Paint Additive Evaluation and Characterization

=Problem Definition= Our goal is to evaluate the thermal resistance, solar heat reflectance, and microstructure durability of two novel paint additive technologies.

Background
Many paint additives have started being tested in many various applications. There have been multiple tests that show that these additives can have some benefits to thermal resistivity, temperature reduction, and some degree of EMF protection. There are two main types of different paint additives that have been tested the first being a nano-ceramic additive and the second being a phase change additive. Both of these additives modify the thermal conductivity (k) and the emissivity (Ɛ) of the base paint. These help to reduce the heat absorption rate from radiated and latent heat. In addition to the beneficial properties, these additives are relatively cheap when compared to the price of a coating system. if a temperature drop could be observed under strenuous testing in a variety of environments and meet paint coating test specifications it could be a great cost per benefit solution to reflect heat and reduce internal temperatures.

Deliverables
The addition of these paint additives must show the following:
 * Show a temperature reduction of 5 degrees Fahrenheit in warm weather
 * Increase thermal resistivity to provide insulation and an increase from the ambient temperature of 5 degrees
 * Meet Salt fog testing (ASTM B117) Requirements for 1500 hours of testing ​
 * Meet Mean Creepback Rating (ASTM D1654, Procedure A) for 1500 hours of testing

Value Proposistion Statement
The lifetime of electronic devices, found inside enclosures, is significantly shortened when exposed to environmental extremes. Because there are thousands of enclosures in rural locations, hot and cold climates, it is essential to develop an affordable, maintenance-free method to extend the life of the enclosure’s internal electronic devices. By using affordable paint additive technologies any improvement in performance and extension of application life will be financially beneficial for the client. The Nano-Vandalizers are offering an affordable, simple solution to reduce the thermal degradation of electrical enclosures in order to extend the battery life and reduce the possibilities of a short circuit due to a buildup of condensation. We will coat SEL’s enclosures with the paint additive technologies to evaluate the thermal resistance, solar heat reflectance, and microstructure durability of the enclosure surface.

=Design Considerations=

Testing Stand Design
A test stand had to be designed to create a uniform and consistent testing environment to achieve the best results from temperature and resistivity testing. In addition to these requirements. The test stands also had to be designed to assemble quickly and take up a minimum amount of room. The test stand was designed to be mounted on a 4' by 4' piece of plywood with a 4" by 4" stand to mount the cabinets with a large lag screw. The 4" by 4" is supported by three 2"x4" struts cut at a 45-degree angle and fastened to the plywood.

Revisions to the test stand
After consulting with the party that was going to house our enclosures and monitor our testing, It was then made clear that our stand had to revise for space and assembly considerations. The design was kept very similar but the sizes of the 2x4 struts and plywood were revised. It was decided to cut the 2x4 struts to an equal length due to the relatively light load of the cabinet being supported. The plywood was decided to be cut to a 28 by 28 square footprint rather than the previously 4' by 4' footprint. The two by fours were then decided to be cut to even lengths of 30" rather than having two sizes of 2x4 cuts. The revised views can be seen below

=Thermal Testing procedures=

Thermal resistivity Testing
In order to create thermal resistivity models, the thermal conductivity constant (k) of each coating had to be found. These values are found by using Fourier's law in one dimension : $$\phi_\text{q} = -k \frac{dT(x)}{dx}$$ With (k) being the thermal conductivity factor, $$\phi_\text{q}$$ representing the heat flux across the surface and $$\frac{dT(x)}{dx}$$ representing the temperature gradient across the surface. The heat flux is measured by the use of a heat flux sensor affixed to the inside of the front door of the box. By using this method, it allows us to sum the amount of heat transferred from radiation as well as conduction. The inside and outside temperatures are measured by temperature sensors place on the inside and outside surfaces of the box. With these measurements, the thermal conductivity and thus the thermal resistivity can be found for each paint additive applied.

Temperature Sensor Placement and outdoor data collection
In the electronics that are placed inside of these containers, There is a battery that powers the previously mentioned electronics. This component is one of the most susceptible to damage from extreme temperatures and extreme temperature fluctuations. In the cabinets, the battery is placed in the bottom right of the enclosure. Because of this, the sensors were placed on the front door of the cabinet, the bottom of the cabinet, and on the inside of the cabinet near the bottom of the enclosure. these locations allowed us to have temperature information where it is most important to the supplier. The types of Sensors that will be used to collect data are called HOBO sensors and can be seen below.

These sensors can have an additional temperature probe plugged into a socket into the base sensor to procure two temperature data measurements from two different locations. The sensors will be mounted to the cabinets with the use of velcro. The temperature data will be collected every 15 minutes and will be taken from the sensor every month.

=Paint durability tests=

Salt Fog Testing
One test that SEL conducts to characterize the durability of their paint coating is a salt fog test. In addition to characterizing the durability of the paint coatings, it can also help characterize the corrosion resistance of a paint coating. In order for these paint additives to be implemented into SEL's existing paint process, each respective coating must be able to protect the base metal underneath the cabinets to a certain standard that meets or exceeds the current paint coating. These Standards are as follows: MEK Test (ASTM D4752-03), Cross-Hatch Adhesion Test (ASTM D3539), Salt Fog Testing Period (ASTM B117), Mean Creepback Rating (ASTM D1654), Maximum Creepback Rating (ASTM D1654), Corrosion and Blisters (ASTM D1654). Multiple Paint samples are used in the evaluation of these tests and must meet the standards for a 1500 hour exposure to be considered a viable addition to the paint proccess.

MEK Standard
This test technique is utilized to decide the level of fix of a heated film by the paint film protection from a predefined dissolvable. The Solvent Rub Test is generally performed utilizing methyl ethyl ketone (MEK) as the dissolvable. The MEK opposition or level of fix applies to paint topcoats and preliminaries.

Creepback Testing
A typical test includes the intentional harm of the covering layer to decide a property alluded to as rust creep, a quantitative proportion of how far the consumption goes along the substrate/covering interface to one or the other side of a precisely actuated scratch during the introduction to a destructive climate—ordinarily an unbiased salt splash or cycle erosion test

Nanoindentation
=Project Learning=

Expected results

 * A vast array of temperature data in various climates
 * Material properties of each respective coating
 * data about the durability of each coating in various environments
 * Thermal conductivity and resistivity information and models
 * EMF protection information for each respective coating

=Validation= =Results=

=External References= Jung Yen Chou - Phase Change Materials.NW.2008

=Team Members=

=Additional Documentation= Meeting Minutes Budget Schedule Snapshot Presentations Concept Design Presentation
 * NanoTech Vandalizers Meeting minutes
 * NanoTech Vandalizers Budget
 * NanoTech Vandalizers Gannt Chart
 * NanoTech Vandalizers Snapshot 1
 * NanoTech Vandalizers Concept Design Review