to the part manufacturing process, through a heated press, autoclave or oven, for example. Time, temperature and pressure are determined according to resin type and system.
Thermosetting resins do not return to their original state even if heated, so they are called thermoset. These resins lose their crystalline structure and mechanical properties if subjected to a temperature higher than their TG (glass transition temperature). That is why parts made with thermosetting resins cannot be cast or remolded.
Unlike thermoplastics, thermoset prepregs have a predetermined shelf life and must be kept in a refrigerated chamber for up to 1 year depending on the type of resin, they are cured by thermal induction, commonly using the “vacuum + autoclave” system, but we cannot forget the artisanal lamination methods with prepreg, which also work very well when molding with or without vacuum + heated oven; however, the mechanical properties are high when the lamination method is refined. Its thermal properties vary between 80ºC and 250ºC (176ºF and 482ºF).
There are several examples of the use of thermoset prepregs in the Brazilian industry, such as for the manufacture of aircraft and competition vehicles. The national prepreg is a reality and with each passing day it is becoming more routine in the life of transformers of parts in advanced composite materials.
Applications: Cars and heavy vehicles, Agricultural machines, Aircraft, Pipes, Wind blades (SparCap), and composites in general.
Thermoplastic Prepregs:
Texiglass Thermoplastic Pre-pregs are available in fiberglass and carbon fiber and can be supplied in fabrics or pre-consolidated sheets (plates) of continuous fibers.
The material is recyclable and does not need to be transported or stored in a cold room.
As it is a thermoplastic material, that is, it can be melted, this type of pre-preg, when heated, returns to its original state and can be softened, remolded, reworked and recycled easily.
The two main polymers developed are PA6 and Acrylic and are applied in heated pressing systems with subsequent cooling, ensuring processing cycles of less than 30 minutes.
In addition to the advantages of handling and indefinite useful life, thermoplastic prepregs provide a high production rate of structural parts with low weight and challenging structural requirements, being able to manufacture up to 1 part every 5 minutes in the stamping process.
Applications: Cars, sporting goods, security, etc.