Tritan™ x Elastomer Welding/Two-Color Molding: Grade Selection Guide for Food and Medical Applications
Due to stricter BPA regulations, primarily in Europe, there is a growing shift in materials from polycarbonate (PC), a leading transparent resin, to BPA-free Tritan™. This article explains a technology that enhances the grip and sealing properties of Tritan™ using a "weldable elastomer" created through two-color molding. It provides an explanation of elastomers that weld to Tritan™, developed by Mitsubishi Chemical, and a grade selection guide. This is essential technical information for materials engineers aiming to balance BPA compliance with the development of high-value-added products.
Table of Contents [hide]
- 1.Features of Tritan™ that are valued in the market
- 1.1.Material properties and positioning as a "PC substitute"
- 1.2.Background of BPA regulations, primarily in Europe, and the expanding adoption of Tritan™
- 1.3.Reasons for increasing adoption in food and medical applications
- 2.Two-color molding with Tritan™ resin: "Weldable" elastomer for enhanced functionality
- 2.1.Image of high-performance enhancement through two-color molding (2K molding)
- 2.2.Details of the welding mechanism
- 3.Recommended grades for food containers/medical devices
- 4.Notes on Summary and Introduction
- 5.ReferenceURL
Features of Tritan™ that are valued in the market
Material properties and its positioning as a "PC substitute"
Tritan™ (Eastman Tritan™) is an amorphous polyester resin developed by Eastman Chemical Company. It is gaining popularity as a glass substitute, particularly in the food and medical fields.
Tritan™ has the following characteristics:
• High transparency: Light transmittance of over 90%, low haze, and an appearance similar to glass.
• Impact resistance: It has high impact resistance comparable to polycarbonate (PC), and is highly regarded for its resistance to cracking from drops and other impacts.
• Chemical resistance: It is said to have chemical resistance that can withstand the high temperature and detergent conditions of dishwashers, and heat resistance that can be used up to about 120°C, making it suitable for bottles and containers that are used repeatedly.
Due to these characteristics, it is positioned as one of the candidate materials to replace PC as a transparent, shatterproof, and reusable plastic.
The background behind BPA regulations, primarily in Europe, and the increasing adoption of Tritan™
Polycarbonate (PC) has long been a representative material for transparent, impact-resistant food containers and bottles, as well as for transparent, rigid resins in medical devices. However, concerns have arisen regarding the endocrine-disrupting effects of bisphenol A (BPA), one of its raw materials, and regulations have been strengthened, mainly in Europe. In Europe, the use of BPA in infant bottles and other products has already been banned, and in 2018, the transfer limit for BPA from food contact materials was significantly lowered.
Furthermore, with the adoption of Regulation (EU) 2024/3190 in 2024 and the entry into force in 2025, the use of BPA and other bisphenols in food contact materials is prohibited in principle, making it increasingly difficult to use polycarbonate (PC) in food contact applications.
In response to these stricter regulations, a shift towards materials with keywords like "BPA-free" and "PC alternative" is progressing, particularly in Europe, and Tritan™ is increasingly being considered as one of the options.
Reasons for increasing adoption in food and medical applications
Various explanatory articles and manufacturer information cite the following reasons why Tritan™ is chosen in the food and medical fields:
• Designed to be a resin that does not contain bisphenols such as BPA and BPS.
• Complies with food contact regulations from FDA, EFSA, etc., and is used in applications where safety is paramount, such as baby bottles and children's bottles.
• It combines a glass-like appearance with impact resistance that makes it less likely to break even if dropped.
• BPA exposure from medical devices is generally limited to a limited period (except in cases of continuous treatment such as hemodialysis), and therefore BPA is not explicitly regulated in the medical field. However, in cases where the impact is significant, such as in medical devices for infants and young children, alternative materials are recommended and therefore should be considered.
As the need for material replacement from PC increases, particularly in Europe, due to stricter BPA regulations, Tritan™ is attracting attention as a candidate material with its transparency, impact resistance, and BPA-free properties.
Two-color molding with Tritan™ resin: "Weldable" elastomer for enhanced performance.
Image of high functionality achieved through two-color molding (2K molding)
When bottles and containers are molded using Tritan™ alone, while transparency and impact resistance may be sufficient, actual product design can present challenges such as being "slippery," "increasing costs due to the need for separate sealing parts," and "difficulty in using adhesives for medical applications." To address these challenges, an approach that combines Tritan™ resin with a "weldable" elastomer using two-color molding to enhance functionality is attracting attention.
Tritan™ is an amorphous polyester resin with excellent transparency and chemical resistance, and is increasingly being adopted for food containers and medical devices.
