Extra Clear EVA Interlayer (Less flow)

HJ-HT Less Flow Extra Clear EVA Interlayer for Laminated Glass

HJ-HT is E&N HONJIA's extra clear EVA interlayer developed for architectural laminated glass where high transparency, strong glass adhesion and controlled EVA movement are important.

Compared with HJ-AT, our high-flow Extra Clear EVA grade, HJ-HT moves less during the heating stage of lamination.

This more controlled flow behaviour makes HJ-HT particularly suitable for processors who want the EVA to remain relatively stable between the glass sheets while still achieving good bonding and optical clarity.

It is a practical choice for clear architectural laminated glass, large flat panels and production lines where excessive EVA movement or edge overflow is not desirable.

Visible Light Transmittance: >90.4%
Haze: <0.25%
UV Blocking: ≥99%
Glass Adhesion: >95 N/cm
Standard Thickness: 0.38 mm / 0.76 mm
Available Width: Up to 2600 mm
Flow Characteristic: Less Flow / Controlled Flow

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PRODUCT OVERVIEW

Extra Clear EVA with More Controlled Flow

EVA does not behave the same way in every formulation.

During lamination, heat causes the EVA film to soften before it crosslinks and bonds with the glass.

A high-flow formulation moves more readily during this stage.

HJ-HT is designed to behave differently.

It maintains a more controlled position between the glass sheets during heating, which can be useful when the processor does not need a large amount of EVA movement.

This makes HJ-HT particularly suitable when you need:

Extra clear laminated glass

More controlled EVA movement

Strong glass bonding

Better control around the glass perimeter

Stable processing for flat laminated glass

Outdoor-grade performance

The objective is not to eliminate EVA flow completely.

The film still needs to soften and wet the glass correctly.

The difference is that HJ-HT provides a more controlled balance between flow, wet-out and bonding.

LAMINATED GLASS STRUCTURE

How HJ-HT Is Used in Laminated Glass

The basic HJ-HT laminated glass structure is:

HJ-HT EVA film is placed between two clean sheets of glass before lamination.

The complete glass assembly is then processed under vacuum and heat.

As the temperature increases, the EVA softens and begins to wet the glass surfaces.

Because HJ-HT has lower flow than HJ-AT, the film movement remains more controlled during this stage.

With the correct heating cycle, the EVA then crosslinks and bonds the two glass layers together.

The result is a clear laminated glass panel with a thin EVA bonding layer between the glass sheets.

WHAT DOES “LESS FLOW” MEAN?

Controlled EVA Movement During Lamination

“Less flow” does not mean that the EVA does not flow.

HJ-HT still softens during heating.

The difference is the amount of material movement that occurs before crosslinking.

Compared with HJ-AT, HJ-HT remains more stable between the glass sheets.

This can be useful in several production situations.

Better Control Around the Glass Edge

When EVA becomes very fluid, more material can move toward and out of the glass perimeter.

HJ-HT's lower-flow behaviour can help processors keep this movement more controlled.

This can reduce unnecessary EVA accumulation around the edge depending on the glass structure and heating cycle.

More Stable Film Position

For simple flat laminated-glass structures, a large amount of EVA movement is not always necessary.

HJ-HT provides sufficient softening for lamination while keeping the interlayer more stable during heating.

Easier Process Control

Processors using stable, repeatable flat-glass structures may prefer the more predictable behaviour of a controlled-flow EVA.

This is particularly useful when the production line has already been optimized around this type of film behaviour.

Suitable for Large Clear Panels

For large architectural glass panels, maintaining consistent EVA distribution across the laminated structure can be important.

A lower-flow formulation gives processors another option where excessive material movement is not required.

LESS FLOW DOES NOT MEAN LOWER PERFORMANCE

Flow level and product quality are two different things.

A lower-flow EVA should not be interpreted as an EVA that cannot bond or laminate correctly.

HJ-HT is designed to soften sufficiently to wet and bond the glass while limiting unnecessary movement during the heating stage.

