How to ensure the hygiene and safety of preform molds in food packaging
一. Introduction
二. Selection and control of mold materials
(I) Choice of food-grade materials
1. Application of stainless steel
2. Consideration of auxiliary materials
1. Factory inspection link
2. Certification and traceability system
三. Key points of hygiene and safety considerations in mold design
(I) Optimization strategy for structural design
1. Avoidance of dead corners and gaps
2. Easy-to-clean design concept
(II) Relevant measures for health protection
1. Anti-pollution design measures
2. Exploration of the application of antibacterial coatings
四. Key to quality control in the mold manufacturing process
(I) Hygiene management standards for the processing environment
1. Workshop cleaning and disinfection system
2. Personnel hygiene management requirements
(II) Control means of processing technology and precision
1. Application of precision processing technology
2. Quality inspection and monitoring system
五. Key points of mold cleaning and maintenance procedures
(I) Procedures for daily cleaning operations
1. Selection of cleaning tools and detergents
2. Setting of cleaning steps and frequency
(II) Measures for regular maintenance and care
1. Arrangement of mold inspection and repair
2. Maintenance measures and record establishment
六. Construction of mold quality inspection and certification system
(I) Methods and key points of internal quality inspection
1. Implementation of appearance inspection and dimensional measurement
2. Performance testing and simulation test implementation
(II) Requirements for external certification and standard compliance
1. Connection between relevant certification agencies and standards
2. Certification process and promotion of continuous improvement
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一. Introduction
In the field of food packaging, the hygiene and safety of preform molds are crucial. It is directly related to food quality and consumer health. As food safety standards become increasingly stringent, the food packaging industry's requirements for preform molds are also rising. Any hygiene and safety loopholes may cause food contamination, threaten consumer life safety and damage corporate reputation. Therefore, it is imperative to fully guarantee the hygiene and safety of preform molds in food packaging.
二. Selection and control of mold materials
(I) Choice of food-grade materials
1. Application of stainless steel
For the core components of preform molds such as cores and cavities, food-grade stainless steel, such as SUS304 and SUS316, is often used. SUS304 contains 18% chromium and 8% nickel, has excellent corrosion resistance and oxidation resistance, can effectively prevent rust and corrosion, and prevent metal ions from penetrating into food. SUS316 has stronger corrosion resistance due to the addition of molybdenum, and performs well in the manufacture of packaging bottle preform molds that come into contact with acidic or alkaline foods. The chemical composition of these stainless steels must strictly comply with relevant food safety standards. When purchasing, suppliers must provide material certification and quality inspection reports to ensure the purity and stability of the materials.
2. Consideration of auxiliary materials
The material selection of mold auxiliary parts is also critical. Silicone is mostly used for seals, which is odorless, non-toxic, high temperature resistant and chemically stable, and meets the hygienic standards for food contact materials. Release agents should be food grade, such as natural oils or synthetic food grade polymers. While ensuring the demoulding effect, no harmful substances will remain on the surface of the bottle preform, and no corrosion will be caused to the mold material.
(II) Material inspection and certification process
1. Factory inspection link
Material must be strictly inspected when entering the factory. Appearance inspection to see if there are surface defects, cracks, etc. For stainless steel, the surface and near-surface conditions can be detected by combining magnetic particle flaw detection and other means. At the same time, sampling and analysis of chemical composition, and accurate determination of element content with the help of spectral analysis to verify whether it meets food grade standards. Physical properties, such as hardness and tensile strength, also need to be tested to ensure that the mechanical properties of the mold are met.
2. Certification and traceability system
The purchased materials must have relevant certifications, such as FDA certification, EU food contact material certification, etc., which is an important basis for complying with international food hygiene and safety standards. Enterprises should establish a complete material traceability system and record the source of procurement information, including supplier details, batch numbers, inspection reports, etc., so that problems can be quickly traced and handled when they occur.
三. Key points of hygiene and safety considerations in mold design
(I) Optimization strategy for structural design
1. Avoidance of dead corners and gaps
When designing preform molds, dead corners and gaps should be avoided as much as possible. These parts are prone to dirt, breeding bacteria, and residual plastic materials, which are difficult to clean and will become a source of pollution. For example, the flow channel design adopts a streamlined shape to reduce melt retention. The parting surface should be flat and smooth, tightly matched, and reduce gaps. For gaps that are difficult to avoid, such as splicing parts, food-grade sealing design is adopted to prevent dirt and microorganisms from invading, and it is easy to disassemble and clean.
