The Medical Industry
Medical Component Manufacturer
Uses Vertrel® for Precision
A small subcontractor for precision metal assemblies used in medical products selected MicroCare CCA as the best replacement for HCFC-141b.
Medical products demand a level of cleaning performance that exceeds almost any other application. Manufacturers worry about inorganic particulate, like metal fining, which could impair the operation of a device. They worry about organic contamination which could cause biological problems – light oils, grease, and fingerprints can carry all sorts of microscopic dangers. The electronics in these systems carry ionic contamination which must be removed. Water cleaning systems used early in the assembly process also generate potential problems with water spots, entrapped cleaning agents, and dry residues. To resolve all of these problems, a small medical subcontractor in Connecticut is keeping their customers happy by using MicroCare CCA as a final cleaning process after assembly.
This company had previously used CFCs for their cleaning process and over the years found it and their vapor degreaser system to be trouble-free. When the Montreal Protocol phased out the use of CFCs, the company migrated to HCFC-141b as an interim step. They used that solvent for about six years. When the E.P.A.’s regulations banned the use of HCFCs in vapor degreasers, they began to search for alternatives.
MicroCare CCA requires cleaning cycles of 2-8 minutes, with an average of 10-15 parts in the basket during each cycle.
While they have an aqueous system for some of their primary cleaning applications, they felt it was too large, slow and energy-intensive for use as their final cleaning process. In terms of solvents, they considered three main products: HCFC-225 from Japan, HFE solvents from 3M Corp. and HFC solvents from DuPont. All three products performed adequately, but in their mind MicroCare CCA came up the clear winner:
- The HCFC-225 solvent is an ozone-depleting material, with a phase-out dated mandated by the Montreal Protocol and the Clean Air Act. Top management did not want to specify in an new solvent only to have to repeat the job a few years down the road.
- The HFE products worked fine but were considerably more expensive than the MicroCare CCA, by about 30%.
- The HFC products from DuPont worked very well and were backed by DuPont’s 50 years of experience in solvent cleaning. Top management felt that their customers would be most comfortable knowing they were using cleaning products from the cleaning experts.
Overall, the company has been very pleased with the conversion to MicroCare CCA. They purchased a brand-new Branson vapor degreaser to run the HFC solvent processes, so the transition was made easy by using state-of-the-art cleaning technology.
All of their parts were then tested for a day immersed in the solvent and no compatibility problems were found (which is to be expected, as HCFC-141b is a very aggressive cleaner). All of their parts were then test-cleaned in the new solvent to confirm the programmed settings on the automatic hoist would deliver the cleaning each assembly required. A few assemblies required some adjustments to their cleaning cycle. Finally, all of their key customers were advised of the change, and as expected none had any problems or questions with the proposal.
The actual change-over took about four hours, as the company took the opportunity to boildown the sumps and clean the system thoroughly. System set-up was fast and predictable – a few thermostat changes were all that was required. In addition, the refrigeration system is now operating at all times, even at night and at weekends, to minimize stand-by losses. By lunchtime the new solvent was in the machine and parts were being cleaned.
At this point the customer is using the machine at about 50% of its maximum capacity. Solvent losses are averaging 2-3 quarts (3.5 liters) per week. Cleaning cycles vary from two minutes to eight minutes, depending upon the assemblies. Labor costs are trivial as the entire process is automated, which frees workers for more productive tasks.
The company expects to use about three drums of solvent annually, and return a substantial portion of that solvent to their vendor for recycling credit. While top management agrees that the cost of the cleaning process is higher than it was when they used HCFC-141b, in terms of each individual part the cleaning cost “is less than pennies,” according to the floor supervisor. “Everybody likes the new solvent,” she adds.
Major Bearing Manufacturer Chooses Vertrel®
Bearing Manufacturer Chooses
A large manufacturer of precision bearings selects a Vertrel product for degreasing because of its overall cost-effectiveness.
The cleaning of ball bearings immediately before and after assembly are critical steps in their manufacture. The reliable performance of the bearings depends on surfaces that are clean and free from particulate. One of the largest producers of ball bearings uses several vapor degreasers to accomplish this cleaning task. Today, those degreasers are equipped with Vertrel® MCA Plusfor this precision degreasing task.
The cleaning process removed both particulate and Houghton MB cutting oil that is used during machining and as a preservative. A variety of concerns with the existing process prompted the evaluation of alternatives.
This manufacturer previously used a co-solvent process consisting of Solvating Agent #19 with PFC 5060 as the rinsing agent. Although the cleaning performance of this system was satisfactory, there were concerns about excessive system change-outs and the long cleaning cycle time (1 hour). The solvating agent in the vapor degreaser had to be changed out every three days in order to maintain the cleaning effectiveness. Additionally, there were concerns about the odor of the solvating agent, the high global warming potential of the PFC 5060, and the need to handle two components.
Alternative Chemistry Evaluation
Several solvents were evaluated as alternatives to the existing process. The solvents evaluated were Vertrel® MCA Plus, Vertrel® MCA, Vertrel® SMT, and HCFC-225. All were evaluated in actual cleaning tests in vapor degreasers equipped with ultrasonics. Cycle times were varied to determine the optimal times. After cleaning, the parts were inspected under a microscope for the absence of particles and staining.
As a result of this testing, Vertrel® MCA PlusPlus emerged as the superior solvent from a cleaning effectiveness standpoint. Additionally, the Vertrel® cleaning agents were preferred due to their more favorable toxicity profile
The New Process
The conversion to Vertrel® MCA Plus in three vapor degreasers went smoothly. The machines required only minor adjustments to the controls to convert to the new chemistry. Some of the key advantages of the new process are:
- Higher Soil-Loading Capability – This allowed the bearing manufacturer to significantly extend the time required between system change-outs. The target change-out time was extended by 100%.
- Shorter Cycle Times – The use of a single solvent eliminated the need to work with two separate components and the extra time required to remove solvating agent from the parts.
- Safety – The low emissions of solvent from vapor degreasers ensures that concentrations near the equipment are well below the allowable exposure limit.
- Low GWP – The global warming potential of Vertrel® MCA Plus is only 652 (100 yr ITH).