Often, customers ask us: "Is making a silicone product very simple? Just put the silicone into the mold and press it down, right?"
Every time I hear this question, I want to laugh, but I also feel that I can understand - after all, customers who haven't witnessed the production process can hardly imagine that a seemingly simple little silicone button requires so many processes and quality checks behind it.
Today, I will take you through the entire process of the birth of a silicone product. After watching it, you will understand: why is it that the same product can be made to last for several years in one factory, but only last a few months in another?
The first step: Mixing the rubber - the good feel starts here.
The raw silicone is in the form of blocks when it is purchased. It cannot be used directly. It is like an unworked dough, hard and lacking elasticity.
The mixing master puts the raw rubber into the open mill and through the repeated squeezing, thinning, and flipping by the two rollers, it gradually becomes softer. Then various additives such as vulcanizing agents and color pigments are added and repeatedly kneaded to evenly distribute them throughout the rubber.
This step determines the hardness, color, and elasticity of the product.
The second step: Mold pressing - "transforming" into shape under high temperature and high pressure.
The mixed rubber is cut into the appropriate size and weight and placed in the mold. Then the mold closes, and under high temperature (about 160-200°C) and high pressure, the silicone flows, fills, and cures in the mold cavity.
After a few minutes, the mold is opened, and the product's shape is formed. At this point, the product still has the joint line - a thin edge formed at the joint of the mold.
This step determines the basic shape and size of the product.
The third step: Edge trimming/finishing - removing the burrs and making the surface smooth
The product just out of the mold still has the joint line and needs to be cleaned up.
Small products (such as buttons): Use a machine to roll and polish, processing simultaneously in large quantities.
Large products (such as watch straps): Use sandpaper by hand to grind the joint line and flaws flat.
This step makes the product have a "smooth surface".
The fourth step: Secondary vulcanization - making the product's performance more stable
After the product is formed, it needs to be placed in a oven and baked again. Usually, it is baked at 150°C for 1-2 hours.
Why this extra step? Because during the first formation, there may still be a small amount of substances that have not fully cross-linked in the silicone. The secondary vulcanization allows these substances to continue reacting, making the product's size more stable, mechanical properties better, and less prone to sticking or oozing.
The fifth step: Surface treatment - putting on a "coat"
After the previous steps, the product is already a "semi-finished product". But the silicone surface still feels rough and is prone to dust. Therefore, surface treatment is needed.
Spraying a hand feel oil is the most common treatment method - spraying a thin layer of coating evenly on the surface to make the product smooth and fine, and less prone to dust.
If the product needs characters or patterns, it will enter the next step.
The sixth step: Character processing - making the product "speakable"
Most silicone products need to be printed with text, numbers, logos, or patterns. There are two mainstream processing methods:
Screen printing: Low cost, high efficiency, can print in multiple colors. The disadvantage is that the characters will wear off.
Laser engraving: Use a laser to "etch" the surface coating, revealing the base color to form the characters. The characters will never fade and can transmit light (suitable for products with backlight). The cost is higher than screen printing.
This step determines whether the product's identification is clear and durable.
The seventh step: Quality inspection - "spotting flaws" step by step
Is the product ready for shipment? It still needs to go through the sharp eyes of the quality inspector. Unqualified products must not be sent to customers.
From the purchase of raw materials to the shipment of the finished product, every step has inspection:
Incoming material inspection: Check if the silicone raw materials are qualified
Process inspection: Regular spot checks during molding and spraying
Finished product inspection: Full inspection or spot check after the product is completed
Outgoing inspection: Another spot check before packaging
Inspection items include: Whether there are defects in appearance, whether the dimensions meet the tolerance, whether the hardness meets the standard, whether the characters are clear, whether the feel meets the requirements...
If the quality inspection is not strict: Products with problems will flow to customers, affecting the user experience and brand reputation.
Chapter 8: Packaging and Shipping - The Final Check
Qualified products are cleaned and packaged.
Packaging is not just putting something in a bag. It requires choosing the appropriate packaging method based on the product characteristics to avoid damage from collisions and friction during transportation. For small batches, use anti-static bags or vacuum packaging boxes, and for large batches, customize packaging solutions.
At this point, a complete silicone product can be said to have truly "graduated".
Hongxianda can do for you:
In Hongxianda, each of these eight processes has standard operation instructions (SOP), and each batch of products has production records. Problems can be traced back to the specific link.
We often say: Making silicone products is like raising children - every step requires attention to ensure a good outcome.
If you are considering making silicone products or are curious about how your product is made, welcome to visit Hongxianda. Walk through the workshop and you will understand that every "eight checks" we mentioned is not empty talk.