China is a major global manufacturing base for fiberglass-reinforced insulation materials, supported by extensive glass-fiber supply chains, epoxy-resin processing capabilities, industrial machining resources, and mature export logistics.

For buyers sourcing G11 fiberglass sheets, China offers a broad selection of manufacturers producing G10, G11, FR4, FR5, EPGC-series laminates, antistatic boards, machined insulation parts, and custom composite components.

However, G11 should not be purchased solely based on a product name, sheet color, or unit price. The real value of a supplier depends on material consistency, resin formulation, thermal performance, thickness tolerance, quality-control process, documentation, production stability, and communication efficiency.

This guide helps procurement managers identify suppliers that may fit long-term electrical insulation, industrial equipment, battery, machinery, mold, transformer, and electronic-component applications.

G11 Fiberglass Sheet Manufacturing Overview

How We Evaluated G11 Fiberglass Sheet Manufacturers

The manufacturers in this list were assessed based on practical sourcing factors that matter during supplier qualification and long-term purchasing.

Manufacturing Capability

A reliable supplier should have a clear focus on epoxy glass laminate materials rather than acting only as a trading company. Buyers should examine whether the manufacturer produces G11 sheets, FR4 sheets, G10 sheets, FR5 sheets, EPGC materials, prepreg, rods, tubes, and finished insulation components.

Technical Product Range

A strong product portfolio often indicates broader technical knowledge and more flexible material selection. Important products may include:

- G11 epoxy fiberglass sheet

- FR5 fiberglass laminate sheet

- G10 insulation board

- FR4 epoxy glass laminate

- EPGC201, EPGC202, EPGC203, EPGC204, EPGC306, and EPGC308 materials

- Antistatic fiberglass sheets

- CNC-machined insulation parts

- Epoxy glass rods and tubes

- Copper-clad laminate sheets

- High-temperature composite materials

Quality Management

Buyers should prioritize suppliers that can provide clear quality-management documentation, stable inspection procedures, lot traceability, and product test reports.

Important verification points include:

- ISO 9001 quality-management certification

- ISO 14001 environmental-management certification

- RoHS and REACH declarations

- Material technical data sheets

- Batch inspection reports

- Thickness and flatness records

- Dielectric-strength test results

- Water-absorption test results

- Flame-resistance data where required

OEM and Custom Processing Support

Many industrial buyers do not require standard full-size sheets only. They may need custom thicknesses, cut-to-size panels, drilled parts, routed components, CNC-machined insulation parts, chamfered edges, or individually packed assemblies.

A capable supplier should be able to support drawing-based production and communicate clearly about tolerance, machining feasibility, material grade, production timing, and packaging requirements.

Delivery Stability

Stable production scheduling is essential for long-term projects. Buyers should confirm raw-material availability, standard lead time, maximum monthly output, stock-sheet availability, export packaging methods, and capacity for repeat orders.

G11 Sheet Supplier Evaluation Process

Understanding G11 Fiberglass Sheet

G11 fiberglass sheet is a high-performance epoxy resin and woven glass-cloth laminate. It is commonly used in electrical insulation and structural applications that require a combination of mechanical strength, thermal resistance, dielectric performance, and dimensional stability.

Depending on the formulation and relevant specification, G11 materials may be associated with NEMA Grade G-11 and IEC 60893 EPGC-series materials.

Typical G11 fiberglass sheet characteristics include:

- High mechanical strength

- Good electrical insulation performance

- High dielectric strength

- Stable performance under elevated temperatures

- Good machining performance

- Low moisture absorption compared with many conventional insulation materials

- Good resistance to industrial oils and many chemicals

- Suitable for drilling, milling, routing, punching, and CNC machining

Typical applications include:

