See Ding Zhou injection molding How to control the mold fabricating cost

The current injection mold market is being affected by rising raw material prices and increased labor costs, resulting in a shrinking profit margin for injection molds. How to obtain orders in fierce market competition, ensure mold quality, and maximize mold profits as much as possible to achieve green manufacturing, Dingzhou Injection Molding is thinking about this issue every day. The cost control of injection mold manufacturing is imperative, and cost control lies in effective spending rather than ineffective savings. In the process of mold manufacturing, mold management can be divided into schedule and delivery management, quality management, cost management, technology and talent management, and after-sales management, among which cost management is a key factor affecting mold profits. The cost of mold manufacturing mainly consists of material cost, design cost, processing cost, assembly cost, trial mold cost, transportation cost, maintenance cost, quality cost, schedule cost, management cost, etc.

Cost control requires the participation of all staff, and the cultivation of cost awareness among mold workers requires continuous promotion and infiltration of corporate culture, strengthening cost awareness training, and gradually establishing personnel's awareness of "cost" and "benefit". The cost control in the mold design stage is the core of the entire mold manufacturing cost control. Mold design is the first step in mold manufacturing, and the importance of cost should be emphasized in the design process to improve the sensitivity of designers to cost.

1.Mold size design

Based on customer standards and reference drawings, preliminarily determine the size of the mold template, and the design leader reviews and controls it; At the final review meeting, jointly evaluate the strength of the mold with the process and mold making personnel. Notify the project and business department when exceeding the budget, in order to negotiate concessions or additional costs with customers or take other remedial measures, such as optimizing the structure, selecting materials reasonably, and ensuring that the overall manufacturing cost of the mold is controlled within the budget.

Mold flow analysis

2. Confirmation of mold processing technology

Designers and programmers review the machining process of the drawings to determine the final machining method and approach. Programmers set different machining parameters and select cutting tools based on the machining accuracy of mold parts, improving machining efficiency and reducing machining costs while ensuring quality. During the design phase, plan the machining process of the parts well, and the designers should understand the machining ability of the factory‘s machine tools. For parts with similar materials and size shapes, splicing machining technology should be used as much as possible .

The non adhesive side R-angle should be designed according to the “safe machining depth” in the table below. In special cases, it should be designed according to the “maximum machining depth”. The larger the side R-angle, the more conducive it is to machining . The size of the trapezoidal flow channel should be designed according to the existing cutting tools, and the diameter of the circular flow channel should be designed according to the size of the ball cutter as much as possible to improve processing efficiency. The mold parting surface and void avoidance surface should be designed as flat as possible to avoid dead corners that cannot be machined by CNC. The process is refined to each step, and the machining benchmark and clamping position for each step are designed in advance to minimize the number of machining and clamping times as much as possible .

The entire mold is composed of different parts, especially complex slider and inclined top component structures, which require advance motion simulation to eliminate interference and ensure stable and reliable mold assembly and movement.

3.Selection of Steel for Mold Parts

The selection of steel materials for mold parts is determined based on the "Mold Manufacturing Cost Budget Table", while the selection of steel materials for mold small parts is based on customer and company standards. When higher material requirements are proposed during customer reviews to meet certain needs (such as service life, cooling efficiency, etc.), the project and business department should be notified in a timely manner to add fees to the customer. Secondly, if there is a quotation error due to a misunderstanding of the customer's needs, and additional fees cannot be added to the customer, other remedial measures should be taken to ensure that the overall manufacturing cost of the mold is controlled within the budget.

4.Cost control during the processing phase

(1) Production scheduling. Firstly, evaluate the machining hours based on the simulation time of the program process sheet, while considering the clamping time of the workpieces . Then, allocate the machine tool processing reasonably according to the requirements of the program process sheet and the machine tool performance, fully leveraging the advantages of the machine tool to improve its utilization rate.

(2) Priority should be given to automatic programming. The deep hole drilling process adopts automatic programming, The total monthly cost can be automatically calculated through a connected computer. Based on this data, the price of deep hole drilling for the same type of mold and the utilization rate of the machine tool can be evaluated.

5.Material procurement cost control

The principle of material procurement cost control is to ensure that project material costs are within the budget range of mold manufacturing costs, and to minimize procurement costs while ensuring quality. The procurement manager checks the cost based on the "Mold Manufacturing Cost Budget Table", evaluates whether the procurement price exceeds the budget, and provides feedback to the design department if it exceeds the budget. The cost control measures for material procurement are as follows.

(1) Eliminate urgent procurement and plan in advance for materials with long procurement cycles.

(2) Under the premise of ensuring product quality, suppliers are required to be sent to different warehouses through batch procurement, in order to make reasonable use of resources and reduce procurement costs.

(3) The quality department and procurement department are seeking high-quality, long-term cooperation with standard component suppliers.

6 Cost control during the trial stage

The cost control measures during the trial stage are as follows:

① Reasonably arrange the trial mold machine tool and build a trial mold environment as much as possible according to the requirements of mass production of the mold, such as water, oil, gas connections, etc ;

② Strictly control the number of mold trials and reduce the cost of mold trials;

③ Conduct trial molding according to the parameters of the mold flow analysis report to improve the efficiency of trial molding;

④ The process parameters of the final injection molded qualified product will be re validated by the engineer through mold flow analysis, while recording the reasons and analysis, and added to the mold flow analysis database as a reference for the next production of similar products.

Mold flow analysis

Cost accounting for mold manufacturing

After the delivery of the mold, professional cost accountants will calculate its cost and organize a summary meeting between the responsible persons for each process of the mold and the person in charge of the quotation. The meeting will be compared with the initial quotation to summarize the causes of problems and preventive measures. This will help to quickly provide a reasonable quotation based on market trends when manufacturing similar molds in the future.