Injection molding machine production quality assessment: detailed explanation of methods and indicators
1、 The importance of injection molding machine and the necessity of production quality assessment
Injection molding machine occupies an important position in modern manufacturing industry, widely used in automotive, electronics, medical, packaging and other fields. With the popularization of industrial automation and lean production concepts, the production quality of injection molding machines has become an important factor in determining product performance and enterprise competitiveness. Therefore, it is particularly critical to evaluate the production quality of injection molding machine scientifically. We will discuss the methods and indicators of evaluating the production quality of injection molding machines to help manufacturers improve product quality and market competitiveness.
2、The main method of evaluating the production quality of injection molding machine
【1】Process control method
Process control method is through the real-time monitoring and adjustment of various parameters in the production process to ensure that each link meets the quality standards. The specific steps are as follows:
(1) Set standards: according to product design and process requirements, develop detailed quality standards and operating specifications.
(2) Real-time monitoring: sensors and data acquisition systems are used to monitor key parameters such as temperature, pressure and speed during injection molding in real time.
(3) Data analysis: Statistical process control (SPC) technology is used to analyze the collected data and identify abnormal fluctuations and trend changes.
(4) Feedback adjustment: According to the analysis results, timely adjust the process parameters or equipment status to ensure that the production process is stable and controllable.
【2】Sampling inspection method
Sampling inspection methods are used to determine the quality level of the whole batch of products by testing a portion of the sample in batch production. Implementation steps include:
(1) Determine the sampling plan: select the appropriate sampling standards and methods according to the production batch and risk acceptance.
(2) Sample testing: samples are randomly selected according to the established scheme, and their dimensions, appearance, mechanical properties and other aspects are tested.
(3) Statistical analysis: Use statistical principles to analyze test results and calculate indicators such as pass rate and confidence interval.
(4) Result feedback: According to the sampling inspection results, evaluate the quality of the whole batch of products, and take corresponding improvement measures.
【3】Failure Mode and Impact Analysis (FMEA)
Failure mode and impact analysis is a preventive quality management method that aims to identify and evaluate potential failure modes and their effects in order to develop targeted improvement measures. The steps include:
(1) Build a team: gather professionals from design, production, quality and other related departments to form an analysis team.
(2) Identification of failure modes: systematically list the various failure modes that may occur in the injection molding machine.
(3) Risk assessment: The risk value of each failure mode is assessed from the three aspects of failure frequency, severity and detection difficulty.
(4) Formulation of improvement measures: for high-risk failure modes, priority should be given to formulation and implementation of improvement measures to reduce risks.
【4】Customer feedback analysis
Customer feedback analysis Through the collection and analysis of customer evaluation and complaint information on product quality, to understand the performance and problems of products in actual use. Specific practices include:
(1) Establish feedback channels: through after-sales service hotline, email, social media and other ways to facilitate customer feedback.
(2) Classification and sorting: the collected customer feedback is classified and sorted according to the type of problem, frequency of occurrence, etc.
(3) Cause analysis: Combined with production process and quality control data, analyze the root cause of customer feedback.
(4) Continuous improvement: Based on the analysis results, develop and implement improvement measures to continuously optimize the quality of products and services.
3、 Evaluate the key indicators of the production quality of injection molding machine
【1】Dimensional accuracy
Dimensional accuracy refers to the degree of conformity between the actual size of the injection molding part and the design size, usually expressed by the tolerance range. High-precision dimensional control not only affects the assembly and performance of the product, but also directly relates to the accuracy of mold manufacturing and the stability of injection molding parameters. The methods for evaluating dimensional accuracy mainly include:
(1) Use coordinate measuring machine (CMM), projector and other precision measuring equipment to detect the key dimensions of injection parts.
(2) Statistical size of the proportion and distribution of excess, analyze the causes of size fluctuations.
(3) Compare the size data of injection parts in different batches and different mold numbers to evaluate the consistency and stability of the production process.