Mitsubishi Chemical's Tefabloc™ TPC is a polyester-based thermoplastic elastomer designed for two-color molding and welding applications with polar resins such as Tritan™, achieving high fusion strength and a good appearance under appropriate molding conditions. Therefore, it can provide slip resistance, grip, and sealing properties without the need for additional adhesives or primers in applications such as integrated soft grip molding onto Tritan™ bottles or integrated sealant molding onto medical device housings.
• Improved grip: Soft touch, non-slip
• Leak prevention: Improved usability through integrated seal (gasketless design).
• Bottom bumper: Improved impact resistance and sound insulation
• Reduced leaching: The adhesive-free structure reduces the risk of leaching from adhesives. This is required in applications where safety is paramount, such as medical and food containers, including biosafety testing for medical devices (ISO 10993, etc.) and pharmacopoeia leaching tests.
Details of the welding mechanism
The detailed welding mechanism in two-color molding (flow, diffusion, and entanglement of molecules near the surface), as well as the types of resins to which Tefabloc™ and TPC can be welded, are explained in detail in Mitsubishi Chemical's technical articles.
Unlike bonding using adhesives, which involves sandwiching another material at the interface, this method creates a "welded" state where the resins are directly bonded together, resulting in a bond with superior sealing properties, durability, and aesthetic reliability.
In addition to two-color molding, you can also choose welding methods that involve post-processing such as laser welding and ultrasonic vibration welding.
The combination of "Tritan™ x weldable elastomer" enables the design of high-performance, high-value-added products.
Recommended grades for food containers/medical devices
According to Mitsubishi Chemical's evaluation results, the following three grades of Tefabloc™ and Zelas™ have been confirmed in internal evaluations as elastomers that can be welded with Tritan™. In addition to the grades listed, it may be possible to select elastomers with different hardness levels. For more details, please contact us.
左線見出し
Tefabloc™およびZelas™には、加工方法、透明性、硬さ、機械特性、熱融着性および用途要求に応じて選定できる複数のグレードがあります。
下表では、TPC標準グレードであるTefabloc™ A1600N、TPC透明グレードであるTefabloc™ A1606C、および医療用途向けエラストマーであるZelas™ MC719について、代表的な基本物性とTritan™との融着強度を比較しています。
A1600NおよびA1606Cは、高い切断時伸びとTritan™に対する融着強度を示しており、一般産業用途や食品包装用途における多層構成・複合部材の検討に適しています。Zelas™ MC719は、低密度と高い引張応力を特長とし、医療機器および医薬品包装用途を想定した材料選択肢です。実際のグレード選定では、最終製品の要求性能、成形条件、相手材、滅菌・使用環境ならびに規制要件を総合的に確認してください。
item | Test method | unit | Tefabloc™ A1600N | Tefabloc™ A1606C | Zelas™ MC719 |
|---|---|---|---|---|---|
製品タイプ | ― | ― | TPC標準グレード | TPC透明グレード | 医療用途向け エラストマー |
メルトマスフローレート（230°C、21.2 N） | ISO 1133参照 | g/10 min | 5 | 4 | 3 |
Density | ISO 1183参照 | g/cm³ | 1.00 | 1.00 | 0.89 |
Durometer hardness A | ISO 7619-1参照 | ― | 67 | 68 | 75 |
Tensile stress at break | ISO 37参照 | MPa | 8 | 7 | 10 |
Elongation during cutting | ISO 37参照 | % | 930 | 880 | 880 |
融着強度（Tritan™との接合）* | MCC Test Method | N/25 mm | 190 | 181 | 53 |
exterior | ― | ― | milky white | translucent | translucent |
日本の食品接触材料ポジティブリスト制度への適合状況** | ― | ― | Compatibility | Compatibility | 対象外 |
主な想定用途 | ― | ― | 一般産業用途、食品包装用途 | 一般産業用途、食品包装用途 | 医療機器、医薬品包装用途 |
*Fusion strength is a representative value that evaluates the bonding strength with Tritan™ TX100N. A 90° peel test (tensile speed: 200 mm/min, specimen width: 25 mm) was performed using MCC Test Method. Sample preparation conditions: A Tritan™ TX100N injection-molded plate (thickness 2 mm) was used as the base material, and each material was injection-molded on it to a thickness of 2 mm to prepare a two-layer test specimen.
**「適合」は、日本の食品接触材料ポジティブリスト制度に関する情報を示します。最終製品としての適合性は、最終用途、食品区分、使用温度・時間、色材・添加剤、製品構成および最新の法規制に基づき、個別に確認してください。
※本表の数値は代表値であり、保証値ではありません。物性および融着強度は、成形条件、試験方法、試験片形状、相手材、表面状態、接合条件および使用環境によって異なります。
For food and general use: Tefabloc™ TPC
Tefabloc™ TPC's A-series offers excellent heat welding performance with hard polar resins such as PC and ABS, and has a long track record of use in grips for electronic devices (cameras, games), toothbrush grips, swimming goggles, dental care products, and more.
