Management summary for the following use case:
How can existing component cleaning processes be optimized for the future?
Industrial cleaning systems are often in existence for 15 years or more
Integrated production processes. With increasing mileage and due to
With outdated technology, these cleaning systems mainly form the bottleneck in production.
Nevertheless, no optimization measures in the cleaning process or new investments for improvement have been made for many years.
If there is a change in workpieces / components or if there is contamination
(such as rust, paint and grease), experience has shown that the cleaning temperature of the process is increased and, if necessary, the cleaning medium is changed.
If these measures reach their limits, manual reworking of the workpieces is gradually introduced in the production process, thus compensating for the lack of cleaning performance.
This is very time-consuming and costly, leads to fluctuations in the cleaning quality and the resulting increased reject rate is reminded again with each audit / certification.
The following use case outlines how to optimize existing industrial cleaning processes works, bad investments can be avoided and various alternative courses of action can be compared.
Use case in detail:
1. Introduction - the customer
The use case described below is outlined using an international construction machinery manufacturer. This offers its customers various types of construction machinery in the “pay per use” business model, so that the end customer only pays for the operating hours used.
When the construction machines reach their technical operating limit, they are dismantled into assemblies and individual parts on site or in specialist workshops. They are then transported back to the construction machinery manufacturer's plant, where they are subjected to an industrial remanufacturing process1.
This includes the complete dismantling of all technical components, the diagnosis and the subsequent exchange or reconditioning of the wearing parts as well as the final reassembly of the assemblies.
1 Alternative terms for reconditioning can also be general overhaul, remanufacturing or remanufacturing
The assemblies and individual parts of the construction machines are characterized by strongly varying component dimensions. Examples include hydraulic cylinders, large diesel engines and heavy-duty axles, but also small components or attachments. They also consist of various materials such as cast iron, steel or aluminum, which must also be taken into account when selecting suitable cleaning processes, technologies and media.
The contamination of the components also varies depending on where they are used, so that the following can be named here:
- Paints of various types and ages
- Rust / oxidation
- Sealing material on the functional surfaces
- Clay, earth and concrete
Where is the challenge in the current process?
In the actual cleaning process at the construction machine manufacturer, all components are initially subjected to a uniform rinsing and spraying process, in which grease, oils and loose paint residues are removed. This then takes place in the process step Disassembly the disassembly of the components into their component parts and then in the manual rework the time-consuming and labor-intensive manual cleaning. In the next Diagnosis all individual parts are checked to determine whether and with what effort the reconditioning can be carried out. If the wear limit is reached or a component is defective, it is rejected.
The challenge arises from the fact that the output volume of the refurbishment process had to be steadily increased in the past due to the increasing demand and the adjustment of the business model. The performance of individual process steps could initially be increased through the use of more staff and modern lean approaches. At the same time, the process time of the cleaning system was reduced and attempts were made to compensate for the resulting reduced cleaning quality by means of higher process temperatures and more extensive manual rework.
Costly, extremely inefficient and just postponing problem solving into the future!
3. Optimization potential and objectives
The described attempt to increase the cleaning performance in the actual cleaning process of the construction machine manufacturer was not successful in the long term and included very high hidden process costs:
- Cleaning processes that lead to poor cleaning results
- high and cost-intensive use of personnel in manual reworking, which does not enable constant cleaning quality
- Bottleneck at the beginning of production so that downstream process stations are not fully utilized
The objective for the target process was to increase the process volume of the entire refurbishment process and to reduce process costs and the scope of manual rework. These can be achieved by increasing the cleaning performance and optimizing the cleaning processes.
How can optimization potential and objectives be implemented?
4. As-is analysis of the components and quantification of requirements
The determination of existing and future process quantities can be determined from the enterprise resource system (ERP system) of the construction machine manufacturer using digital parts lists. On the basis of this data, a quantity structure can be created to which the weights, dimensions and material alloys can be assigned.
This is a decisive success factor in order to take into account the current and future utilization of the cleaning process. Time-consuming and labor-intensive, but necessary!
