design and provide a visual added value to the entire package.

The tube placement depends on the manufacturer's decision and the visual effect producer wants to obtain. Most bottles have a slightly concave bottom (viewed from the outside) and a straight tube closure that meets the highest part of the bottom of the bottle looks better but does not allow the media to drain completely as its residues remain in the bottom recesses. Using a slightly curved tube, the end of which will come in contact with the edge of the bottom of the bottle or the deepest point on the bottom of the bottle will allow the product to be used almost in 100%. It is important to note that the bending of the tube cannot be too strong. You cannot allow it to break or bend upwards, as this can limit your full dose or even completely make the application of the medium impossible.

At this point it is worth mentioning about the material from which the tubes can be made. The most popular and most commonly used material is LDPE (low density polyethylene). The tube made of it is stable but capable of forming and light bending. The second type of polyethylene (PE) used for tube production is HDPE (high density polyethylene). This material is harder and less transparent than previously discussed. PP tubes (polypropylene) are characterized by the highest stiffness and deformation resistance. They are used most often in sprayer or dispenser products at the customer's request.

An important aspect is also the choice of the right diameter of the tube to the density of the medium that is contained in the package. Too little tube diameter can cause us not to reach full dosage or the application will not be possible at all, but ... about it the next time.

Feel free to visit us!