bachmann engineering ag - systemhaus für …...bachmann engineering ag - systemhaus für automation...

24.04.2015bachmann engineering ag - Systemhaus für Automation und Robotik - www.bachmann-ag.com 1

Replacing tapes, sheet metal, thimbles and waxes with UV curing polymers

Automated Masking


• Sand blasting / Shot peening

• Galvanic coating

• Anodizing

• Thermal spray (APS, HVOF*)

• Acid stripping

* GF only

Masking is widely used in:


• Masking Tape

• Slide-on caps / thimbles (silicon, polyurethane, etc.)

• Sheet metal shielding

• Solid metal casing

• Wax, paint

Common masking methods:


• Extensive manual work

• Susceptible to misplacement / human errors

• Not adequate for complex geometries

• Multilayer affects edge definition

• Leaves residues

Disadvantages of tape:


Dummy hip implant Manually masked with glass reinforced silicon tape


Same implant after blastingGrit blasting with Al2O3 F70 / 2.5 bar rips tape edge


Masking of the dummy implantManual masking with glass reinforced silicone tape; time required 3.8 min


https://youtu.be/QAQSlAjBtEk?list=PLgAjQzuBhuNo2hgaWrAsl3dXciFRR87kc

• Require manual mounting, involving labor costs and positioning inaccuracies

• Only last 10 to 20 cycles

• Only good for one specific geometry

Disadvantages of caps (thimbles):


• Require manual mounting, involving labor costs and positioning inaccuracies

• Need to be replaced / recycled frequently

• Do not really seal the surface

• Only good for one specific geometry

Disadvantages of metal shielding:


• Require manual application involving inaccuracies and labor costs

• Only good for low energy processes (galvanic, acids)

• Removal is problematic and involves aggressive chemicals

Disadvantages of wax/paint:


Considering Polymer Masking:

• The right polymer for the process

• Dispensing technology

• UV equipment

• Removal method and equipment

• Material handling

https://www.dymax.com/images/pdf/literature/sg009_speedmask_masking_resins_selector_guide.pdf






Masking with polymerDummy hip implant masked with Dymax SpeedMask 730-BT and cured, process time <1.5min


• Move parts vs. move tools

• Parts handling

• Dispensing technology and equipment

• Trajectory and positioning accuracy (0.25-1mm)

• Integration into a production line (BFS, BFM, BFH, …)

• Safety and compliance

Considering the right automation:


Dispenser testingTesting start/stop for:

• dripping

• tailing

• on/off response time

• line accuracy and repeatability


https://youtu.be/F2mj-PNyDLU?list=PLgAjQzuBhuNo2hgaWrAsl3dXciFRR87kc

Dispense testing: sprayTesting for overspray, uniformity and speed


https://youtu.be/5323KYh1K6k?list=PLgAjQzuBhuNo2hgaWrAsl3dXciFRR87kc

• Manually by peeling

• Automatic by water jet (< 250 bar)

• Automatic by blasting with dry ice pellets

• Incinerating at 650°C (batch process)

Mask removal options:


Manual peeling


Removal of masking by low pressure water-jet (0.2 sec)


masking removal with dry ice pellets


https://youtu.be/Fyftj3W5cX8?list=PLgAjQzuBhuNo2hgaWrAsl3dXciFRR87kc

• Excellent edge definition

• Very fine lines possible

• Complex 3D geometries

• Polymer does not absorb blast particles (zero cross contamination)

• Fast application by line dispensing or spraying

• Fast curing 10 to 30 sec

Quality attributes of polymer masking:


Dymax SpeedMask 734 BT on a clear metal test plate; strip width = 1.0 mm


Same masking strips (Dymax 734 BT) after grit blasting with Al2O3 F22, 2.5bar; notice edge integrity and zero imbedded particles in mask


Same sample after coating with T800 (Plasma) showing the manual peel-off of one polymer strip


Same sample coated with T800 showing clear metal surface after removing the masking strip; notice the integrity of the edges


Cross section analysis of former part after mask removal; notice the very straight and almost vertical walls of the trough


Testing a Liquidyn dispenser with long needle 0.5mm dia., with heater activated, running at 25mm/sec. Polymer is Dymax SpeedMask 717-R


Cross section analysis of the sample above after grit blasting and removing one strip. Notice the clean edge and the neutral wetting angle of the polymer on steel


Testing Liquidyn dispenser


https://youtu.be/QPCLXOMcwKo?list=PLgAjQzuBhuNo2hgaWrAsl3dXciFRR87kc

• Bachmann Engineering AG (Zofingen, Switzerland) offers a complete line of modules to create a production line with material handling, stacking, in-feed / out-feed, vision, in-line QC, and controllers.

