Polishing Technology of High Quality Injection Mold for Injection Molded Products

After the mold processing is completed, it also needs to be polished. So how to polish high-quality injection molds? What are the requirements for high quality injection mold polishing? Now let's have a look.

I. Preparation before grinding and polishing of high quality injection mold

1. The polishing personnel in the injection molding factory must be trained, pass the examination and obtain the work license before beginning work.

2. Specify the process requirements, materials and initial state of injection molded products, and the processing position, shape, size and polishing accuracy requirements of this process.

3. Before polishing, relevant personnel of the injection moulding factory must check whether the surface to be polished has defects such as edge collapse, angle collapse, over cutting, deformation and sand holes, and whether the polishing allowance is sufficient.

4. According to the process specification of injection molded products, reasonably select the tools, fixtures, main and auxiliary materials applicable to this process.

5. The workpiece shall be properly protected according to the process requirements.

6. Carry out the operation procedure after reconfirming steps 1-5.

II.  Clamping and protection of injection molded products

1. For higher or longer injection products below 20kg, it is required to use bench clamp on the polishing workbench.

2. For large and heavy injection products, front and rear magnets and screw clips must be used on the polishing workbench for fastening.

3. When grinding and polishing injection molded products with a work car, wedges or relevant measures must be taken to ensure stable work and work safety.

4. For injection molded products with small and easy to be bruised and scratched, rubber plates must be used to protect this type of surface.

5. Injection molded products with sharp corners and edges must be protected with adhesive tape and adhesive paper to prevent injury or damage to personnel and injection molded products.

6. For the injection molding products that need to maintain the edge and glue sealing position, the side not to be polished can be fixed and protected with a blade (saw blade or iron blade) or stop to prevent edge chamfering and rounding.

III. Content and scope of self inspection of injection molded products

1. Whether the sealing surface is collapsed and rounded;

2. Whether the original die inclination is damaged;

3. Check the size of each polished surface of injection molding products to see if it exceeds the reserved amount;

4. Whether the fillet at the bottom of the cavity is concave into the side and bottom;

5. Whether there is any inclination;

6. Whether the roughness meets the drawing requirements;

7. After passing the self inspection, it shall be inspected by the team leader (or inspector).

IV. Precautions for polishing of injection molded products

1. Before grinding, check whether the grinding allowance of injection molding products is sufficient, and the grinding and polishing amount shall not exceed the reserved amount;

(1) The grinding and polishing amount of the ground plane shall not exceed the reserved amount by 0.05 ~ 0.06mm;

(2) The grinding and polishing amount of ungrounded surface, electro erosion or wire cutting surface shall not exceed the reserved amount by 0.08 ~ 0.1mm;

(3) The single side and depth grinding and polishing amount of reinforcement shall not exceed the reserved amount by 0.03 ~ 0.08mm.

2. Relevant personnel in the injection molding plant shall pay high attention when operating the polishing machine to prevent grooves from exceeding the allowance. It is not allowed to process the same part for a long time;

3. After each grinding, it must be cleaned with Weishi cloth, and then grinding in the next step;

4. After each polishing, it must be wiped with cotton or soft paper before the next polishing.

5. Before polishing high quality injection mold, first determine the processing procedure:

(1) According to different original surface conditions and roughness, select appropriate processes and tools (specific diamond file, sandpaper and oilstone) for starting sequence and required sequence;

(2) According to the geometry, basic roughness and process requirements of high quality injection mold cavity, the application scope of electric tools and grinding tool heads is determined to achieve targeted processing.

6. Attention shall be paid to the grinding and polishing of the sealing surface. In particular, the penetration of special identification symbols of injection molding products and the sealing surface shall not cause fillet and corner collapse;

7. The grinding and polishing area shall be clean and tidy, and attention shall be paid to the protection of the polished surface during the polishing process;

8. Some parts to be polished together after assembly are not allowed to be polished separately;

9. After polishing, the polishing surface shall be sprayed with antirust oil after self inspection and, and protection shall be done to prevent bumping and scratching;

10. All kinds of oilstone, sandpaper, diamond grinding paste and diamond file must be placed in the special tool box with corresponding labels according to their models and specifications.