Capping technology, in search of flexibility and modular solutions


The manufacturers are always longing for systems that are faster, more efficient, compact, versatile and easy to use. The research is directed toward flexible and modular solutions. Capping in the history of the beverage industry have always been in the spot light. The drivers of the capping development have always been: increased productivity; flexibility resulting from necessity of manufacture not just large batches but also a limited number of bottles with a high degree of customization and flawless quality. The high-speed automatic capping machines operate in different ways depending on the type of cap to be applied (crown cap, aluminum capsule etc.).

How it works

The loading phase is relatively similar for all. The deposition of the caps on the bottles and the closure section vary significantly though. The caps loaded into the hopper are transferred to a rotating wheel that orients the caps in vertical position into the feeder through which the single cap is conveyed downstream. The cap is now placed onto the mouth of the container, the machine has a specific chuck for each different cap size. (Cap, crown, etc.). In order to have a flawless closure, the axis of the heads capping must precisely coincide with the axis of the bottles, while, to reduce to minimum mechanical impact between the capping head and the finish, the placement must be done very gently. In the case of crown, the deformation of the cap and the subsequent closure around to the neck finish is obtained by the simultaneous action compression and contraction. The deformation the crown is obtained when the applied force reaches 300 kg. If it ‘s rotary capping machine, the caps are sorted and fed through chute conveyed to cap starwheel from where the caps are picked up by capping heads; when bottles come under this head the containers are aligned automatically by spring loaded guides. The capping head grips the caps by clutch arrangement lined with hard rubber pads. The torque on the head can be adjusted for handling different sized and shape of bottles and caps with little change parts

The servo allows more flexibility

A servomechanism, or servo in brief, boosts flexibility; it is an automatic device used to perform a mechanical control in distance. For example, it may be used to adjust and remotely control the mutual position of two mechanical components. The connection between the two components is usually the electrical or electronic, while the mechanical force is usually generated by a electric motor, other types of servos use hydraulics, pneumatics, or magnetic principles. The servo-mechanisms apply the principle of feedback: where the feedback or error-correction signals help control mechanical position, speed or other parameters.  Any difference between the actual and wanted values is boosted and employed to drive the system in the right direction to reduce or eliminate the error. In this way the feedback control makes stable a system highly unstable. Applied early especially in pharmaceutical packaging machines, servomechanisms are now popular also in bottling sector, the costs once high are now within range of plants of small and medium size suitable for companies facing first time automation. The advantages that a company can derive from the use of a single block or a servo are many and interesting. First there is the remarkable reduction of changeover times format, an integrated closed loop feedback control system using a computer for setting parameters for precise torquing of different caps onto containers of various sizes. Servo automatic cap and container delivery mechanisms provide synchronous advancement of the caps and containers to different stations within the machine for continuous processing. Another significant advantage servo system is the accuracy of the moment of a force that can fluctuate an interval not exceeding +/-0.5% of set value. The remote diagnosis allows to program the maintenance prior informed cause, and to minimize the downtime due to wear out. The system is able to detect an abnormal increase friction in the heads capping or in the engine, of report it to identify cases, allowing maintenance of intervene in good time. In cases it’s required a aligned cap position, for instance for ensure an opening facing towards the front of the package, a special servo can facilitate the orientation of the capsules before and during the application. The servo can be programmed to recognize whether the capsules are to be rotated before screwing and it is able to distinguish bottles capsules not aligned, deformed or with faulty thread and promptly ejecting them. Using the servo and the related actuators the risk of particle contamination is greatly reduced.

Caps and closures

Caps and closures had a long evolutionary process in terms of composition and refining materials, the correct sizing and research how best to production and usage. Still they shouldn’t be considered packaging without any ample room for improvement. For many the cap is just an object that keeps the liquid from leaking or from evaporating. For a technician the choice of a closure isn’t just manner of aesthetic or adaptability to a finish. It is rather one of the many factors that influence the quality characteristics and stability of the product over time. Closures are required to perform some or all of these functions: provide an effective hermetic seal to prevent the passage of solids, liquids or gases into or out of the container, provide easy opening and in cases of resealing, provide evidence of inviolability as roll on pilfer proof closures, such as aluminium roll on closure used on bottles, leave a tell tale ring around the bottom of the neck ring after opening providing evidence of tempering. The technology of the closures is constantly changing and moves in parallel substantial conformance with the by the development of new products, with the demands of more practical due to the changing habits of consumers and with the growing concerns related to sustainability. The cap is a packaging primary and all its components are therefore subject to compliance with the legislation on materials for contact with food. Demanding are specific barrier properties. Concerns are about the possible disposals/interactions container-contained especially in the presence of volatile substances. For example, if the raw polymeric materials or the ready to use caps are stored in an unsuitable environment, the seal can absorb smells that may affect organoleptic characteristics of the product. Another concerning case is the adsorption of the aromas by the gasket. It is therefore always necessary to evaluate attention to the compatibility between closure and content, as a function of the critical presented by the recipe product and the possible heat treatment at which will be subject the bottles. Today the market is mainly oriented towards the use of plastic closures generally either compression or injection molded, the former being based on urea-formaldehyde or phenolic-formaldehyde resins, and the latter on a variety of thermoplastic polymers including PS, LDPE, HDPE, PP and PVC. The sealing components, the gaskets are made from rubber or plastisols the liners are suspections of finely divided resins in a plasticizer, which can be flowed in or molded. The research is directed to the sustainability, the main way to reduce the environmental impact is focused on reducing material by 10 to 20% in weight without decreasing the functionality of the closure. An interesting driver of innovation are the ergonomic capsules associated to the increasing consumption of beverages outdoor and the need to able to drink without much afford making other activities at all ages. For elderly people, children or people suffering from particular disabling diseases are projected easy opening caps with knurls or in TPE Soft-touch resins that can enhance the grip.