Procurement Specifications and Inquiry for Powder Coatings

Powder Coatings Procurement Specifications and RFQ Guide
To assist buyers in determining color, gloss, texture, formulation, and procurement specifications

I. Purpose of This Document
This document is intended to help buyers and procurement managers clearly define their requirements before contacting powder coatings suppliers. Precise written specifications reduce quotation errors, expedite sample approval, and ensure a fair comparison among different suppliers.

II. Core Procurement Specification Parameters
When requesting quotes from all suppliers, the same written requirements should be provided. Please clearly specify the following:
1. Substrate and Pretreatment

Parameter
Required Information
Substrate
Steel, aluminum, galvanized steel, or other
Pretreatment
Phosphating, chromating, sandblasting, or other methods
Surface Condition
Oil-free, rust-free, scale removed
The pretreatment method directly affects adhesion, corrosion resistance, and the long-term performance of the coating. Do not assume that a single pretreatment method is suitable for all substrates.
2. Color Specifications
Authoritative references must be provided:
• RAL color codes, Pantone color codes, or Federal Standard colors
• When appearance is critical, physical samples or parts must be provided
• Custom colors: Send color standards (color swatches, fabric, metal parts, or even shoe samples) to the supplier for color matching
Important Notes:
• White is the most difficult color to match—the human eye is particularly sensitive to variations in white
• The appearance of metals, textures, and translucent effects may vary under different lighting conditions and viewing angles
• Color chart numbers serve as a starting point for communication and are not necessarily the final production standard
3. Gloss Level

Grade
Reflectance
Typical Applications
Matte
0–20%
Industrial, outdoor, parts requiring flaw concealment
Satin
20–40%
Interior, office, retail
Semi-gloss
40–60%
Kitchen appliances, interiors
High-gloss
80% or higher
Easy-to-clean surfaces, decorative applications, high-end products
Gloss is measured at a 60° angle according to the ASTM D523 standard. Target gloss levels and acceptable tolerances should be clearly defined, rather than relying solely on terms such as “matte” or “high-gloss.”
4. Texture

Texture Type
Description
Compatibility
Smooth
Classic, clean surface
Compatible with all gloss levels
Sand-textured
Fine texture, slip-resistant
Best suited for satin or lower gloss levels
Wrinkled
Coarser, deeper texture
Not compatible with high-gloss finishes
Hammered
Classic “orange peel” pattern
Reduces reflectivity
Textures add depth to the tactile experience and help mask surface imperfections. Not all textures are compatible with all gloss levels.
5. Chemical Systems

Type
Best Suited For
Notes
Epoxy
Indoor use, chemical resistance
Poor weather resistance
Polyester
Outdoor use, architectural profiles
Good weather resistance
Epoxy-Polyester Hybrid
General indoor applications
Balanced performance
Polyurethane
High-durability applications
Higher cost
The chemical system affects weather resistance, corrosion resistance, flexibility, and cost. Specify whether the system is epoxy, polyester, a hybrid, or another approved system.
6. Film Thickness
• Standard range: 60–80 µm
• Film options: As low as 30 µm under specific conditions
• Excessive film thickness may cause insulation issues
Specify the target dry film thickness range and measurement method.
7. Curing Conditions
Provide the metal temperature window available on your production line. For example:

Workpiece Temperature
Minimum Time
Maximum Time
180°C
15 minutes
25 minutes
190°C
10 minutes
15 minutes
200°C
8 minutes
12 minutes
Supplier laboratory curing parameters must not be used directly in production without verification of actual workpiece metal temperatures.
8. Order Quantity and Packaging

Item
Items to Confirm
Minimum Order Quantity
Price Differences Between Small and Large Batches
Packaging
20–25 kg cartons, small packages, or custom
Recycled Material Policy
Mixing ratio of new powder to recycled powder
Lead Time
Stock items vs. custom production

III. Supplier Comparison Checklist
When comparing quotes, do not focus solely on the price per kilogram. A lower unit price may result in a higher cost per qualified product.

Comparison Factors
Items to Inquire About
Actual Yield
Theoretical coverage based on density and specified film thickness
Single-Pass Application Rate
Request actual test data, not general percentages
Recycled Material Policy
Is the use of recycled powder permitted? What is the mixing ratio?
Color Tolerance
What is the guaranteed ΔE value? What is the measurement method?
Batch Consistency
How is color consistency verified across batches?
Testing Evidence
TDS, SDS, COA, batch identification, test reports
Trade Terms
FOB, CIF, DDU, or DDP? Which port/location?
Sample Lead Time
Custom color matching typically takes 3–10 business days
Production Lead Time
Off-the-shelf vs. custom formulations
Red Flags When Comparing Quotes
• The supplier cannot clearly define the chemical system or product line
• No physical samples provided

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