When making silicone products, one of the things that customers dread most is: the color of the first batch of goods is fine, but when they receive the second batch, they find that the color is incorrect.
When comparing them side by side, one is darker and the other is lighter; one is redder and the other is yellower. It may not be obvious when viewed individually, but it stands out when placed together.
Today, let's talk about color management for silicone products - how color differences occur and how factories control them.
First, let's figure out how color differences come about.
The color of silicone products is achieved by adding color gel during the mixing stage. It sounds simple, but in actual production, several steps can cause the color to deviate.
Reason 1: Color gel has batch variations
The color gel is the raw material for color mixing. Even if they are the same color number, different batches of color gel may have subtle differences. If the factory does not manage the color gel by batch, today they use this batch and tomorrow they use that batch, the color may not match.
Reason 2: Color mixing is all about "gut feeling"
Some small factories do not have standard formulas for color mixing and rely solely on the master's experience and eyesight. Today the master is in a good mood and mixes a certain color; tomorrow a different master mixes another color. Without records and standards, color differences are inevitable.
Reason 3: The color gel is not well mixed during mixing
The color gel is added, but the mixing time is insufficient or the kneading is not thorough, resulting in uneven color distribution. The produced products may be darker in one area and lighter in another, or the overall color may be pale.
Reason 4: The molding temperature affects the color
Some colors are sensitive to temperature. If the molding temperature is too high, the color may darken or turn yellow; if it is too low, the color may be lighter. If the molding process is unstable, the color will also fluctuate.
Reason 5: The raw materials themselves have base color differences
The silicone raw materials are semi-transparent milky white, but different suppliers and batches of raw materials may have slight differences in base color. Even if the same color gel is added, the final color may still have deviations.
How do factories control color differences?
Knowing the reasons, control has a direction. At Hongxianda, we start from five aspects:
The first step: Color gel batch management
When the color gel arrives at the factory, we record the brand, color number, and batch number. For the same product, it is advisable to use the same batch of color gel. If it is necessary to change the batch, we will first make a small sample comparison to confirm that the color is consistent before it is put into production.
The second step: Standard formula + sample retention
After each color is mixed, we record which color gel was used, the proportion, and form a standard formula. At the same time, we will retain a standard color plate as a reference for subsequent production.
When producing this color again, directly follow the formula and do not rely on the master's "gut feeling" for mixing. After comparing the mixed gel with the standard color plate and confirming that the color is correct, it is then sent to the next process.
The third step: Control of the uniformity of the mixing process
After the color gel is added, ensure sufficient mixing time and kneading frequency to allow the color to be evenly distributed throughout the gel. We will take samples and press them into sheets, compare them with the standard color plate, and confirm that the color is correct before starting production.
The fourth step: Stabilization of molding parameters
For colors that are sensitive to temperature, we will fix the molding temperature and time to avoid color changes due to parameter fluctuations. After the first piece comes out, we will first compare it with the standard color plate to confirm that the color is qualified before mass production.
The fifth step: Sample retention for each batch
After each batch of products is produced, we will retain samples for storage. In case customers report color issues, we can take the retained samples for comparison to confirm whether it is a production issue or other reasons. Silicone color mixing involves multiple variables such as color paste, raw materials, temperature, and time. Minor differences between different batches are normal. The key is whether the differences are within an acceptable range.
Secondly, color discrepancy issues should be prevented rather than remedied. If the color of the product is found to be incorrect after production, it is usually impossible to salvage it. Therefore, the factory should focus its efforts on the production process - recording the formula, using standard color charts, and comparing the process step by step. None of these can be omitted.
Thirdly, both the customer and the factory should align on the standards beforehand. Color is a subjective matter. What you call "red" and what the factory understands as "red" may not be the same. Confirm the standard color chart during the proofing stage, and then follow this standard. Both parties will be relieved.
How does Hongxianda do it?
At Hongxianda, color management is not based on the eye power of a certain master, but on a set of executable and traceable processes:
Each color has a standard formula, and color mixing is not done by intuition
Each color has a standard color chart, and is compared batch by batch during production
After each batch of rubber is refined, samples are taken and pressed into sheets for confirmation. Only when it is qualified can it be put into production
Each batch of finished products is kept as a sample for future reference
For temperature-sensitive colors, fixed forming parameters are set to reduce fluctuations
We cannot claim to achieve zero color discrepancy, but we can ensure that each batch of color is within the standards confirmed by both parties, and the batches are stable and controllable.