What Materials Can Be Processed by Cryogenic Deflashing?

Meta Title: What Materials Can Be Processed by Cryogenic Deflashing? | PEGE

Meta Description: Complete guide to materials for cryogenic deflashing: which rubbers, engineering plastics, and die-cast metals work — and which don't. Includes verified processing parameters and real-world examples.

Quick Answer

Cryogenic deflashing works on three broad material categories: rubber/elastomers (NR, NBR, HNBR, ACM, EPDM, FKM, and more), engineering plastics (PA+GF, PC+GF, POM, PPS, PBT, PET, PEEK, and most thermoplastic elastomers such as TPU, TPO, TPV, EVA), and zinc/magnesium die-cast alloys. However, it is not a universal solution — certain unfilled or general-purpose plastics such as pure PA, pure PC, ABS, PP, HDPE, and ETFE are not suitable based on years of production experience. Silicone is also difficult to process with a low success rate. The process relies on the principle that thin flash becomes brittle at cryogenic temperatures before the thicker part body does — a property that only applies when there is a sufficient differential between the two. PEGE Frozen Shot machines offer adjustable temperature settings down to -130°C, but we always recommend sample testing before committing to production.

Key Takeaways

• Cryogenic deflashing is effective for rubber, a wide range of engineering plastics, thermoplastic elastomers, and zinc/magnesium die-castings — but not every material is suitable.

• Rubbers generally require the coldest temperatures (-60°C to -110°C); plastics work at warmer settings (-60°C to -30°C); die-cast metals need only -40°C to -20°C.

• Suitable engineering plastics include POM, PPS, PBT, PET, PEEK, PA+30%GF, PC+30%GF, and most thermoplastic elastomers; pure PA, pure PC, ABS, PP, HDPE, and ETFE are generally not suitable.

• Silicone is the most difficult rubber to process; results depend heavily on part geometry and flash thickness.

• PEGE recommends sample testing for any new or unusual material before full production.

How Material Type Affects the Process

The key factor is the glass transition temperature (Tg) — the point at which a material becomes brittle. Thin flash cools faster and reaches Tg before the part body, creating a processing window. However, this differential embrittlement principle only works when the part body is substantially thicker or more thermally resistant than the flash. If both thin out equally, there is no reliable processing window.

Different materials require different temperature settings and cycle times:

• Rubbers generally need the coldest temperatures because they remain elastic at higher temperatures (-60°C to -110°C).

• Engineering plastics become brittle at warmer cryogenic temperatures (-60°C to -30°C).

• Die-cast metals require the warmest settings (-40°C to -20°C) to make residual flash friable.

All PEGE PG-series machines offer a cooling range of -130°C to +50°C, covering the full spectrum of deflashing requirements across these material groups. For a detailed explanation of the underlying process, see How Does a Cryogenic Deflashing Machine Work?

Rubber & Elastomers

Rubber is the most common application for cryogenic deflashing. The process is widely used on O-rings, gaskets, seals, and custom-molded rubber components.

Common Rubber Materials

Practical Example: NBR O-Rings on PG-80T

When processing NBR O-rings (ID 2mm, OD 20mm) on the PG-80T, a typical parameter set is:

• Temperature: -75°C

• Blasting time: 5 minutes

• Media size: 1.0mm polycarbonate

• Blasting speed: 6,000 RPM

• Barrel speed: 20 RPM

• Load per cycle: ~3.5 kg

This configuration consistently delivers clean flash removal with zero surface damage.

Silicone: A Difficult Case

Silicone is the most challenging rubber for cryogenic deflashing. Success depends on very specific conditions:

• Parts should have a round or robust shape with no fragile edges.

• Flash must be thin (less than 0.1mm) and not sticky on the part body.

• Temperatures often need to drop below -110°C, resulting in higher nitrogen consumption.

• Even with optimal settings, the success rate is lower than with NBR or EPDM.

PEGE strongly recommends sample testing for silicone parts before purchasing equipment.

Engineering Plastics

Cryogenic deflashing can be effective on certain precision injection-molded plastic parts, but it is not suitable for all plastics. Based on years of production experience, PEGE has verified which materials respond well and which do not.

Suitable Plastic Materials

Practical Example: PA+30%GF Components on PG-60T

When processing PA+30%GF plastic components (plastic housings or liners, less than 50mm, ~20g) on the PG-60T, a typical parameter set is:

• Temperature: -55°C

• Blasting time: 5 minutes

• Media size: 0.75mm polycarbonate

• Blasting speed: 6,500 RPM

• Barrel speed: 15 RPM

• Load per cycle: ~3 kg

Plastics NOT Suitable for Cryogenic Deflashing

The following materials have been verified through years of production experience as generally unsuitable:

• Pure PA (unfilled Nylon) — Becomes overly brittle, risking part cracking or surface damage; glass fiber reinforcement (PA+30%GF) is required

• Pure PC (unfilled Polycarbonate) — Does not provide a reliable flash-to-part differential without glass fiber reinforcement

• ABS — Does not embrittle selectively; flash and part body harden together

• PP (Polypropylene) — General-purpose polyolefin that does not respond well to the process

• HDPE — General-purpose polyolefin; insufficient embrittlement differential

• ETFE (Tefzel) — Not suitable for cryogenic deflashing

This list is not exhaustive. PEGE recommends sample testing for any plastic material not explicitly listed as suitable.