- Electrical insulation components

- Transformer insulation structures

- Motor and generator parts

- Switchgear insulation

- Battery-pack insulation components

- High-voltage electrical equipment

- Industrial fixtures and jigs

- Mold components

- Mechanical wear-resistant structures

- Electronic equipment insulation boards

- Railway, wind-energy, and industrial control applications

G11 Fiberglass Sheet Material Structure

Top 10 G11 Fiberglass Sheet Manufacturers in China

Manufacturer	Established	Main Product Focus	Suitable Buyer Profile
Guangdong Weishi New Materials Co., Ltd.	2007	G11, G10, FR4, 3240, antistatic sheets, custom machining	Buyers needing flexible OEM support and responsive communication
Jiujiang Xinxing Insulation Material Co., Ltd.	2003	G11, FR4, FR5, EPGC laminates, semiconductor insulation materials	Buyers requiring recurring industrial-volume supply
Guangzhou Shengrui Insulation Materials Co., Ltd.	2012	FR4, G10, FR5, G11, prepreg, ESD sheets, CNC parts	Buyers requiring multiple insulation-material categories
Guangde Huachang New Materials Co., Ltd.	Publicly listed	FR4, FR5, G10, G11, prepreg, antistatic sheets	Buyers sourcing both sheets and machined insulation parts
Qingdao Yilong Insulation Material Co., Ltd.	Publicly listed	G11 sheets, rods, tubes, mica products, engineering plastics	Electrical-power and high-voltage insulation projects
Zhejiang Jingjing Insulation Materials Co., Ltd.	Publicly listed	G10, G11, FR4, epoxy glass laminates	Buyers requiring broad thickness options
Xiongyihua / XYH Plastic	Publicly listed	G11, G10, FR4, engineering plastics, machined parts	Buyers combining laminate and engineering-plastic sourcing
Wuxi Chifeng Metal Products Co., Ltd.	2014	G10, G11, FR4 insulation materials	Buyers requiring standard industrial insulation sheets
Jiangyin Hucheng Insulating Material Co., Ltd.	Publicly listed	Electrical and electronic insulation laminates	Buyers seeking traditional electrical-insulation materials
Suzhou Huayan Fuji Advanced Materials Co., Ltd.	2014	Insulation materials and composite solutions	Buyers focused on R&D and management-system documentation

1. Guangdong Weishi New Materials Co., Ltd.

Guangdong Weishi New Materials Co., Ltd. is a professional manufacturer focused on epoxy insulation boards and composite materials. Established in 2007, the company supplies FR4, G10, G11, 3240 epoxy sheets, antistatic fiberglass sheets, copper-clad laminates, high-density composite materials, and related engineering plastic products.

The company operates a 16,000 m² manufacturing facility and has built its product development around electrical insulation performance, mechanical strength, machining stability, and application flexibility.

Guangdong Weishi is particularly suitable for buyers that need more than standard stock sheets. Its manufacturing model supports custom dimensions, thickness selection, cut-to-size panels, CNC-machined insulation components, drilled parts, routed profiles, and customer-specific packaging.

Its key advantage is its ability to work with small and medium-sized industrial buyers that require fast communication, flexible order handling, and technical coordination during the sampling and production stages.

Instead of only supplying standard sheet formats, the company can support buyers who need finished or semi-finished insulation components for applications such as battery packs, electrical equipment, industrial machinery, transformers, fixtures, mold components, and electronic assemblies.

Suitable for:

- OEM buyers requiring custom G11 sheet dimensions

- Importers sourcing CNC-machined insulation components

- Battery-pack and electrical-equipment manufacturers

- Industrial machinery and fixture manufacturers

- Buyers requiring flexible sampling support

- Small and medium-sized industrial brands

- Buyers seeking a long-term supplier with efficient communication

2. Jiujiang Xinxing Insulation Material Co., Ltd.

Jiujiang Xinxing Insulation Material Co., Ltd. was established in 2003 and focuses on high-performance electrical and electronic rigid insulation laminated sheets.

The company offers a broad range of insulation products, including G10, G11, FR4, FR5, EPGC201, EPGC202, EPGC203, EPGC204, antistatic laminates, semiconductor laminates, and related insulation materials.

Its product range makes it suitable for industrial procurement programs requiring multiple electrical insulation materials from one supplier. Buyers may consider Jiujiang Xinxing for transformer, motor, generator, switch cabinet, PCB fixture, electrical equipment, and industrial insulation applications.

