In the early days, the main beam of wind turbine blades mainly used processes such as glass fiber injection or carbon fiber injection, carbon fiber prepreg, etc. However, with the increase of blade size, the cost of raw materials significantly increased, and the structural performance of injection glass fiber was limited; Meanwhile, the strict process requirements of traditional process methods in blade manufacturing and application limit their application in large blades. The most effective solution currently is to use pultruded plate composite materials, which have been widely designed and used by blade factories for the main beam of blades in the past two years.

The main problems with the material of wind turbine blade extrusion plates are:

Due to the inherent process characteristics of the pultruded plate material, there may be some defects during the production process, which directly affect its application in wind turbine blades.

1、 Dimensional deviation:

1) The meter meter has errors;

2) The scheduling mixed loading records are not standardized, and the lengths of the two rolls are different;

3) Discovered issues after rewinding, and recorded non-standard records after re cutting.

2、 Stripping cloth inclusion:

1) The pre drying temperature of the demolding cloth is too high, resulting in the demolding cloth sticking too tightly to the board;

2) Uneven tension at the edge of the demolding fabric with ruffled edges;

3) Mismatch between the position of the tooling guide rod and the tearing torque parameters for removing the demolding cloth.

3、 Bubble/semi dry yarn: demolding fabric has a high moisture content.

4、 Cracking:

1) Uneven stress during the winding/packaging process;

2) The cutting knife is not sharp.

5、 Surface pollution: pollutants accumulate during the operation of the protective plate of the pultrusion plate winding machine.

6、 Rich resin: Uneven yarn arrangement during pultrusion process.

7、 Plate tear:

1) During the heating process of pultrusion plate forming, it is difficult to tear off due to the influence of thermal expansion and mold extrusion;

2) Factors affecting the angle, speed, and size of the applied force when the equipment is tearing off the demolding cloth.

8、 Color difference of pultruded board: mixed use of different batches of yarn.

The pultrusion plate production process is a continuous method of producing composite material plates. Any errors in certain aspects such as personnel operation level, equipment maintenance requirements, raw material re inspection upon entry, environmental temperature/humidity, and dust control measures can lead to the occurrence of quality problems in batch products, and must be taken seriously.