Coating preparation plant CPP is largely diffused in hand moulding, both for steel and iron castings mainly for applying the foundry coating on cores/moulds by spray or, even more frequently, by flow coating. In case you are evaluating a CPP for feeding dip tanks for cores dipping give a look to ARENA All-in-ONE.
CPP Coating Preparation Plant
ARENA CPP is the stand-alone unit for the automatic coating control and preparation for any type of foundry coatings (alcohol and water based coatings). CPP mixes, controls, prepares and doses dense coating and solvent keeping the density always within a tight range of acceptability, 100% automatically without the variable of the operators. It is ready for iIndustry 4.0. Since 2004 (year of the first unit installed), Proservicetech has installed successfully more than 200 equipment using this technology.
Why ProserviceTech and CPP?
- CPP works perfectly with all foundry coatings (Durrans, ASK Chemicals, HA Huttenes Albertus, FOSECO, etc.) without signing contracts for foundry consumables
- Do you know CPP allows you to save coating? Dense coating can be delivered with less water saving numbers of containers, moreover CPP avoids manual preparation and mixing and moving coating from different containers
- ProserviceTech takes care the engineering, programming, assembling, installation and service of the CPP without using third companies
- As an option, CPP can be provided also with coating temperature control, automatic Viscosity control (Viscosity Sentinel), water treatment to take out bacteria from the inlet water, heating and cooling system of the coating
- Density Sentinel can be tested in water in short time (mandatory for controlling sensors in foundry)
- CPP is almost maintenance free (< 5 min / month)
- Integration: Arena E-PUMP and ARENA CPV for flow coating application, ARENA Vibro-filter for sand and dry coating filtration, ARENA drying solutions
- CPP is designed to automatize and simplify the dense coating dosing according the way it is delivered (drums, containers or trucks, …)
- CPP can be built according ATEX directive for alcohol based coatings
Main defects related to coating
The coating layer thickness is directly related to the features of the coating and to the cost and quality of the castings, for this reason its consistency is critical. Coating contamination by sand and dried coating, bacterial attacks are also cause of casting defects, re-work or scrap. In the previous chart, the main defects are linked to possible causes/sources.
Sometimes, the real source of these defects is difficult to determine. Veining is the best example. Sand grain size and grain particle size distribution, compaction, metal pouring temperature, type of moulding material and coating features are just some of the variables responsible of this common defect. The correct application of a “high quality” coating is an effective method to cover, reduce or even solve problems related to this casting defect. Even the most-sophisticated coating needs to be kept at constant and predictable conditions, otherwise the coating itself becomes the possible source of those defects.
From traditional methods to ProServiceTech solutions
Traditionally foundries use several methods to check the coating, the most common ones are:
- Ford or DIN cups (viscosity),
- Baumè stick (Baumè),
- Weight / volume (density) in laboratory.
The main limits of those methods are:
- Dependent on the skill of the operators
- Batch measurements (possibility of variation between 2 next measurments)
- Very temperature dependent (Viscosity)
- Measurable in laboratory and not in the foundry
- Manually recorded on paper
Unreliable coating measurements make the coating layer thickness inconsistent and unpredictable. Density is definitively more closely related to the solid content responsible for a layer build up and therefore to the final dried coating layer. That’s why we have developed the Density Sentinel: a continuous monitoring densimeter used as the core for all our coating equipment: CPP (tailor made and Smartline) and dip tanks ALL-in-ONE.
The ProServiceTech branded densimeter is the core of our control system, it continuously monitors the density of the coating. The probe is in contact with the coating while it is placed into the preparation tank to detect even minor variations in the density of the coating.
The Density Sentinel is the main control, as it is standard in all CPP’s including the standard CPP Smartline range. The Density Sentinel probe is easily removable for quick testing. In fact, its accuracy can be tested by simply placing the probe into water. In less than two minutes the results of the test can be saved on the database for audit control purposes.
The density measured in equipment utilizing sensors which are attached to the shield of the preparation tank or with the load cell / level control method (an indirect method of calculate the density) cannot be tested without draining the preparation tank first. All controlling sensors in foundries must to be periodically checked.
Dried coating adheres to the inside and to the cover of the preparation tank, tools forgotten on top the preparation tank during maintenance, vibrations, sedimentation due to no or insufficient mixing …these are just some of the issues which can influence the accuracy of the of the density if measured indirectly by utilizing the load cell and level control method.
CPP main options
Viscosity Sentinel, ProserviceTech branded viscosimeter. It allows batch automatic measurements of viscosity taking the sample of coating directly from the preparation tank using a standard Ford B cup or DIN cups. The Viscosity Sentinel includes the automatic cleaning of the cup after each measurement. Viscosity control can be useful to detect and return an alarm in case of bacterial attacks on water based coatings or in case the foundry is familiar with this method of coating control.
Heating and cooling unit. Some coatings are very sensitive to temperature variation and, as consequence, also the coating layer thickness change a lot in between summer and winter. For this reason, we have provided some CPP’s with a unit to keep the coating always inside a specific range set on HMI during the whole year.
WLT: Wet layer thickness control. Some “lost foam” foundries, using high dense coating (coating layer thickness up to 2 mm), uses to dip a stainless steel plate into the coating. Changes of coating properties are related to changes of the weight of the sample covered by the coating. ProserviceTech has fully automatized and integrated this concept to the CPP, measuring the coating layer thickness by laser control as complementary coating control of the Density Sentinel.
UV water treatment: water coating can be contaminated affecting a lot the coating features and causing defects as explained in the previous paragraph. Before dosing the water into the CPP for the automatic density correction, the water is many times recirculated in a closed loop passing through a high-efficiency UV lamp. For each single passage, 99% of the microorganism are destroyed limiting the need of chemical additions into the coating and the costs to waste the infected coating and to empty and disinfect the equipment.
Standard, Simple, reliable, ready.
If you are looking for a simple solution capable of matching the all the previously mentioned features of the ARENA CPP Coating Preparation Plant, but with a standardized design and that quickly pays for the initial investment, CPP Smartline 300 and 600 is the answer.
They are designed to be space-saving with ergonomic design and low-maintenance requirements. Yet flexible enough to be adapted to your existing process (flow coating, dipping or spraying). CPP Smartline can be commissioned in 1 day without ProService technicians, thanks to the “plug and play “features.
The CPP Smartline 300 and 600 are provided with a Density Sentinel as well as coating temperature monitoring.