The company is especially relevant for recurring-volume projects where a buyer requires stable supply and a wider catalogue of epoxy glass laminate materials.

Suitable for:

- Transformer and motor manufacturers

- Electrical-equipment suppliers

- Buyers requiring G11 and FR5 materials

- Industrial buyers with recurring-volume orders

- Buyers sourcing EPGC-series laminate grades

- Suppliers serving electrical and power-generation sectors

3. Guangzhou Shengrui Insulation Materials Co., Ltd.

Guangzhou Shengrui Insulation Materials Co., Ltd. was founded in 2012 and manufactures FR4, G10, FR5, G11, epoxy fiberglass sheets, prepreg, copper-clad laminates, ESD materials, carbon-fiber products, and CNC-machined components.

The company is suitable for buyers that require several material categories within one project. For example, a buyer may need G11 insulation sheets for electrical barriers, antistatic materials for production fixtures, prepreg for composite fabrication, and CNC-machined parts for equipment assembly.

Its custom-development capability makes it relevant for applications involving non-standard dimensions, special component shapes, advanced composite materials, and industrial insulation assemblies.

Buyers should request product-specific thermal, electrical, mechanical, and machining data because performance can vary according to resin formulation, thickness, glass cloth, and intended application.

Suitable for:

- Buyers requiring FR5 and G11 materials

- Electronics and electrical-equipment manufacturers

- Companies requiring prepreg and insulation boards

- Buyers sourcing CNC-machined composite components

- Projects combining ESD, fiberglass, and carbon-fiber materials

4. Guangde Huachang New Materials Co., Ltd.

Guangde Huachang New Materials Co., Ltd. supplies FR4, FR5, G10, G11, antistatic boards, non-halogen boards, prepreg, synthetic stone, and insulation-board processing parts.

The company is a potential sourcing option for buyers that need different insulation grades from one supplier. Its product range may be useful for industrial projects requiring conventional epoxy glass sheets together with antistatic boards, machined components, or non-halogen materials.

The availability of OEM and custom processing support can be beneficial for buyers that need materials cut, drilled, or machined according to drawings.

Before finalizing a supplier, buyers should verify the exact G11 grade, resin system, temperature rating, thickness tolerance, surface quality, and batch-testing process.

Suitable for:

- Buyers sourcing several laminate grades

- OEM projects requiring custom insulation parts

- Buyers requiring antistatic or non-halogen materials

- Industrial equipment manufacturers

- Companies requiring sheet and machined-part supply

5. Qingdao Yilong Insulation Material Co., Ltd.

Qingdao Yilong Insulation Material Co., Ltd. offers epoxy fiberglass sheets, rods, tubes, mica products, phenolic laminates, and engineering plastics.

The company is relevant for buyers requiring insulation materials in more than one form. In addition to G11 sheets, buyers may also source fiberglass rods, insulation tubes, mica components, and other electrical insulation products.

Its G11-related product range may be suitable for electrical systems where thermal stability, dielectric performance, tracking resistance, and mechanical strength are important considerations.

For high-voltage or high-CTI applications, buyers should request specific test reports for the selected material rather than relying only on a general product description.

Suitable for:

- High-voltage electrical equipment

- Power-distribution applications

- Transformer and switchgear components

- Buyers requiring epoxy sheets, rods, and tubes

- Industrial electrical-insulation projects

6. Zhejiang Jingjing Insulation Materials Co., Ltd.

Zhejiang Jingjing Insulation Materials Co., Ltd. offers G10, G11, FR4, epoxy glass cloth laminates, and related insulation products.

The company may be suitable for buyers that require a wide selection of thicknesses and standard panel formats. Its products are commonly associated with applications such as electrical equipment, transformers, electronic devices, industrial machinery, lithium-battery systems, and communication equipment.

For buyers requiring thick G11 panels, custom dimensions, or specific flatness requirements, it is important to clarify the maximum available thickness, pressing process, internal quality consistency, and machining behavior before placing a large order.