The correct flow level depends on the structure.

Some laminated glass works better with high-flow EVA.

Other glass structures work better with controlled-flow EVA.

The objective is to select the EVA that matches the production process.

PRODUCT FEATURES

Extra Clear Appearance

HJ-HT provides visible light transmittance above 90.4% with haze below 0.25%.

The low haze makes it particularly suitable for architectural laminated glass where a clear visual appearance is important.

Strong Glass Adhesion

HJ-HT provides glass adhesion above 95 N/cm under the specified test conditions.

Good adhesion helps maintain the bond between the glass and EVA after the correct lamination cycle.

Actual adhesion is also affected by glass cleanliness, vacuum conditions and heating parameters.

Controlled Flow During Heating

HJ-HT is designed to move less than HJ-AT during the heating stage.

This gives processors more control where excessive flow is not required.

High Crosslinking Rate

HJ-HT has a crosslinking rate above 85% under the specified processing conditions.

Proper crosslinking is an important part of achieving stable EVA performance after lamination.

UV Protection

HJ-HT blocks at least 99% of UV radiation in the 280–380 nm range under the specified test conditions.

The current product data also records a UV aging ΔYI value below 1.

Low Water Absorption

HJ-HT has water absorption of ≤0.1%.

This characteristic supports its use in laminated glass applications where resistance to moisture-related conditions is important.

Flexible Mechanical Performance

HJ-HT has tensile strength above 17 MPa and elongation at break of at least 750%.

This provides a combination of strength and flexibility for handling and laminated-glass production.

WHEN CONTROLLED FLOW IS USEFUL

Simple Flat Laminated Glass

A standard Glass + EVA + Glass structure usually does not require the EVA to move into complex internal spaces.

In these structures, controlled flow can make processing easier to manage.

Glass with Visible Edges

Some architectural laminated glass leaves the perimeter of the glass visually exposed.

Keeping excessive EVA movement under control can help processors achieve a cleaner edge before final finishing.

The long-term suitability of exposed-edge installations should still be evaluated according to the complete glass structure and installation conditions.

Large Panels

Large flat panels may benefit from a formulation that maintains a relatively stable EVA distribution during heating.

Proper vacuum and temperature uniformity remain important.

Production Lines Already Using Lower-Flow EVA

If your current EVA behaves well in your furnace and you want to change suppliers without significantly changing the flow characteristics, HJ-HT may be a more suitable product to evaluate than HJ-AT.

APPLICATIONS

Where HJ-HT Extra Clear EVA Can Be Used

HJ-HT is mainly intended for architectural laminated glass where clear appearance, outdoor performance and controlled processing behaviour are required.

Architectural Façades

HJ-HT can be used in clear laminated façade panels where transparency and consistent glass appearance are important.

Its lower-flow characteristic is useful for processors producing large flat architectural panels.

The complete façade structure should be selected according to the engineering requirements of the project.

Glass Balustrades

Clear laminated glass is widely used for balcony and staircase balustrades.

HJ-HT provides an extra clear EVA option for these applications when processors prefer more controlled flow during production.

Glass thickness and construction should be selected according to the required structural and safety performance.

Frameless Glass Systems

Architectural projects increasingly use large transparent glass panels with minimal visible framing.

For these applications, optical appearance and edge finishing can both be important.

HJ-HT's combination of low haze and controlled flow makes it a useful EVA option for processors producing this type of laminated glass.

Large Shopfront Glass

Large transparent laminated panels are used in commercial buildings, showrooms, hotels and retail environments.

HJ-HT can be considered where a highly transparent finished appearance is required together with stable lamination behaviour.

Glass Canopies

HJ-HT can be used in suitable laminated canopy structures where the glass configuration and engineering design meet the project requirements.

For overhead applications, the complete laminated-glass design must be determined according to relevant structural and safety requirements.

Skylights and Roof Glazing

For clear overhead laminated glass, HJ-HT provides an EVA interlayer option with high optical clarity and controlled material movement.

