The CM33 Washdown and CM35 Washdown combination systems are aimed at processors that require a quick-cleaning, advanced contaminant detection and precision weighing solution in one unit.
The CM33 Washdown is based on Mettler Toledo's C33 PlusLine Washdown Checkweigher, which it announced in 2020, but also has an integrated metal detector. According to the company it can handle up to 250 weighings per minute, with weighing accuracy of up to +/- 0.2g. The CM35 Washdown is a high-frequency and high-sensitivity system.
Both systems offer a choice of three stainless steel Mettler-Toledo Profile metal detectors. These are the Profile Combi LS for small, packed product applications, Profile Advantage for maximum sensitivity to take on challenging applications and Profile R/RZ for advanced inspection of bulk, dry products.
The combination CM33 Washdown and CM35 Washdown systems reduced downtime when cleaning due to their smart hygienic design, Mettler Toledo claimed. This makes them ideal for use with applications that require stringent cleaning processes using caustic cleaning agents to combat bacterial contamination risks, without compromising weighing accuracy and detection sensitivity.
Potential applications include yoghurt cups and cheese trays without aluminium foil lids, where ingredients can spill over and contaminate product inspection machinery, hence requiring robust washdown cleaning.
Quick and efficient cleaning is aided by the washdown systems’ sloped surface design, which discourages liquid or debris collection. Ingress protection is also a key design factor: the CM33 Washdown and CM35 Washdown and their Human-Machine Interfaces (HMIs) are IP69 rated, so able to resist the most caustic detergents and disinfectants. Together, these hygienic design features are meant to reduce the operational downtime needed to efficiently complete rigorous cleaning regimes.
Components such as the metal detector conveyor and the product collection bin are easily dismantled and reassembled, while tool-free maintenance improves uptime.
Range of options for rejected products
A self-adjusting elastic belt removes the need for tensioning, and ensures the belt is correctly aligned in the centre of the conveyor. This helps to reduce the possibility of damage to the belt and subsequent unexpected downtime. Customers can choose from a range of options for dealing with rejected products, including a tunnel for under- and over-weight products, and swing gate, air jet and pusher mechanisms.
The systems could save more time by storing task parameters in the HMI, which could be instantly recalled for automatic job set up on both the checkweigher and metal detection system, Mettler Toldeo said. Up to 250 recipes can be stored in the HMI and additional memory for more recipes can easily be provided when required.
“The CM33 Washdown and CM35 Washdown systems bring something new to the market,” said Frank Borrmann, market manager at Mettler-Toledo Product Inspection.
“These are highly automated, high performance machines, utilising Mettler-Toledo’s well-known precision technology packed into a compact, open frame unit that is proven to be able to work in the harshest of washdown environments with no loss of quality.
"In addition, by combining checkweighing and metal detection in a single machine, food manufacturers can also save space in their factories, and benefit from service and support from a single supplier."
Mettler-Toledo began developing combination product inspection systems in response to customer issues such as the difficulty of fitting all the inspection technologies they require into limited factory floorspace.
X-ray, vision inspection and track and trace
As well as metal detection, Mettler-Toledo’s combination systems can also include x-ray, vision inspection and track and trace technology.
The integration includes not only hardware but also software. The CM33 Washdown and CM35 Washdown, as with other combination systems, have two HMIs that run in parallel – one for the checkweigher, one for the metal detection system – communicating with each other, and giving the combination systems built-in redundancy.
If one HMI fails, the other automatically takes over, ensuring no unnecessary downtime is incurred and all Critical Control Points continue to function.