Die-Cast Metals

In addition to rubber and plastic, cryogenic deflashing effectively removes residual flash from zinc and magnesium alloy die-castings. These non-ferrous metals form thin flash during the die-casting process that is difficult to remove manually without damaging precision surfaces.

• Zinc alloys — Common in automotive trim, hardware, decorative items, and electronic enclosures

• Magnesium alloys — Used in lightweight structural components and consumer electronics

The metal part body remains structurally unaffected at cryogenic temperatures, while the thin flash becomes brittle and is cleanly removed by polycarbonate media.

Practical Example: Zinc Alloy Components on PG-60T

When processing small zinc alloy components (automotive or decorative parts, less than 50mm, under 40g) on the PG-60T:

• Temperature: -40°C

• Blasting time: 5 minutes

• Media size: 0.75mm polycarbonate

• Blasting speed: 7,000 RPM

• Barrel speed: 8 RPM

• Load per cycle: 5–6 kg

Materials and Parts NOT Recommended

While cryogenic deflashing is versatile, it is not a universal solution. The following conditions generally do not yield acceptable results:

• Certain unfilled or general-purpose plastics — Pure PA, pure PC, ABS, PP, HDPE, and ETFE (as listed above)

• Parts with very thin or fragile bodies — If the part itself is as thin as the flash, the differential embrittlement principle does not apply

• Materials that become overly brittle at cryogenic temperatures — Some unfilled plastics may crack or stress-fracture

• Parts with embedded inserts that have different thermal contraction rates — Risk of delamination or insert loosening

• Very soft silicone parts with fragile edges or thick, sticky flash — Low success rate; sample testing is essential

PEGE recommends sample testing for any new or unusual material before committing to full production. Contact us to arrange a trial.

FAQ

1. Can cryogenic deflashing process silicone rubber?

Silicone is the most difficult rubber to process. It can work only when parts are round or robust in shape (no fragile edges), flash is thinner than 0.1mm and not sticky on the body, and temperatures are pushed to -110°C or below — resulting in higher nitrogen consumption. Even under optimal conditions, the success rate is lower than with NBR or EPDM. We strongly recommend sample testing first.

2. Will the process damage my plastic parts?

Not when the material is suitable and parameters are correctly set. The process targets only the brittle flash while the part body remains above its embrittlement threshold. However, certain plastics — pure PA, pure PC, ABS, PP, HDPE, and ETFE — do not provide a sufficient flash-to-part differential and can crack or suffer surface damage. We use the right media size and blasting speed to ensure no damage, and sample testing is always recommended for new materials.

3. What is the coldest temperature a PEGE machine can reach?

All PG-series machines offer a cooling range of -130°C to +50°C, suitable for all standard deflashing applications from silicone (very cold) to die-cast metals (relatively warm).

4. Can one machine handle both rubber and plastic parts?

Yes. PEGE Frozen Shot machines process rubber, suitable plastics, and die-cast metal parts. Parameter settings (temperature, time, media size, blasting speed) are adjusted per material and saved as recipes on the touchscreen control for quick changeover.

5. How do I know if my material is suitable?

The most reliable way is to send samples to PEGE for trial testing. Based on nearly 20 years of experience across rubber, plastic, and die-cast metal applications, we can assess material suitability, recommend starting parameters, and provide a documented test report. Operators can then save verified parameter recipes on the machine for production.

Related Products

• PG-40T Cryogenic Deflashing Machine — Compact model, ideal for small-batch testing and multiple materials

• PG-80T Cryogenic Deflashing Machine — Versatile mid-range model for mixed material production

• PG-120T Cryogenic Deflashing Machine — High-capacity model, including PU bumper applications

• PG-150T Cryogenic Deburring Machine — Largest capacity for high-volume multi-material production

Why Choose PEGE Frozen Shot?

NANJING PEGE TECHNO MACHINE CO., LTD has nearly 20 years of cryogenic deflashing experience across rubber, plastic, and die-cast metal applications. Our Frozen Shot PG-series machines use SUS304 stainless steel construction, offer a cooling range of -130°C to +50°C, and feature touchscreen recipe management for quick material changeover. Exported to 15+ countries, PEGE machines deliver 15%–20% lower LN₂ consumption, a 1-year free warranty, and lifetime after-sales support.

Not sure if your material is suitable? That is exactly what we want to discuss honestly. Contact PEGE today — we will help you determine whether cryogenic deflashing is the right solution for your parts, and arrange sample testing if needed. Response within 24 hours.