Suitable for:

- Buyers requiring G11 sheets in different thicknesses

- Transformer and motor component manufacturers

- Lithium-battery equipment projects

- Industrial equipment manufacturers

- Standard electrical-insulation applications

7. Xiongyihua / XYH Plastic

Xiongyihua, often marketed as XYH Plastic, supplies G11 epoxy glass cloth laminates, G10 sheets, FR4 sheets, 3240 laminates, and various engineering plastics.

Its mixed product range can be useful for buyers that need both fiberglass laminate materials and engineering plastics such as POM, nylon, polycarbonate, PVC, or other machining-grade polymers.

This makes XYH suitable for industrial buyers that prefer to consolidate sourcing across several material categories. Buyers should clearly identify whether their requirement is standard G11, FR5/G11, EPGC-grade laminate, or another high-temperature epoxy glass material.

Suitable for:

- Industrial machinery manufacturers

- Buyers sourcing both G11 sheets and engineering plastics

- CNC-machining companies

- Fixture and jig manufacturers

- Distributors with mixed material portfolios

8. Wuxi Chifeng Metal Products Co., Ltd.

Wuxi Chifeng Metal Products Co., Ltd. was established in 2014 and supplies epoxy insulation materials, including FR4, G10, and G11 fiberglass laminate sheets.

The company may be a suitable option for buyers requiring standard industrial insulation sheets in regular formats. It can be considered for electrical equipment, industrial machinery, motor insulation, fixture boards, and related applications.

Buyers should confirm whether the quoted product is designed for the required thermal class and whether the performance data is applicable to the exact thickness and sheet construction being purchased.

Suitable for:

- Standard G10 and G11 sheet sourcing

- General electrical-insulation applications

- Industrial machinery insulation components

- Buyers requiring regular panel sizes

- Buyers seeking a one-stop material sourcing discussion

9. Jiangyin Hucheng Insulating Material Co., Ltd.

Jiangyin Hucheng Insulating Material Co., Ltd. specializes in electronic and electrical insulation laminated products.

The company is relevant for buyers seeking conventional insulation materials for power equipment, electrical assemblies, industrial machinery, and electronic applications.

Its long-term focus on electrical insulation laminates may make it suitable for buyers that prioritize basic G11, G10, FR4, and related laminate-sheet procurement.

Because public technical details may vary by product, buyers should request product-specific documentation before approval, including technical data sheets, quality certificates, sample reports, production lead time, and material traceability information.

Suitable for:

- Conventional electrical-insulation applications

- Industrial equipment manufacturers

- Electrical assembly suppliers

- Buyers requiring epoxy glass laminate sheets

- Procurement teams with detailed internal quality-control procedures

10. Suzhou Huayan Fuji Advanced Materials Co., Ltd.

Suzhou Huayan Fuji Advanced Materials Co., Ltd. was established in 2014 and combines research, manufacturing, and sales activities in the insulation-material sector.

The company may be a suitable option for buyers that value development capability, product documentation, and quality-management-system review.

For buyers considering this supplier for G11 fiberglass sheets, the first qualification step should include confirming available G11 grades, thickness range, panel size, machining capabilities, test documentation, and export packaging methods.

The supplier may be particularly relevant for projects where material development, environmental documentation, and long-term quality-management processes are important selection factors.

Suitable for:

