As a new chemical material, silicone material is widely used as a release agent for products made of different materials and applications.
ONE. Thermoplastics
During the injection or extrusion process, the plastic melt contacts the mold surface, often creating negative pressure between the melt and the mold, or causing adhesion between the two due to physical adsorption or chemical bonding. The molding process for thermosetting plastics uses both pressure and heat, which exacerbates adsorption or adhesion between the molding resin and the mold, making it difficult to remove the finished plastic product from the mold.
In order to weaken the adsorption or adhesion between plastic products and molds, an additive that can form an effective isolation film is often used - a release agent. A release agent is an interface film layer used on the surfaces of two objects that are easy to adhere to each other, which forms an isolation between the adhesive and the adherend, thereby weakening the peeling force and making the product demolding easier and more effective.
There are many types of silicone-based release agents. They are classified according to the product characteristics as follows:
1) Silicone Oil-Based Release Agents: Release agents based on inert linear high-molecular-weight silicone polymers such as methyl silicone oil, methylphenyl silicone oil, and various modified silicone oils.
2) Solvent-Based Release Agents: Solutions prepared with the aforementioned silicone oils or silicone resins as the main component and organic solvents such as ethanol, toluene, and gasoline added.
3) Emulsion-Based Release Agents: Emulsions prepared with the aforementioned silicone oils or silicone resins as the main component and emulsifiers and water added.
TWO.Composite Materials
Release Agent Product Application Analysis
Composite materials, based on their raw materials, are primarily composed of fibers (carbon fiber, glass fiber), resins (epoxy resin, unsaturated resin, etc.), and auxiliary agents. Since insulator products are primarily made of epoxy resin, this has implications for composite material release, and therefore is categorized as composite material release.
In epoxy resin mold release, release agents are primarily based on a combination of silicone oil and silicone resin.
Glass fiber, made from glass fiber and unsaturated resin, is generally larger in size. Products are primarily based on a combination of silicone and fluorine-based products. Currently, the release agents on the market are primarily imported, though some can be replaced by domestic products.
Carbon fiber products have a wide range of applications but are niche, offering high added value, and customers primarily use imported release agents.
As the application scope and usage of composite materials expand, demand for composite material release agents is also increasing. Due to the impact of the trade war, downstream manufacturers are increasingly interested in domestic end-use products. However, due to the diverse raw material content and complex end-use products in the composite material market, it is difficult to cover them with a single product. Therefore, there is a market demand for high-performance raw materials.
THREE. Polyurethane
Polyurethane is a polymer with repeating urethane segments, produced by the reaction of isocyanates and polyols.
Polyurethane is currently widely used in shoe soles. Compared to ordinary rubber soles, polyurethane soles offer advantages such as lightweight and improved wear resistance. They are widely used in the production of casual shoes, athletic shoes, work shoes, sandals, travel shoes, men's and women's leather shoes, and protective shoes.
At the same time, polyurethane has excellent bonding properties with other materials, but this property is unfavorable in foam molding. In order to quickly and smoothly remove the product from the mold, a release agent must be used.
An ideal release agent should have the following performance characteristics: good thermal and chemical stability, no corrosion to the mold, no residual decomposition products on the mold surface; give the product a good appearance, do not affect the product's color, adhesion, paint resistance, etc.; minimize mold cleaning time; be non-toxic, safe, and easy to operate;
FOUR. Die-casting Applications
Die-casting is a precision casting method that uses high pressure to force molten metal into a complex metal mold. Because die-casting molds are precise and complex, and the molten metal is at a high temperature, a release agent is required during the molding process.
Therefore, an excellent die-casting release agent should possess the following characteristics: superior release properties; excellent wettability and spreadability; strong adsorption to the mold; reduced deposition on the mold surface; no reaction with the mold or product; excellent temperature resistance; no impact on subsequent coating and bonding; non-toxic, non-flammable, low-emission, and environmentally friendly.
As a compound, each component in the die-casting release agent formula impacts its overall performance:
