Technical Information

Types of Bottles

Types of Plastics

TOYO SEIKAN manufactures and sells various types of plastic bottles and related products.

  • 1. Major materials are polyolefin such as polyethylene and polypropylene, and PET (Polyethylene Terephthalate).
  • 2. Single and multiple layered bottles, and bottles and tubes with various shapes and functions are offered.
  • 3. Widely used in the areas of food and daily commodities and for medical purposes.
Features of Major Plastics Used for Containers
[Polyethylene (PE)]

Polyethylene (PE) is a crystalline plastic produced from the polymerization of ethylene.    
PE has the features of (1) lower specific gravity, (2) chemical stability and water and chemical resistance, (3) excellent strength and flexibility (soft and bendable) and (4) high formability.
PE is classified into High Density Polyethylene (HDPE or PE-HD), Low Density Polyethylene (LDPE or PE-LD) and Linear Low Density Polyethylene (LLDPE or PE-LLD). 
HDPE (PE-LD, High Density Polyethylene): Has excellent water and chemical resistance and relatively high resistance to hot and cold temperatures.
LDPE (PE-LD, Low Density Polyethylene): Has excellent flexibility, and water and chemical resistance.
LLDPE (PE-LLD, Linear Low Density Polyethylene): Has higher tensile strength and cold temperature resistance.

(Note) Abbreviations such as PE-HD, PE-LD and PE-LLD are defined under JIS K6899-1:2006 (amended from JIS K6899-1:2000) to conform to the international standards after a comparison between JIS and ISO standards. Abbreviations like LDP (Low Density Polyethylene), HDPE (High Density Polyethylene) and LLDPE (Linear-Low Density Polyethylene) had been used before.
Please see the JIS easy reference site (

[Polypropylene (PP)]
Polypropylene is a plastic made mainly of propylene, and has superior rigidity, heat resistance, and water and chemical resistance. Compared with PE, PP has better high-temperature resistance but inferior low-temperature resistance. Ethylene copolymers such as random PP and block PP are used for packaging depending on their features.

[Ethylene-Vinyl Alcohol Copolymer (EVOH)]
EVOH has an excellent gas barrier performance to oxygen and also provides high flavor protection and high oil and abrasion resistance. This material is used for lamicon bottles developed by Toyo Seikan as well as cups and tubes.

[Polyethylene Terephthalate (PET)]
PET is a kind of polyester produced from the polymerization of terephthalic acid and ethylene glycol. Compared with polyolefin, it provides higher heat resistance, transparency and strength, and can be used for various purposes. A PET bottle for beverage is a typical package.

[Plant-Derived Plastics]
To globally reduce environmental burden, we have conducted R&D to increase use of plant-derived plastics in packaging. Typical materials include polylactic acid (PLA) derived from corn which will be converted into a low-molecular through hydrolysis process and finally decomposed into carbon dioxide and water through microbial action.
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