Rubber release agent is an additive used to prevent the product from sticking to the surface of the mold during the vulcanization process of the rubber product so that it can be released smoothly without tearing. Spray or smear on the cavity surface to form an effective barrier film.
The main requirements of the mold release agent are: it has a certain thermal stability and chemical inertia, does not corrode the surface of the mold cavity, has no residual decomposition on the surface of the mold cavity, does not affect the color, quality, and post-processing of the product, but can give the product a good appearance. Reduce the cleaning time of the mold, improve the production efficiency, reduce the product defect rate, and improve the service life of the mold.
The main mechanism of the release agent:
The polar chemical bond and the mold surface interact to form a regenerable adsorption film; the silicon-oxygen bond in polysiloxane can be regarded as a weak dipole. When the release agent is laid in a unidirectional arrangement on the surface of the mold, the molecules adopt a unique extended chain structure; the free surface is covered by densely packed alkyl groups, and the release ability increases with the increase of the density of the alkyl groups; but when the alkyl groups occupy more When the space resistance is large, the stretching structure is limited, and the demolding effect is reduced; the molecular weight and viscosity of the release agent are also related to the demoulding effect. Small molecular weight, good layability, but poor heat resistance.
The specific performance requirements of the release agent:
The demoulding effect is good, and the product will not tear during demoulding, which improves the product qualification rate and production efficiency;
Good demoulding semi-permanence, strong adhesion on the surface of the mold cavity, and long duration;
The appearance of the product is smooth and beautiful, without stains;
Excellent post-processing performance, no adverse effects on product surface painting, printing, bonding and other processing;
No peculiar smell, low toxicity; no impact on product quality, such as product surface cracks, rubber frame parts bonding, etc.
Current mainstream release agent types:
1. Fluorine mold release agent: Fluorine mold release agent inherits the characteristics of fluorine materials, which can significantly reduce the surface energy of the solid, making it difficult to penetrate and adhere, and is not easy to dissolve with other substances, which solves the problem between the finished product and the mold. Adhesion problems. When preparing the release agent, the amount of the fluorine compound is very small. It is suitable for all kinds of rubber products, with smooth surface, no stains, and excellent post-processing performance.
2. Silicon release agent: Silicon release agent is made of siloxane. Its advantages are good heat resistance, moderate surface tension, easy to form a uniform isolation film, and long demolding life. The disadvantage is that there is a layer of oil on the surface of the product after demolding, which affects the post-processing. If used improperly during the vulcanization process, it may cause cracks on the surface of the product and affect the bonding of skeleton parts. Commonly used are silicone oil, silicone grease and so on. Silicone release agent is currently the mainstream product in the mid-range market of rubber and plastic release agents, and is widely used in the processing of polyurethane, rubber and resin.
The release principle of water-based release agent:
Adhesion of rubber and plastic to mold surfaces is generally thought to be caused by two reasons. First, the surface of the mold is usually covered with a very thin, even monomolecular, water film. This extremely thin water film has strong adhesion after reacting with isocyanate. Second, the adhesion is caused by the chemical bonds created by the reaction of the polar groups on the inner surface of the mold with the polar groups of the polyurethane and polyurea. In order to make the product release well, the mold surface must have a consistent smooth film), which requires the film not to react with the raw materials, but also to have a certain adhesion to the mold, and at the same time, it has a certain flexibility. Effective demoulding material (usually inert material) is evenly sprayed on the mold through the medium (water), and a smooth film is formed after the medium (water) volatilizes, so as to exert the demoulding effect.
The performance characteristics of water-based mold release agents are as follows:
1. This product is a high-concentration water-based environmental protection product, which is smooth, isolated, demoulded, and resistant to high and low temperatures;
2. No corrosion to the mold after use, no transfer to the finished product, easy to process;
3. Easy demoulding, high dilution ratio, low cost of use and good effect;
4. It can improve the lubricity between the mold and the polymer, and there is no scaling on the surface of the mold, which is easy to clean.
Disclaimer: The picture materials and articles on this platform come from the Internet, so the copyright belongs to the original author. If there is any infringement on your copyright and interests, please contact us, we will apologize and delete it quickly. Article source: Internet
Latest news
- The Combination and Foaming Process of
- Famous tire enterprise with multiple d
- Ministry of Commerce Initiate a final
- The Effect of Carbon Black on the Cutt
- Stop work orders encounter rising pric
- Lanzhou Petrochemical's carboxylated n
Contact us
- ADD: Room 4210, CEC Business Hall, No. 121-4, Nanjing South Street, Heping District, Shenyang
- TEL: 13644907299
- FAX: 024-25361668
- E-mail: boss@long-green.cn
> Company new