Questions Answers_12444326Q0066 Updated as of 11SEP2026.pdf

SOL 12444326Q0066 NTDP - Injection Molding - WFCS Corrosion Tests Improvements Questions and Answers as of 11SEP2026

Q1. Please provide the proprietary PDF part prints and available native CAD files for the four parts, preferably in STEP format. If STEP files are not available, please let us know which CAD formats are available.

A1. PDF part prints and the CAD files shared are stereolithography or STL files, and standard exchange of product model data STP or STEP files.

Q2. Please also provide or confirm the required PEEK resin material specification, including the grade and any manufacturer or equivalent-material requirements, as the posted documents identify only PEEK resin.

A2. Confirming that Polyetheretherketone (PEEK) is the required material and the commercial name for Polyether Ether Ketone used in injection molding. Resin is the raw baseline material supplied as pellets, granules, or fine powders before manufacturing. Polymer defines the cured, solid-state of the engineered plastic of the finished parts.

Core Properties of PEEK Thermal Stability: Continuous use temperature up to 250°C–260°C, with a melting point around 343°C.

Mechanical Strength: High tensile strength (around 90–100+ MPa) providing a strong alternative to metals in demanding engineering settings.

Chemical Resistance: Exceptional inertness against hydrocarbons, acids, solvents, and steam hydrolysis.

Q3. PDFs are actually 3D models of the parts. Do you have 2D, GD&T prints you can send? Unfortunately, with the ones I have, I can’t get tolerances, draft angles, etc. for tooling and QC purposes.

A3. The images shared are conceptual models and rendering of 3D printed parts that were used to further the “proof of concept design” to improve the testing process of the lab. They are a prototype that require coordination with the Wildland Fire Chemical Systems program to complete additional/final design prior to tooling of the molds to be used for the injection molding. They are not intended to be used as the final design to generate the parts but as examples of the concept design and structural features to meet the functional need.

Q4. None of the cap drawings/models have threads. I may have missed where the thread size is called out but, do you have a model showing the threads in the cap?

A4. Correct the concept of the interchangeable ring lid thread and dipper thread is what is desired for all rings to be interchangeable, and all dipper ends will have threaded ends that are the same. Customer will see if they can get the thread size that is shown in the attached PDF titled interchangeable ring lid thread and dipper thread concept.

Q5. For the glass jars, is this something that we will need to supply, or will they be providing them?

A5. Glass jars, no, we mention the glass jars as the standard test jars we use for the lab testing as a reference to the opening and the positioning of the ring and dripper assembly so they will fit in the universal jar we use and the lid can still be sealed/closed tight. We can give them a jar or two if they need them to ensure the parts made work with the jars we use.

Q6. The material specification calls out PEEK resin. Does it need to be a specific PEEK brand, or can a generic equivalent be used? I ask because PEEK is currently around $60.00 per pound.

Given the relatively low production volumes and the minimum purchase quantities required by material suppliers, the material cost could have a significant impact on the overall part pricing.

A6. Yes, PEEK is the material needed and we understand the price of the product, it is durability, longevity and performance needs that it is particularly well suited to meet.

Q7. Which specific PEEK is required.

A7. Unfilled, Pure PEEK (Low-to-Medium Viscosity)

• Core Entities/Brands: Victrex 450G, Solvay KetaSpire KT-820, Evonik

VESTAKEEP 2000.

• Why: Unfilled PEEK is the most chemically inert grade available. Because it contains 100% pure polymer matrix, there are zero fillers, fibers, or metallic traces to leach out, conduct electricity, or cause localized galvanic cells. It offers the maximum possible baseline chemical resistance against aggressive acids, bases, and organic solvents.

The part being made will be submerged in chemical formulation to test those formula’s potential to cause uniform, galvanic, and crevice corrosion to test metal alloy coupons. Other forms of PEEK would have graphite, carbon and glass in them which has the potential to impact the test results due to the electrochemical properties they would have.

Q8. Do you have .stp files for the Dipper Shaft and Dipper Shaft Crevice?

A8. Working to see if we have something other than the STL files, specifically STP files.

Q9. Can I have .stp files for the Crevice & Galvanic Dipping Shafts – the .stl files are not for tooling.

A9. See question 8. In addition - All image files of the parts have been provided, and all the image files shared, and the configuration represented were different iterations of prototypes used to refine what the most universal and functional design would be.

Q10. Are there any coloring requirements for this PEEK material and parts?

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A10. There is no color requirement natural color of the product is fine.

Q11. Are these the only requirements for the PEEK (Dishwasher, incubator at 70-120 deg for 28-to 90 days, exposed to foams, gels, and retardants?)what else will be tested? Any other requirements of the PEEK resin than what has been shown or shared?

A11. See question 7.

Q12. What are the estimated part weights?

A12. Customer has no idea what the estimated final weight of the parts will be.

Q13. What are the final dimensions of the parts?

A13. The final dimensions of the parts should be provided in the drawing files.

Q14. Will USDA finalize the part data?

A14. USDA WFCS program staff will coordinate with the vendor to complete any final refinements of the design prior to production.

Q15. What are the thread size on the Dippers and the Rim Ring?

A15. Working to get this specification.

Q16. Can the outside threads on the dippers have a parting line?

A16. Yes, if they do not interfere with the screwing/threading action for repeated assembly disassembly.

Q17. Do all 3 dipper shafts have the same thread, size and pitch?

A17. Yes, the preferred design is for all the dipper shafts to have the same thread size and depth as the one shown on the pinch dipper shaft and rim ring to all be the same as well so they are universal/interchangeable where all the dippers would be able to be threaded into all the rim rings so that the rim ring can be used with any of the dippers. (see image provided below). The final preferred design is shown below and would not have a threaded poly nut inserted as shown in early prototype iterations.

That design was the first attempt to change the rectangular slide design shown in the drawing for the galvanic and crevice dipper, both were problematic and led to the design shown in the image below the threaded rim ring and dipper shaft.

The preferred rim ring design and dipper design threading.

Q18. Is the Rim-Ring of 1 piece construction? All plastic?

A18. Yes, see the image provided above. The rim ring design should be as shown and not the early prototype example of the drawing with a poly nut inserted, that is not the final desired design. The final desired design is shown in the image above so all rim rings and dipper shafts can be used as being universal/interchangeable to maximum utility and versatility of testing runs the lab will perform.

Q19. Please confirm the Galvanic dipper has only 1 thru hole for hardware mounting.

A19. Yes, the galvanic dipper has only one thru hole for hardware mounting, working to get the dimension of that thru hole for hardware mounting.

Q20. Please confirm the Crevice dipper has 2 thru holes for hardware mounting.

A20. The crevice dipper has only one thru hole for hardware mounting, working to get the dimension of that thru hole for hardware mounting. The bottom of the crevice dipper is not a hardware mounting point it is a brace point for the test specimens and is solid with no thru hole.

Q21. Please verify the threads position and location on the Galvanic and Crevice Shafts, they are not shown in the data.

A21. The thread position and location on the galvanic and crevice dippers would replace the rectangular top shown in the earlier prototype drawing to be threaded instead.

Galvanic dipper shaft Crevice dipper shaft