Properties | PET (Polyethylene Terephthalate) | PP (Polypropylene) |
Flexural strength (MPa) | 2,400 - 4,100 | 1,000 - 1,800 |
Weight ratio (g/cm3) | 1.38 | 0.91 |
Transparency | Excellent | Good |
Barrier properties | Good oxygen and carbon dioxide barrier | Poor barrier properties |
Chemical resistance | Good resistance to acids and bases | Good resistance to solvents and chemicals |
Electronic insulation | low dielectric constant and low dissipation factor | low dielectric constant and High dissipation factor |
Recyclability | Widely recyclable | Recyclable |
*The above is the reference value; it may vary depends on the specific material.
Flexural strength, also known as stiffness, is a measure of a material's resistance to bending. When comparing PET and PP in terms of flexural strength, PET is generally stiffer and has a higher flexural modulus than PP. This means that PET can withstand greater loads before bending or breaking.
The flexural strength of PET and PP also depends on other factors such as the thickness of the material and the manufacturing process. In general, PET is a more rigid and stiff material compared to PP, which has a lower flexural modulus and is more flexible.
The TOYOBO KAMIHSINE® series provided by the company has the physical advantages of PET at the same time. with the weight ratio down to 1.0; it has the advantages of PET's straightness, cushioning properties in addition to PP's softness and low production cost.
----- 1. Label manufacturing Compared with PP, PET is usually considered a superior choice for label manufacturing. First of all, PET has better clarity and a smoother surface, which makes it an ideal choice for printing high-quality images and text. In addition, compared with PP, PET has better dimensional stability and higher stiffness, which ensures that the label retains its shape and does not warp or curl during the label process. PET also has excellent moisture resistance and chemical resistance, making it suitable for use in harsh environments. In addition, PET has better tensile and tear strength than PP, which ensures that the label can withstand handling and transportation without tearing or wear. PET also has excellent heat resistance, making it suitable for product labels that require high-temperature processing or disinfection.
2. Electronic insulation characteristics
PET is a popular choice for electronic insulation due to its excellent media performance, including high resistance and low media loss. The low dielectric constant and low dissipation coefficient of PET make it very suitable for high-frequency applications such as electromagnetic interference (EMI) shielding and radio frequency (RF) transmission.
(For more details on Dk/Df value; please refers to our Knowledge articles.
[!] Measuring dk/df and its requirement in RFID etc's application.
On the other hand, compared with PET, PP has a relatively low dielectric constant and a high dissipation coefficient, which makes it less suitable for electronic insulation applications that require high electrical performance.
The End-user side will prefer PP mainly because compared with PET, PP has impact resistance, softness and low cost derived from low specific gravity. Therefore, it is adopted by the industry for a large number of uses such as OPP. In contrast, heat resistance, electronic insulation, and anti-chemical alcohol needs are often limited by the limitations of the material itself.
In general, the excellent physical performance of PET makes it a good choice for high-end and special label manufacturing, especially for applications that require high-quality printing and excellent dimensional stability.
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For more information in related to TDS, physical properties, etc. of KAMIHSINE®,
please contact C&T.
References: McKeen, L. W. (2013). Polypropylene: The definitive user's guide and databook. Elsevier.
Schmidt, R. C. (2019). Guide to polyethylene terephthalate (PET) recycling. Springer.
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