Release agents are preparations used to release elements from moulds.
Their function is to reduce the adhesion of the material to the mould, formwork or any other element. These agents are used as sliding additives to prevent the adhesion of polymer, ceramic and concrete products. They are most often used in the form of oil-based mixtures applied to the surface of the mould. The release agents enable easy release of the shaped element without damaging it and also protect the moulds and formwork from damage. They are used in the rubber and plastic industry, as well as in the construction industry.
Most of us have probably already encountered this term, however, not everyone can characterise the very wide group of compounds belonging to anti-adhesive agents. So what is an anti-adhesive agent? The term is used to refer to substances that create sort of a barrier between the profile of a specific shape or element, and the surface of the part being moulded, which makes the replication simpler and faster. It is worth taking a closer look at these compounds because many industrial branches would not exist without the use of anti-adhesive agents, and the growing demand on the market means that manufacturers offer increasingly cleaner, safer, and, most importantly, environmentally-friendly preparations.
What is anti-adhesion?
Adhesion is when two surfaces of materials, different bodies (solid or liquid), cling together or connect. It occurs as a result of intermolecular attraction. Anti-adhesion, on the other hand, is an opposite process to adhesion and consists in separating the surfaces of two adherent bodies, as a result of using separatory substances, i.e., anti-adhesive agents.
Most of the commonly available anti-adhesive agents are based on silicone, but there are also silicone-free versions of the currently used preparations. Silicone plays the role of a lubricating ingredient. Silicone is used in approximately 70% of manufacturing processes. It is chemical- and heat-resistant, and flameproof. Nevertheless, silicone tends to transfer to the surface of the moulded element, from where it is difficult to remove it. In such cases, it will be more favourable to apply silicone-free preparations. They are based on waxes, glycols, or plant-derived oils. They are characterised by slightly worse parameters as compared to their silicone-based counterparts, but they do not contaminate the surface of the material being moulded.
Anti-adhesive agents can be divided into two categories: those that form a layer separating two adherent surfaces, and agents that enter a chemical reaction with the material that they are placed within. As a result of this chemical reaction, the process of adhesion is prevented.
When should anti-adhesive agents be used?
An appropriately selected anti-adhesive agent reduces the bonding between two adhering materials. Professional products of such type may help increase the effectiveness and service life of profiles and moulds. The number of deficiencies and defects that can significantly hinder achieving satisfactory results is reduced.
The benefits of anti-adhesive agents:
increased number of moulds between applications,
increased number of moulding cycles for one working shift,
a small amount of the preparation is usually needed for a single application, and, therefore, more environment-friendly working conditions and lower stock demands,
reduced waste, e.g., scrap.
Method of use of anti-adhesive preparations
Anti-adhesive agents most commonly come in the form of aerosols and liquids. There are diverse methods of applications, which naturally depend on the form, consistency and adhesiveness of the product we are dealing with. Let’s follow the instructions of use proposed by the manufacturer.
Products in the form of aerosols are best sprayed, if possible, on the previously cleaned surface. While dispersing the product, it is worth remembering to spray the surface evenly. If the surface that needs to be covered with an anti-adhesive preparation is large, it is worth considering the use of nozzles or special atomisers.
Preparations in the form of liquids can be successfully dispersed with the use of a brush or a roller. This is cost-effective on small elements. For large surfaces, it is best to use professional atomisers or nozzles, similarly as in case of anti-adhesive preparations in the form of aerosols.
While using anti-adhesive agents, use an amount that will guarantee the preservation of the mould and its easy separation. It is not advised to use the product in excessive amounts because the overabundant layering of anti-adhesive preparations will not cause any extra benefits, but may only drastically increase the costs. The currently marketed anti-adhesive agents have one common feature: the thinner the layer applied, the better.
How do you select an appropriate product?
Using anti-adhesive agents considerably helps ensure the top quality of the manufactured goods. Since the preparation may affect the qualities of the very element, appropriate selection and application are of key importance for the satisfactory final effect. The optimal anti-adhesive agent prevents damage to parts, and does not accumulate on the mould or the part being moulded. It ensures the good condition of the mould in a long run. This makes the manufacturing process faster, more cost-effective and thus more profitable.
