Prepreg, you may have heard of it or maybe you are searching for it. It is a high-tech reinforcement fibre that is widely used in the automotive and aerospace industries. In this article we dive into the world of prepreg, discuss the advantages and disadvantages, the applications and the differences with traditional reinforcement fibres.
Prepreg is an abbreviation of "pre-impregnated fibres", which means that the fibres are already impregnated with a resin. This material consists of a reinforcing fibre, such as carbon fibre, fibreglass or aramid (kevlar), that is already impregnated with a thermosetting resin, usually epoxy. The resin is partially cured so that the material is still flexible and easy to handle before it is fully cured at elevated temperatures.
The prepreg production process starts with impregnating the fibres with resin. After this, air bubbles are removed from the laminate using rollers to create a bubble-free product. This combination is then cooled and stored at low temperatures. Low temperature storage is very important to prevent the resin from curing prematurely. Once you are ready to use it, remove the prepreg from the cooler and process the material as desired, after which it cures at elevated temperatures (often in an oven or using an autoclave).
Prepreg is widely used in sectors where strength and weight are of great importance. In aviation, prepreg is often used for aircraft parts (such as wings and fuselage structures) because of its high strength and low weight. It is also a widely used product in the following industries:
The high-tech laminates are not used in various sectors for nothing. Prepreg has many advantages, such as:
The Prepreg material is flexible and easy to cut and shape before it hardens. Very useful for complex shapes. An additional advantage is that you work 'clean'.
In addition to the advantages of Prepreg, there are of course also properties that can be perceived as disadvantageous, especially for do-it-yourselfers.
Although Prepreg offers many advantages, this product is not available at Polyestershoppen. Prepreg is not accessible to every do-it-yourselfer. That is why we have not included it in our range. Fortunately, there are other methods to process composites. Three popular alternatives are vacuum injection, wet bagging and hand lay-up. These methods require no or less advanced equipment and are much more accessible than Prepreg!
Hand lay-up is the most traditional and simple method of making laminates. In this method, the resin is applied to the reinforcement fabric by hand and then placed in the mould. Although this method requires less complex equipment and is less expensive, it can be more difficult to laminate complex shapes and achieve an ideal resin/fibre ratio this way.
In vacuum injection, dry tissue is placed in a mould and then covered with a vacuum bag. Resin is then injected into the mould under vacuum, which completely impregnates the material with minimal air entrapment. This method offers high fibre volume and excellent mechanical properties, very similar to prepreg. For this method, you need a suitable vacuum pump, epoxy resin, reinforcement fibre and some vacuum materials.
Wet bagging is similar to vacuum injection, but instead of injecting the resin, the fabric is manually impregnated with resin before the vacuum is applied. This technique is simpler and less expensive than vacuum injection but still provides good results with less air entrapment and better fibre volume than hand lay-up.
There are a number of differences between Prepreg and traditional fibre reinforcements (such as carbon fabric and glass fabric)
| Prepreg | Traditional reinforcement fabrics |
| Pre-impregnated | Resin must be impregnated |
| Relatively expensive | Cheaper alternative |
| Store in a cooled place | No storage requirements |
| Oven/autoclave curing | Curing at room temperature |
| Optimal resin-fibre ratio | Optimal resin-fibre ratio to be determined by yourself |
As you may have read earlier in this article, Prepreg is not for sale at Polyestershoppen. However, Polyestershoppen is a specialist in the field of other reinforcement fabrics. If you are looking for high-quality materials for your next DIY project, you have come to the right place. We offer a wide range of top-quality glass fabrics, carbon fabrics and aramide fabrics, suitable for various applications.
Do you have questions about the right reinforcement fabric for your project? Our expert support team is ready to help you choose the right material and answer all your questions. Whether you are a beginner or an experienced professional, we will make sure your project is a success!
Do you have a specific question? Call one of our specialists for free advice +3185 0220090
