Silicone Vacuum Bags: U Seals VS E Seals

U Seals Silicone Vacuum Bags For Glass Lamination

Table of Contents

It all started with an inquiry from a customer in the UK.

“Good afternoon, I am looking to purchase 2 x U seal silicone vacuum bags with 1 vacuum nozzels & PTFE Mesh (3100 x 1700mm). This is for an EVA laminating oven. Can you please provide me with a quote & your current lead time.”

Inquiry For U Seal Silicone Vacuum Bags

So, I decided to search on for some clues, like keywords ”silicone vacuum bag for laminating machine” or “silicone vacuum bags for laminated glass”. Most of the organic searching results or images display a kind of silicone vacuum bag with E seals on the edges.

Google Search Silicone Vacuum Bag For laminating machineGoogle Search Silicone Vacuum Bags For Laminated Glass

Where are silicone vacuum bags with U sealing strips?

Which is better for laminated glass industry, U-seal bags and E-seal bags?

However, there is limited information available about these U sealing bags. To provide more insight, I would like to share a blog post that discusses the two types of vacuum silicone bags in detail.

Now, here we go!

Silicone vacuum bags are specialized bags used in the glass lamination process to create a vacuum seal around the glass and interlayer. This vacuum helps to remove any air bubbles and ensures a strong bond between the layers.

The bags are made of high-quality silicone material that can withstand high temperatures and pressure. They come in various sizes and shapes to accommodate different glass sizes and shapes. Silicone vacuum bags are an essential tool for any glass lamination process.


Selecting the right silicone vacuum bag is crucial for achieving optimal lamination results with EVA laminating ovens. The glass industry normally uses two types of vacuum bags: U-seal silicone vacuum bags and E-seal silicone vacuum bags.

To help you make an informed decision, we’ll delve into the features and benefits of each type of vacuum bag. Whether you’re a seasoned professional or a beginner, this information will guide you in picking the perfect vacuum bag for your lamination projects.

What are U Seal Silicone Vacuum Bags?

U Seals Silicone Vacuum Bags For Laminated Glass

U seal silicone vacuum bags are a type of specialized bag that creates a vacuum chamber when sealed due to their unique U-shaped seal. These bags are made from high performance silicone rubber compounds, which are known for their durability, heat resistance, and non-stick properties.

U-sealing bags are commonly used in lamination processes that require vacuum sealing, such as in laminating furnaces, ovens and autoclaves. To make the most of it, a bag must be connected to a vacuum pump with suction hoses.

Top 5 Key Features

(1) A reusable and durable system saves your cost compared to traditional consumable bags.

(2) Customized dimensions according to the customer’s exact requirements.

(3) A range of compatible vacuum hoses and nozzles are available.

(4) U-seal locking design is easy to open and close.

(5) Maintenance and repair are very convenient.

Product Properties

Maximum working temperatures: 250ºC (482ºF)

Color: blue and transparent

Hardness: 50-55 (Shore A)

Tensile strength: 1377 psi

Elongation at break: 650%

*Other grades and colors of silicone rubber available

Four Major Hardware

To apply vacuum to the bag, a range of silicone parts is required. This is a very simple range of products which offer excellent heat resistance, durability and vacuum integrity.

Components available include:

1. Silicone membranes: top pad and base pad

U Seals Silicone Vacuum Bags For Laminating Machine

When it comes to creating vacuum bags, silicone membranes have long been the preferred choice for both the top and bottom layers. This is because of their exceptional heat resistance, high tear strength, and good elongation properties.

Typically, both upper and lower sheets are used at a thickness of 3mm. However, in situations where customers might prefer lightweight bags, a thickness 2mm rubber membrane that is highly puncture resistant may be chosen instead.

2. Male and female U seals

Male and female U seals for a silicone vacuum bag

U seals, also referred to as U-shaped interlocking silicone rubber seals, are essential components in the lamination process. Their primary function is to prevent air leakage, which could negatively impact the quality and effectiveness of laminated safety glass.

