What are the common problems in silicone plastic processing?

Silicone plastic processing is a complex and sophisticated process that involves multiple aspects such as material selection, mold design, process control, and quality control. This process often encounters some problems during the manufacturing process, which affect the quality and production efficiency of the product.

1、 Material selection and matching issues

1. Compatibility issue between silicone and plastic
Silicone has excellent high temperature resistance, cold resistance, electrical insulation, and biocompatibility, but its surface energy is low and it is not easy to form strong intermolecular bonds with other materials. There are many types of plastics, and different types of plastics have significant differences in hardness, toughness, weather resistance, and compatibility with silicone. Therefore, choosing the appropriate plastic substrate is crucial.
Solution: Choose plastic types that have good compatibility with silicone, such as certain specially modified polyolefins or thermoplastic elastomers. At the same time, pre-treatment of the plastic surface, such as plasma treatment, chemical etching, or coating with thickening agents, can be considered to increase its surface energy and enhance its adhesion with silicone gel.
2. Mismatch in material shrinkage rate
The shrinkage rate of plastic materials should match that of silicone to reduce dimensional deviations after molding. If the shrinkage rate does not match, it will cause problems such as warping and deformation of silicone plastic products.
Solution: When selecting materials, special attention should be paid to the shrinkage rate of plastic materials, and materials with a shrinkage rate similar to that of silicone should be chosen. In addition, corresponding adjustments should be made in mold design and process control to compensate for the dimensional changes caused by material shrinkage.

2、 Die design and manufacturing problems

1. Insufficient precision and durability of the mold
Mold design needs to consider the molding characteristics of silicone and plastic to ensure accuracy and durability, in order to produce products that meet the requirements. If the precision of the mold is insufficient, it will lead to unstable product dimensions; If the durability is insufficient, the mold is prone to wear and tear, which affects product quality and production efficiency.
Solution: Improve the design and manufacturing accuracy of the mold, adopt advanced processing technology and materials. At the same time, strengthen the maintenance and upkeep of molds, regularly inspect and replace severely worn mold components.
2. Unreasonable exhaust design
Silicone releases gas during the curing process. If the exhaust design of the mold is not reasonable, it can lead to the generation of bubbles and affect product quality.
Solution: When designing the mold, exhaust issues should be fully considered, and reasonable exhaust holes and channels should be set up to ensure smooth gas discharge. At the same time, in process control, it is necessary to adjust the injection pressure and speed reasonably to avoid gas being compressed inside the mold.

3、 Process control issues

1. Improper injection process parameters
The injection pressure, speed, and temperature parameters in the silicone injection process have a significant impact on product quality. If the parameters are not set properly, it can lead to problems such as insufficient silicone filling, overflow, and bubbles.
Solution: Reasonably set injection pressure, speed, and temperature parameters based on the fluidity of silicone gel and product shape. At the same time, strengthen process monitoring, timely detect and adjust process parameters, and ensure stable product quality.
2. Unstable vulcanization process
The vulcanization process of silicone directly affects its adhesion strength with plastic. If the control of parameters such as vulcanization temperature, time, and pressure is unstable, it can lead to incomplete or excessive vulcanization of silicone gel, affecting product quality.
Solution: Optimize the vulcanization process and precisely control parameters such as vulcanization temperature, time, and pressure. At the same time, strengthen the monitoring and detection of the vulcanization process to ensure that the silicone is completely vulcanized and its performance is stable.
3. Plastic injection molding process parameters do not match
The injection temperature, pressure, and timing parameters in the plastic injection molding process have a significant impact on the bonding quality between silicone and plastic. If the parameters do not match, it can lead to loose bonding between plastic and silicone, resulting in problems such as detachment or cracking.
Solution: Set injection temperature, pressure, timing and other parameters reasonably according to the characteristics of plastic materials. At the same time, strengthen the monitoring and detection of the injection molding process to ensure a tight bond between the plastic and silicone.

4、 Quality control issues

1. Insufficient online detection
Online testing is an important step in ensuring product quality. If the online detection is insufficient, it will result in unqualified products flowing into the next process, affecting the quality of the final product.
Solution: Strengthen online detection efforts and use visual inspection, size measurement, and other methods to monitor semi-finished products in real-time during the production process. At the same time, establish a comprehensive production record system to record and analyze various data during the production process, providing a basis for continuous improvement.
2. The finished product inspection is not strict enough
Finished product inspection is the last line of defense to ensure product quality. If the finished product inspection is not strict, it will result in unqualified products leaving the factory, affecting customer satisfaction and corporate reputation.
Solution: Conduct a comprehensive inspection of the finished product, including appearance, dimensions, performance, and other aspects. At the same time, strengthen the training and assessment of inspection personnel, improve their inspection level and sense of responsibility.

5、 Follow up handling of issues

1. Inadequate deburring and trimming
The formed product often has defects such as burrs and burrs. If the deburring and trimming are not done properly, it will affect the appearance quality and performance of the product.
Solution: Strengthen deburring and finishing work, use appropriate tools and process methods to ensure smooth and tidy product surfaces.
2. Incomplete cleaning and disinfection
For products that require cleaning and disinfection, incomplete cleaning and disinfection can result in residual stains or microorganisms on the surface of the product, affecting its hygiene and safety.
Solution: Develop reasonable cleaning and disinfection processes based on product usage and hygiene requirements. At the same time, strengthen the monitoring and testing of cleaning and disinfection processes to ensure that products meet relevant standards and customer requirements.

summary

The common problems in the processing of silicone plastic packaging involve multiple aspects such as material selection, mold design, process control, quality control, and subsequent processing. To solve these problems, it is necessary to start from multiple aspects, such as selecting suitable materials, improving mold accuracy and durability, optimizing process parameters, strengthening quality control, and subsequent processing. By continuously improving and optimizing production processes, the quality and production efficiency of silicone plastic products can be steadily improved, meeting customer needs and market requirements.