1. Appearance inspection
First, you can make a preliminary judgment on whether the PET bottle preform mold needs to be replaced by appearance inspection. Observe whether there is obvious wear, scratches, cracks or corrosion on the mold surface. If the mold surface is severely worn, it may affect the dimensional accuracy and surface quality of the preform. Scratches and cracks may gradually expand during the production process, causing mold damage or even safety accidents. Corrosion will reduce the strength and service life of the mold. In addition, check whether the various parts of the mold are loose, deformed or damaged, such as whether the fasteners are loose, whether the slider is smooth, etc.
2. Dimensional accuracy
Secondly, dimensional accuracy is an important indicator for judging whether the mold needs to be replaced. Regularly measure the dimensions of the produced preforms and compare them with the design requirements. If the dimensional deviation of the preform exceeds the allowable range, it may be caused by mold wear or deformation. You can use measuring tools such as calipers, micrometers, etc. for precise measurement, and check whether the wall thickness of the preform is uniform. If the dimensional accuracy cannot be improved by adjusting the process parameters, then the mold may need to be replaced.
3. Production efficiency
The production efficiency of the mold is also a factor in judging whether it needs to be replaced. If you find that the mold opening and closing speed slows down, demolding is difficult, and the production cycle is extended during the production process, there may be a problem with the mold. For example, the wear of the mold's guide mechanism will cause the mold to open and close unsmoothly, and the blockage of the cooling system will affect the cooling speed of the preform, thereby reducing production efficiency. In addition, if the mold frequently fails and needs frequent repairs, it will also affect the production progress. At this time, you can consider replacing a new mold.
4. Cost considerations
Consider whether the mold needs to be replaced from a cost perspective. If the mold maintenance cost is too high, or it still cannot meet production requirements after repair, then replacing the mold may be a more economical option. At the same time, consider the relationship between the investment cost of the new mold and the expected production benefits. If the new mold can improve production efficiency, reduce scrap rate, and improve product quality, then the investment cost of the new mold can be offset to a certain extent. In addition, the mold's service life and depreciation cost can also be considered to comprehensively evaluate whether the mold needs to be replaced.
Through appearance inspection, dimensional accuracy, production efficiency and cost considerations, it can be more accurately judged whether the PET bottle preform mold needs to be replaced. In actual production, a comprehensive analysis should be conducted based on the specific situation, and decisions should be made in a timely manner to ensure the smooth progress of production and stable product quality.