【2】Surface quality
Surface quality refers to the appearance and microstructure of the surface of the injection molded part, which directly affects the beauty and coating effect of the product. Common assessment indicators include:
(1) Surface finish: Observe whether there are obvious defects on the surface of the injection parts through a visual or optical microscope, such as gas marks, weld marks, flash edges, etc.
(2) Surface roughness: The use of surface roughness meter to measure the micro-convex degree of the surface of the injection parts to evaluate its fine degree.
(3) Color consistency: For injection parts with color requirements, use a color difference meter to measure the color difference value of different parts to ensure uniform color.
【3】Mechanical property
Mechanical properties refer to the ability of injection molded parts to withstand external loads during use, including strength, toughness, hardness and other indicators. The main methods for evaluating mechanical properties are:
(1) Tensile test: test the tensile strength and elongation of injection parts under the action of tensile load.
(2) Impact test: measure the impact resistance of injection parts under impact load.
(3) Hardness test: Use Rockwell hardness tester or Vickers hardness tester to evaluate the surface hardness of injection molded parts.
【4】Thermal stability
Thermal stability refers to the ability of injection molded parts to maintain their stable performance under different temperature environments. Indicators to assess thermal stability include:
(1) Thermal deformation temperature: The use of thermal deformation temperature tester to determine the critical temperature of deformation of injection parts under a certain load.
(2) thermal aging test: the injection molded part is placed in a high temperature environment for a period of time to observe its performance changes.
(3) Cold resistance test: test the embrittlement and performance decline of injection parts at low temperatures.
【5】Chemical stability
Chemical stability refers to the ability of injection molded parts to maintain their structure and properties stable when exposed to chemicals. The main methods for assessing chemical stability are:
(1) Solvent resistance test: the injection molded part is soaked in a certain concentration of chemical solvent to observe the changes in its appearance and performance.
(2) Corrosion resistance test: The injection molded part is exposed to a certain humidity and corrosive gas to evaluate its corrosion resistance.
(3) Weather resistance test: Through ultraviolet irradiation, salt spray and other methods, simulate the aging process in the natural environment to evaluate the weather resistance of injection parts.
【6】Repeatability and stability
Repeatability and stability refers to the ability of the injection molding machine to maintain the consistency of product quality in the continuous production process. Ways of assessing this indicator include:
(1) Short cycle repeatability: in a short production cycle, multiple samples are taken to detect the quality of injection parts, calculate its mean and standard deviation, and evaluate the quality fluctuations in a short period of time.
(2) Long cycle stability: in a long production cycle, regular sampling to detect the quality of injection parts, draw quality control charts, and analyze the quality trend and stability in the long-term production process.
4、Comprehensive evaluation and continuous improvement
Evaluating the production quality of injection molding machine not only needs to choose the appropriate method and index, but also needs to carry out comprehensive evaluation and continuous improvement. Here are some suggestions:
Establish a quality management system: with reference to international standards such as ISO 9001, establish a sound quality management system, clarify the responsibilities and work processes of each department, and ensure the systematic and normative quality control.
Strengthen staff training: Regularly carry out quality management training to improve the quality awareness and skill level of employees, so that they can master various evaluation methods and tools.
Promote technological innovation: introduce advanced production technology and equipment, improve production processes and processes, and improve production efficiency and product quality.
Strengthen supply chain management: Establish good cooperative relations with raw material suppliers and outsourcing manufacturers to jointly improve raw material quality and outsourcing processing quality.
Establish feedback mechanism: Establish effective internal feedback and external customer feedback mechanism, timely detect and deal with quality problems, and achieve continuous improvement.
In short
Scientific evaluation of the production quality of injection molding machine is an important means to enhance product competitiveness and enterprise market position. Through reasonable selection of evaluation methods and indicators, comprehensive analysis and improvement of all aspects of the production process, it can effectively improve the quality stability of injection parts and customer satisfaction, and promote the sustainable development of enterprises.
