KNOWLEDGE BASE

Reference material
for material people.

Guides, reference sheets, and technical articles. Written by our engineers for procurement managers, product designers, and anyone who touches a material spec.

REFERENCE
MFI vs. MVR: Which Flow Test Do You Actually Need?
MFI and MVR measure the same thing - almost. This is when each one matters and why specifying the wrong one gets you in trouble at the press.
5 MIN READ · SEPT 2026
ARTICLE
The UL 94 Flame Ratings Explained for Non-Chemists
V-0, V-1, V-2, 5VA - what each rating means, what test produces it, and why your customer might care about one but not another.
8 MIN READ · AUG 2026
GUIDE
How to Write a Resin Specification That Procurement Can Actually Use
A good material spec locks in the grade, the supplier, the test method, and the incoming inspection criteria. Here's the template we use with our clients.
10 MIN READ · AUG 2026
ARTICLE
When a Material Substitute Isn't Really a Substitute
Your supplier wants to swap a grade. "Equivalent" on the datasheet doesn't mean equivalent in your process. The questions to ask before you approve it.
6 MIN READ · JUL 2026
REFERENCE
Polymer Families Quick Reference: Properties at a Glance
One-page property comparison across PP, PE, PC, Nylon, ABS, TPU, and PEEK. Download and post it next to your desk.
REFERENCE SHEET · JUL 2026
GUIDE
Gamma vs. EtO vs. Autoclave: Choosing a Sterilization Method for Plastic Components
Each sterilization method degrades plastics differently. This guide maps common medical resins against the three primary sterilization chemistries and what survives each.
12 MIN READ · JUN 2026

Standard test methods by property. Reference these when reading a supplier TDS or writing an incoming inspection procedure.

PropertyASTM MethodISO MethodUnitNotes
Melt Flow IndexD1238ISO 1133g/10minLoad and temperature must be specified - D1238 and ISO 1133 use different default conditions
Tensile Strength / ElongationD638ISO 527MPa / %Type I or IV specimens; speed affects elongation result significantly
Flexural Modulus / StrengthD790ISO 178MPaSpan-to-depth ratio matters for filled grades - 16:1 is ASTM default
Izod Impact (Notched)D256ISO 180J/m or kJ/m²Notch radius and conditioning temperature must match your end-use environment
Heat Deflection TemperatureD648ISO 75°C66 psi (0.45 MPa) and 264 psi (1.82 MPa) - always specify which load was used
Flame RatingUL 94IEC 60695V-0 / V-1 / V-2 / 5VRated at specific thickness - confirm the rated thickness matches your part geometry
Specific Gravity / DensityD792ISO 1183g/cm³Required for part weight calculation; use actual grade value, not family average
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