Because of its strength, durability, and versatility, polyester resins are used extensively in many different industries. However, these resins must go through a procedure known as polymerization in order to reach their full potential. This is where hardeners come into play; they are an essential part of the process that turns liquid resin into a sturdy, solid substance.
To give polyester resins the desired qualities, proper hardener use is crucial. Poor outcomes could result from the resin remaining tacky, weak, or not properly cured without adequate hardening. You can make sure your resin projects are sturdy and long-lasting by knowing the proper methods and ratios.
You can use this guide to learn the necessary procedures and advice for using hardeners with polyester resins. Regardless of your level of experience, these guidelines will assist you in achieving the best possible polymerization, which will produce a high-quality finish for your projects.
Everything will be covered, including choosing the appropriate hardener, combining it with the resin, applying the mixture, and curing it. With these useful tips, you’ll be ready to work with polyester resins with assurance and produce works of art that are both exquisite and long-lasting.
| Instruction | Details |
| Preparation | Ensure the surface is clean and dry before application. |
| Mixing Ratio | Mix 2% hardener with the polyester resin. |
| Stirring | Stir thoroughly to achieve a uniform mixture. |
| Application | Apply the mixture evenly using a brush or roller. |
| Curing Time | Allow 24 hours for complete curing at room temperature. |
| Safety | Wear gloves and work in a well-ventilated area. |
| Storage | Store unused hardener in a cool, dry place. |
- Curing – physics and chemistry of the process
- At room temperature
- Proportions of initiators and accelerators
- Rejection at elevated temperature
- Causes of incomplete curing
- Video on the topic
- Hardener
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- How to breed polyester resin. In what proportions
- Polyester resin what is it for what is used
Curing – physics and chemistry of the process
Paintwork material curvature is an action that causes liquid substances to permanently change into solid forms. Conventional LCMs gain their final physicochemical properties when they evaporate from them using liquids such as water and solvents. However, this process is far more challenging for polyester-based resins, as they can only become harder through a chemical reaction. The composition becomes more stable and polymerizes when it comes into contact with specific ingredients.
Substances with additives, such as catalysts, accelerators, and initiators, are used for this purpose. Different groups of funds are introduced into resins in a specific order, and mixing them together is not permitted. The temperature of the resin can rise significantly after adding components, occasionally rising above +100 degrees.
In order to contribute to the polymerization of the resin, the hardener initiates the reaction that results in the material becoming stained. Accurate proportions and skill in resin breeding will enable you to produce high-quality work. Which are employed as cements? These are the drugs that are most in demand:
- carboxylic acids;
- Diamines of carboxylic acids;
- Carboxylics of carbon acids.
The polymerization process is greatly accelerated by the addition of hardeners. The latter is triggered by chemical reaction-generated radicals. The resin will turn viscous, cease to flow, and enter a gel state as soon as the inhibitor is used up. Eventually, after hearing finally, the gel will "freeze," taking on the properties of rubber.
At room temperature
It is advised to breed at temperatures higher than +23 degrees. "Butanoks," a cyclohexanone peroxide solution, is used as the initiator (a part of the hardener). An octiata cobalt solution is applied to a styrene (OK) as an accelerator. An accelerator that contains cobalt naphthenate (UNK) can be used in its place.
The following phases are included in the work:
- to measure the right amount of polyester resin and accelerator;
- Connect the components;
- knead the composition well;
- Add the initiator, mix again;
- carry out molding before gelatinization (after 50-120 minutes, depending on the type of resin);
- If the beginning of gelatinization is required faster, you can increase the temperature in the room;
- hardening usually occurs in 12-24 hours.
The process can take longer than 14 days, and the strength increase will be more gradual at standard room temperature. Within an hour, heat treatment at +100 degrees will shorten this time to several days.
Proportions of initiators and accelerators
To what extent should resin be hardened? Three elements are needed for polymerization, as was previously mentioned: the resin, accelerator, and hardener (initiator). The only way to calculate the ratio is to follow the guidelines that each manufacturer affixes to the product. The required volume of the components can be independently determined in the future; this will be evident based on the rate and caliber of curing.
Only the necessary number of components should be applied because the resin viability is not maintained for very long after the hardener is introduced. The remainder will perish forever. Starting with a small volume—less than a liter—is preferable. Each substance is added, and then the mass is carefully mixed to ensure that no additional air bubbles form. It is advised that you have two minutes to complete this.
Rejection at elevated temperature
Higher temperatures than those found indoors hasten the resin curing process. It is preferable to use 50% benzoid peroxide as an initiator in the form of a dibenzoate solution. Typically, 2–3% of the resin weight is sufficient. Following the administration of the solution, the mass is kneaded and heated to a temperature of +100… +30 degrees. Using a wild peroxide solution raises the temperature to +160 degrees.
For polyester resins to polymerize and produce strong, long-lasting finishes in a variety of painting and coating applications, hardeners are a necessity. To ensure the best possible curing and performance, this article offers clear instructions on how to choose the appropriate hardener, mix it with the resin correctly, and apply the mixture effectively. You can guarantee professional-grade quality and resilience in your polyester resin projects by adhering to these steps.
Causes of incomplete curing
Occasionally, the resin may not reach the appropriate hardness at the end of the process. The strength is low and the surface is still sticky. Raising the temperature to +100–+130 degrees makes it simple to remove incomplete curing if it is only temporary. Constant incomplete stagnation will not work to remove it; instead, the mass will become spoiled. How can one prevent these issues? The following are the principal suggestions:
- Do not be engaged in curing at a temperature of less than +23 degrees, moisture more than 65 %;
- Do not change the proportions of components recommended by the manufacturer for a specific polyester resin;
- exclude the penetration of pollutants, impurities, use only clean dishes.
The last point is particularly crucial to remember because even minute amounts of fats, water, and other substances interfere with the polymerization process. The quality of the mixture and contaminated air, particularly with phenol vapor, have little effect on it. After the work is finished, a film covers the resin’s surface. Because of this, the mass won’t be able to touch the air.
The process of polymerizing polyester resins with hardeners is simple but essential to getting the right final product in terms of strength and durability. You can make sure that the resin sets correctly and provides a sturdy and dependable finish by closely adhering to the instructions regarding mixing ratios, temperature, and curing times.
Precise measurement and thorough mixing of the hardener with the resin are crucial. Weak spots or a tacky surface can arise from incomplete polymerization caused by inaccurate measurements or inadequate mixing. The outcome is also greatly influenced by observing the recommended working conditions, which include humidity and ambient temperature.
Prioritizing safety is crucial when working with resins and hardeners. Health risks and accidents can be avoided by wearing the proper protective gear, working in a well-ventilated area, and adhering to safety regulations. Over time, the efficacy of these materials can be preserved by storing them properly, away from moisture and direct sunlight.
You can get the best results possible from your polyester resin projects if you follow these instructions. The proper understanding and application of hardeners will result in strong, long-lasting, and superior finishes, whether for DIY projects or industrial applications.