The glass structure should be evaluated according to loading, installation and environmental conditions.

Multi-Layer Clear Laminated Glass

HJ-HT can also be considered for suitable multi-layer laminated structures where excessive interlayer flow is not required.

Multi-layer configurations should be tested with the actual glass thicknesses and EVA layers before mass production.

HJ-HT VS HJ-AT

Less Flow or High Flow — Which One Should You Use?

HJ-HT and HJ-AT belong to our Extra Clear EVA series.

Their performance specifications are not identical, but the most important practical difference for a glass processor is their flow behaviour.

CHOOSE HJ-HT WHEN:

You want more controlled EVA movement during heating.

Your laminated-glass structure does not require high EVA fluidity.

Too much EVA tends to move toward the glass edges during your current process.

You are producing primarily flat architectural glass.

You value strong glass adhesion.

Your existing production line already works well with a lower-flow EVA.

CHOOSE HJ-AT WHEN:

You need the EVA to move more during heating.

Your glass structure requires more wet-out or filling.

Your current lower-flow EVA does not sufficiently reach some areas of the laminated structure.

The production process has already been developed for a higher-flow EVA.

THE CORRECT EVA DEPENDS ON YOUR PROCESS

Two glass factories can use the same glass thickness and still prefer different EVA flow levels.

This can happen because they use different:

Vacuum systems

Furnace designs

Heating rates

Panel sizes

Loading quantities

Glass structures

Production cycles

For this reason, we do not recommend choosing HJ-HT or HJ-AT based only on one technical value.

The actual processing behaviour should be evaluated in your production conditions.

AVAILABLE SPECIFICATIONS

Standard HJ-HT Specifications

Standard thickness:

0.38 mm

0.76 mm

Available width:

Up to 2600 mm

Standard roll format:

0.38 mm × required width × 100 m

0.76 mm × required width × 50 m

If you require another specification, please send:

Required EVA thickness

Required width

Roll length

Glass dimensions

Glass structure

Application

Estimated quantity

We can check the production arrangement before quotation.

LAMINATION PROCESS

Stable Results Depend on More Than the EVA Film

The performance of laminated glass depends on both the EVA material and the processing conditions.

1. Prepare the Glass

Glass surfaces should be clean and dry.

Remove:

Dust

Oil

Fingerprints

Water

Cleaning residues

Contamination between the EVA and glass may affect bonding or optical appearance.

2. Place the EVA

Lay the required HJ-HT EVA film evenly between the glass sheets.

Avoid unnecessary contact with the film surface during cutting and assembly.

3. Assemble the Glass

Align the glass and EVA according to the required laminated structure.

The amount of EVA left around the glass perimeter should be determined according to your normal production method.

4. Vacuum

Good air removal is important before and during heating.

Vacuum performance should be checked according to the equipment and panel size.

5. Heat and Laminate

During heating, HJ-HT softens and wets the glass.

Because it is a lower-flow formulation, its movement remains more controlled than HJ-AT.

The heating cycle should provide enough time and temperature for wet-out, bonding and crosslinking without unnecessarily increasing EVA movement.

IF TOO MUCH EVA FLOWS FROM THE EDGE

Excessive edge flow does not necessarily mean that the EVA film itself is defective.

Possible factors include:

EVA flow grade

Heating temperature

Heating time

Film thickness

Glass pressure

Vacuum conditions

Glass structure

If you are currently experiencing excessive EVA overflow, HJ-HT may be worth testing.

However, we recommend reviewing the complete production process at the same time.

IF THE EVA DOES NOT FLOW ENOUGH

The opposite problem can also happen.

If HJ-HT does not provide enough movement for a particular structure, simply increasing temperature may not always be the best solution.

A high-flow grade such as HJ-AT may be more appropriate.

This is why we recommend selecting the EVA formulation first and then optimizing the lamination cycle around that product.

PRODUCTION AND QUALITY CONTROL

Consistency for Regular Glass Processing

HJ-HT is inspected during production and before shipment.

