2K Injection Molding Manufacturing Custom Plastic bowl for Wedgwood

Project Background With the advancement of global environmental policies, PP food grade plastic reusable tableware has become an important development direction for the food tableware industry. Food grade PP plastic (polypropylene, recycling code 5) is a safe material widely used in reusable tableware. It is non-toxic and odorless, can withstand high temperatures up to 120 ℃, can be repeatedly heated and not easily deformed, and does not contain bisphenol A. It has stable chemical properties and is not easily reactive with food. After authoritative certification, it can be in long-term contact with food. This project aims to design and manufacture one set of injection molds for the production of tableware for a certain catering chain enterprise, in order to meet its large-scale and environmentally friendly production needs. Project objectives 1. Design one moldbase with 3 interchangeable cores to enable 3 different sized bowl products, effectively reducing project costs for customer. 2. Optimize the mold structure to ensure uniform product wall thickness (± 0.05mm) and avoid deformation or shrinkage defects. 3. Adapt to the characteristics of PP material (easy to shrink), optimize the hot runner system and cooling system. 4. The moldlife over 1 million cycles, meeting the long-term production needs of customer.

Project design process 1. Product analysis and mold scheme determination -Product mapping: Obtain CAD models of three bowls using 3D scanning technology, and annotate key dimensions such as box diameter, height, and wall thickness tolerances. -Material characteristic adaptation: PP material has a narrow melting temperature range (170-230 ℃), requiring the design of an independent temperature controlled hot runner system to avoid local overheating or insufficient mold filling. -Mold frame selection: Standard HASCO mold frame is used to ensure the stability of mold installation. 2. Mold structure design -Design of parting surface: Select the boundary between the bottom of the tableware and the box body as the parting surface to simplify the demolding structure. -Pouring system: *Cannon nozzle R angle: R15.5, connected to the injection molding machine nozzle. *Hot runner brand: MOLDMASTERS, from Canada. *Gate: one valve gate at the center of the bottom of the product to avoid welding marks on the surface. -Cooling system: Circular cooling water channel with a diameter of 8mm, arranged around the cavity, reducing cooling time to 10 seconds. -Demoulding mechanism: Pushing block+air ejection to ensure smooth demoulding.

Project Implementation and Validation 1. Mold manufacturing -The cavity and core inserts are made of 1.2343ESU steel with a hardness of HRC48-50, ensuring wear resistance, polishing resistance, and corrosion resistance. -Precision machining center processing, surface roughness Ra ≤ 0.4 μ m, tolerance with ± 0.01mm. -The hot runner system adopts HeatingZone independent temperature control, with a temperature difference controlled within ± 2 ℃. 2. T1 trial molding and problem solving -Problem 1: The plastic products have gas entrapment during the initial trial. *Solution: Adding air groove to the mold and optimizing injecting parameters effectively solved the problem. 3. Continuously produce for 8 hours and calculate the defect rate: -Size deviation: 0% -Surface defect: 0.1% -Difficulty in demolding: 0% -Production efficiency: One molding cycle of 20 seconds, with a daily output of 4000 pieces.

Project achievements 1. Technical indicators -Mold lifespan: 1.05 million cycles (exceeding the target by 1 million cycles). -Product qualification rate: 99.65% (customer requirement ≥ 99%). -Material utilization rate: 92% (85% for traditional molds). 2. Economic benefits -The cost of a single piece has been reduced by 20% (thanks to good mold design and a good cooling system). -The customer's annual production capacity has been increased to 1 million pieces to meet market demand. 3. Environmental benefits -Reduce PP material waste by 15%, in line with the company's ESG goals.

Experience summary 1. PP material adaptation key: -Strictly control the melt temperature and mold temperature. -Adopting high-precision temperature controlled hot runner to solve the problem of insufficient mold filling. 2. Optimization direction of mold design: -Increase the number of cooling water channels to further shorten the molding cycle. -Test the design of the first mock examination with multiple models, and improve the utilization rate of mold embryo. 3. Customer feedback: -The high stability of the mold reduces the maintenance time of the injection molding machine. -The plastic bowls have passed the EU green environmental certification.

Appendix 1. Mold structure picture (1 attached figure: mold assembly picture; 2 attached figure: real mold picture; 3 attached figure: plastic bowl product picture). 2. Machine parameter table (injection pressure, holding time, cooling time, etc.). 3. Customer acceptance CMM report (mold-inserts inspection). Conclusion: This project has successfully solved the technical problem of PP material injection molding by optimizing the mold structure and process parameters, providing a reliable solution for the large-scale production of bowls tableware, and creating significant economic and environmental benefits for the enterprise.