PLEASE READ ABOUT TOOLING SOLUTIONS IN THE NEXT CHAPTER.
THERMOSET POLYESTER RESINS, HARDENERS, ADDITIVES
THERMOSET RESINS, HARDENERS AND CURING ADDITIVES
Unsaturated polyester resins
Unsaturated polyester resins are thermosetting resins made when glycols and saturated or unsaturated dicarboxylic acids combine to form polyester. The final combination is created by dissolving the resultant resin, which is a solid polymer at room temperature. The solvent used is often styrene, which is unsaturated and reactive.
By adding organic peroxide, which acts as an initiator in the crosslinking reaction, a complex three-dimensional network is created, creating a solid irreversible state.
In order to create polyester resins, Bang & Bonsomer togerher with Polynt produces a number of anhydrides (such as phthalic and maleic anhydride) and dicarboxylic acids (such as fumaric acid). Using these raw materials and the solid formulation expertise it has accumulated over the years, we have created the following families of resins.
Epoxy resin and an unsaturated monocarboxylic acid react to create vinyl ester resins. A reactive monomer, like styrene, is used to dissolve the resulting polymer, creating a solution that can be used and hardened like normal polyester resins.
Because of its advantageous combination of good mechanical qualities, high thermal deflection temperature, and resistance to corrosive attack from a wide range of chemicals, polynt vinyl ester resins are utilized in high performance composites.
These resins can be produced for infusion, lamination, and filament winding and are available un- or promoted.
Gelcoats and Topcoats
A flexible and robust main layer used in the creation of composite parts is called a gel coat.
Most Gel Coats are applied as in-mold coatings, which is the first step in the creation of composite parts.
Throughout the remaining stages of manufacturing, in-mold gel coats shield the mold from abrasion and chemical attack and offer a releaseable covering to facilitate de-molding operations.
For composite parts, Gel Coats frequently serve as the outer coating, giving the part both color and texture.
They can have a variety of appearances, from transparent tints that let you see through to pigmented coats that can be combined with an infinite number of colors.
Moreover, they shield the components from corrosive chemicals, moisture, and the elements.
SMC, BMC compounds
SMC and BMC are thermoset composite materials mainly composed of unsaturated polyester resins, mineral fillers, reinforcing fibers and additives.
BMC and SMC can be moulded by hot plate technologies such as compression moulding, injection and transfer.
During the moulding, due to the temperature and pressure, a crosslinking reaction occurs and the material takes the shape defined by the moulds geometry. Demolding and deburring are the final stage of the process.
The Polynt laboratories’ experience and expertise allow us to customise products to specific customer needs.
SMC (Sheet Moulding Compunds)
SMC are composite materials reinforced with glass or carbon fibres, lengths range from 12mm to 50mm, they are produced as sheets of 1300 mm width and 2-3 mm thickness. SMC are particularly suitable for compression molding of flat medium-large sizes geometries.
The product can be packaged in rolls or in boxes as per the customers’ specifications.
BMC (Bulk Moulding Compounds)
BMC are composite materials reinforced with glass or carbon fibres, lengths range from 3mm to 24mm, they are produced as homogeneous bulk. BMC are particularly suitable for compression molding, injection and transfers. The product is packaged in 10-20 kg bags according to the customers’ requirements.
Compared to the more common thermoplastic polymers, the thermosetting compounds have superior technical characteristics and performance, such as, inter alia:
- high mechanical properties in terms of rigidity and impact resistance;
- dimensional stability at high temperatures, due to the intrinsic nature of the thermoset materials;
- fire resistance, halogen-free materials filled;
- chemical and weathering resistance, especially formulated for outdoor applications;
- high quality surface “CLASS A” for automotive and transport industry.
The parts made with traditional materials, such as steel, aluminium and concrete, have a high environmental impact in terms of energy consumption, raw materials and carbon dioxide emissions. For these reasons, SMC and BMC are the best answer to today’s needs:
- weight reduction of the component with a consequent significant decrease in fuel consumption and CO2 emissions;
- reduced processing following steps such as drilling and welding;
- the thermosetting compounds are sustainable and recyclable through co-processing in cement kilns in compliance with the European Waste Framework Directive (WFD) 2008/98/EC.
Bang & Bonsomer works closely with one of the world leading chemical companies Mäder Group to offer fire-retandant thermoset coatings, resins and gel coats.
Total EN 45545 Solutions for Flame retardant Composites: Gel- & Topcoats, Resins and Coatings
Mäder develops and produces coatings, resins and gelcoats on their own
This allows fast customer oriented developments which fulfill as systems the various requirements.
R118 compliant flame retardant composite solutions: Gelcoats, Topcats and Resins
Mäder develops high value-added products for the transport sector, in particular for buses. The solutions offered are characterised by ease of use and fire/smoke protection in accordance with the R118 standard. They can be used for many interior and exterior parts.
We work with Arkema to provide our clients with suitable peroxide solution.
Epoxy Resins and Hardeners
The family of basic elements or dried end products known as epoxy includes epoxy resins. The collection of reactive prepolymers and polymers known as epoxy resins, commonly referred to as polyepoxides, include epoxide groups. Epoxy is another name for the functional group made up of epoxides. An oxirane is the term given to an epoxide group by the IUPAC.
Epoxy resins can react (cross-link) with a variety of co-reactants, such as polyfunctional amines, acids (including acid anhydrides), phenols, alcohols, and thiols, as well as with themselves through catalytic homopolymerization (usually called mercaptans). The cross-linking reaction is frequently referred to as curing, and these co-reactants are frequently referred to as hardeners or curatives.
A thermosetting polymer is created when polyepoxides react with one another or with polyfunctional hardeners. This polymer frequently has good mechanical properties and great thermal and chemical resistance. Metal coatings, electronics/electrical components/LEDs, high tension electrical insulators, paint brush manufacture, fiber-reinforced plastic materials, and structural and other adhesives are just a few of the many uses for epoxy.
Bang & Bonsomer offers a wide portfolio of epoxy resins and hardeners together with Entrophy Resins, Pro Set, West Systems and Elantas.
Read more about our products here:
Additives for thermosets
Accelerators and Inhibitors
A substance that, when combined with a catalyst-catalyzed resin, will accelerate up the chemical reaction between the two, either in the polymerization of resins or the vulcanization of rubber. also referred to as “promoter.” Diethylaniline, cobalt naphthana, and cobalt octoate are a few examples.
The cross linking procedure that cures a thermoset resin is started and controlled by initiators, catalysts, and inhibitors.
With thermoset resins, initiators, also known as catalysts, are employed to produce the curing (molecular cross-linking) process. In a variety of room temperature curing molding applications, methyl ethyl ketone peroxide (MEKP) and benzoyl peroxide (BPO) are employed in different formulations. There are more initiator formulations that are heat activated or have certain curing properties.