CIRUS heat sealing system for thermoplastic films.
Machines with a high product output, special packaging applications or packaged goods requirements, selection of the film material under mounting cost pressure – all of these factors result in film types that present daunting challenges for the sealing system.
Users are thus increasingly shifting their attention towards issues such as seam quality and consistent repeatability, the shortest possible sealing times and minimal heat stress to the packaged goods – not to mention demands for less downtime due to maintenance, the replacement of wearing parts or retooling. ROPEX has the ideal solution to these problems: the CIRUS range of sealing systems and associated complementary components.
The perfect solution
The ROPEX CIRUS (Cermet Integrated Resistive Ultrafast Sensorless) heat sealing system is the perfect solution when it comes to heat sealing applications: it is ideal whenever high temperature dynamics are required to heat and cool the sealing tool, the sealed seam or pouch has a complex contour and no – or only minimal – heat stress to the packaged goods is allowed. Furthermore, the CIRUS sealing tool needs virtually no maintenance because – unlike conventional impulse sealing bars – it has no moving parts like bar end blocks, which could break or become jammed, to compensate the linear thermal expansion of the metal strip. The CIRUS technology also eliminates product changeover times because different film widths can be processed without altering the actively heated tool length (in other words, the tool works independently of specific formats).
Heating up & cooling down in a few milliseconds
The extremely high temperature dynamics of our CIRUS tools are a result of their special structure: several insulating layers are printed on a planar stainless steel underlay in a screen process prior to applying the actual heating line as a power resistance. An electrical insulating layer is additionally incorporated to insulate the tool and protect the resistance layer against external influences. Each printed layer is burned in by sintering, so that a firm bond is created both between the individual layers and with the underlay. The heat seal element obtained in this way is then fused onto a stainless steel cooling substructure with an integrated channel through which water flows.
This special tool design enables novel characteristics compared to classic heat sealing systems: for instance, since the heating line is only a few µm thick, and the heat capacity is also low, extremely high temperature dynamics are possible, namely 6000 K/s.
The heat transfer between the film and the integrated water cooling unit is excellent because the printed layers are exceptionally thin. The sealed seam therefore cools down very fast and very efficiently. The combination of the CIRUS tool’s extremely high temperature dynamics and the water cooling system ultimately results in significantly shorter process times and higher productivity than are possible with conventional heat sealing methods. The thermal expansion which occurs due to the temperature rise in the heating line and the underlay is reduced as a result of the special tool structure, so that CIRUS heat sealing bars require no mechanical parts to compensate this effect. Broken springs or jammed bar end blocks, which can be a problem with metal heat seal elements, are consequently ruled out.
Individual heating line contours
If standard UPT sealing bars are not suited for the task at hand, a customized tool can be manufactured explicitly for your application. In this case, a heat sealing tool is designed and built in close cooperation with the customer based on your detailed specifications. Owing to the special production technology which is used for the heat seal elements, the heating line contour can be tailored to individual requirements. Curved sealing geometries are also possible, for example circular or elliptical shapes. Overlapping temperature profiles can likewise be realized.
In addition to the actual sealing tool, the CIRUS sealing system comprises a temperature controller and various complementary components such as a current filter, impulse transformer, current transformer and counter bar. The cooling unit is a further essential part of the system. The electrical and thermal design of this integrated system is taken care of by ROPEX. You always acquire a complete system, ready to use in your application: by observing our technical recommendations, you can profit from the optimized functionality of this technology, which reduces the effort for installation, startup and maintenance to a minimum.