xPEEK147 Application Notes

Introduction

xPEEK147 was developed with material partner LoctiteAM / Henkel. This high strength and high temperature plastic is suitable for plastic molding tooling.  This material is relatively slow curing and has a thermally cured chemistry requiring a post-cure bake cycle to achieve advertised properties. This is a strong but brittle material when fully cured.

 

PRE-HEAT REQUIREMENTS: xPEEK147 requires pre-heat to condition the material before use for best results. Heat it in the provided container at 60°C for 24 hours. Let the resin and container cool down to ambient temperature and shake well before dispensing. We recommend heating in a water bath such as a sous-vide apparatus or heated ultrasonic washer with ultrasonics turned off. Keep container below 65°C to avoid softening the plastic. Re-heating may be required if not used within 1-2 months.

Store resin in original plastic container above 20°C to prevent crystal growth. Dispense through a 190um filter to check for crystallization. If crystallization occurs, return material to the container and complete the pre-heat cycle before use.

Printing Tips for Tooling / Molds

xPEEK147 molds and tooling should use solid part enhancement for best results. This exposes outer perimeter separately from inner volume reducing shrinkage lines and gelling.

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xPEEK147 tooling may be printed directly on the build plate with injection mold halves printing last (up-skin), or vertically if self supporting blow-mold cavities.  Minimize shrink induced surface defects and minimize resin cost by targeting constant-thickness mold designs using ~10mm thick walls and ribs. Or consider hollowing with lattice fill if redesign is not an option.

Base layers will over-cure, so add ~1mm chamfer to compensate to all build-plate touching edges. 

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Base layers directly on the build plate will result in some stripes which must be removed after printing by sanding or machining. If printing a large area (> 25% of the build plate area) directly on the build plate, reduce the base layer exposure time 10-20% to make removing a bit easier.

Scaling Factor

The Custom Settings menu of NexaX Pro can be used to adjust XY scaling factors.

Note: XiP users will need a NexaX Pro license in order to use the Custom Settings Menu

xPEEK147 normally uses factor .0025 for Green parts, .0044 for post-cure, and .0065 for post-bake accuracy. This scaling factor can be adjusted to fine tune fit of XY features.

Post Processing

Validated Workflows

WASH

CURE

Post BAKE

Flex Stress (MPa)

Flex Mod (MPa)

HDT @ .45 MPa

HDT @ 1.8 MPa

  1. 1min rinsing in Dirty Batch xCLEAN

  2. 1min rinsing in Clean Batch xCLEAN

  3. Rinse-off in IPA

 

60 min in xCURE 

No post-bake

110

3307

222°C

68°C

  1. Heat up with oven. (1.5°C increment per minute)

  2. After reaching 170°C, bake for 3hrs.

  3. After baking, cool down with oven.

134

3491

230°C

184°C

2x 10min @66% Uvitron600

No post-bake

122

3582

238°C

107°C

 

Generally tooling parts can be washed and cured off the build platform without significant warping. Tools may be difficult to remove from the plate without damage if the contact area is too large. Consider hashing the bottom surface to reduce surface area.

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Many customers observe surface crazing (see magnified image below) when first developing the workflow. We recommend validating your internal process with small coupons before starting the wash of tooling parts. Crazing is a result of excessive exposure to solvent prior to post-bake.

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Washing

xPEEK147 will craze (surface cracking) if exposed to IPA or xCLEAN for too long. Wash for 1-2 minutes with a soft brush in xCLEAN or IPA. Complete a secondary rinse immediately in clean IPA for 1 min in ultrasonic. Remove the solvent from the surface immediately after washing by forced air dry (IPA). Let parts dry for a few hours before curing.  Crazing damage may not be apparent after washing, but will manifest itself during cure or post bake. Note ultrasonic washing in water after washing in xCLEAN can result in cavitation damage to the part surface.

Curing

Cure off the build plate when possible. Validated workflows are based on 4mm wall thickness specimens, and achieving complete post-cure in the core of thicker parts may not be possible, or may require modification to the validated workflow. Improve penetration of the post cure by curing at 50 or 60°C instead of room temperature, or including IR radiation during curing (in arc-lamp chamber).

Post Bake

For post-bake a convection-type programmable oven with controllable range 50-200°C is required. We recommend Yamato DKN402C.

 

Updated

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