Tefabloc™ A1600N: A balanced grade combining the flexibility of a durohardness of 67 with excellent weld strength of 142 N/25mm. It complies with Japan's Positive List System for Food Utensils, Containers, and Packaging, and is ideal for applications requiring both tactile feel and airtightness, such as tumbler handles, non-slip grips on water bottles, and food container lid seals. Its milky white appearance harmonizes with simple and sophisticated product designs.
Recommended uses: Tumblers, soup containers, water bottles, grip parts, anti-slip bottom pads, sealing parts, baby products
Tefabloc™ A1606C: This grade achieves high welding strength (161 N/25mm) while maintaining excellent optical properties ranging from transparent to translucent. It complies with Japan's Positive List System for Food Utensils, Containers, and Packaging, and is suitable for applications where you want to enhance the design value of "visible" soft parts, such as the finger grips on transparent tumblers or decorative rings on wine glass-shaped containers. It is designed to meet the high-performance requirements when switching containers from PC to Tritan™.
Recommended uses: Transparent tumblers, high-end food containers, and products where transparency is important.
For medical device applications: Medical-grade compound Zelas™
Zelas™ MC719: This grade is designed to be weldable with difficult-to-weld resins such as COP and COC, and has a proven track record in pharmaceutical packaging, including IV bags. Internal evaluations have confirmed its weldability with Tritan™. Two-color molding with Tritan™ medical device parts allows for adhesive-free integration of the seal area, simultaneously simplifying the assembly process and reducing the risk of leaching.
Recommended medical applications: Gaskets for medical devices and pharmaceutical packaging parts using Tritan™, infusion and drug solution containers, medical test and diagnostic chips, Luer medical standard connectors, etc.
Compliance with safety tests: ISO 10993-5 cytotoxicity test, Japanese Pharmacopoeia 7.02 (elution test 121°C, 1 hour autoclave, ashing test)
For an explanation of welding with COP for this grade, please see the article below.
Summary and Introduction Notes
Due to stricter BPA regulations, primarily in Europe, the shift from polycarbonate (PC) to BPA-free Tritan™ is accelerating in the food and medical sectors. Tritan™ is highly valued in the market as a glass and PC substitute due to its transparency, impact resistance, and BPA-free properties. However, to achieve complete product functionality, high-performance materials are effectively created by combining Tritan™ resin with a "weldable" elastomer using two-color molding.
Please feel free to contact us with any questions regarding grade selection, welding condition optimization, or sample requests.
Compliance with regulations for food-contact elastomers requires an understanding of market-specific standards and accurate information dissemination within the internal supply chain. Since food-contact material regulations in each country and region are frequently revised, be sure to check the latest public information and guidelines before implementation.
This article is a general explanation based on publicly available information and market and regulatory information obtained by our company, and does not guarantee suitability for specific products or applications or compliance with laws and regulations. We assume no responsibility whatsoever for the results of decisions or actions taken by customers based on this article. When actually applying this information, please be sure to check the latest laws, standards and public guidelines and evaluate and judge it at your own responsibility.
Reference URL
[1] Nagase & Co., Ltd. Official Website - Eastman Tritan Introduction Page
URL: https://www.nagase.com/eastman-tritan
[2] Nagase & Co., Ltd. Official Website - Tritan Premium Tableware Page
URL: https://www.nagase.com/eastman-tritan/eastman-tritan-premium-tableware
BPA Regulation Information
[3] “EU bans bisphenol-A in food contact materials”, Lifocolor, March 2025
https://www.lifocolor.de/en/news-events/bisphenol-a-ban-in-food-contact-materials/
[4] "Bisphenol A | EFSA", European Food Safety Authority (EFSA), January 2026.
https://www.efsa.europa.eu/en/topics/topic/bisphenol
[5] “Bisphenol A: Occurrence in Food and the Risk to Health”, IFST, December 2024
https://www.ifst.org/resources/information-statements/bisphenol-occurrence-food-and-risk-health
[6] "The new European Regulation 2024/3190 on Bisphenol A", BRC, January 2026.
https://brc.org.uk/news-and-events/news/associate-insight/2025/the-new-european-regulation-20243190-on-bisphenol-a/
Medical device regulatory information
[7] SCENIHR “The safety of BPA in medical devices”:
https://health.ec.europa.eu/document/download/4d94b47e-81fb-4d67-9948-4a5cc33230ca_en