Our routine product control focuses on practical properties required by glass processors.

Thickness

Film thickness is checked according to the ordered specification.

Width

The finished film width is checked before packing.

Film Appearance

The EVA is inspected for visible production defects and roll condition.

Optical Properties

Transparency and haze-related performance are checked according to the applicable product requirements.

Adhesion and Crosslinking

Relevant laminated-glass performance is evaluated according to our product control procedures.

Roll Inspection

Finished rolls are checked before protective packaging and shipment.

WHY WE OFFER BOTH HJ-HT AND HJ-AT

We do not believe one EVA formulation should be forced into every laminated-glass process.

Some customers need more flow.

Others need less.

HJ-AT was developed for customers requiring higher EVA movement.

HJ-HT was developed for customers who prefer more controlled EVA movement together with extra clear optical performance and strong glass adhesion.

Selecting between the two depends on the glass you actually manufacture.

FAQ

1. What is HJ-HT?

HJ-HT is an Extra Clear EVA interlayer developed for architectural laminated glass.

Its main processing characteristic is lower, more controlled flow compared with HJ-AT.

2. What does “less flow” mean?

It means the EVA moves less during the heating stage of lamination.

HJ-HT still softens and wets the glass, but the amount of material movement is more controlled than with our HJ-AT high-flow grade.

3. Is HJ-HT a no-flow EVA?

No.

EVA needs to soften during lamination.

“Less flow” refers to relative flow behaviour compared with higher-flow formulations.

4. What is the difference between HJ-HT and HJ-AT?

HJ-HT provides more controlled flow.

HJ-AT provides higher flow and greater EVA movement during heating.

HJ-HT is normally selected when flow and edge control are more important.

HJ-AT is normally considered when more wet-out or filling is required.

5. Which product is clearer, HJ-HT or HJ-AT?

Both belong to the Extra Clear EVA series.

According to the current technical data:

HJ-HT: VL >90.4%, Haze <0.25%

HJ-AT: VL >90.6%, Haze <0.29%

Final laminated-glass appearance also depends on the glass type, glass thickness and complete laminate structure.

6. What thicknesses are available?

Standard HJ-HT thicknesses are:

0.38 mm

0.76 mm

7. What is the maximum width?

HJ-HT is available in widths up to 2600 mm.

Please provide your required width when requesting a quotation.

8. Can HJ-HT be used for outdoor laminated glass?

HJ-HT is developed for architectural laminated-glass applications, including suitable exterior applications.

Final suitability should be evaluated according to the complete glass structure and installation environment.

9. Can HJ-HT help reduce excessive edge flow?

Its more controlled flow behaviour may help when excessive EVA movement is part of the problem.

However, edge flow is also affected by temperature, processing time, EVA thickness and glass structure.

10. Is HJ-HT suitable for exposed-edge glass?

Exposed-edge performance depends on the EVA, glass preparation, glass structure, installation environment and other project conditions.

We recommend reviewing the specific application rather than making a general exposed-edge guarantee.

11. Can I get a sample?

Yes.

Samples can be provided for evaluation.

For the most useful test, please tell us:

Current EVA thickness

Current EVA flow type

Glass structure

Application

Lamination equipment

12. What is the normal production lead time?

For standard specifications, production normally takes approximately 7–15 working days after order confirmation.

Actual lead time depends on specification, quantity and production schedule.

13. Can you help us choose between HJ-HT and HJ-AT?

Yes.

Send us:

Glass structure

Glass dimensions

EVA thickness

Current EVA type

Vacuum equipment

Heating equipment

Current lamination settings

Any current production problem

We can compare HJ-HT and HJ-AT according to your actual production conditions.

NEED BETTER CONTROL OF EVA FLOW?

If your current EVA moves too much during heating, creates excessive edge overflow or simply does not match your existing lamination process, send us your production information.

We can help determine whether HJ-HT's more controlled flow behaviour is suitable for your laminated glass.

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