China Customized Thermos Flask Glass Refill Suppliers - Cheap Thermos Flask Glass Refill

Wholesale Thermos Flask Glass Refills | Direct Manufacturer & OEM Solutions

Founded in April 2018, Kairun International Co., Ltd. is a manufacturer of Thermos Flask Glass Refills for OEM brands, wholesalers and distributors worldwide. Based in Dongyang, we supply vacuum glass refills in multiple capacities and specifications for household and commercial insulated containers. Our products are exported to Southeast Asia, Africa, the Middle East and South America, supported by standardized manufacturing, quality inspection and export packaging.

As a dedicated manufacturer of Thermos Flask Glass Refills, we focus on stable production, dimensional consistency and reliable vacuum insulation performance. Every refill is manufactured through standardized production and inspection procedures to support OEM projects, wholesale distribution and long-term supply for international customers.

Glass Refill
The Glass Refill is a double-wall vacuum borosilicate glass liner designed for thermos manufacturers and replacement-part suppliers, delivering reliable 24–36 hour insulation with consistent...

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Flask Refill Thermos
Flask Refill Thermos is a commercial-grade, glass-lined vacuum flask built for wholesale buyers, offering 24–36 hour insulation and transit-ready durability.

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Vacuum Flask Glass Refill
Vacuum Flask Glass Refill is a high-vacuum, silver-coated double-wall glass liner designed for thermos manufacturers and distributors to ensure 24–36 hour thermal insulation and high-assembly yield.

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Key Performance Advantages

Automated high-temperature vacuum equipment evacuates every refill to below 5 × 10⁻³ Pa. Vacuum performance is checked during production to help maintain consistent insulation.

A mirror-finish silver coating improves thermal reflection. Coating adhesion is verified according to ASTM D3359 (Level 4B–5B) to help reduce peeling and oxidation.

Premium 3.3 borosilicate glass with uniform wall thickness helps improve thermal shock resistance. Internal testing indicates resistance to temperature changes of up to 150°C under controlled conditions.

The double-wall vacuum structure and reflective silver coating help reduce heat transfer. Internal laboratory testing indicates water can remain above 75°C after 12 hours under standard testing conditions.

Crafted from premium borosilicate glass with a low thermal expansion rate (3.3 × 10⁻⁶/K). Completely free of lead, cadmium, and toxic chemicals, fully complying with FDA and LFGB standards.

Core Product Categories Available

By Capacity

Compact Sizes (0.45L, 0.6L, 0.8L): Ideal for office or personal use.
Standard Household Sizes (1.0L, 1.2L, 1.5L): The market staple for family dining and daily hydration.
Large Capacity Sizes (1.8L, 2.0L, 3.2L, 5.0L): Perfect for hospitality, catering, and commercial applications.

By Mouth/Neck Type

Screw-Type Necks: Designed for secure twist-lock plastic or metal shells.
Press-Type (Push-Button) Necks: Engineered for one-touch stopper mechanisms.
Wide-Mouth & Narrow-Mouth Designs: Customized to match various aesthetic and functional flask profiles.

OEM & Customization Support

Custom Dimensions

Height, diameter, neck size and bottom shape can be customized according to drawings or samples.

Lid Compatibility

Glass refills can be matched with different screw-top, push-button or wide-mouth lid designs.

Logo & Packaging

Support for logo printing or laser etching, along with customized retail boxes, barcodes and user instructions.

Protective Packaging

Export packaging with customized cushioning helps reduce breakage during sea freight and e-commerce transportation.

Bulk Production

Stable manufacturing and flexible packaging solutions for long-term wholesale and OEM projects.

Applications & Target Markets

Household & Kitchenware Brands

Serving as the core inner liner for daily family water jugs, thermal carafes, and dining table warmers, meeting consumer demands for long-lasting heat retention and healthy drinking.

Hospitality & Commercial Catering

Engineered for large-capacity thermal pots used in hotels, restaurants, cafes, and conference rooms, supporting high-frequency, long-duration commercial hot water supply.

E-Commerce & Amazon FBA Sellers

Backed by drop-tested packaging and precise structural fitting, our refills seamlessly match online best-selling outer shells to help digital sellers minimize return rates caused by breakage or poor insulation.

Promotional & Corporate Gifts

Fully supportive of custom logos and premium gift box packaging, making them an ideal choice for corporate giveaways, trade show souvenirs, and seasonal promotional campaigns.

Manufacturing Process & Quality Control Flow

Step 1: Raw Material Inspection

Strict spectral analysis and purity screening of 3.3 borosilicate glass to ensure optimal thermal resilience.

Step 2: Precision Blowing & Shaping

Automated forming processes that guarantee uniform wall thickness, accurate dimensions, and seamless shell compatibility.

Step 3: Silver Coating & Curing

High-purity silver mirror coating applied and thermally cured to achieve certified adhesion (ASTM D3359 Level 4B-5B) without peeling.

Step 4: High-Temperature Vacuum Evacuation

Advanced systems evacuate the double-wall space to under 0.005 Pa, eliminating thermal convection for peak insulation.

Step 5: Vacuum & Thermal Shock Testing

Rigorous batch testing for rapid temperature swings up to 150°C and 24-hour heat retention verification.

Step 6: Drop-Tested Packaging Audit

Protective export packaging with multi-layer cushioning is designed to help reduce the risk of breakage during international transportation.

OEM/ODM Workflow

Inquiry & Specification

Share your 2D/3D drawings, physical samples, or outer shell dimensions.

Prototyping & Testing

Custom sample development with rigorous dimension and thermal performance testing (7–10 days).

Mass Production

Automated manufacturing executed under our strict 6-step quality control system.

Secure Delivery

Drop-tested export packaging and reliable global logistics for safe arrival.

FAQ

Q: What is your Minimum Order Quantity (MOQ) for glass refills?

A: Our MOQ depends on the specific model, capacity, and customization requirements. We support flexible trial orders for new partners. Contact our team with your exact specifications for a tailored quote.

Q: Do your products meet international safety standards?

A: Absolutely. All our glass refills are made of high-purity borosilicate glass and comply with major global food safety regulations such as FDA and LFGB, backed by third-party testing reports from SGS and Intertek.

Q: What is your standard production lead time for bulk orders?

A: Typically 25 to 30 days, depending on order volume and custom requirements. We also maintain buffer stock for regular models to support urgent shipments.

Q: Can you provide samples for quality and shell-fit testing before placing a bulk order?

A: Yes. We offer free or low-cost sample kits so your engineering team can verify dimensions and thermal performance firsthand.

Q: How do you pack the glass refills for international sea freight to prevent breakage?

A: We use custom EPE cushioning, 5-layer reinforced master cartons, and ISPM 15 fumigated palletization to guarantee a sea-freight breakage rate under 0.5%.

Q: Can you manufacture according to our existing flask dimensions?

A: Yes. We can produce glass refills based on technical drawings, samples or dimensional specifications to match existing thermos flask designs.

Q: How do you ensure consistency between production batches?

A: Standardized manufacturing procedures, in-process inspections and final quality checks are carried out throughout production to help maintain consistent dimensions and vacuum performance.

As one of the most professional thermos flask glass refill suppliers in China, we're featured by quality products and good service. Please rest assured to wholesale customized thermos flask glass refill made in China here from our factory. Welcome to contact us for more cheap products.