Rubber Product Production Process

Rubber product production process:

Cutting and weighing of raw rubber→Plastic compounding in the mill, weighing of ingredients→Rolling in the mill→Kneading and discharging☆→Quick inspection→Vulcanization molding→Edge trimming→Finish product→Inspection→Storage

The above process of rubber rolling is a key process, and vulcanization is a special process. Time and temperature are quality control points for rubber mixing, and time, temperature and pressure during vulcanization are quality control points.

2. Guidance for vulcanization process

(1) Vulcanization process

1. Preparation: Before starting up, check whether the power supply, lines, pipelines, etc. of the rubber and silicon compression machine are safe and in good condition; start up and check whether all parts are operating normally, and wipe the machine clean at the same time. Select the mold according to the plan and drawings, wipe the mold, focus on the inspection of the inner cavity, wipe and clean, then preheat the mold to reach the required temperature, and check whether the cavity is clean.

2. Check the accuracy of the case scale.

3. The operator cuts and weighs the film according to the "Rubber Product Process Card", puts the quantitative film into the preheated mold and the injection tank according to the program requirements, and then covers the mold top cover.

4. Put the installed mold into the central symmetrical part of the vacuum compression molding press to pressurize the glue or close the mold.

5. Lift and lower the plate of the  Compression molding machine  two to three times to remove the air in the mold and make the rubber fill the cavity. The prescribed constant pressure and temperature are then maintained.

6. Curing time, temperature and pressure control. The vulcanization time, pressure and temperature are operated and recorded according to the "Vulcanization Process Card".

7. After the rubber press is running normally, put the operating tools and other items in the specified area of the workshop, and do not mix them; store the remaining rubber trim in a special container for re-smelting.

8. When the product is out of the mold, it is strictly forbidden to use sharp objects to pry it open, so as not to damage the appearance quality of the product. After the mold is out, clean the mold once, and then proceed to the next mold operation.

9. After the product is out of the mold, it will be trimmed and self-inspected. After passing the self-inspection, it will be placed in the waiting area for inspection by a full-time quality inspector.

Rubber product formula technical support we can discuss.

(2) Records of vulcanization process of rubber products

1. The product name, batch number, date and operator must be indicated in the process record.

2. According to the length of vulcanization time, record pressure and temperature at a certain frequency, not less than 3 times. Key processes and change nodes must be recorded, and abnormalities must be recorded.

3. The actions required by the "Rubber Products Process Card" must be faithfully executed and recorded, and shall not be increased or decreased arbitrarily.

4. The records required by the "Rubber Products Process Card" must be available.

5. The records must be true and effective, and no advance records or post-records are allowed.

3. Regulations on working pressure control of flat vulcanizing press

1. According to the technical requirements of rubber products, some products stipulate the unit clamping pressure.

2. Due to different machine models and product specifications, it is stipulated that various types of vulcanizing machines should be vulcanized when vulcanizing products of different specifications.

3. When controlling the working pressure of the machine, it should not be less than the calculated value and not higher than the rated working pressure of the vulcanizing machine.

4. Inspection of rubber products

1. Quality inspection personnel for plasticized rubber and mixed rubber should take samples for inspection and make test indicators for matching test pieces.

2. Each product needs to go through self-inspection and sampling inspection. The self-inspection is for the operator to visually observe the finished product to check whether there are any defects such as less glue, air pockets, damage, and burrs. If any problems are found, they must be eliminated and stored uniformly without mixing them. Qualified products; sampling inspection by quality inspection personnel, including visual inspection and anatomical inspection. Appearance inspection All products weighing more than 0.5kg shall be inspected; products below 0.5kg shall not be less than 20% of the finished products. If the sampling defective rate is higher than 5% or unqualified products must be inspected in full. Anatomical inspection is to take 1-3 pieces of each batch of products and cut them open according to their shape to check the product density, whether there are bubbles, the degree of vulcanization, etc.

3. For the defects with high frequency found in the inspection, it is necessary to submit to the R&D department for consideration of improving the process or repairing and improving the mold.

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