So how do you select an appropriate product? It is worth taking into consideration the few most important aspects:
The process and conditions the structure will be subjected to. One should take into account e.g., whether the anti-adhesive agent will bear the working conditions or whether its application will not conflict with the subsequent steps such as painting or gluing.
An important factor is price. You should consider the influence of the price on the unit cost of a specific element, and any extra costs should be taken into account. While considering the purchase of an anti-adhesive agent, it is particularly crucial to be guided by operating costs rather than the primary price of the product, because it is the aspect that matters from the long-term perspective.
Another aspect to be considered is the process duration, i.e., the total amount of time needed for the hardening of the end product.
Anti-adhesive agents for concrete
Anti-adhesive properties are now used in the construction industry. They are also called concrete mould agents or oils. They are classified as follows:
oily, labelled with the symbol (O),
emulsive, labelled with the symbol (E).
An appropriately selected product creates a separating layer between the concrete and a shuttering profile, which is usually a reusable mould. If anti-adhesive agents are skipped, hardened concrete will tightly adhere to the profile. This is because cement, which is a binder in concrete, as a result of transformations and reactions, will form calcium hydroxide, which apart from caustic properties, is also responsible for reactions on surfaces. Anti-adhesive coatings not only facilitate work related to concreting and boarding, but they also make the concrete surface smooth and elastic. Any possible damage to concrete usually requires fixing to ensure the designed durability of the construction. In the case of architectonic concrete, where specific visual effects are expected, this may lead to its disqualification. Read also about concrete additives and admixtures.
Anti-adhesive agents for plastics
The construction industry, and concreting in particular, is not the only branch in which anti-adhesive agents are successfully used. By and large, any specialisation or technological undertaking where it is necessary to reproduce the shape of specific goods, e.g., made of glass, ceramics, as well as plastics, faces the problem of separating the moulded shape from the profile.
In order to separate the mould from the profile during the plastics and elastomers manufacturing process, with the use of the injection, vacuum, and extrusion methods, as well as when forming and welding plastics, such anti-adhesive agents such as aroma-free hydrocarbon fractions, polyamides or waxes in the form of suspensions are used.
Preparations with anti-adhesive properties for polymer technologies should meet the following basic requirements:
create an even and durable layer,
not accumulate on the surface of the profile,
prevent any possible strain cracks,
withstand the high temperature that the plastics are subjected to,
seal the profile.
Plastics intended for the production of toys or food packaging need to fulfil rigorous requirements and the same applies to the anti-adhesive agents used for their production.
PCC Group Range
Some industries where anti-adhesive factors play a critical role are aircrafts and aviation, motorisation, metalworking, rubber moulding, composite moulding and many more. Many of the technological processes are hard to imagine without anti-adhesive agents. Here is how PCC Group responds to the demand with their extensive offer. Exemplary agents that can be purchased from PCC Group are:
ROKAmer PP450 is a polyol. This preparation belongs to polymer compounds, featuring a dual-function structure, thanks to the presence of two hydrophilic groups in a molecule. It is an antifoaming, cold-water soluble product. The appealing advantage of the product is undoubtedly the high concentration of the active substance, which activates the effect of the anti-adhesive agent. ROKAmer PP450 is a universal product, whose application is safe and the substance is biodegradable.
It is a complex mixture of chemical compounds. It serves as a mineral oil emulsifier, which is used, among others, in the metallurgical industry. It is free of such substances as nitrites, phenols, and any compounds of chlorine and barium, which are harmful for health. The product comes in the form of a clear liquid with lubricating properties and is used in the metallurgical and construction industries.
Soon consumers will have the chance of purchasing the preparation called POLIkol 8000, belonging to the group of polyethylene glycols. This product is available as a solid, in the form of flakes in the colour range from white to bright yellow. Such formula of the product may be a considerable convenience in terms of dosing and storing. Moreover, the product is safe, toxin-free, and causes no irritation to the skin. POLIkol 8000 will successfully find applications during the manufacture of packaging, in the construction industry, or in ceramics production.
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