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PolyJet Perfection: Unveiling the Artistry and Versatility of 3D Printing Materials

Introduction to PolyJet Technology

Definition and Overview

PolyJet technology is an advanced additive manufacturing process that enables the production of intricate, highly detailed 3D printed objects. It utilizes a unique inkjet-style printing system to deposit ultra-thin layers of liquid photopolymer resin onto a build tray.

These layers are then instantly cured using UV light, resulting in the solidification of the material. The process is repeated layer by layer until the complete object is formed.

PolyJet technology stands out for its ability to produce parts with exceptional surface quality, complex geometries, and fine details, making it ideal for applications requiring high precision and aesthetic appeal. It offers a versatile range of materials that can mimic different mechanical properties, colors, and textures.

Stratasys Polyjet Printing Technology
polyjet technical schematic diagram
Stratasys PolyJet Technology

Historical Background

The roots of PolyJet technology can be traced back to the early 1990s when Stratasys Inc., a pioneering company in 3D printing technologies, started developing inkjet-based systems for additive manufacturing. The aim was to create a method that could produce accurate models with multiple materials simultaneously. Stratasys introduced its first commercial PolyJet-based printer in 2000 under its brand name Objet.

This breakthrough innovation opened new avenues for rapid prototyping and product development across various industries. Over the years, advancements in photopolymer formulations and printer hardware have further refined PolyJet technology, enhancing its capabilities and expanding its applications into fields such as aerospace engineering, automotive design, medical modeling, consumer products development, and more.

Advantages and Applications

  • PolyJet technology presents several significant advantages over traditional manufacturing methods as well as other 3D printing technologies. Firstly, it offers unrivaled precision with layer thicknesses as small as 14 microns (0.014 mm), resulting in smooth surfaces free from visible staircasing effects. This level of detail makes it ideal for producing complex prototypes and intricate models.
  • Moreover, PolyJet technology allows for the simultaneous printing of multiple materials in a single build, enabling the creation of parts with varying mechanical properties, colors, and levels of transparency. This versatility opens up countless possibilities in product design and testing.
  • Furthermore, PolyJet printers can create parts with a wide range of material properties, including rigid and flexible resins that can simulate rubber-like textures or high temperature-resistant materials. This adaptability makes it highly suitable for applications such as functional prototyping, concept modeling, architectural visualization, and even end-use production.
  • The unique advantages offered by PolyJet technology have made it a preferred choice for industries seeking quick and accurate prototyping solutions while maintaining the highest levels of precision and aesthetics. As the technology continues to evolve, its applications are expected to expand further into new frontiers such as personalized medicine, art and sculpture fabrication, and custom consumer products manufacturing.

Understanding PolyJet Materials

Composition and Properties

PolyJet technology utilizes a unique combination of photopolymer resins and support materials to achieve remarkable results. The key component in this process is the photopolymer resin, which is a specialized liquid material that solidifies under the influence of ultraviolet light.

These resins are composed of a mixture of monomers, oligomers, and various additives, each serving specific purposes. Monomers act as building blocks that form the polymer chains during the curing process, while oligomers provide viscosity control and contribute to the final material properties.

In addition to photopolymer resins, support materials play a crucial role in PolyJet printing. Support materials are designed to temporarily hold up overhanging or complex geometries during printing and then be easily removed after completion.

These support materials are typically water-soluble or require mechanical removal. Their composition varies based on their intended purpose, but they are also formulated using similar principles as photopolymer resins.

Material Selection Criteria

When choosing polyjet materials for a specific application, several factors must be considered to ensure optimal performance and functionality. One of the primary considerations is mechanical properties such as strength and flexibility.

Different projects may require varying levels of rigidity or elasticity in order to withstand specific forces or movements. Optical properties also play a significant role in material selection for applications where transparency or opacity is desired.

For instance, if a project requires clear components with high light transmission capabilities, selecting an appropriate transparent resin would be essential. Chemical resistance is another crucial criterion when selecting polyjet materials for applications that may come into contact with different substances such as solvents or harsh chemicals.

