Dry Ice Deflashing & Deburring is a CO2 blast cleaning process used in the removal of residual flash and burr material. This process employs dry ice particles accelerated by compressed air to blast away mold flash and machine burrs. Dry ice sublimates (transitions from solid to gas) upon impact with the part surface. This makes the dry ice process an effectively media-less process. The parts are either manually held or secured with a fixture to a workbench.
The video below shows the dry ice process in action:
The technology has demonstrated success in cleaning the spectrum of plastic materials (excluding UHMWPE). Even fine metal flash or burring can be cleaned with this process. The process is not well suited to flexible rubbers which tend to be insufficiently rigid. As the Dry Ice process cleans piece-by-piece, it is a second line of defense to batch methods such as cryogenic deflashing or tumbling. Nonetheless, for suitable candidates Dry Ice Deburring & Deflashing offers an effective cleaning with unique benefits.
The below part characteristics are identifiers of parts well-suited for dry ice processing:
Small holes or cavities (<0.015” opening)
In batch cryogenic deflashing and deburring, polycarbonate beads are used as a blast media which allow the cleaning of ID features such as holes or channels. This polycarbonate media comes in a range of sizes but tends to lose its aggression below 0.015” (0.381mm). For parts requiring finishing in smaller holes, molders and machinists turn to the dry ice process for its microscopic particle size. Though dry ice sublimates too quickly to be reliably measured at smaller sizes, Nitrofreeze® has cleaned cavities as small as 0.003” (0.0762mm) with this process.
Excessively thick flash or burrs
Traditional cryogenic processing offers a wide range of aggressions and most often this process can be dialed to remove the undesired material. However, if flash or burrs prove too robust for this process, dry ice can be used as an effective alternative. In addition to offering a more directed blasting than batch processes, dry ice blasting can reach significantly higher aggressions, up to 140PSI. These high velocity media particles can knock away the heaviest plastic burrs and even fine metal burrs.
Large and heavy parts.
Some parts simply cannot be tumbled. Cryogenic deflashing and deburring baskets can measure up to 24” in (60.96cm) diameter and oversized parts cannot be submitted into this process. Other parts that should avoid tumbling are large plastic parts having delicate outer diameter features and heavy metal parts (~>0.5 lbs) with cosmetic tolerances.
Challenging flash/burr positioning
Some parts have difficult features such as deep, narrow through-holes which require blasting at precise angles. The narrower the hole opening, the shallower the area accessible by media-driven batch methods. For these parts dry ice blasting may be an appropriate substitute. When in doubt, speak with a finishing expert to learn which process is appropriate for your parts.
Learn more on the process
Nitrofreeze’s team of product experts is available to review technical drawings, photos, and samples to recommend a process appropriate for your project needs. For qualified parts, Nitrofreeze offers no-cost sampling at our Worcester, MA facility. You can reach our team at (508)459-7447 x105 or via email at firstname.lastname@example.org. Additionally, you may submit a contact form to have one of our engineers call on you.
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- High-value parts
- Dry Ice Deflashing & Deburring is a manual process and is inherently more labor intensive than batch processes. As a result, it is most often reserved for higher-value components. Medical/surgical, aerospace, and electronics components are the most frequent dry ice candidates.
Nonetheless, if traditional batch processes are unsuited for your parts, it may be worth getting a quote to learn if dry ice processing is economical for your project. Nitrofreeze® offers free quotes and even sampling for qualifying parts.
- Parts that cannot be tumbled or blasted
- Again, it’s advisable to first explore batch solutions for flash and burr removal such as tumbling or cryogenic processing. These high throughput processes tend to be more cost-effective.
However, some parts should not undergo tumbling. Parts with delicate outer diameters, metal parts with cosmetic tolerances, or simply heavy/oversized parts do well processed with dry ice outside of a tumbler.
Similarly, parts with geometries that encourage media lodging should avoid blast media-driven finishing solutions. Dry Ice Deflashing & Deburring is an effectively media-less process as blasted dry ice sublimates from solid carbon dioxide to gaseous CO2 upon impact with the part surface. This characteristic has made dry ice increasingly popular in medical applications. Benchtop Dry Ice Blasting units can be found in many clean room operations.
- Parts with obscured flash or burrs
- Traditional Cryogenic Deflashing & Deburring tumbles and bead blasts the parts, reaching most areas of concern to remove flash and burrs. However, some part geometries such as narrow and deep through-holes require blasting at very precise angles. For these parts dry ice blasting may be a more suitable alternative.