Producing a part by stereolithography - or SLA - can be a lengthy process. This advanced method of additive manufacturing can take between 24-48 hours. After the part has been produced it needs to be cleaned in order to remove the resin debris - one of the fallouts of SLA production.
Historically the resins have been removed by placing them in a stirring tank full of IPA - not the beer but ispropyl alcohol - which is highly flammable; or with TPM - tripropylene glycol methyl - which leaves large amounts of residue on the part.
The stirring tanks are then powered up to high temperatures of 60 degrees or more in order for cleaning to be effective. Once the part has been washed, the spent cleaning liquid has to be disposed accordingly. It cannot be recycled and so contributes to a lengthy and costly waste chain because is it classed as hazardous waste.
In summary there are numerous issues with the standard method of post-production cleaning in the SLA industry:
Using IPA as a cleaner - HIGHLY FLAMMABLE
Using TPM as a cleaner - LEAVES RESIDUES
Necessary to clean at HIGH TEMPERATURES therefore an ENERGY INTENSIVE process & POTENTIALLY UNSAFE for the operators
High amount of HAZARDOUS WASTE PRODUCED therefore expensive and unsafe HAZARDOUS WASTE CHAIN - cost of storage, disposal, compliance, insurance, training, ventilated areas, PPE, etc
RECYCLING of IPA & TPM NOT POSSIBLE - high repurchasing costs & waste of resources
Stirring tanks have no ATEX certification and are not explosion proof. Highly flammable liquid + electronic parts = explosion risk.
There is an alternative, and guess what - BIO-CIRCLE has the answer!
FT 400 is a label free cleaner and has been shown to be just as effective as IPA at post production cleaning. FT 400 is ideal as a manual cleaner. It is non-flammable and with rapid evaporation leaves almost no residue. It can also be filtered after use so it can be reused in a subsequent process.
CB 100 is a very versatile cleaner and works for an automated or a manual cleaning process - i.e. it is suitable for use in an automated parts washer. CB 100 is completely VOC-free and therefore entirely eliminates the waste chain, improving safety and cost control. For our customers who have switched to using CB 100, we have seen their wash times reduced to just 30 minutes in a hot wash machine operating at a reduced temperature of 30-40 degrees.
We recommend using CB 100 in conjunction with HTW with an increased bar pressure of 6-7 bar. This acts as an agitator to gently remove resins from parts with complex geometries, without risking damage to the part itself.
CB 100 is also recyclable and we have seen our customers recycle their liquid every 4 weeks and able to reuse 66% of CB 100!
The HTW will remove 95% of resins but for parts with crevices and corners where resins accumulate during the modelling process, we recommend the GT Maxi manual parts washer. Traditionally this hand washing finishing process was also done with IPA, but again we use CB 100 in the Maxi for a safer, VOC-free and waste chain-free alternative (that is still just as effective at cleaning!)
Get in touch to find out more about how we can improve your cleaning processes in the SLA industry. Call 03300 415 396 or email sales@bio-circle.co.uk