Quick Mold Change: Giving Injection Molders
a Competitive Edge

Reduced labor costs and time to market have become important issues in the injection molding industry. Increased competition has caused shops to find ways to reduce production runs, high inventory levels and extended mold change times.

Implementing Quick Mold Change

In recent years, to survive in today's competitive, worldwide market, manufacturers are reducing inventory cost by running smaller batch sizes and making shorter production runs. One way to maximize press uptime in an environment like this is to implement faster, more effective mold changes.

A quick mold change means that the material for the next part is in place, the automation is set-up and the mold is located and clamped in position, the same place, the same way, everytime, in the shortest time possible.

When Quick Mold Change (QMC) is implemented, companies will enjoy the benefits of:

1. Reduced Inventories, due to smaller quantities runs and more frequent changeovers.
2. Increased Machine Capacity, by improving production and its revenues.
3. Improved Lead Times, due to quick change overs.
4. More Competitive, through just-in-time deliveries and better service to customers.
5. Improved Quality of parts, due to repeatable positioning and clamping forces.
6. Reduced Labor Costs, mold changes can often be done by the operator in a fraction of the previous time.
7. Improved Safety Level, the molds are under control and roll smoothly in and out of the injection mold machine during the mold change, and with automated systems, if the mold is not clamped properly, the injection molding machine simply will not operate.

How to Get Started

Step 1. Create a Quick Mold Change Team
Step 2. Select and Analyze a Machine and Its Molds
Step 3. Analyze the Present Mold Change Process
Step 4. Research and Implement the New Processes and Standards
Step 5. Evaluate the New Process
Step 6. Follow-Up and Repeat the Process

Step 1
Create a Quick Mold Change Team

Select a team and appoint a Team Leader

Step 2
Select and Analyze a Machine and Its Molds

Each QMC application is different. There is no single method that is best for all applications. The most appropriate method to be used for each machine is determined by carefully examining all production requirements and related data. The following is some of the information that needs to be reviewed.

• What are the present and long range production requirements?
• What is the goal for mold change time?
• How is the plant layout?
• Which machines are involved?
• How many molds are used in the machine?
• Minimum and maximum sizes and weights of molds.
• Present clamping method; the quantity and size of the bolts used.
• Clamping points: locations, shape, clamping heights, depth of ledge.

Step 3
Analyze the Present Mold Change Process

First, carefully review your present method of changeover. You have to know where you are now to decide what steps are needed to achieve your goals.

1. Analyze every step and the sequence required to make a mold change.
2. Break down each step to help determine how it can be reduced or eliminated.
3. How much time is required for each step? To get accurate times, casually observe a set-up team on several occasions. Obviously an authority figure standing near the machine with a watch or a video camera will produce figures less than the actual times occuring day to day.
4. Who is involved in the mold change process?
5. What is required? What tools? What materials?

Step 4
Research and Implement the New Process and Standards

After the present mold change process has been analyzed, look for ways to improve the process. The objective is to minimize the steps required and not to duplicate your work. Develop ways that will make the work easier and faster.

Start with things that are simple and low cost:
• Have new mold(s) prepared and staged in advance near the machines.
• Mold storage areas should be located near press.
• Minimize raw material handling.
• Have clamps and tools prepared before the machine shuts down for the mold change.

Standardization must be evaluated to achieve your Quick Mold Change goals. The variety and sizes of molds that have been accumulating in plants everywhere make changeovers time consuming and tedious, since standardization was not a consideration when the molds were designed and built.

Step 5
Evaluate the New Process

Step 6
Follow-Up and Repeat the Process