- Buyers requiring insulation-material development support

- Procurement teams focused on quality-management documentation

- Industrial equipment and electrical-component manufacturers

- Buyers requiring long-term supplier evaluation

- Projects requiring technical discussions before production

Manufacturer Comparison: Capacity, MOQ and Documentation

Manufacturer	Capacity Information	MOQ Consideration	Documentation to Request
Guangdong Weishi New Materials	More than 100 tonnes per month; 16,000 m² facility	Flexible depending on thickness, dimensions, and machining scope	Material TDS, sample report, thickness inspection, RoHS/REACH declaration
Jiujiang Xinxing Insulation Material	More than 4,000 tonnes per year	Suitable for repeat industrial orders	ISO certificate, TDS, batch inspection report, RoHS declaration
Guangzhou Shengrui Insulation Materials	Confirm during quotation	Depends on material type and custom-development scope	G11/FR5 test report, machining specification, sample approval records
Guangde Huachang New Materials	Confirm during quotation	Varies by sheet grade and processed part complexity	Product specification, OEM drawing confirmation, compliance documents
Qingdao Yilong Insulation Material	Confirm during quotation	Depends on G11 sheet, rod, tube, or mica format	ISO certificates, high-voltage test data, CTI report where applicable
Zhejiang Jingjing Insulation Materials	Confirm during quotation	May vary significantly for thick sheets	Thickness report, flatness report, RoHS/REACH documents
Xiongyihua / XYH Plastic	Confirm during quotation	Depends on standard or OEM processing requirements	Grade confirmation, machining tolerance sheet, material test report
Wuxi Chifeng Metal Products	Confirm during quotation	Standard panels may have lower MOQ than custom sheets	ISO certificate, technical sheet, thickness tolerance confirmation
Jiangyin Hucheng Insulating Material	Confirm during quotation	Depends on product specification and order frequency	TDS, production-lot information, sample test records
Suzhou Huayan Fuji Advanced Materials	Confirm during quotation	To be confirmed based on product development needs	ISO certificates, environmental documents, technical specifications

Common G11 Fiberglass Sheet Sourcing Risks

Material Grade Substitution

One of the most common sourcing risks is receiving a product labelled as G11 that does not meet the expected thermal, electrical, or mechanical properties.

Some suppliers may offer a generic epoxy fiberglass sheet, a lower-temperature laminate, or a material with a different resin formulation while using similar language in quotations.

A green sheet is not automatically G11. Color should never be used as proof of grade.

To reduce this risk, buyers should include the following information in the purchase order:

- Required material grade

- Applicable standard

- Thermal requirement

- Target thickness and tolerance

- Sheet dimensions

- Electrical performance requirement

- Mechanical performance requirement

- Flame-resistance requirement if needed

- Required batch test report

- Approved sample reference number

The Internal Quality Trap: Surface Looks Good, Core Is Not Stable

A sheet may appear smooth and visually acceptable while still having internal defects such as resin-starved areas, uneven curing, dry glass-cloth zones, voids, or weak bonding between layers.

These problems can become visible only after drilling, milling, edge machining, or high-voltage use.

Potential warning signs include:

- Excessive edge chipping during CNC machining

- Layer separation around drilled holes

- Visible dry glass cloth after machining

- Cracking under mechanical pressure

- Uneven color through the sheet cross-section

- Delamination after heat exposure

- Unstable dielectric performance in humid conditions

Buyers should inspect sample cross-sections and complete real machining tests using their actual cutting tools, drill diameters, spindle speeds, and assembly conditions.

For thick G11 sheets, it is especially important to verify internal consistency rather than checking the surface only.

Confusing Thermal Ratings With Actual Operating Conditions

A material's stated thermal rating should not be treated as a guarantee that it will perform indefinitely at that temperature in every application.

Actual performance can be affected by:

- Continuous operating temperature

- Peak temperature

- Thermal cycling

- Mechanical load

- Electrical voltage

- Humidity

- Oil or chemical exposure

- Clamping pressure

- Contact with hot metal components

- Surface contamination

Buyers should provide their real operating conditions when requesting a material recommendation.

Incomplete Certification Verification

A certificate may be expired, issued to a different legal entity, linked to a different factory address, or limited to a scope unrelated to the product being purchased.

Before approving a supplier, buyers should verify:

- Legal company name

- Factory address

- Certificate number

- Issuing organization

- Certificate scope

- Issue date

- Expiry date

- Accreditation body

- Whether the certified facility is the actual manufacturing site

Unrepresentative Samples

A sample may be produced from a preferred material lot that is not representative of future mass production.

To avoid this issue, buyers should identify the approved sample with a unique code and require the supplier to maintain material consistency for future orders.

The purchase order should state that material formulation, glass cloth, resin system, pressing method, and core raw materials cannot be changed without written approval.