2. Easy-to-clean design concept
The overall structure of the mold should be easy to clean and maintain. A simple and reasonable structure is adopted to reduce complex internal channels and grooves. The cooling channel is designed to be straight or simple spiral, which is convenient for cleaning tool operation and medium circulation. The mold surface is set with a drainage slope to facilitate drainage after cleaning. Removable modules are designed for hard-to-reach parts, which can be handled separately during cleaning. The mold is equipped with a hanging storage structure on the outside to facilitate drying and reduce bacterial growth.
(II) Relevant measures for health protection
1. Anti-pollution design measures
Effective filtering devices are installed at the mold feed port, exhaust port and other parts. A high-precision filter is installed at the feed port to filter impurities in the plastic raw materials to prevent them from entering the cavity to affect the quality of the bottle embryo and avoid impurity accumulation and pollution. The exhaust port uses a one-way valve or filter cotton to prevent dust and microorganisms from entering in the opposite direction. Protective covers or hoods are set on the mold operation interface and the outside to reduce operator contact and external pollution. Ensure that the operating environment is clean during installation and disassembly, and the operator is well protected to avoid bringing in pollutants.
2. Exploration of the application of antibacterial coatings
Antibacterial coatings can be considered to be applied to the mold surface. For example, coatings containing antibacterial ingredients such as silver ions and titanium dioxide can inhibit the growth and reproduction of microorganisms. They work by destroying the cell wall and cell membrane of microorganisms or inhibiting the metabolic process. When applying, ensure that the coating is uniform and firm, and does not contaminate food or migrate harmful substances. The coating thickness meets the standard. Too thick will affect the mold size accuracy and heat dissipation performance, and too thin will have poor antibacterial effect.
四. Key to quality control in the mold manufacturing process
(I) Hygiene management standards for the processing environment
1. Workshop cleaning and disinfection system
The preform mold manufacturing workshop should be kept clean and hygienic. Regularly clean and disinfect the floor, walls, equipment surfaces, etc., and use a non-residue disinfectant spray to control the number of microorganisms. The workshop is well ventilated and pollutants such as dust and smoke are discharged. Set up clean areas and contaminated areas to store raw materials, semi-finished products and finished products separately to avoid cross contamination. Clean up waste materials and waste in a timely manner to prevent accumulation and breeding of bacteria.
2. Personnel hygiene management requirements
Operators strictly abide by personal hygiene standards. Wear protective equipment and wash hands and disinfect before entering the workshop. Regular health checks, sick people are strictly prohibited from entering. Do not touch irrelevant objects at will during operation to avoid bringing in pollutants. The company provides training to enable them to master correct operation and hygiene knowledge, and improve hygiene awareness and sense of responsibility.
(II) Control means of processing technology and precision
1. Application of precision processing technology
Adopt advanced precision processing technology, such as high-precision CNC machining center for milling and drilling, to control the mold size tolerance within a very small range, such as ±0.01mm or even higher. Use mirror processing technology for the surface of the cavity and core, such as polishing after EDM, to make the surface roughness reach Ra0.4μm or less, reduce the adhesion of plastic melt, facilitate demolding and reduce the possibility of dirt residue. Slow wire cutting technology is used to process complex shapes and high-precision parts to ensure processing accuracy and quality, and avoid mold structure or quality problems caused by errors. Strictly follow the process regulations during processing and accurately control parameters.
2. Quality inspection and monitoring system
Establish a complete quality inspection system to inspect and monitor each processing stage of the mold. Inspect the size and performance of raw materials before processing. During processing, online detection technologies such as laser measuring instruments and three-coordinate measuring instruments are used to monitor key dimensions and shapes in real time, and timely detect errors and make adjustments. After the mold is processed, it is fully inspected, including dimensional accuracy, shape accuracy, surface quality, assembly performance, etc. Only molds that pass the inspection can enter the subsequent process or be delivered for use. Record the processing process and inspection data to provide a basis for quality improvement.
五. Key points of mold cleaning and maintenance procedures
(I) Procedures for daily cleaning operations
1. Selection of cleaning tools and detergents
Select soft, lint-free cleaning cloths or brushes, such as nylon brushes or sponge brushes, to avoid metal brushes scratching the mold. The detergent is food-grade, the ingredients meet food safety standards, are non-corrosive and have no harmful substances left, such as alkaline or neutral detergents, which effectively remove oil, dirt and residual plastic. Prepare the detergent according to the prescribed dilution ratio.
