Quality control process of injection molding workshop

Quality control process of injection molding workshop

In order to ensure that all processes that have an impact on the quality of injection molding products operate according to the specifications, so as to ensure that these inspections are in a controlled state. Ensure that the manufacturing process of products meets the warehousing requirements.




Inspector is responsible for product quality control of injection molding process according to order requirements or corresponding process documents.



Sampling inspection is responsible for the overall inspection of injection molding products on duty before warehousing.



If there is any doubt or dispute during the inspection, it must be handled by the superior.



Quality control process of injection molding works


1. First inspection, record and identification:


1.1 in the process of injection molding production, the operator must make self inspection record, inspect the appearance of the product, and the inspector shall sign and seal the first product before starting the machine, and fill in the first article inspection report. During the production process, the product sampling inspection shall be carried out according to the requirements of the inspector, and each inspection item shall be complete, at the same time, the three links of packaged products, worktable products and machine random products are verified, and problems are found, timely corrected and coordinated;


1.2 the sampling inspector has the right to require the operator to rework the unqualified products in self inspection, and record, mark and review the reworked products until they meet the product quality requirements, otherwise, they are not allowed to be put into the warehouse. For the unqualified products, the information shall be fully transmitted to the off-duty personnel to prevent the continuous generation of defective products;


1.3 the inspection supervisor shall take back the inspection report and check the inspection record every day. If the record is not true or there is any doubt, the relevant quality inspector shall be consulted for confirmation. If it is careless, wrong or lack of sense of responsibility, it is required to circulate a notice of criticism, and the personnel who fail to follow the inspection instructions for many times will be considered to change the post or other punishment;


1.4 after the finished products of each injection molding section are qualified, the operator should make a good statement on product outsourcing before moving to the next process. the finished products, semi-finished products, qualified and unqualified products of injection molding should be placed neatly in the specified area and identified according to the principles of identification and traceability management. the inspector has the right to control and coordinate the process.Have the right to require employees to rectify or stop the machine for rectification if the logo is not standard.


2. Process reconfirmation:


2.1 Inspection and confirmation of products after refueling and mold changing

During the inspection, when the machine is refueled or changed, the quality inspection shall confirm the appearance, engineering size, performance strength and assembly degree of the product item by item according to the first article inspection standard, and investigate and understand whether the batch of materials used has changed, so as to facilitate recording and preventing the occurrence of defects;


2.2 Inspection and confirmation of products after mold repair

In case of abnormal maintenance of the mold, the quality parameters such as appearance, engineering size, performance strength and assembly degree of the product should be confirmed item by item according to the first article inspection standard, and the batch production can be put into operation after comparing with the previous samples. If the mold is a major maintenance matter, the process team can produce it in batches after passing the inspection according to the above items, and it needs to carry out verification and tracking for a long time when necessary;


2.3 inspection and confirmation of products after new employees work

In case of machine substitution or new person's operation, the foreman and patrol inspection must strengthen the frequency of patrol inspection, clearly inform the products of the precautions and ensure that all employees understand them. During the process, check the novice's operation proficiency repeatedly, correct any abnormality in time, and replace skilled employees when necessary to ensure the stability of quality;


2.4 Inspection and confirmation of products after shutdown

In the production process, the machine is restarted for production due to abnormal operation due to special reasons. At this time, the work of the machine is in an unstable state. The inspector should confirm the quality parameters of the product, such as appearance, engineering size, performance strength and assembly degree, item by item according to the first article inspection standard, and compare with the previous samples to confirm that the products are qualified before mass production. And continue to follow up until the machine runs and the product quality tends to be stable;


2.5 inspection and confirmation of products after process adjustment

In the production process, the product is mutated, and the workshop foreman or workshop supervisor readjusts the machine. After changing the molding parameters of the machine and overcoming the original problems, the inspector should reconfirm whether the quality of other inspection items is mutated and whether various performances meet the requirements, such as raising the temperature to overcome whether the poor appearance of the product will affect the physical properties of plastic and make the product brittle. Avoid batch quality accidents caused by new bad problems;


2.6 inspection and confirmation of products in the process of succession

During the shift handover in the workshop, due to personnel changes, new materials are not confirmed to be the shift change time, the inspectors forget to complete the handover or other reasons, etc., which may cause the risk of batch quality accidents, the successor inspectors must confirm the inspection table and self-inspection table of the shift. Understand the use of materials, etc., get familiar with the quality of work time in time, and take measures to ensure timely response to changes affecting process capability.


3. Defective product processing flow:


3.1 concession release

When the production is in urgent need, but the mold has problems, the process can't be corrected, or the process control neglects, resulting in batch problem products, the release review process is strictly implemented. If the release can be compromised through evaluation, the workshop will handle the application for concession release, which will be submitted to the relevant leaders for approval after quality confirmation and superior review, and the relevant supervisors will fulfill their responsibilities and punish them.The quality inspection of the products to be processed that have not gone through the examination and approval procedures shall not be released, and the warehouse management shall not enter the warehouse or transfer the order;


3.2 Rework and retest

When the process control is neglected or the employees fail to process the products according to the inspection requirements, resulting in poor batch processing, the workshop shall arrange the employees to rework the products outside the normal working hours according to the Management Regulations of Injection Molding Workshop, and only after the rework is completed and the inspectors pass the re-inspection, can they bill for warehousing or transfer order;


3.3 Bad and Scrap Treatment

The release of products shall comply with the relevant provisions of the review process. If the products cannot be reused after passing the review, scrap or recycled scrap shall be handled, which shall be applied by the production workshop, signed and confirmed by the relevant leaders and approved by the leaders before being scrapped or broken. Major adverse accidents must be handled by the general manager.


4. Process improvement:

Quality control process of injection molding works

4.1 If problems are found, correct them in time, analyze and find out the improvement methods, control them according to the control procedures of corrective and preventive measures, contact the workshop for treatment, and have the right to stop the machines and molds that have not been improved for rectification until the problems are solved before production;


4.2 The handling of defective products must implement responsibilities and penalties, and implement corrective and preventive measures through investigation reports, and order relevant departments and personnel to improve. After being verified as qualified by the Quality Department, the case will be considered closed, and the follow-up and feedback of the process will be arranged and implemented by the Quality Department, and other departments must cooperate with the implementation;


4.3 When the improvement of injection molding process involves modifying process documents or quality management documents, it should be in accordance with the requirements of document and data management procedures, and discuss the deficiencies and missing items in the inspection specifications and operation instructions in view of the abnormalities and causes of out-of-control of the process, so as to gradually improve the process control documents and improve the process control ability.