G11 Fiberglass Sheet Industrial Applications

Buyer's Guide: How to Qualify a G11 Supplier

Prepare a Technical RFQ

A complete request for quotation should include:

- Material grade requirement

- Product application

- Operating temperature

- Voltage requirement

- Sheet thickness

- Thickness tolerance

- Sheet size

- Flatness requirement

- Surface finish requirement

- Required quantity

- Estimated annual volume

- Drawing for CNC machining

- Compliance documents required

- Packaging specification

- Delivery location

- Shipping terms

Compare Specifications Before Prices

Do not compare prices until suppliers quote the same material specification.

A lower quotation may reflect a different resin system, lower thermal performance, wider thickness tolerance, lower-density construction, or fewer quality-control requirements.

Compare the following items side by side:

- Material grade

- Glass-cloth type

- Resin system

- Thermal classification

- Dielectric strength

- Water absorption

- Flexural strength

- Density

- Thickness tolerance

- Flatness

- Flame resistance

- CTI requirement

- Compliance documentation

- Packaging method

- Production lead time

Test Samples Under Real Conditions

A good sample test should include more than visual inspection.

Buyers should evaluate:

- Thickness consistency

- Surface flatness

- Edge quality

- Drilling performance

- Milling performance

- Chipping behavior

- Delamination risk

- Heat resistance

- Moisture resistance

- Electrical insulation performance

- Compatibility with final assembly

Conduct Factory Due Diligence

For repeat orders or high-value programs, buyers should conduct a remote or on-site supplier review.

Areas worth checking include:

- Raw material inspection

- Prepreg storage conditions

- Lamination and pressing equipment

- Temperature and curing control

- Sheet trimming and finishing process

- Thickness measurement equipment

- Flatness inspection process

- Laboratory testing capability

- Production-lot traceability

- Packaging process

- Handling of non-conforming materials

Plan Export Packaging Carefully

G11 fiberglass sheets can be damaged during transport if they are not packed properly.

Buyers should clarify:

- Protective film requirements

- Corner protection

- Pallet type

- Moisture-barrier packaging

- Sheet separators

- Carton or plywood case requirements

- Labeling method

- Mixed-size pallet arrangement

- Final destination port or warehouse requirements

For CNC-machined parts, individual separation and scratch-prevention packaging may be necessary.

Summary

Selecting a G11 fiberglass sheet manufacturer requires more than comparing sheet prices. Buyers should evaluate the supplier's technical understanding, material consistency, documentation, production stability, machining support, sample-management process, and ability to communicate clearly throughout the project.

For standard industrial sheets, large-volume insulation programs, custom-machined components, or application-specific composite parts, the most suitable supplier will depend on the required material grade, project complexity, order size, and quality-control expectations.

Guangdong Weishi New Materials Co., Ltd. is a suitable option for buyers seeking a practical balance of material capability, flexible OEM support, custom processing, responsive communication, and long-term cooperation for G11, G10, FR4, and related insulation material projects.

FAQ

1. How can I verify whether an ISO certificate is expired?

Request the full certificate and review the company name, factory address, certificate number, issuing body, certificate scope, issue date, and expiry date. Buyers should also check the certification body's public verification system or contact the issuing organization directly.

2. Is G11 always better than FR4?

Not always. G11 is generally selected for applications requiring improved thermal performance and mechanical strength at elevated temperatures. FR4 may be sufficient for many standard electrical-insulation applications. Material selection should be based on operating temperature, voltage, humidity, mechanical stress, compliance requirements, and budget.

3. What documents should I request for high-voltage insulation projects?

Buyers should request a technical data sheet, dielectric-strength report, insulation-resistance data, thickness report, density report, water-absorption data, thermal-performance information, flame-resistance report if needed, and lot-specific inspection records.

4. How can I ensure that production material matches the approved sample?

Use a signed sample approval process. The approval document should identify the grade, thickness, size, color, test data, sample number, and date. The purchase order should require all production batches to match the approved sample and require written approval before any material or process change.

5. What MOQ should I expect for G11 fiberglass sheets from China?

MOQ depends on thickness, panel dimensions, material grade, color, custom resin system, machining requirements, packaging, and whether the order is based on stock sheets or new production. Standard sheet sizes may support lower trial quantities, while thick panels, special dimensions, strict tolerance requirements, and CNC-machined components usually require larger orders.