Technical Bulletin SPECIALTY POLYMERS

Laser Marking High-Performance PolymersUpdated FDA guidelines require a Unique Device Identifier (UDI) on medical devices and packaging, creating a need to mark these items in a way that is clearly visible and permanent. Markings on surgical instruments and devices, both single-use and reusable, must withstand a range of sterilization technologies, from gamma radiation to steam sterilization, as well as repeated cleaning cycles.

Laser marking has long been an accepted method for precisely marking a variety of materials, using minimal equipment without the need for special preparation, chemicals or curing steps. Some of the main restrictions for laser marking are the limited control of the marking’s appearance and the need to have a flat, uniform surface for precise marking resolution.

In order to better serve customers needing to mark non-metallic devices, Solvay invested in a laser marking system to study the effects of laser energy on our medical-grade, high-performance polymers, which include:

• Radel® polyphenylsulfone (PPSU)

• Udel® polysulfone (PSU)

• Ixef® polyarylamide (PARA)

• AvaSpire® polyaryletherketone (PAEK)

• KetaSpire® polyetheretherketone (PEEK)

Recommendations for Laser MarkingAn Infrared (IR) Laser was used to laser mark test samples. Because each polymeric material and color has slightly different burn characteristics, fine-tuning the parameters may be required to achieve optimum contrast with minimum surface damage.

For the images in this report, a test pattern was burned on the surface of each color chip to show the dependence of laser power vs. line speed. Each circle in the test pattern had two passes, with the second pass conducted at 90 degrees to the first pass. Individual chips were then burned at different frequencies. Typically, power, speed and frequency are the main parameters to control as they have the greatest effect on the quality and degree of contrast.

As you can see with the test pattern in Figure 1, there may be more the one set of conditions that is suitable for your needs, and different conditions can change the color of the burn. General practice would favor conditions that give the highest contrast with the minimum amount of surface damage, preferring the fastest speed and lowest power setting that achieves this contrast.

Equipment: Tykma Minilase™ Laser type: DPSS (Diode Pump, Solid State) YV04Laser energy: Wavelength: 1,064 nm, max. output: 6 WSpeed: 100 to 1,200 mm/sec (100 mm/sec increments per line, bottom to top)Power: 50 to 95 % (5 % increments per column, left to right)Frequency: 15, 30, 45 and 60 kHz per chip

Figure 1: Laser marking parameter effects

2 \ Laser Marking High-Performance Polymers

Table 1: General starting point recommendations

Material Color Frequency [kHz] Power [%] Line Speed [mm] AppearanceAvaSpire® AV-651 BG15 20 85 800 Dark gray

AvaSpire® AV-651 GF30 BG20 20 80 800 Black

AvaSpire® AV-651 GF30 BK95 20 60 800 Beige / Light gray

Ixef® 1022 0006 20 80 100 Dark gray *

Ixef® 1022 9006 20 60 800 White / Beige

Ixef® GS-1022 WH01 20 90 1,000 Light gray

Ixef® GS-1022 GY01 20 85 1,000 White / Beige

Ixef® GS-1022 GY02 20 80 100 White *

Ixef® GS-1022 GY51 20 80 1,000 White

Ixef® GS-1022 BU01 20 85 1,000 Yellow / Beige

Ixef® GS-1022 GN01 20 80 700 Yellow / White

Ixef® GS-1022 BN01 20 80 1,100 White / Beige

KetaSpire® KT-820 NT 20 85 700 Black

KetaSpire® KT-880 NT 20 85 700 Black

KetaSpire® KT-880 GF30 BG20 20 80 700 Black

Radel® R-5000 NT 20 85 500 Black

Radel® R-5000 CL301 20 80 600 Black

Radel® R-5100 NT15 20 70 100 Dark gray

Radel® R-5100 BK937 20 55 300 White / Beige

Radel® R-5100 BU1027 20 55 100 Beige / Light gray

Radel® R-5100 BN1164 20 55 300 White / Beige

Radel® R-5100 GY1137 20 70 800 Dark gray / Black

Radel® R-5100 YL1337 20 85 200 Black

Radel® R-5100 GY1037 20 70 700 Dark gray

Radel® R-5100 RD1018 20 75 100 Light gray

Radel® R-5100 OR1145 20 95 1,000 Black

Radel® R-5100 GN1007 20 75 300 Light gray

Radel® R-5100 GY874 20 55 300 Beige / Light gray

Radel® R-5100 VT2585 20 65 100 Black

Udel® GF-120 NT 20 85 700 Black

Udel® GF-120 BK937 20 55 600 White / Beige

Udel® P-1700 NT06 20 90 500 Black

Udel® P-1700 CL2611 20 90 500 Black

Udel® P-1700 BK937 20 55 400 White / Beige

Udel® P-1710 NT15 20 85 600 Black

* Multiple passes may be required

Effect on Mechanical PropertiesA short study was conducted to evaluate the effect of laser marking on the mechanical properties of Radel® PPSU. Laser marking conditions are summarized in Table 2.

Standard ASTM tensile bars and flex bars were marked with two levels of contrast using in-house equipment. Normal conditions were chosen to provide a good, clear contrast of the surface with no significant damage to the material. Aggressive conditions were extreme choices based on the level of burning. As can be seen in Figures 2 through 5, damage was clearly visible to the surface of the samples.

