3D Printing Solvent Reclaiming System

Some Facts about 3D printing

3D printing is an emerging industry and has potential in a wide range of applications including manufacturing, medical, industrial, cultural, and many more. In manufacturing, it can revolutionize the way our products are designed, manufactured, and supported. Nothing less. The 3D printing process deals with different kinds of resins, plastic filaments, dyes, and inks. These substances should be properly removed from equipment in order for it to be maintained in optimal working condition. One of the major problems that 3D printers face is having filament buildup or uncured resins clogging the extruder nozzle or causing friction on critical moving parts like the extruder gear, print head, cooling fan, or extruder motor. As research and development activities advance on 3D printing materials and technologies, there are several substrates, which can be used, in today’s 3D printers (nylon, resin, thermoplastic, metal, etc.). All of them have different properties and structures, as well as strengths and weaknesses. Therefore, the choice of the substrate will depend on the application and the way or condition in which the printed object will be used. Since all substrates have different properties – melting point, solubility, durability, flexibility, and strength level – the methods used to dislodge them vary from one material to another. For example, some materials will dissolve easily in solvents, while others will not. Some will break apart readily when scrubbed at room temperature, and some will require heating and harder brushing. Organic solvents – such as acetone – are very efficient cleaning agents when it comes to dislodging chemicals like plastic resins, ink, dyes, and dirt from 3D printer components. However, they are also very hazardous and should be disposed of properly in order to avoid polluting the planet. Or even better: they should be recycled and reused to save resources. First, let’s take a look at what causes filament to build up in some critical components and how to get rid of it.

What Causes a 3D Printer to Malfunction and How to Fix It?

Clogged Printing Nozzle

Even a partial clog of the extruder nozzle will affect the performance of the 3D printers by curving the filament as it exits the nozzle, leading to improper layer bonding. A complete blockage of the nozzle will paralyze the entire system and require a good clean up before it can start running again.

What causes the extruder nozzle to clog?

There are many reasons that could lead to a complete or partial blockage of the extruder nozzle. Here are the most common ones:

• Incorrect printing height: If the nozzle is too close to the print bed, resins could accumulate while reaching the nozzle orifices, which eventually dry and cause a blockage. Do not think that reversing the situation by setting the nozzle too high will solve the problem, because your material layers will not bond correctly. The printing nozzle must be adjusted at the right height according to the manufacturer’s specifications.
• Incorrect printing temperature: Most of the time when this situation occurs, it is due to a change of material during a print job. Since all resins have different extruding temperatures, the printing sequence when changing materials is critical in order to avoid clogging the extruder nozzle. For example, material A melts at a higher temperature than material B, so when you change the substrate and adjust the printing temperature accordingly, there could be some material A residue caramelized inside the nozzle, forming a partial or complete clog.
• Poor quality filament: Chemically unstable or poor quality material could cause filament buildup inside the nozzle head, leading to a partial and eventually complete clog of the nozzle tip.
• Accumulation of dirt and dust: Like any equipment, the accumulation of dirt (lint, dust, or other dirt) can create a great hub for retaining resin filaments as they pass through the nozzle. Eventually, these will end up clogging the nozzle.

Contaminated Mechanical Parts

Filament buildup on moving parts – like the extruder gear, print head, cooling fan, or extruder motor belt – causes friction, which may lead to a premature system failure or issues related to overheating. Moving parts in friction with one another may overheat and affect the operating temperature of the printer. Raising the printing temperature on most substrates will not only affect the printing performance, but could also slow down the curing process and lead to a malformed printed product. Debris caught in the belts or pulleys, coating the rods, or coating the Z-Axis screw can impede the smooth movement of your machine. For all of these reasons, it is very important to keep your 3D printer components free of any contaminants, resins residue, and uncured materials. But how?

How to Clean 3D Printer Nozzle and Parts?

There are many methods to fix a clogged nozzle and break uncured resins found in 3D printed parts. The number one method should always be preventive care – keeping your 3D printer clean and performing scheduled maintenance periodically in between print jobs is the best way to both avoid premature system failure and keep it in optimal operating condition. However, if you notice an accumulation of filaments or other dirt in your parts, it should be completely removed and cleaned prior to putting the 3D printer back in function. Methods include “cold pull”, using acupuncture needles or other pointy objects to scrub residues away, forcing a filament through the nozzle using a material that has a higher strength level and melting temperature than the one caramelized inside, and as a last resort, disassembling the contaminated components and cleaning them with solvent. The best way to get rid of resins located in blind spots and hard-to-reach blind holes is to let it soak for a few hours in solvent. Alternatively, parts cleaners like ultrasonic cleaners or high pressure parts washers have proven to be efficient for cleaning small mechanical parts. The downside of these methods is the cost associated with the purchase of pure solvent and the elimination of waste solvent. Not to mention the risks associated with storing solvent drums in the shop and having to deal with EPA report. That is where Kresco comes into play! Kresco Solvent Distillation Technologies provides the ideal solution to safely separate cleaning solvents from contaminants through a controlled distillation process.

Kresco's Line of Solvent Distillers

Kresco's line of Solvent Recyclers allows you to reclaim and recover your waste solvent through a controlled and fully-automated solvent distillation process. With our systems, you will be able to separate pure solvent from 3D printing resins and other contaminants with optimal efficiency, safety, and consistent quality. Depending on the components included in the substance, you should expect recovery rates yielding from 95% to 99.9% of the original product. We have a large variety of equipment to choose from to accommodate your production volume:

• Batch-Type Solvent Distillers are available in 8, 16, 32, 48, and 64-gal tank capacity.
• Continuous Solvent Distillers are custom fabricated to your needs and can yield production levels of up to 100 gal per hour.

All of our equipment is automation ready and almost maintenance free. It is explosion proof and requires very little expertise to operate. It is QPS certified to UL standard 2208 in Canada and the U.S. for class I, Div.1, Group D hazardous locations. Standard components:

• Built with a strong 304-grade stainless steel tank insulated with 4″ polyurethane on the side wall and bottom.
• Explosion-proof electrical heater and heat transfer oil for optimal indirect heating.
• Working temperature of up to 210 ºC / 410 ºF.
• Process parameters are regulated by programmable logic controllers (PLC) and interfaced with an intuitive, touch panel human-machine interface (HMI).
• Meet NFPA codes (30,33 and 70) and International Fire Codes (IFC).

Optional Components:

• Vacuum assisted system.
• Auto-fill transfer kit.
• All stainless steel components.
• External alarm light box.
• Overfill protection.
• Oil cooling system.
• Lifting arm for collecting industrial sludge.

Contact your Kresco representative today to find out more about our line of solvent distillers and how we can help you improve your 3D printers cleaning processes.