Leshrinkage rate of 3D printing materials is a critical factor in 3D printing projects—it directly impacts the dimensional accuracy, intégrité structurelle, et qualité finale des pièces imprimées. Que vous fabriquiez un petit prototype ou un gros composant industriel, ignorer le retrait du matériau peut entraîner une perte de temps, argent, et impressions ratées. This guide breaks down what material shrinkage is, why it happens, and how to control it effectively.
1. Concepts de base: What Is 3D Printing Material Shrinkage?
Before tackling solutions, it’s essential to understand the core of3D printing material shrinkage.
Définition
Shrinkage refers to the percentage of volume or size reduction that occurs when a 3D printing material cools down after being melted (in fused deposition modeling, or FDM) or cured (in resin-based printing). Par exemple, if a PLA part is designed to be 100mm long but measures 99.8mm after printing, its shrinkage rate is 0.2%.
Key Influencing Factors
Several elements affect how much a material shrinks. Here are the most common ones, organized for clarity:
- Type de matériau: Different materials have unique thermal expansion coefficients (how much they expand when heated) and curing behaviors—this is the biggest driver of shrinkage.
- Paramètres d'impression: Settings like printing temperature (too high can increase shrinkage), fill density (higher density often means more shrinkage), et hauteur de couche (thicker layers may cause uneven cooling) all play a role.
- Environmental Conditions: Ambient temperature (fluctuations can disrupt cooling) and humidity (especially for hygroscopic materials like PETG) can worsen shrinkage.
Cas: A team printing ABS brackets for a robotics project noticed parts were 0.6% smaller than designed. After checking, they found the workshop temperature dropped by 8°C during printing—this uneven cooling increased the shrinkage rate beyond ABS’s typical range.
2. Shrinkage Rates of Common 3D Printing Materials
Not all materials shrink the same way. Below is a detailed table of the most widely used 3D printing materials, their typical shrinkage rates, and use cases to help you choose wisely.
| Material Name | Chemical Composition | Typical Shrinkage Rate | Avantages clés | Suitable Applications |
|---|---|---|---|---|
| ABS | Copolymère acrylonitrile-butadiène-styrène | 0.4% – 0.8% | Haute résistance aux chocs, durable | Pièces automobiles, boîtiers électroniques |
| PLA | Acide polylactique | 0.2% – 0.8% | Biodégradable, low odor, facile à imprimer | Prototypes, jouets, articles ménagers |
| PETG | Polyéthylène téréphtalate glycol | 0.8% – 1.2% | High transparency, incassable | Contenants alimentaires, clear prototypes |
Note: These rates are averages. Par exemple, a PLA part printed at 210°C may have a 0.3% taux de retrait, but the same PLA printed at 230°C could shrink by 0.6%.
3. How to Control the Shrinkage Rate of 3D Printing Materials
Controlling shrinkage doesn’t have to be complicated. Here are four practical methods, with actionable steps:
1. Optimisation de la conception
Compensate for shrinkage in your 3D model before printing. If your material has a 0.5% taux de retrait, enlarge the model by 0.5% in your CAD software (par ex., SolidWorks, Mixer). Par exemple, a 200mm-long ABS part should be designed as 201mm to end up at 200mm after shrinkage.
2. Smart Material Selection
Choose a material with a shrinkage rate that matches your project’s accuracy needs:
- Need high precision? Go with PLA (0.2% – 0.8%) instead of PETG (0.8% – 1.2%).
- Need durability? ABS (0.4% – 0.8%) travaux, but be sure to adjust printing parameters to minimize shrinkage.
3. Adjust Printing Parameters
Tweak these settings to reduce shrinkage:
- Printing Temperature: Lower the temperature by 5–10°C (par ex., from 250°C to 240°C for ABS) to slow cooling and reduce size loss.
- Fill Density: Use 50%–70% fill density instead of 100%—lower density means less material to shrink.
- Bed Temperature: Keep the print bed warm (par ex., 110°C for ABS) to ensure slow, even cooling.
4. Post-traitement
Après l'impression, use these methods to fix minor shrinkage:
- Traitement thermique: For ABS parts, bake them at 80°C for 30 minutes to “relax” the material and reduce residual shrinkage.
- Lissage chimique: For PLA or PETG, use isopropyl alcohol (API) to gently smooth surfaces and correct small dimensional gaps.
Yigu Technology’s Perspective on 3D Printing Material Shrinkage
Chez Yigu Technologie, we believe controllingthe shrinkage rate of 3D printing materials is a mix of science and practice. Many clients struggle with failed prints due to uncompensated shrinkage—our solution is to pair material expertise with tailored tools. We recommend using our 3D printing material test kits (which include ABS, PLA, and PETG samples with pre-tested shrinkage rates) to find the right material fast. En plus, our design software plugin automatically calculates and applies shrinkage compensation, cutting prototype rework by 40%. For high-precision projects, we also offer post-processing services like heat treatment to ensure parts meet exact dimensions.
FAQ
- Q: Why does my PLA part still shrink even though PLA has a low shrinkage rate?
UN: PLA’s low rate (0.2% – 0.8%) doesn’t mean no shrinkage. Check your printing temperature—if it’s too high (over 220°C), shrinkage increases. Try lowering it by 5–10°C and ensure the print bed is at 60°C for even cooling. - Q: Can I use the same shrinkage compensation rate for all parts made with the same material?
UN: Mostly, but adjust for part size. Pièces plus grandes (over 300mm) may shrink slightly more due to more material cooling. Par exemple, a 400mm ABS part might need 0.6% compensation instead of 0.5% for a 100mm part. - Q: Does humidity affect the shrinkage rate of PETG?
UN: Yes—PETG absorbs moisture, which causes uneven cooling and higher shrinkage. Dry PETG filaments in a dehydrator (50°C pour 4 heures) before printing to reduce shrinkage by up to 0.3%.