The traditional approach of installing a unit to control and prepare the coating and then pumping the controlled coating to the single dip tanks is tricky and source of potential casting defects without a proper traceability. ALL-in-ONE controls, prepares, filters, pumps the coating and dips the cores for the highest consistency.
ALL-in-ONE is available in different standard sizes (Smartline) and tailor-made (Custom) solutions.
Benefits and Features of ARENA ALL-in-ONE
- Coating consistency and control into the dip tanks
- Repeatable dipping operations and layer thickness thanks to the ProserviceTech Manipulator
- Noise level < 60 dB
- The level in the dip tank is always constant: useful for ergonomics in case of dipping by operator and for the installation in robotic cells
- Lower coating consumption
- Sedimentation free
- Almost maintenance-free equipment
- Optional: ATEX certification (not just ATEX components!!) for alcohol-based coating
- Flow coating is available without additional pump, simply bypassing the existing ARENA E-pump
Controlled coating right where the cores are dipped!
In the past, many foundries have developed their own dipping systems. In fact coating suppliers have insufficient knowledge or they simply do not consider it advantageous or are not interested in providing solutions for the correct application of the coating.
It also frequently happens that the dipping tanks are part of a larger scope of supply (including core shooters, drying ovens, robotic cells, etc.). In those cases, the common suppliers consider them as an appendix and of secondary importance. This leaves the customers facing the daily problems caused by an inferior design of this equipment. High maintenance demands, casting defects (veining, sand inclusions, syneresis, runs and drips, etc.), frequent downtime, inconsistent coating thickness, sedimentation, no filtration of the sand or dried coating particles: these are just few of the main issues related to the coating by dipping , which most of the foundries are commonly facing with.
Very often the coating is controlled only in a preparation area and then the coating is moved or pumped into the dip tanks. In case there is not a preparation area, the coating is commonly controlled with low frequency (max. 1 or 2 times per shift).
This process conceals many potential problems including: sedimentation, solvent evaporation or bacterial attack. This can result in a variation in terms of coating density when compared to the preparation area, where the coating is monitored or between 2 measurements into the dip tanks. This creates unreliable traceability problems and extremely difficult troubleshooting to identify the real reason of casting defects.
For this reason, the ProserviceTech All-in-One dip tanks are provided with their own CPP with density control and preparation in one unit. The coating is then constantly monitored by Density Sentinel, handling automatically the dosing of dense coating and solvent. In this way you can control the coating features right where the cores are dipped.
Are you aware coating sedimentation, dipping operations and the way the cores are handled after dipping can affect the coating layer thickness up to 50-60%? In fact those variables act often independently independently of each other, making the process and the coating layer thickness often out of control and unpredictable.
In collaboration with the company James Durrans Ltd, using their water-based coating RWB 3521-MOD-P, Proservicetech has performed the following tests to measure the variation introduced by the previously listed variables. An ARENA ALL-in-ONE DT5X5S with manipulator and an ARENA Drying oven RO1400 have been used.
TEST 1: Wet layer thickness (WLT) Vs Dipping time / speed
The next chart shows the effects on the coating layer thickness caused by different speeds and dwell time of the core in the coating: for example “1sec-1sec-1sec” means: 1sec (time to dip), 1sec (timeo at max depth), 1 sec (time to take out). Coating dipping operations can have a relevant impact on WLT as they depend 100% by the operator and vary between operators and also with the same operator between the beginning and the end of the work shift. This difference can be even increased with heavier cores as it impacts on the strength and fatigue of the operator. Just 1 extra sec while the core rests in the coating can add, on average, 50 microns in terms of the WLT.
TEST 2: Coating Density to simulate effects of sedimentation
The design and concept of the dip tank is extremely important. When the mixing is inconsistent, the coating sediments in some areas of the dip tank and after dipping the coating can present different WLT day by day and sometimes also on the same core. In order to simulate the effects on the WLT, the cores were dipped in 3 separate times at 3 different densities prepared by ALL-in-ONE DT5X5S:
Density: 1,21 Kg/dm3 , Viscosity 10,8 sec. – 28°Be
Density: 1,26 Kg/dm3 , Viscosity 12 sec. – 37°Be
Density: 1,29 Kg/dm3 , Viscosity 14 sec. – 40°Be
To avoid any additional variables interfering with the results, all samples were dipped by using the ProserviceTech manipulator.
The results are clear: coating sedimentation and different coating features (density) generate a huge variability in terms of WLT even if the dipping operation are 100% repeatable (robot or ProserviceTech manipulator).
TEST 3: WLT Vs Cores handling after dipping
The way the cores are dipped and handled after dipping can affect the WLT. The graph shows the 3 main methods:
- manual dipping;
- dipping by Proservitech manipulator;
- manual dipping followed by cores flicking / shaking.
The difference in terms of average WLT between the various methods, shown on the first chart, gives only a partial view, in fact the real variance generated by the operator in case of bad dipping and handling of the cores can be mainly described by the two previous charts.
Flicking / shaking the cores not only reduces the WLT but it becomes totally unpredictable (WLT varies from 150 to 225 microns).
On the contrary, ProserviceTech manipulator allows a perfect control of the dipping operations (thanks to PLC, frequency converter and absolute encoder) and it can be provided even with clamping and rotation system of the cores for the best dripping and distribution of the coating over the core surface. Robotic dipping solves most of the issues but robots cannot be applied in all foundries. ProserviceTech has designed standard and tailor-made manipulators to replace the manual dipping, making the coating application much more consistent, without runs and drops, independent by operator’s capabilities, at reasonable cost and flexible enough to be used in case the foundry produces different types of cores.
If you are looking for a simple solution capable of matching all the previously mentioned features and benefits but with a standardized design and that quickly pays for the initial investment, ALL-in-ONE Smartline is the answer.
They are designed in different sizes and concepts to be adapted to various sizes of the cores, to be space-saving with ergonomic design and low-maintenance requirements. Yet flexible enough to be adapted to your existing dipping process (manual by operator or automatic by robot). for alcohol or water based coatings, ALL-in-ONE Smartline can be commissioned in short time even without ProserviceTech technicians, thanks to the plug and play features.
All the ALL-in-ONE dip tanks are provided with a Density Sentinel for continuous density control and automatic preparation and, most of them, with ARENA E-pump to keep the constant level and to flow coat some cores and with the manipulator to dip the cores at controlled speed and depth.
Do you want a deeper or larger dip tank? Do you want to combine a dip tank with a flow coating station? Do you have any restrictions due to the available layout and space? Must it be installed in an existing robotic cell to replace an old and/or unreliable dip tank?
In limited cases, it is not possible to use a standard ALL-in-ONE Smartline and it is necessary to 100% design the equipment according to the specific needs of each customer. Our engineer will design the best solution to match your requests.