User guidelines on VOC emissions and safe working environment preparation

Printing with filaments in the Metal Expansion kit can release volatile organic compounds that cannot be filtered with the Air Manager, especially formaldehyde. Therefore, adequate ventilation is required. More general information about 3D printed emissions can be found here.

Users are requested to set up their printing environment in terms of proper air exchange rate and room volume to be complaint with regional Threshold Limit Values (TLV). As formaldehyde of substances emitted has the most critical TLV, focus will be on this substance in the guidelines below.

The estimated exposure concentration for chemical i,   (μg m-3), for a particular room model m, was calculated using the following equation:

Screenshot_2022-07-25_at_13.21.20.png

Where Screenshot_2022-07-25_at_13.22.17.png  is the emission rate of a compound, in this case Formaldehyde, (ERformaldehyde= 1162 μg h-1) 1 when printing Ultrafuse® 17-4PH or Ultrafuse® 316L together with Ultrafuse® Support layer, A is the number of printers in the modelled room.  Vm and Nm are the volume and air exchange rate of the modelled room.

According to the German AgBB LCI and the ECHA (EU) public DNEL for inhalation, the TLV for formaldehyde is 100 µg/m³. Here are some examples of work environment preparations to set up a safe and compliance printing environment.

Example 1

  • Number of printers = 1
  • Type of room: Office Room
  • Room volume: (30 m³)
  • Air exchange rate : 1.8 h-1
  • Relative Formaldehyde concentration under these conditions = 22 µg/ m³

Example 2

  • Number of printers = 5
  • Type of room: Laboratory
  • Room volume: (30 m³)
  • Air exchange rate: 10 h-1
  • Relative Formaldehyde concentration under these conditions = 20 µg/ m³

Caution: Specifically for the state of California, the CDPH SMCREL limit is 9 µg/m³. In this case, the following is recommended:

  • 1 printer in 30 m³ with 10 Air Exchange Rate.
  • Alternatively, an extraction system should be used, see below.

Example 3

  • Number of printers = 1
  • Type of room: Laboratory
  • Room volume: (30 m³)
  • Air exchange rate: 10 h
  • Relative Formaldehyde concentration under these conditions = 4 µg/ m³

Alternatively, users can ensure a high and confined air exchange by connecting the Air Manager to their Central Exhaust System (CES) via an adaptor, see below.

Option - Extraction system setup

In some cases, the available room volume and/ or Air Exchange Rate (AER; general ventilation) are insufficient to ensure relevant Threshold Limit Values (TLV) of VOCS or UFPs are not exceeded. This is especially true when the room volume and/or AER are too small or low relative to the number of printers or other emitters in the room. For a very small or poorly ventilated room even one printer can cause exceedance of TLVs, or Lowest Concentration of Concern associated with standards like UL2904 or AgBB. In these cases, customers may choose to connect the Air Manager to their Central Exhaust System (CES) or Local Extraction System (LES).

The Air Manager is equipped with an opening at the back with four holes that allows to install an adaptor which, in turn, can engage with a given exhaust system interface (i.e., the suction hose). Exhaust systems also come with different architectures and capabilities; the user shall assess the health-related hazards and benchmark among different solutions to come up with the optimal filtration system. Therefore, Ultimaker recommends users to adapt and supply the adaptor upon consultation of the responsible EHS manager at users’ facility. Extraction1.jpg

Caution: when emissions from printers via the Air Manager are extracted to a CES or LES, it must be ensured that these emissions do not end-up unfiltered in the same, or other working areas. Exhaust to outside air is recommended if the CES or LES is not fitted with an adequate filter. Especially VOCs need to be filtered; UFPs are largely removed by the Air Manager Filter already.

a. Design validation process

An adaptor may be designed and printed directly in-house to best fit the exhaust system interface, whereas a smoke test machine can be used to validate the adaptor design.

  1. Although very specific for a specific tested configuration (adaptor + exhaust system), suction flow values spanning from 41 m3/h to 70 m3/h have proven optimal to guarantee smoke extraction (i.e., emissions) on one hand, whilst guaranteeing the same printing conditions within the chamber (i.e., temperature and flow) on the other hand.
  2. The adaptor should be designed in a way that minimizes turbulence from the suction flow provided by the exhaust system. More specifically, depending on Exhaust system flow rate present at users’ s facilities, connector design must be adapted accordingly to avoid:
  3. Excessive Build volume cooling down effect
  4. (Only) Partial extraction due to Insufficient extraction speed, causing:
    1. Fume leakages at the gap between Air Manager and printer
    2. Fume Turbulences within the build chamber
  5. Once the smoke machine is placed into the printer’s chamber and the chamber is filled with smoke, the exhaust system should work in a way that all the smoke goes through the Air Manager filter running down the exhaust system, without smoke spilling from the back gaps of the Air Manager or the adaptor.

