apertures 29 therein aside from apertures 29 enclosure 21 should be airtight an air moving means such as fan 31 withdraws air from enclosure 21 the vacuum produced by fan 31 draws air through apertures 29 and into enclosure 21 any article a positioned above apertures 29 is drawn towards table 13 the force with which table 13 retains article a depends upon the amount of suction force created by fan 31 as seen in fig2 enclosure 21 preferably is compartmentalized and has an area of reduced volume or plenum 33 fan 31 preferably resides with the downstream compartment of enclosure 21 see fig2 as a result the suction force on articles a that are positioned downstream is greater than the suction force on articles a that are positioned further upstream the relative sizes of enclosure 21 and plenum 33 along with other factors determine the relative suction force gradient along table 13 as seen in fig1 the apparatus can include adjustable rails 35 extending along side walls 15 rails 35 are positionable at selected distances relative to side walls 15 depending on the size of the article carried thereon and the amount of guidance needed rails 35 help guide articles a downstream and help maintain alignment of the article on the conveyor belts 23 25 27 conveyor belts 23 preferably extend the entire length of table.