Why Do Silicone Products Release Oil Over Time? (Silicone Oil Bleeding Explained)
Some people may find it strange that after using the silicone spatulas, silicone bowls, lick mat, or silicone spoons for a long time, there will be a layer of oil on their surfaces. Does this mean that the product is unsafe? Is the material of poor quality? Is it toxic? Is it safe?
If you are a brand owner of silicone products, an Amazon seller who wants to sell, or someone planning to enter the silicone product category, then you need to read this carefully. As a professional manufacturer.
Mar 3rd,202672 Views
If silicone products are left for a long time, they tend to develop an oily layer. This is not because they have "aged", but because the additives (such as silicone oil and release agents) added during production have seeped onto the surface. Just like a sponge that has absorbed a lot of water, over time, the water will gradually seep out.
Many brand owners or store owners have this question: Why do our customers report that the silicone spatulas, silicone bowls, silicone spoons, silicone slow-cooking pads, silicone slow feeder dog bowls, silicone food boxes, and silicone dinner plates and other products they bought, after being placed for a period of time and then taken out, have a layer of oil on them. Is this oil safe? For these products that come into contact with food, are the products themselves safe and non-toxic?
The main specific reasons are as follows:
1. The addition ratio of silicone oil is inappropriate. This is the main reason. To increase softness, the manufacturer might have added too much silicone oil or used inferior white mineral oil (a type of petrochemical product) instead. These oils are poorly compatible with the silicone gel, and over time, they will precipitate.
2. Excessive addition of additives. If too much internal demolding agent or sprayed demolding agent is used during production, the residues may gradually seep out later and form "oil".
3. Problems related to the raw material formula. The silicone oil came into physical conflict with the base material (silica powder), which disrupted the stability of the material and caused the oil to seep out.
High-quality silicone products strictly control the amount of silicone oil added (generally recommended to be no more than 5% - 10%), and rarely produce oil. If the product in your hand has already become oily, you can simply clean it with dish soap. If oil continues to leak, it might be a quality issue.
Do the silicone products leak oil, affecting their safety for use?
This depends on the situation, the usage scenario, and the category of the product. If it is silicone tableware, kitchenware, baby products (silicone plates, silicone bowls, silicone spoons), or silicone pet products (silicone slow-eating bowls, silicone licking mats). The presence of oil indicates that the additives may not meet the standards for food contact, and there is a risk that harmful substances could migrate into the food.
If it is a phone case, remote control, or other non-contact food-related items, the risk is relatively low. Since there is no direct contact with food or the mouth, the problem mainly lies in the discomfort of the touch. Just using dish soap for cleaning will do. However, if there is continuous oil leakage, it indicates that the material is aging or of poor quality. It is recommended to replace it.
As a manufacturer, JOYI aims to eliminate oil leakage from silicone products at the production stage. The key lies in proposing a comprehensive control system covering the entire production chain, from formula design, raw material control, production process, to final product inspection.
Formula design: Eliminate the risk of silicone oil leakage from the very beginning 1. Selection of basic raw materials: Select high-quality raw silicone: Choose the base polymer with low volatiles and a narrow molecular weight distribution to reduce the residue of small molecules.
Control the amount of silicone oil: The addition of silicone gel is strictly controlled within 5% to 10%. Excessive addition will damage the molecular weight of the silicone gel, resulting in oil leakage.
Reference patent formula: For example, by combining low-viscosity ethylene-based end-capped silica with high-viscosity ethylene-based end-capped silicone oil, the oil output rate can be significantly reduced.
2. Optimization of additives: Avoid using white mineral oil. It is strictly prohibited to substitute silicone oil with petroleum-based products such as white mineral oil. This is one of the main reasons for the oil leakage.
Control the amount of release agent: Both the internal release agent and the external spray release agent need to be precisely controlled. Excessive use will result in precipitation later on.
Using functional silicone oil: Carboxyl silicone oil and amino silicone oil can be used as alternatives to ordinary silicone oil to enhance the dryness of the surface.
Production process: Ensure complete cross-linking and purification. 1. Sulfurization process control is carried out to ensure complete sulfurization. The sulfurization temperature, time, and pressure are strictly controlled to avoid incomplete sulfurization and the residue of low-molecular substances. After the product is formed, a secondary sulfurization (baking) is conducted at a temperature of 200-250 degrees Celsius to completely remove the unreacted low-molecular substances.
2. Control the processing environment, regulate the heating temperature, and duration to prevent excessive heating from causing the analysis of silicone oil to occur. Keep the environment clean to prevent oil and other impurities from mixing into the rubber compound. For the filler treatment, ensure that fillers such as silica are fully treated for hydrophobicity to reduce the adsorption of small molecules.
Carry out accelerated aging tests by placing the samples in a 60-70 degrees Celsius oven and leaving them to stand for 24-48 hours. This will quickly reveal the oil trend. Regularly inspect the inventory products and suggest the implementation of a quality traceability system.
For brand owners, Amazon sellers, store owners, and wholesalers, choosing a reliable and stable manufacturing factory is a very important matter. JOYI, as a manufacturer with over 8 years of experience in the silicone industry, we have our own processes and systems for quality control. Strictly control the quality, provide excellent service to every customer, and establish long-term business relationships.
The silicone pet products (pet slow-feed mats, pet slow-feed bowls, pet folding bowls), silicone household items (silicone food boxes, silicone soup and ice containers, silicone preservation bags), silicone baby and children's products (silicone dinner plates, silicone bibs, silicone bowls, silicone spoons), and other silicone accessories that we produce have all been widely recognized by our customers.