b. Boundaries conditions

The adapting system has been validated by Ultimaker and for Ultimaker facilities only under the following boundary conditions to keep the build volume temperature deg C  and 50 deg C and ensure VOC extraction during Ultrafuse 17-4PH and 316L printing:

Exhaust. system flow rate:

Air manager speed: 2700rpm (full speed) 

Air manager flow: 100%

c. Adaptor configuration

The adaptor system is made of two important parts​:

The Adaptor

Functionality: link the Air manager hood to the Central exhaust system​

The Bumper

Functionality: adapt to the shape of the filter box when closing the Air Manager hood and limit all kind of leakage that can be induced by flow differences between the central Exhaust System and the Air Manager. The bumper seals the interface filter box / Hood​

Extraction2.jpg

c. Adaptor preparation

In case you assess that the solution provided by Ultimaker complies to your internal requirements and safety standards, make sure to print the adaptor and the bumper using the STL files provided and/or CAD files in case the adaptor or bumper has to be adapted to fit the extraction system.

STL files CAD files
Adaptor Adaptor
Bumper Bumper
  • For better efficiency, use an AA 0.8 Print Core to print the Adaptor
  • For better fit, use an AA 0.4 Print Core to print the Bumper
  • It is recommended to print the adaptor as well as the bumper in PLA or T-PLA.​

e. Adaptor installation

These are the tools required for the installation:

  • 1x Printed Adaptor​
  • 1x Printed Bumper​
  • 4x Screws and nuts (provided with the Air Manager)​
  • 1x Allen Key (provided with the Air Manager)​
  • 1x Pliers or nut holder

Here are the steps for Adaptor and bumper installation:

 

Step 1:

Remove the Air Manager hood form the printer by pushing the clips on each side of the Air Manager balcony

Step 2:

  • Place the Bumper inside of the hood and maintain it with the screws (head of the screw inside the hood)
Extraction3.jpg

Note: Picture shows the hood in an upside-down position

  • the opening of the Bumper MUST be facing inside the hood (it will cover the shape of the filter box)
  • The Bumper MUST be with the thicker side facing the bottom of the hood and the thin side facing the top of the hood (towards the sealing)
Extraction4.jpg

Step 3:

  • Place the Adaptor at the outside of the hood, making sure that all screws are placed into the holes.
  • Place the nuts and tighten them together with the screws using the Allen key and the pliers or any nut holder tool.
  • Tighten it until the adaptor and the bumper are fixed to the hood and cannot move freely anymore.
  • The use of washers is possible but not mandatory
Extraction5.jpg

Step 4:

  • Place the Air Manager back on the top of the printer, by sliding the clips inside the intended holes
  • You will hear two clicking sounds (one on each side)
  • The hood is then well installed, and the bumper will take the outer shape of the filter box when closing the hood.
  • Connect the adaptor to the central exhaust system

 

Extraction6.jpg

Caution: The filter of the Air Manager MUST NOT be removed from the Air Manager

Step 6.

Test the set-up by placing a smoke generator in the build volume while checking:

  • All smoke passes through the filter into the exhaust
  • No turbulence is created
  • No smoke escapes at the interfaces between the Air Manager, the adaptor, or the connecting hose to the central extraction system

If needed adapt the extraction flow speed by adjusting valves of the local extraction point of the central exhaust system.

Extraction7.jpg

Disclaimer 

Ultimaker have designed an adapter that can be used to connect an Ultimaker Air Manager to a central exhaust system. It is user’s sole responsibility to assess whether this adapter fits user’s needs and allows for a safe and working connection between the Air Manager and customer’s air extraction system. Ultimaker explicitly states that the use of an adapter and air extraction system that does not meet full requirements between the Ultimaker Air Manager and your central exhaust system may result in, among others: overheating, damage to the printer and / or Air Manager, exceedance of Threshold Limit Values of Ultra Fine Particles and VOCs in the print room, and reduced print quality (list is non-exhaustive). This document is intended purely as a guidance document. This document was drawn-up with great care. However, given the uniqueness of every customer’s environment and use situation, Ultimaker shall not make any guarantees about the accuracy of this document and the operation and/or suitability of the Ultimaker Air Manager and/or any other Ultimaker product. Ultimaker hereby waives any and all liability or loss that you or any person or entity associated may suffer or incur as a result of the use of the Ultimaker Air Manager and Ultimaker shall not be liable to the user for any type of damages, including direct, indirect, special, incidental or consequential loss or damage related to the use of the Ultimaker Air Manager and/or any other Ultimaker product.

References

Emission test measurements at Fraunhofer institute in accordance with international standards as listed under UL-2904. Test performed on Ultrafuse® 17-4PH together with Ultrafuse® Support Layer

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