Situation
A medical-device OEM needed a fully corrosion-resistant slide for a sterilisation-cart drawer that would be wiped down repeatedly with alcohol and chlorine-based disinfectants. The slide had to operate smoothly after thousands of cleaning cycles and could not shed particles or retain cleaning fluid in crevices.
Load requirement was moderate (35 kg per drawer) but the deflection limit was tight: less than 1 mm at full extension under rated load. The customer also required full material traceability and a surface finish that met their internal biocompatibility risk assessment.
Because the cart is sold globally, the slide had to be available with consistent performance across multiple production lots over several years.
Engineering response
We selected a 304 stainless steel ball-bearing slide with a fully crowned ball race to reduce particle trapping. All seams were orientated away from the wiping direction, and the retainer was opened slightly to allow drainage after wet cleaning.
To control deflection we increased the slide member thickness by 0.3 mm and added an additional intermediate member, giving the slide three telescoping stages while keeping the closed length within the cart envelope. The preload was tuned so the slide feels light at low load but stiffens predictably near the rated capacity.
Each production batch is supplied with a material certificate and a dimensional inspection report. We also hold a pre-production sample as a golden unit for future lot comparison.
Verification
Real figures from the project file.
Outcome
The slide passed the customer's 2,000-cycle loaded test and a 30-day accelerated cleaning test with no measurable corrosion or increase in operating force.
Deflection at full extension under 35 kg measured 0.7 mm, within the 1 mm requirement. The medical OEM has approved the slide for two additional cart models and placed a three-year supply agreement.
Traceability and lot-to-lot consistency have been 100 % on the eight production lots shipped to date.