Type = 645 Nylon 3D Printer Filament Co-Polymer, consists of the purest form of a delta transition of Nylon 6/9, Nylon 6 and Nylon 6T with a crystallinity optimization process in addition to post processing for maximum bonding during a thermal transition (3D Printing).
Construction = From granule form through nylon extruding systems to a 12 station extrusion to draw, 4 chiller loops with 2 post processing stations to a final draw of 3mm or 1.75mm round line.

Physical Properties            Metric                    English               Comments
Water Absorption                3.09 %                      3.09 %             ISO METHOD 62
 
Mechanical Properties       Metric                    English                Comments
Tensile Strength, Yield                                     12,428 psi           ISO METHOD 527
Elongation at Break             >= 300 %                >= 300 %         ISO METHOD 527
 
Thermal Properties             Metric                   English                Comments
Melting Point                         214 °C                 17 °F                     ISO METHOD 3146C
Glass Transition Temp      68.2°C. 
 
Processing Properties       Metric                      
Print Temperature               235 – 260 °C     –    Part and printer dependent.
Pyrolysis                               350 – 360 °C
UV                                          There are no UV Inhibitors within 645 as they reduce bonding

Safety                                     645 meets the EU’s “REACH” requirements as defined by the ECHA European Chemicals                                                             Agency.  There are NO additives or chemicals in 645 that are listed in the REACH Directive.

                                                645 Contains NO toxic chemicals and is “inert” to the body.  

As with all 3D Printing using heated polymers, Caution should be used so as NOT to come into contact with the molten 645 (214C+) as it will adhere to ALL cellulose surfaces, including skin.

1. Bone repair and replacements – US Clinic Evaluations

2. Real-time build of custom prosthetic – Hague University of applied sciences Department: Technology, Innovation & Society

3. Real-time build of custom orthopedic items. – Hague University of applied sciences Department: Technology, Innovation & Society

4. Real-time build of custom prosthetic with internal sensors – Sensors installed during the active printing process. – Hague University of applied sciences Department: Technology, Innovation & Society

5. Real-time build of custom pressure sensing braces and prosthetic. – US Clinic Evaluations

6. Build of custom bone replacement with targeted support prosthetic. – Hague University of applied sciences Department: Technology, Innovation & Society

7. Custom heavy support fabric/film for less restrictive outpatient activity. – Hague University of applied sciences Department: Technology, Innovation & Society

Usage:

Bone:

1.  Refer to the “Maximum layer bonding Page” to set your printer for best layer bonding.

2. As 645 is an extremely strong material, it is still important to build the replacement in such a fashion to maximize resistance to stress.  

    The greatest strength is always along the nozzle flow axis.  As newer printers and older printers with updated SW can provide a form of rafting or

support for high print angles, it is better to plan a print with support to obtain the best structural and slippery features.

Settings:

Current feedback from actual usage shows a better end replacement when printed with the following settings:

1. Perimeters  = Minimum of 4 – Maximum depends on the number of screws used to attach to existing structure.
            
2. Layer thickness/height = .1mm maximum for small joints and .04mm for larger joints.

3. Temperature = From “Maximum layer bonding Page” determination.

4. Speed = Printer dependent, however speeds greater than 44mm/s begin to reduce bonding on some nozzles.

5. Perimeter Speed = This should be the slowest of all your print speed settings. – Some reports @ 22-24mm/s

6. Nozzles:
                
                0.23mm – 0.5mm – Brass with flat tip
            
                0.5mm –  1.0mm  – Brass, Copper, Copper Alloy with domed tip

                Aluminum was not preferred in a nozzle.  (This is as a function of material.  High TS was not tried)

            7. Retraction – 5-6mm with 1.75mm 645 and 4-5mm with 3mm 645

NOTE:  Other than making sure the idler pressure on extruders was tight, retraction seems to be the only other setting required when changing from ABS/PLA to 645

8. Skirt – Minimum of 4 @ 1 layer height. – Due to 645‘s viscosity, it will take 645 longer to equalize 1st layer pressure in the nozzle than ABS/PLA

9. Bonding surface:  Precision Bond = Machinable Garolite (LE) McMaster Carr PN 8474K141, 8474K151, 8474K161, 8474K171 Warning: Keep surface area to the Garolite at a minimum or you will break your part trying to remove it.

                Secure Bond = Cast Nylon block/sheet

                Secure Bond = 645 printed block/sheet

                Nylon Raft – using a 50% fill cross section with exposed fill crosshatch

                3/8″ sheet of Poplar Wood – unfinished – 645 like other nylons bonds well to cellulose fibers.

                Printed Circuit Board – Hobby Style with no copper, just holes spaced at 0.100 centers

                Various Masking/Painting tapes as 645 will stick to the wax backing of these tapes.