3D Printing Material: Flexible Polyurethane CLIP Resin – the Q&A | Sculpteo Blog

3D Printing Material: Flexible Polyurethane CLIP Resin – the Q&A

Posted By Sculpteo on Mar 22, 2017 | 0 comments

Flexible Polyurethane is now available in our online 3D printing service platform in addition to our other CLIP resins for 3D printing: Prototyping Acrylate, Rigid Polyurethane, Cyanate Ester and Elastomeric Polyurethane. Following the previous article about FPU and other Clip Resins, today we will explore in detail about the FPU Clip Resin, in a complete Q&A.


What is the Flexible Polyurethane CLIP resin?

FPU CLIP Resin is a semi-rigid material with good impact, abrasion and fatigue resistance. It is designed to withstand repetitive stresses such as hinging mechanisms and friction fits. It completes our range of CLIP resins that are 3D printed with Carbon’s technology.

FPU 3D printing CLIP


With which 3D printing technology is FPU printed?

The Flexible Polyurethane is 3D printed using a Carbon M1 3D printer, like our 4 other mechanical resins.

3D Printing Carbon M1 machine


What is the CLIP 3D printing technology?

Continuous Liquid Interface Production or CLIP is a method of 3D printing that uses a photochemical process in order to create parts that have both an excellent, smooth surface finish, and high mechanical properties. It uses photosensitive resins, on which light is projected through an oxygen-permeable window. The UV-light projected continuously solidifies the resin progressively, while the build platform rises. The 3D printing process thus created is very fast compared to other 3D printing techniques. The secret in this technology is the thin liquid interface of uncured resin that stays between the window and the part that is being 3D printed, allowing the resin to flow beneath the curing part, and the printing process to be continuous. 


What is the company Carbon?

Carbon is a company that develops and manufactures 3D printers that use their CLIP technology. Its first commercial product is the Carbon M1 3D printer which 3D prints mechanical resins. CLIP works on innovating in the way 3D printing is done, by making it faster, and creating parts with high mechanical properties.


What does the Flexible Polyurethane CLIP Resin look like?

Available in black color,  FPU creates final objects that are smooth on the outside and solid on the inside. Its flexibility makes FPU stand for hard pressure. However, Flexible Polyurethane is not an elastic rubbery material like Elastomeric Polyurethane (EPU).

FPU Clip resin sculpteo


What resolution can be expected using the Flexible Polyurethane CLIP Resin for 3D printing?

Using the technology of M1 3D printer, it enables to print at very high resolution. Features as thin as 0.25 mm can be 3D printed, but the recommended thickness for certain structural features will vary based on their specific nature.


What are the size limitations and design guidelines for Flexible Polyurethane?

In terms of size limitation, the maximum size to build an object is 144 x 81 x 330 mm (5.7 x 3.2 X 12 in). If you need to build objects larger than this maximum size, you can design several objects and include in them an assembly mechanism: FPU’s strength is best seen in its resistance to assembly and disassembly.  A distance of at least 0.5 mm needs to be left between the different parts of the object.

CLIP FPU Maximum size Sculpteo

With CLIP resins, it is recommended to avoid wall angles and sharp angles. If you do create wall angles, it is best to only use angles of less than 40 degrees as above this specific size, the part will need extra supports. It the part requires less supports, it uses less resin, it can be 3D printed faster, it requires less post process, and it reduces the risk to have supports marks on the finished part. Moreover, for sharp angles, it is better to smooth them and to add fillets or ribs to directly in the 3D design.

For a successful 3D print, the minimum thickness of the walls for the FPU resin is 0.5 mm. A wall with this thickness, 3D printed in FPU, will be quite flexible. If you want your object to be more flexible and also resistant, you will need a minimum of wall thickness of 0.8 mm. At 1.0 mm of wall thickness, your object will become fully rigid.


What kind of 3D printed parts is the Flexible Polyurethane CLIP Resin good for?

3D printing with resins enables to create an object which is smooth and precise which can be used for mechanical or ornamental objects. Part of Carbon’s CLIP 3D Printing Resins, Flexible Polyurethane is an excellent 3D printing material, to 3D print objects for housewares, boxes and assemblies that need clipping, toys, rigid packaging, living hinges and everything that requires a lightweight and flexible plastic material.

Flexible Polyurethane CLIP Resin Part

How much does it cost to 3D print Flexible Polyurethane with the M1 3D printer?

To measure the cost of using 3D print an object using FPU, it will be determined automatically the moment your design is placed on our online 3D printing platform. When you modify your object; the price will change automatically and it is also based on the series of factors including: volume of material used, size of object, choice of 3D printing material and finishing. To see how much your object costs, you can upload your 3D file and adjust your file to change the 3D printing price. You’ll get a quote instantly, easily, and for free.


How should I prepare my file for a 3D print in Flexible Polyurethane CLIP Resin?

Before using the 3D printing to print your object, you need to create a 3D model using a CAD software dedicated to 3D modeling. You can then upload the file into our 3D printing platform. Sculpteo offers an online solidity check tool to help determine parts of the print that may be too thin to 3D print. From this tool, you are able to tweak your design (either with our thickening tool or by redesigning your object yourself)  in order to create an object that matches the required thickness. To be able to use this check tool, you only need to upload your 3D file, select material and click on the ‘Verification’ tab. Once your have your final 3D model, it will directly send to our Carbon printer and arranged within the next available batch.

If you need more information on how to design your 3D file specifically for 3D printing, you can check our 3D design tutorials (on many CAD software, such as Fusion 360, Rhinoceros, Blender, and many more), and our free ebooks about 3D printing and digital manufacturing.


How does the 3D printer work?

When you upload your 3D model into our platform, we will check your file, and, if needed, our automatic repairing tools will repair some elements. Applying the method of CLIP technology, a continuous sequence of UV projected images is projected as the object is drawn out. After the process of photopolymerization is finished, the build platform is removed from the 3D printer and ready to be detached. The supports used are carefully being removed and gently sanded and polished to remove the support marks. The part is then finished with mineral oil.


What kind of finishing can I get?

The Flexible Polyurethane Resin is already colored, which means there is no post-processing color application on the object. However, it also has two types of finishing:

  • Raw: we cut the supports
  • Polishing: the sanding post-process comes with every CLIP part to remove any support scars.


What other choices do I have to 3D print Carbon resins?

Check out the four other Carbon CLIP resins that are available on our online 3D printing platform:

All of these are now out of the Beta Program, and directly available online. You can upload a 3D file now.


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