With the cooperation of the shop floor employees, the contamination can be assigned to the existing data. How is the degree of contamination of the components with paint, corrosion or oils and greases to be classified? Or to evaluate the cleaning performance for individual contaminations? At this point, a systematic approach is required in order to then be able to quantitatively evaluate the findings in a structured manner and to be able to maximize the gain in knowledge.
The next step is the analysis of the cleaning results, taking into account the employees in the manual rework. Which contaminations are not removed by the cleaning system and must be cleaned by manual rework? Which material alloys, geometric elements and part numbers are to be assigned to them? If the part numbers and process times are recorded during manual reworking, this data can also be evaluated and an allocation of contamination, part numbers and material alloy is possible.
Intermediate result: Material alloys and contaminations are assigned part numbers, a detailed quantity structure has been created!
The quantity structure is the basis on which suitable methods can then be selected for the specific material and contamination. Do the workpieces have functional surfaces? Are mechanical or chemical cleaning methods suitable? Is there any contamination that requires special chemical or thermal cleaning processes? Based on a matching of workpiece requirements and the subsequent cluster formation, a pre-selection of cleaning technologies and processes is made that are suitable for the existing component and process requirements, see Figure 1.
Figure 1: DIN 8592 for the limitation of suitable cleaning methods
To limit suitable cleaning processes, media and system manufacturers, bfirm also has a comprehensive database in which requirements and providers are compared. Which cleaners favor the discoloration of aluminum components after the paint stripping process? Which cleaning medium is suitable for joint degreasing of all components, but requires the components to be neutralized before the paint stripping process? These and many other questions are based on bfirm's expertise and can be supplemented with chemical or material-metallurgical investigations if necessary.
In addition to the technical process parameters, additional influencing variables can be taken into account when developing cleaning processes, depending on the customer's requirements.
When should these be identified and investigated?
The process know-how required to select and determine the further process parameters and requirements has now been achieved. The quantity structure as well as suitable cleaning technologies are identified in order to enter into a detailed exchange of information with the purchasing department, quality assurance or environmental management.
Process parameters are given below as examples. The respective certification of the company and the requirements of the specialist departments must be taken into account individually, see Figure 2.
Figure 2: Selection of further process parameters to document the process properties
In the next step, the selection of suitable manufacturers of cleaning systems and media takes place in order to then put together and dimension a suitable cleaning strategy and procedural combinations, see Figure 3 ensure downstream paintability of the components.
Figure 3: Exemplary representation of the development of process combinations
5. Realization of potential and result
The available data from the quantity structure, the clustering and the derived cleaning strategies finally enable the selection of suitable manufacturers of cleaning systems and media.
The identified optimization potential can be quantified in the cleaning process on the basis of the results obtained and enables management to make a number-based decision-making basis for the following questions:
- What measures are required to optimize the cleaning strategy?
- How can the cleaning strategy be adapted with existing systems?
- How high (quantitative) is the savings potential?
- In which order should the potentials be implemented?
In the case described, the construction machinery manufacturer was able to make the cleaning processes more efficient, reduce rework by 60% and select and purchase a new cleaning system based on detailed monetary and technical parameters.
Do you also have cleaning or coating processes with optimization potential? A checklist is available in the download portal to independently identify initial potential for optimization.
Do you have any questions? We are happy to support you in identifying potential, evaluating and optimizing existing cleaning and coating processes.
Feel free to make an appointment for a free exchange by phone, screen sharing or directly at your site! We look forward to you.
Brief introduction to bfirm - from research into industry
The bfirm company was created in the research environment of the Chair for Environmentally Friendly Production Technology at the University of Bayreuth and the Fraunhofer Institute for Automation and Robot Technology (IPA). International industrial companies were faced with the challenge of optimizing existing cleaning and coating processes and receiving manufacturer-independent consulting services. For this purpose, a procedure was developed to optimize industrial cleaning and coating processes and to transfer scientific know-how to industry as a consulting service. With increasing interest from industry, the research and development service was continuously expanded and systematically developed into a sustainable business model. At the beginning of 2020, bfirm was spun off into an independent company in order to offer research and development services to other industrial companies. Due to the proximity to university research and research-related service providers, the existing network is continuously expanded so that, if required, customer-specific development services can also be implemented with renowned research institutions.