레진 3D 파트 경화 방법

광경화성 수지 조형 방식(SLA) 3D 프린터를 사용하려면 레진 3D 프린트를 경화하는 방법을 필수적으로 알고 계셔야 합니다. 파트를 후경화하면 강도가 최고치에 이르는 안정적인 파트 얻을 수 있습니다. 그렇지만 레진마다 최적의 물성에 이르는 후경화 소요 시간과 온도 등의 조건이 제각기 다릅니다.

저희가 마련한 레진 프린트 후경화 가이드를 다운로드하여 후경화의 기초와 후경화가 Formlabs 레진에 각각 끼치는 영향을 알아보세요

Any resin used in SLA 3D printing can be thought of as a highly cross-linked macromolecule, or a continuous network of polymer chains (monomers and oligomers). Within that macromolecule, there are still some reactive groups that can further cross-link the polymer network when exposed to light and heat.

As more cross-links form, material properties, such as modulus and tensile strength, improve. The objective of post-curing is to link as many of these unreacted groups as possible to bring a part to its maximum material properties.

Once optimal material properties are reached, further post-curing of certain resins can sometimes cause brittleness or warping. The post-curing protocol must therefore be specific for both time and temperature in order to avoid curing too much, and will be unique to each resin and part geometry.

Optimal post-curing starts with heat. Rising temperatures increase the energy, and therefore mobility, in the polymer network. This gives reactive groups a higher probability of finding each other and creating more connections. Formlabs post-curing machines, the Form Cure and the Form Cure L, both use a heater to help the curing chamber quickly reach the desired temperature and then maintain it throughout the postcure.

Once the desired temperature is reached, light is introduced. Photons of light activate remaining photoinitiators, causing nearby reactive groups to form bonds and finish the cross-linking process. With each new cross-link the polymer network becomes more securely linked together and material properties improve.

As more cross-links form in the resin, the network slightly densifies, resulting in some minor shrinkage of the whole part. This is normal for any parts produced with a resin 3D printer. PreForm, Formlabs’ free print file preparation software, automatically compensates for this shrinkage to ensure your post-cured prints are dimensionally accurate to your original CAD designs.

이상적인 후경화 환경에서는 최적화된 시간 이내에 소재에 필요한 물성이 생깁니다. Formlabs 일반 용도 레진의 경우, Form Cure V2를 사용하면 1분 만에 빠르게 경화할 수 있습니다. 강도, 뒤틀림 없는 강성 및 내열성이 필요한 경우, Formlabs 엔지니어링 레진을 후경화 하드웨어에 따라 최대 120분까지 후경화할 수 있습니다.

Formlabs은 자체적인 인하우스 후경화 연구를 통해 Formlabs의 다양한 레진 소재별로 최적화된 후경화 환경을 확인했습니다. ASTM(미국재료시험학회)의 방식을 참조하여 Formlabs의 소재 개발 엔지니어들이 소재별로 기계적 물성과 다양한 온도 환경을 실험했습니다.

Form Cure V2, Form Cure V1, Form Cure L V2, 또는 Form Cure L V1에 대한 모든 최신 권장 후처리 설정을 웹사이트에서 확인할 수 있습니다. 소재 데이터 시트에서 경화를 마친 소재의 특정 기계적 특성을 확인할 수 있으니 공식 홈페이지에서 다운로드해주세요.

As more dental and medical professionals adopt 3D printing in their workflows, 3D printing companies have to ensure that the entire process is controlled to consistently manufacture high performing parts with biocompatible safety for the end user. Biocompatibility requirements require careful adherence to these pre-approved processes, and this applies to the post-cure step of the printing process as well.

Formlabs technology has been validated in FDA-cleared workflows, which means that for each resin intended for use in a biocompatible application, there are certain printing, washing, and curing steps that must be followed without deviation in order for the final part to be considered a biocompatible device.

The Form Cure and Form Cure L are important parts of these workflows. After careful testing and a thorough regulatory process, the validated settings for post-cure times ensure that each printed part for biocompatible applications has optimal mechanical properties and is consistently safe for use.

Find specific post-curing recommendations for each material in the Manufacturing Guide for each material.

An ideal post-cure setting achieves the properties you need in optimal time. Formlabs developed an in-house post-cure study to identify optimized settings for each individual Formlabs Resin. Using the ASTM method, our materials scientists tested a variety of mechanical properties at various temperatures for each material.

