A good blow moulded part starts from the design. The design of blow-moulded parts of plastic containers is the key to manufacturing competitive and high-quality containers. It is a systematic and comprehensive engineering plan. That is, first consider meeting the use function; then select the material and determine the blow moulding method (particularly pay attention to the parting, demoulding, exhaust, etc.) of the blow moulding; finally, the blow mould structure size and technical requirements are determined. At the same time, the craftsmanship of mould processing must be taken into consideration. The whole process must be closely integrated with production cost and efficiency.
The description of the design steps of blow moulded parts is as follows:
(1) Design object. According to the purpose and use requirements of blow moulded parts, determine the functional characteristics, environmental conditions, and load conditions of the product. This is the most important part of the general design (2) the shape and structure design. It is designed according to the functional characteristics, environmental conditions, and load conditions of the blow moulded parts, so as to meet the requirements of use, beautiful appearance, reasonable size, appropriate strength, and save materials.
(2) Reasonable selection of materials. The selected blow moulding material should meet the requirements of performance and moulding processing. If blow moulding parts have special functional requirements (such as anti-static, anti-aging, sterilization, etc.), appropriate additives should be considered when formulating.
If a material is difficult to meet the design requirements of blow moulded parts, a variety of materials should be considered, and the blending modification or co-extrusion blow moulding method should be used to improve the technical performance of blow moulded parts.
If there are multiple materials to choose from, the price of the materials and the convenience of purchasing the materials in the local market should be considered.
(3) Preliminary design of samples. Including formula design, process design, structural modeling and mould design. These three aspects must be taken into account at the same time, and the purpose is to take care of the completeness of the preliminary design of the sample. Multiple plans should be considered, and alternate plans should be substituted when necessary. After the design is completed, raw materials, technology, cost, quality and other aspects can be compared for comprehensive evaluation.
Formulation design. Consider the combination of base resin and additives according to the performance requirements of blow moulded parts.
Process design. Clarify the moulding equipment and its influence on the design of blow moulded parts. According to the production quantity and technical performance of blow moulded parts, select the appropriate blow moulding method. Design the process flow, process conditions and main process parameters of blow moulding. When there are multiple blow moulding equipment to choose from, the cost of equipment and moulds, the proficiency of technical workers, and the material loss rate when producing blow moulded parts should be considered.
Structural modeling and mould design. According to the structure and shape of the blow moulded part, the requirements of the modeling design are determined, the mould design drawing is drawn, and the mould processing technology conditions are determined.
(4) Trial production of samples. This is a practical overall inspection of the various design concepts in the preliminary design of the above-mentioned samples. In the trial production, the mould is tested at the same time and the sample obtained from the test is inspected. As a result of trial production, a variety of samples and process conditions of different schemes can be obtained, and various indexes of samples of different design schemes can be tested and evaluated.
(5) Performance testing, quota calculation and cost accounting. Perform performance tests on the trial-produced samples to check whether they meet the design requirements and determine the technical quality indicators of the products. Through batch trial production, the production efficiency, raw and auxiliary material consumption and scrap rate are calculated, and the raw material cost and wage cost are calculated to obtain a reasonable product cost. If, in this procedure, the quality of the product has not yet reached the design requirements or there are deficiencies, it should be returned to the preliminary design procedure for appropriate modifications.
(6) Modification of product design. The modification of the product design is carried out many times and repeatedly, including the modification after the product design review, the modification after the product trial, and the final modification by the user.
(7) Compile technical documents such as technical design specifications. The product design of important projects should adopt the form of appraisal meeting and review meeting to gather expert opinions and carry out final confirmation of products and technical documents. Technical documents include production processes, process operating procedures, product technical standards, safety operating procedures, user trial reports, product performance test reports, and product user manuals.