The compatibility between the material and these substances needs to be evaluated thoroughly to prevent degradation or failure over time. Biocompatibility becomes paramount when considering applications involving medical devices or any direct contact with the human body.

Polyjet materials used in such applications must meet stringent standards to ensure that they are non-toxic, hypoallergenic, and do not provoke any adverse reactions when in contact with living tissue. By carefully considering these material selection criteria, manufacturers and designers can unlock the full potential of PolyJet technology and create products that meet specific performance requirements while ensuring durability, aesthetic appeal, and safety in various applications.

Types of PolyJet Materials

Rigid Resins

Rigid resins are a popular category of materials used in PolyJet technology due to their exceptional strength and stability. These resins offer high precision and durability, making them ideal for creating rigid prototypes and functional parts. Within the rigid resin family, there are various subcategories that cater to specific requirements.

Clear Rigid Resin

Clear rigid resin is a transparent material that allows for the production of see-through parts, making it particularly useful for applications where visual clarity is essential. This resin not only possesses excellent mechanical properties but also exhibits remarkable resistance to moisture, chemicals, and UV radiation. Its optical clarity makes it perfect for prototyping lenses, clear enclosures, and other transparent objects.

Full-color rigid resin

Full-color rigid resin brings the mechanical strengths found in other members of the rigid resin category, but with the added advantage of vibrant color versatility. This material can reproduce a spectrum of colors, making it ideal for projects where visual differentiation and aesthetics are paramount. Whether it’s to replicate realistic appearances or to achieve color-coded functionalities, this resin delivers consistently, even under varying environmental conditions.

Its durability coupled with color fidelity makes it a preferred choice for applications such as consumer goods with detailed color specifications, architectural models with terrain or zoning distinctions, and any project where a broad palette of color representation is essential. The high resolution and precision of full-color rigid resin ensure that the minutest details are captured, paving the way for both functional and artistically rich end-products.

Flexible Resins

PolyJet technology also offers a range of flexible resins that simulate rubber-like materials with varying levels of flexibility and elasticity. These flexible resins provide excellent tactile properties while maintaining durability and dimensional stability.

Rubber-like Flexible Resin

Rubber-like flexible resin mimics the properties of soft rubber, offering high elongation and tear resistance. It exhibits excellent flexibility, allowing for the creation of parts that can be bent, twisted, or compressed without losing their original shape. This material is perfect for producing gaskets, seals, grips, and other flexible components found in automotive, consumer goods, and medical applications.

Tango Family of Flexible Materials

The Tango family of flexible materials provides a range of shore hardness options to simulate various levels of flexibility. With TangoBlack and TangoPlus being softer resins while TangoGray offers a medium level of hardness.

These materials are commonly used in product design to prototype flexible hinges, snap-fit features, and overmolded parts. The ability to combine rigid and flexible materials within a single print job enables designers to create fully functional models with complex geometries.

Specialty Resins

In addition to standard rigid and flexible resins, PolyJet technology offers specialty resins tailored for specific applications that require unique material properties.

High Temperature Materials

Polyjet high-temperature materials are engineered to withstand elevated temperatures without compromising structural integrity or dimensional stability. The RGD525 series is capable of withstanding temperatures up to 200°C (392°F) while maintaining excellent mechanical performance. These high-temperature resins find extensive use in functional testing under extreme conditions such as hot air flow analysis or thermal testing for automotive components.

High Temperature Material (RGD525)

RGD525 is a polypropylene-like material that closely replicates the characteristics of engineering-grade thermoplastics like polypropylene itself. Its ability to withstand higher temperatures makes it suitable for demanding applications such as hot air flow analysis or functional prototypes requiring resistance against heat distortion.

Bio-compatible Materials

PolyJet bio-compatible materials are extensively used in medical and healthcare industries where compatibility with human tissues is critical. These resins meet stringent regulatory requirements and exhibit excellent biocompatibility while facilitating complex designs and intricate details.

MED610 Bio-compatible Material

MED610 is a bio-compatible material that has been tested and certified for prolonged contact with human skin tissue. It offers exceptional clarity, enabling the production of transparent surgical guides, hearing aids, orthodontic trays, and other medical devices requiring precise fitment.