2. Setting of cleaning steps and frequency
The mold should be cleaned in time after each use. First, remove the injection molding machine and place it on the cleaning table. Use compressed air to remove loose dust and debris, and then use a clean cloth dipped in detergent to wipe the external surface, parting surface, gate, runner and other parts. Use special tools to clean difficult-to-clean parts, and pay attention to the water pressure and water flow direction. After cleaning, rinse the detergent with clean water and wipe it dry with compressed air or a towel. The cleaning frequency depends on the production situation. Generally, it is cleaned after production every day, and cleaned at any time when contamination or failure occurs.
(II) Measures for regular maintenance and care
1. Arrangement of mold inspection and repair
Regularly and comprehensively inspect the mold, including structural integrity, component wear, cooling and demolding system performance, etc. Check whether the core and cavity are worn, deformed, cracked, etc., and repair or replace them in time if there are any problems. Check whether the cooling system pipes are blocked or leaking, and whether the medium flow and temperature are normal. Check whether the demolding system components are flexible and whether there is any jamming or damage. Check and record the problems found and formulate a maintenance plan, and have professionals repair them.
2. Maintenance measures and record establishment
During regular maintenance, lubricate moving parts with food-grade lubricants, such as silicone oil or grease, to ensure flexible operation and reduce wear. Protect the mold surface, such as applying anti-rust oil or wrapping with anti-rust paper, to prevent rust. Establish detailed maintenance records, record the time, content, problems and treatment measures of each maintenance, provide a basis for repair and replacement, analyze the cause of the failure, take preventive measures, and improve the reliability and life of the mold.
六. Construction of mold quality inspection and certification system
(I) Methods and key points of internal quality inspection
1. Implementation of appearance inspection and dimensional measurement
Appearance inspection of the mold surface for scratches, pits, rust, etc., whether the parting surface is flat, and whether the parts are firmly assembled. Use high-precision measuring tools, such as calipers, micrometers, three-coordinate measuring machines, etc. to measure key dimensions, such as core cavity, gate runner, mold thickness, etc., to ensure that the dimensional accuracy meets the design requirements, and analyze the reasons for the out-of-tolerance parts and adjust and repair them. Inspections are carried out in accordance with quality standards and procedures, and the inspection personnel are professional and experienced.
2. Performance testing and simulation test implementation
Carry out cooling performance test, place temperature sensors on the cavity surface, measure temperature changes during injection molding, and evaluate cooling efficiency and uniformity. The demolding performance test simulates the demolding process to see whether the preform is demolded smoothly, whether the demolding force is appropriate, and whether there is any damage. You can also conduct a simulated injection molding test, use actual production materials and parameters to inject in the laboratory, observe the quality of preform molding, including appearance, dimensional accuracy, internal structure, etc., find problems and improve them in advance, and ensure the stability of formal production.
(II) Requirements for external certification and standard compliance
1. Connection between relevant certification agencies and standards
Enterprises actively apply for external certification, such as ISO 22000 Food Safety Management System Certification, which covers food safety management in the design, manufacturing and use of molds. You can also apply for US FDA or EU food contact material certification, which has high international recognition and is conducive to market development. Domestically, you must follow the food packaging material hygiene standards and specifications formulated by relevant departments, such as the "Implementation Rules for the Production License of Plastic Packaging Containers and Tools for Food".
2. Certification process and promotion of continuous improvement
The certification process includes document review, on-site audit and product sampling inspection. The enterprise prepares quality management documents, such as quality manuals, procedure documents, etc., to record the management system and production process. During the on-site audit, the certification body inspects the workshop, equipment, personnel, testing methods, etc. Product sampling inspection is sent to professional institutions for comprehensive inspection, including material composition analysis, hygiene index inspection, performance testing, etc. After passing the certification, pay attention to standard updates, timely adjust and improve the quality management system and production process, collect feedback information to optimize mold design and manufacturing processes, and improve the level of hygiene and safety.
In summary, ensuring the hygiene and safety of preform molds in food packaging requires strict control of multiple links from materials, design, manufacturing, cleaning and maintenance to quality inspection and certification, so as to provide solid and reliable protection for food packaging, meet consumers' demand for food safety and promote the healthy development of the food packaging industry.
Foshan Heyan Precision Mould Technology Co., Ltd.'s main business is preform moulds, bottle blowing moulds, bottle cap moulds and other products. It has a strong engineering, R&D, technology and sales team, advanced processing equipment and rich project experience. If you want to know more or have special needs, please call us at 13318345050, WeChat ID is the same.pet bottle mold
