The industry, more and more, needs to optimize the working times and the correct functioning of all the equipment of the installation (injection machines, plastic and silicone injection molds (LSR), cooling equipment, etc.).
This has led to a great evolution in industrial maintenance. We have gone from waiting for breakdowns to methods for predicting them. And even get to determine the causes of the problem and eradicate them.
Types of maintenance in plastic injection molds and silicone injection molds (LSR)
Maintenance tasks in injection molds can be classified into three categories: preventive, corrective and predictive.
- Preventive maintenance: This is based on carrying out certain checks on the molds, regardless of whether they have failed or are working properly, in order to minimize the number of future failures. This includes inspections, cleaning and lubrication.
- Corrective maintenance: This consists of repairing mold failures due to deficiencies that could not be detected during preventive maintenance or during the production process. This type of maintenance cannot be planned, so it disrupts the work plan and can cause stoppages during production.
- Predictive maintenance: It is used to ensure the correct operation of the molds through the inspection of the control parameters, such as the general condition of the injected parts, if any scratches or burns are visible, if the filling is incomplete, etc. This inspection is carried out without the need to disassemble or stop the machinery, simply by visual inspection and analysis of the parts.
Personnel training at OSF
Maximum care must be taken in the handling of the injection molds during maintenance, therefore, the training of personnel in the maintenance of plastic and silicone injection molds is essential to:
- Reducing errors: Well-trained personnel are less likely to make mistakes that can damage molds or affect product quality.
- Improved efficiency: With the right knowledge, operators can perform maintenance tasks faster and more effectively.
Technology and techniques are constantly evolving, so it is important to provide regular updates to keep staff up to date with the latest practices and technologies.
Maintenance management and control
Documentation in injection mold maintenance is essential to ensure proper tracking of activities performed, as well as to facilitate training and continuous improvement.
Types of Documentation used:
- Maintenance Records: Detailing all maintenance activities performed, including dates, specific tasks, and signatures of personnel in charge.
- Mold History: A document that compiles all relevant information about each mold, such as its date of manufacture, modifications made and historical repairs.
- Mold manual: Include technical specifications, operating and maintenance instructions, as well as diagrams or schematics of the mold.
Frequency of maintenance
The amount and frequency of injection mold maintenance is determined by several factors:
- Injection mold material: Aluminum molds are going to suffer greater wear over the same period than molds made of steel.
- Complexity of the injection mold: Molds that have intricate mechanisms or parts that require very tight tolerances will require more extensive maintenance than a simple mold.
- Wear: Injection molds can be subject to more wear due to applying incorrect parameters or not taking proper care of the mold. Examples of this are: high injection pressures, lack of lubrication of components, improper transportation, etc.
- Injection material: A mold that is injecting materials carrying fiberglass or carbon fiber fillers will wear out much sooner than one that is working with unloaded plastics.
Recommended frequency of preventive maintenance:
- Daily: Quick visual inspections and basic cleaning after each production cycle.
- Weekly: More thorough cleaning and overhaul of critical components, such as cooling and lubrication systems.
- Monthly: Detailed inspections, including functional testing and wear checks on key components.
Maintenance procedures
- Regular Cleaning: Use of appropriate solutions to remove plastic residues.
- Overhaul or inspection: Inspect parts such as cavities, cores, and cooling systems, general condition.
- Lubrication: Apply specific lubricants to prevent wear.
An example of overhaul can be visual inspection to identify wear and damage to injection molds. Inspectors should look for the following:
- Cracks or chips in the mold surface: These compromise the integrity of the mold and will affect the quality of the molded part.
- Rust or corrosion: Corrosion will weaken the mold, shorten its life and require immediate maintenance.
- Misalignment of mold halves: Misalignment will result in poor part quality and wear, so accurate alignment is necessary.
- Ejector pins and bushings: Worn ejector pins and bushings produce defects and increase maintenance.
- Cooling channels and water lines: Blockages or damage will affect cooling efficiency, cycle time, and part quality.
- Cavities and core pins: Wear or damage in these areas will produce dimensional inaccuracies and poor part quality.
- Mold vents and gates: Blocked vents and gates will produce defects such as air traps and short shots, and overall part quality will suffer.
In some cases when deemed necessary, in addition to visual inspection, dimensional inspection is important to verify the condition of the mold. This will allow the identification of wear that is not visible but affects the mold performance and causes defects in the final product.
Dimensional inspection uses measuring and control equipment that allows accurate measurement of critical dimensions and tolerances. Regular dimensional checks will help to detect problems early and minimize production downtime.
At OSF, mold maintenance is a fundamental pillar of the production process, since strict care and management of the molds can increase their useful life considerably, in addition to ensuring that the parts that are manufactured for the demanding sectors (medical, automotive, electrical, industrial, etc.) with which we work meet the requirements of our customers.
We have a highly specialized maintenance team, with the necessary equipment and continuous training, to ensure efficient and quality maintenance.
This comprehensive approach reflects our commitment to excellence and customer satisfaction.