To see how post-curing influences mechanical properties, this guide looks at changes in the tensile modulus, which shows a change in stiffness of a part, for each resin over time in Form Cure or Form Cure L. An object with a higher tensile modulus will have a greater resistance to changing shape under stress. Modulus of elasticity is closely related to how completely crosslinked photopolymer chains are within the part, which is why Formlabs uses modulus to represent overall completeness of post-curing.

The “green” shape of a model is formed by laser-curing the resin during printing, but some potential polymer connections remain unbonded. Cross-linking the remaining polymer proportionally improves strength, stiffness, and temperature resistance. Post-curing also causes some part shrinkage. Formlabs measures accuracy and mechanical properties based on a standard post-cure of parts, and material settings are tuned to account for shrinkage under the same conditions.

The following graphs will help you understand how Formlabs materials respond to post-curing, viewed as a percentage increase in tensile modulus. Familiarity with post-curing behavior saves time and improves accuracy when post-curing parts for your particular application.

In this example, Rigid 4000 Resin exhibits a sharp rise in modulus of elasticity over the first 15 minutes of post-curing, increasing by 116%. After 15 minutes, no further improvements are observed. 

Rigid 4000 Resin is a glass-filled composite material designed for parts requiring high stiffness and strength, as well as low deformation under load. Post-cure directly increases strength and stiffness by further crosslinking the polymer matrix surrounding microparticles of glass, holding them rigidly in place. Post-cure of Rigid 4000 Resin is substantially impacted by temperature. At higher temperatures, a large improvement in modulus of elasticity is gained over a short period of time. Post-curing beyond 15 minutes will not affect properties but will begin to cause cosmetic yellowing, and is not recommended. For most applications of Rigid 4000 Resin, post-cure for 15 minutes at 80 °C in Form Cure.

The most common issues encountered when post-curing parts are under-curing and warping. If parts seem weaker or less rigid than expected, they may be insufficiently post-cured. Undercuring can occur when a part is particularly thick or large, as larger parts take longer to heat. Light alone cannot post-cure much beyond the surface of a part, which is why Form Cure and Form Cure L apply both heat and light. If a part is significantly larger or thicker than Formlabs’ test geometries, it may require a longer post-curing time or higher temperatures to reach a full internal post-cure.

Warping during post-cure may occur if a part is especially thin, and is not equally exposed to light on all sides. Form Cure and Form Cure L help prevent warp by rotating the part on a turntable during post-curing, and by exposing the part to light from all directions — including underneath the turntable.

Post-cured parts also tend to be more brittle than green parts. Typically, as modulus increases elongation will decrease; because of this, over-cured parts can be undesirably brittle.

간단하게 빛(자연광, UV 네일 살롱, UV 경화 스테이션, DIY UV 경화 상자)으로 경화하는 데서부터 빛과 열을 모두 사용한 경화까지 다양한 후경화 방법이 있습니다. 열은 공정을 가속하고 분자간 결합이 훨씬 더 완전해지도록 하여 재료의 물성을 빛만으로는 달성할 수 없는 수준까지 증가시킵니다.

Formlabs의 데스크톱 및 대형 SLA 전문 3D 프린터용 후경화 솔루션인 Form Cure와 Form Cure L은 Formlabs의 레진으로 프린팅한 파트를 빠르고 일관성 있게 후경화하도록 설계한 제품입니다. Form Cure와 Form Cure L를 사용하면 SLA 방식으로 3D 프린팅한 파트를 소재에 필요한 광원 파장과 온도, 노출 시간으로 정밀하게 후경화할 수 있습니다.

Form Cure uses a 405 nm light source, which was determined through an extensive internal testing process to be the most effective at creating the best modulus and tensile strength in parts printed on Formlabs printers. In comparison, when the time and temperature were the same, but a 365 nm light source was used, the modulus reaches only 67% as that of the 405 nm samples. There is a significant difference in the post-cured properties at each wavelength, especially so at shorter post-cure times.

Formlabs 후경화 가이드를 참고하여 후경화가 각 Formlabs Resin의 주요 특성에 어떻게 영향을 미치는지 이해하고 응용 분야에 따른 최적의 후경화 계획을 세워보세요.

가이드를 다운로드하여 다음 내용을 알아보세요.

• 후경화가 각 Formlabs 소재의 주요 물성에 미치는 영향
• 소재별 응용 분야에 따른 최적의 후경화 권장 사항
• 후경화 과정의 일반적 문제 방지 전략