Agilus 30 (Rubber-like) 30A-95A

Agilus30 material offers a harmonious balance between flexibility and toughness, boasting a Shore hardness range of 30A to 95A, making it adaptable for a diverse array of applications. Thanks to the expansive array of PolyJet materials available – from rigid to flexible resins, high-temperature options to bio-compatible solutions – designers are endowed with a vast selection to realize their innovative ideas. This ensures that they can meet specific functional requirements across a multitude of industries.

Support Materials for PolyJet Printing

Water-soluble Support Materials

Subtle yet crucial, the support materials used in PolyJet printing play a pivotal role in the successful fabrication of intricate and complex models. One major category of support materials is the water-soluble kind, which offers several advantages. Two notable water-soluble support materials in the PolyJet realm are FullCure®705 and FullCure®707.

FullCure®705 is a non-toxic gel-like support material known for its exceptional dissolvability in water. It exhibits remarkable compatibility with a wide range of PolyJet photopolymer resins, making it an invaluable option for creating detailed models without compromising on structural integrity.

Its gel-like consistency allows for easy removal after printing using standard post-processing methods, saving valuable time and effort. On the other hand, FullCure®707 is another remarkable water-soluble support material that perfectly complements various PolyJet resins.

With its unique gel-like properties, it provides excellent stability during printing while ensuring effortless removal afterward. Moreover, this material offers enhanced solubility characteristics even at lower temperatures, further expanding its versatility and ease of use.

Non-water Soluble Support Materials

In certain circumstances where water-based support materials may not be ideal or suitable due to specific requirements or design considerations, non-water soluble support materials become indispensable alternatives. Among such options are FullCure®712 and FullCure®713 – both offering exceptional non-toxic gel-like properties that ensure effective support structures throughout the printing process.

FullCure®712 stands out as a non-water soluble support material that demonstrates remarkable stability during printing while allowing easy removal through mechanical means like peeling or breaking away from the model. This property makes it particularly beneficial when dealing with intricate designs that require precision post-processing techniques.

Similarly, FullCure®713, another non-water soluble support material, offers excellent support capabilities while enabling clean and hassle-free removal. Its unique gel-like composition facilitates easy detachment from the printed model, ensuring minimal damage to delicate features or fine details during the post-processing stage.

These non-water soluble support materials, such as FullCure®712 and FullCure®713, provide valuable options for PolyJet printing projects where water-soluble supports may not meet specific design or application requirements. Their compatibility with a wide array of PolyJet resins allows for greater flexibility in material selection without compromising on the quality and complexity of the final printed product.

Post-processing Techniques for PolyJet Parts

Enhancing Surface Finish

Although the surface of Polyjet is already very smooth, if a higher quality finish is required, we can use hand sanding and polishing to achieve a layer-free effect.

Additionally, a variety of polishing compounds and techniques can be employed, such as using a buffing wheel or hand polishing with fine-grit abrasive pads. These methods help achieve a high-gloss finish, suitable for aesthetic applications or when a smooth surface is essential for functional purposes.

Painting and Coating

PolyJet parts can be painted or coated to enhance their appearance or provide additional protective properties. Prior to painting, the part’s surface should be properly prepared through steps such as cleaning with isopropyl alcohol and applying a primer suitable for the chosen paint type.

Various painting techniques can be used, including airbrushing, spray painting, or hand-painting with brushes. Furthermore, specialized coatings like clear coats can be applied to add durability and resistance against environmental factors.

Conclusion

PolyJet technology offers incredible versatility in creating highly detailed prototypes and functional parts with a wide range of materials that possess exceptional mechanical properties. With its ability to print multiple materials simultaneously and produce complex geometries with precision, it has revolutionized various industries including automotive design, medical device production, and consumer goods manufacturing. As technology continues to advance rapidly in the additive manufacturing field, we can expect further improvements in polyjet materials expanding even more possibilities for its applications.

The ability to create custom-tailored products at an unprecedented speed will unlock new avenues of innovation and design freedom for individuals and businesses alike. Embracing the boundless potential of polyjet materia will undoubtedly drive progress towards a future filled with limitless creativity and unparalleled efficiency in manufacturing processes.