**3.2 Experimental apparatus**

Ultraviolet light has a wavelength of 10 to 400 nm. Among such ultraviolet rays, the part with a wavelength of 10 to 300 nm is absorbed by the atmosphere. The ultraviolet rays with a wavelength of 300 to 400 nm have a destructive effect, and their light energy is very large.

Various plastics are affected in different wavelength areas. The most influential wavelengths are 325 nm for polyester; 318 nm for polystyrene; 300 nm for polyethylene; 310 nm for polypropylene; 310 nm for polyvinyl chloride resin; and 322 nm to 364 nm for vinyl chloride-vinyl acetate copolymer [53].

UVA-340 can perfectly simulate the sunlight spectrum in the critical shortwavelength range, and the wavelength range is 315-400 nm. Its luminescence spectrum energy is mainly concentrated at the wavelength of 340 nm. UVA-340 fluorescent ultraviolet lamp can well simulate the short-wave ultraviolet (<365 nm) part of the spectrum. UVA-340 nm lamp was used in this study, with power 100w, lamp intensity: 30 mW/cm2 , made by Shenzhen Anhongda Optoelectronics Technology Co., Ltd.

**Figure 3.** *Sectional view of the test bench.*


### **Table 1.**

*Samples for aging test.*

As pyramid skylight has relatively higher Standard Visible Transmittance (Tvis) average than the most of other skylight [54].

Based on this, we choose two identical pyramid skylight structures (single-glazed with clear glass) as the experimental platform to receive the light source as shown

*Accelerate the Aging of Polymer as Energy-Saving Method Prior to the Pyrolysis Process DOI: http://dx.doi.org/10.5772/intechopen.99995*

in **Figure 2a** and **b**. Pyramid skylight was manufactured by Guangzhou Fineland Windows & Doors Co., Ltd.

A sample tray holder is placed in each pyramid skylight structure, and each sample tray is divided into multiple grids, which can separate different samples for simultaneous experiments, as shown in **Figure 3**.

### **3.3 Sample preparation**

Cut PP, PE, PS, EPS, Natural rubber raw materials to prepare two sets of identical samples. Each sample size is 50 mm × 40 mm, the average thickness is 4 mm. PP granules 6 kg (**Table 1**).