• The Bachmann Modular Masking Cell (BMC-M) can work as a stand-alone or be fully integrated in a production line

Automated production line:


• Case: simple hip-implants, tape vs. automated polymer masking, 150’000 parts / year

• Manual: 1m tape per part = $1.2; 3min labor = $1.2

• Automatic: Masking cell (CAPEX) = $200K to $350K (we will use $300)

• Cost of polymer per part = $0.75

• ROI = 300’000 / (2.4-0.75)*150’000 = 14.5 months

A conservative ROI example:


A standard masking cell for batch processing of turbine blades


Bachmann Feed-Stacker BFS

batch processing of small parts with an input stacker and a conveyor belt for unloading; these functions can be reversed


The simplest load/unload by means of a double pallet trolley, manual push/pull of pallets; adequate for small parts e.g. turbine blades, medical implants, etc.

Variation 1: Standard masking cell

A conveyor belt can be added to the cell to allow for continuous feeding or unloading; very commonly it is used for reject parts

Variation 2: Conveyor belt

ModularityThe cell is modular and allows adaptation to many different applications with customized process relevant components.

The following configurations demonstrate the many combinations which are possible.

All modules shown here are compatible and are operated automatically from one master controller BFH Bachmann Flex Handling, commonly the cell controller)


The different modules are compatible throughout the line; mechanical docking guarantees flawless material handling with interchangeability

Variation 3: Conveyor belt & stacker

To increase the autonomy a moveable stacker can be attached to the cell (Picture 1 above).

The stacker is a standard module and holds 10 customized pallets.

Variation 4: Double conveyor belt & double stacker

To further increase the autonomy two stackers can be attached right and left with two conveyor belts at the back.


The BMC is designed to accommodate most available robots, tooling and equipment necessary for a job


Bachmann Modular Cell (BMC) comprising a dispenser and a UV light-box, built for the Hannover trade show 2015


Bachmann Masking Cell (BMC-M) integrated with grit blasting as an autonomous and automated system (CAD rendering)



Front view of the integrated system, operator’s side;This system comprises a masking cell (BMC-M) with an input stacker (BFS), an output conveyor belt, and a parts handling robot serving the sand blaster - the last two elements are integrated in a BFM unit (Bachmann Feed Master) and a sand blasting machine. The Bellows, the gripper mechanism and the locking arm establish a BB Unit (Bachmann Blasting Unit).The complete line is controlled via the HMI (Bachmann Flex Handling controller BFH) at the front of the BMC.Finished parts are put back in the pallet and unloaded to a lifting trolley (seen partially behind the conveyor).

Backside view of the integrated system. The empty lifting trolley (Bachmann Lifting Device BLD) can be seen on the right of the conveyor waiting for first pallet with finished parts. Optionally, the trolley can be replaced with a stacker.


Applying a collar shaped mask to a small tube in a fully automatic process. The robot controls the dispenser on/off.


Dispensing two masking stripes on a tube;

Material: Dymax SpeedMask 730-BT;

Dispenser: Liquidyn


https://youtu.be/gjI13qiPirw?list=PLgAjQzuBhuNo2hgaWrAsl3dXciFRR87kc

Automatic sand-blasting of the tube with the two masked stripes after curing;

Machine: Sandmaster (Zofingen, Switzerland)

Medium: Al2O3 F170


https://youtu.be/VdNaK-Np5C8?list=PLgAjQzuBhuNo2hgaWrAsl3dXciFRR87kc

bachmann engineering ag - systemhaus für …...bachmann engineering ag - systemhaus für automation...

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