Masking

BMC-M Bachmann Modular Cell for Automated Masking
The first masking cell on the market.


The majority of parts undergoing surface treatment like coatings, blasting, stripping etc. are being masked to protect certain areas from the treatment. Masking was and is still done by applying mechanical protection e.g. sheet metal, protective tape, silicon caps, waxes or paints. Obviously, the masking must be removed after the surface treatment is done. To date, 99% of masking are applied manually by skilled labor. The development of a new generation of UV curable polymers opened the way to mechanized / robotic application of masking, with all the advantages involved. At bachmann engineering ag in Zofingen, Switzerland we have developed robotized solutions for automated masking, readily available in form of closed cells, conforming to CE regulations. Our cells are compatible with all other Bachmann modules e.g. Stacker module, Feed module etc., allowing for streamlined manufacturing.

Masking	Advantage	Problem
Glass reinforced sticky tape	Cost effective; applicable on demand; flexible adaptation to different shapes; withstands blasting and thermal spray (not HVOF LF)	Limited accuracy, depending on skill; not adequate for complex shapes, cavities or very small areas; not compatible with galvanic or chemical processes

Pre-fabricated silicon / polyurethane caps	Adequate for complex forms with a single cap; faster application than tape	Accuracy dependent on operator’s skill; good for 10 to 20 cycles only; no flexibility – fits one shape;

Pre-fabricated sheet metal covers	High resistance to blasting/ thermal spray including HVOF LF;	Only adequate for blasting and TS; shadow effect must be considered; requires mechanical fixation; will not produce a clean edge; good only for limited number of cycled if not refurbished;

Grease, wax	Can be applied by brush to large areas; adequate for chemical and galvanic processes	Not adequate for TS; not applicable to small and accurate features; removal of wax can be difficult

Masking	Advantage	Problem
UV curable polymer, e.g. Dymax SpeedMask	The use of liquid UV curable polymer allows controlled dispensing and “writing” of any shape and size masking with high accuracy by servo controlled, programmable robotic equipment; high accuracy and repeatability are given; excellent edge definition and adhesion; adequate for very complex contours and small features; easy to remove; adequate for many processes e.g. blasting, TS, galvanic and chemical; adequate for large batches in mass production; allows in line and real time QC and data logging / traceability	Requires initial investment in equipment; contours and features to be masked must be pre-programmed (high skill level)

BMC-M Bachmann Modular Cell for Automated Masking