Table 2: Laser marking conditions for Radel® PPSU *

MaterialLine Speed

[mm]Power

[%]Frequency

[kHz] Radel® R-5100 BK937

Normal 800 70 30

Aggressive 100 75 30

Radel® R-5100 BU1027

Normal 700 85 35

Aggressive 100 85 35

* Tykma Technologies: DPSS YV04, 1,064 nm, 6 W max. output

3 \ Laser Marking High-Performance Polymers

Table 3: Mechanical properties of Radel® PPSU after laser marking

MaterialLaser

Mark Level

Flexural Stress at 5 % Strain

[MPa (psi)]

Tensile Strength at Yield

[MPa (psi)]

Tensile Strain at Yield

[%]

Tensile Strain at Break

[%]

Tensile Modulus [MPa (psi)]

Radel® R-5100 BK937 Control 96.5 (14,000)

74.4 (10,800)

7.4 65 2,434 (353,000)

Normal 96.5 (14,000)

74.4 (10,800)

7.3 60 2,427 (352,000)

Aggressive 93.1 (13,500)

73.1 (10,600)

7.4 10 2,372 (344,000

Radel® R-5100 BU1027 Control 98.6 (14,300)

73.8 (10,700)

7.3 52 2,448 (355,000)

Normal 97.2 (14,100)

74.4 (10,800)

7.4 57 2,434 (353,000)

Aggressive 94.4 (13,700)

73.1 (10,600)

7.4 11 2,406 (349,000)

* Tykma Technologies: DPSS YV04, 1,064 nm, 6 W max. output

Standard ASTM tensile testing was conducted using Type I bars tested at 51 mm/min (2 in./min). Flexural testing was conducted at 1.3 mm/min (0.05 in./min) on a 51-mm (2-in.) span with the laser marking facing down. Test results are summarized in Table 3 and presented graphically in Figures 6 through 9.

Figure 4: Aggressive mark break area of Radel® R-5100 BK937, 20x

800 mm/sec, 70 % power, 30 kHz

Figure 2: Normal laser marking of Radel® R-5100 BK937

Figure 5: Aggressive mark break area of Radel® R-500 BU1027, 20x

100 mm/sec, 8 % power, 30 kHz

Figure 3: Aggressive laser marking of Radel® R-5100 BU1027

Safety Data Sheets (SDS) are available by emailing us or contacting your sales representative. Always consult the appropriate SDS before using any of our products. Neither Solvay Specialty Polymers nor any of its affiliates makes any warranty, express or implied, including merchantability or fitness for use, or accepts any liability in connection with this product, related information or its use. Some applications of which Solvay’s products may be proposed to be used are regulated or restricted by applicable laws and regulations or by national or international standards and in some cases by Solvay’s recommendation, including applications of food/feed, water treatment, medical, pharmaceuticals, and personal care. Only products designated as part of the Solviva® family of biomaterials may be considered as candidates for use in implantable medical devices. The user alone must finally determine suitability of any information or products for any contemplated use in compliance with applicable law, the manner of use and whether any patents are infringed. The information and the products are for use by technically skilled persons at their own discretion and risk and does not relate to the use of this product in combination with any other substance or any other process. This is not a license under any patent or other proprietary right. All trademarks and registered trademarks are property of the companies that comprise Solvay Group or their respective owners.

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ConclusionBased on test results, laser marking has no effect on the mechanical properties of Radel® PPSU. Tensile strength, tensile strain at yield, and tensile modulus are all within normal variability to the control. There is a 5 % drop in flexural strength under aggressive marking conditions, which is likely due to damage of the skin layer caused by marking. The most significant change is the tensile elongation at break; aggressive marking has created significant defects on the surface of the material and reduced the material’s ability to be elongated to high strain levels.

However, it should be noted that the material was elongated past the yield point, which is technically the functional limits of the material under load. The loss of high elongation properties is expected based on the severe damage seen on the aggressively marked surface. This would be the same as if the material were deeply scored by a sharp instrument.

Aggressive marking reduces the part’s ability to take high strain, but it still has practical properties up to and just beyond the material’s yield strength. Based on this, it could be concluded that laser marking has no significant effect on the performance of a part made from Radel® PPSU that’s used in typical applications. Based on similar polymer chemistries and performance attributes, it is reasonable to conclude that results would be similar for Solvay’s other medical-grade polymers and that laser marking can be used with confidence on these materials.

Figure 6: Flexural stress at 5 % strain after laser marking

Figure 9: Tensile elongation at break after laser marking

Figure 7: Tensile strength at yield after laser marking

Figure 8: Tensile elongation at yield after laser marking

14,200 60

12,000

7

14,000

8

9

14,400 70

16,000

10

13,800 40

8,000

5

14,000 50

10,000

6

13,200 10

2,000

1

2

13,400 20

4,000

3

13,600 30

6,000

4

Fle

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[psi

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Ten

sile

elo

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atio

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]

Ten

sile

str

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th [p

si]

Ten

sile

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atio

n [%

]

Control Control

Control

Normal mark Normal mark

Normal mark

Aggressive mark Aggressive mark

Aggressive mark

13,000 0

0

0Control Normal mark Aggressive mark

Radel® R-5100 BU1027Radel® R-5100 BK937

Radel® R-5100 BU1027Radel® R-5100 BK937

Radel® R-5100 BU1027Radel® R-5100 BK937

Radel® R-5100 BU1027Radel® R-5100 BK937