Select the Right Plastiform
Choosing a Plastiform product means filtering the range through three criteria in a specific order. Each step eliminates products until only a few remain. Then pick the most versatile one, or the one that best fits your needs.
The three filters are:
- Initial consistency. How you apply the material.
- Final hardness. What you can do with the cured impression.
- Removal constraint. Whether the impression can be extracted without tearing.
Step 1: Initial Consistency
Ask yourself where the impression will be taken.
- Internal shape, complete impression, fine detail: Fluid (F)
- External shape, vertical or overhanging surface: Pasty (P) or Manual Putty (M)
- Prefer to apply products by hand: Manual Putty (M)
- Large volume: Fluid XL (F…XL)
Rule of thumb:
| Shape | Consistency |
|---|---|
| Internal bore, thread, groove | Fluid |
| External surface, vertical face | Pasty or Manual Putty |
| Large volume, complete impression (over 50 mm in diameter) | Fluid XL |
Step 2: Final Hardness
What do you need to do with the cured impression?
- Need to extract from threads, grooves, or undercuts: Flexible (40 Shore A and below)
- Need to slice the impression for profile analysis: Medium (between 40 and 80 Shore A), or one of the Flexible products the Double Blade Cutter accepts (F40, P25, P35 and M25), if the removal constraint allows it.
- Need to measure with contact instruments (calipers, CMM, roughness tester): Rigid (80 Shore A and above), with a zero removal constraint only. Some Medium products also accept contact measurement, as their technical sheet states.
Rule of thumb:
| Requirement | Hardness |
|---|---|
| Extraction from complex shape | Flexible |
| Slicing with the Double Blade Cutter | Medium, or F40, P25, P35 and M25 |
| Contact measurement | Rigid (zero constraint only) |
Step 3: Removal Constraint
Calculate the removal constraint from the part geometry. Compare it to the product’s maximum tolerance.
Eliminate any product whose max constraint is less than or equal to your calculated value.
Example:
- Shape: internal thread, bore 16 mm, minor diameter 14 mm
- Constraint: (1 − 14 / 16) × 100 = 12.5%
- Need: complete internal impression, sliced to read the profile
Filter 1: Internal shape → Fluid
Filter 2: Slicing needed → a product the Double Blade Cutter accepts
Filter 3: 12.5% constraint → F50 (10%) and F65 (5%) eliminated. F40 (35%) is eligible and compatible with the Double Blade Cutter.
Result: F40 is the natural choice. It is Fluid, tolerates a 35% constraint and can be sliced. If no slice is needed, F20 (30%) also fits.
When the Choice Is Not Obvious
The choice is usually obvious. Some cases do not fit the standard filters:
- High constraint and slicing: Medium products slice well but may not tolerate the constraint. Among the Flexible products, the Double Blade Cutter accepts F40 (35%), P25 (30%), P35 (20%) and M25 (15%). Above 35%, no sliceable product tolerates the constraint, so take a partial impression or read the complete impression without slicing it.
- High constraint and contact measurement: Rigid products cannot be extracted from complex shapes. You must use a Flexible or Medium product and measure without contact.
- Temperature extremes: The times on the technical sheets are given at 23°C. Polymerization is slower when it is colder and faster when it is warmer. For very hot or cold environments, read the technical sheet or contact support.
The Plastiform Finder
If you prefer a guided process, the Plastiform Finder asks questions until it finds the best product for your situation. It handles the filtering automatically.
The Finder covers roughly 95% of applications. For the remaining 5%, contact a Plastiform Expert to get customized recommendations.