U seals are designed to easily locate and securely close, ensuring a tight seal and optimal performance. Without these seals, the lamination process would be compromised, and the resulting product would not meet safety standards.

3. High temp silicon rubber tubes

Our silicone tubes are built to withstand high temperatures and pressure, making them ideal for use in laminating ovens and autoclaves. With a standard inner diameter of 6mm (0.25in) and outer diameter of 12mm (0.5in), our tubes are both durable and versatile. Plus, if any damage occurs, they can be easily repaired on-site by the customer. Choose our high strength silicone tubes for reliable performance in your industrial applications.

  • Other diameters(ID/OD) are available with 10mm/20mm and 9mm/17mm.

4. Vacuum suction nozzles

When selecting the suction nozzles for your tubes, you have the option of choosing between silicone or metal (aluminum). While both options are available, the majority of our customers (90%) prefer to use silicone nozzles, which we provide for free.

However, some customers may opt for metal nozzles, possibly due to influence from a foreign supplier. Ultimately, the choice between silicone and metal nozzles is up to you.

Where to Buy U-seal Vacuum Bags For Laminated Glass?

Where to Buy U-seal Vacuum Bags For Laminated Glass

Deer Hunter is a premier manufacturer and supplier of laminating vacuum bags that can be reused multiple times. The U sealing bags and Teflon coated PTFE mesh are specially designed for use in the vacuum bonding process of safety and architectural glass laminates.

We have built a reputation for not only offering high-quality products but also for providing exceptional technical support and customer service. This dedication to customer satisfaction has made Deer Hunter a standout in the industry.

Considerations Before Ordering a Silicone Vacuum Bag?

We believe you have found the right supplier. Below steps seem very useful for you to follow.

Seal Type: E seals or U seals?

There are two types of seal designs available for silicone vacuum bags, including U seal and E seal. The seal type you choose will depend on the size and shape of the item you want to laminate. U seal bags are typically made in foreign lands, while E seal bags are popular in China.

What is the External Size?

The size of the vacuum bag is one of the most critical factors to consider. You need to make sure that the bag you choose is large enough to accommodate the max glass you want to laminate. You should measure the size of your item and choose a vacuum bag that is slightly larger than the item to ensure a secure and thorough lamination process.

About Vacuum Suction Nozzles

How many nozzles do you want? Their location? Material is silicone or metal?

When assembling our products, we typically place the two silicone nozzles on either the short or long side. However, a customer from Brazil has requested that the nozzles be placed diagonally. Silicone nozzles are a popular choice due to their cost-effectiveness, but if metal nozzles are preferred, they can be provided for a fee of $20 per piece. Generally, silicone nozzles are durable enough for most applications and can withstand use until the bag is disposed of.

About Silicone Hose

What is the diameter of the suction pipe? What is the length of each?

It is commonly chosen from below diameters.

ItemsInner Diameter (ID)Outer Diameter (OD)
Nozzle A6mm12mm
Nozzle B9mm17mm
Nozzle C10mm20mm
  • 70%-80% of customers prefer OD-12mm and ID-6mm vacuum silicone tube.
  • 20%-30% of customers ever choose OD-20mm and ID-10mm silicone pipe.

Silicone tubes come in a standard length of 2 meters, but can also be customized to fit specific lengths, such as 3 meters or 5 meters. This flexibility allows for greater versatility in their use and ensures that they can meet the needs of a wide range of applications.

Do You Also Want Teflon Mesh Sheet 4mm*4mm?

Teflon mesh is made from high temperature PTFE coated glass fabrics. Its function is to ensure vacuum is evenly distributed and enable air to be removed from the laminate. It is placed flat between laminated glass and vacuum bag. This material is used as a barrier and effectively prevents the vacuum bag from puncturing and scratching. The breather fabric can also be a protective cover to avoid loose PVB/EVA residues contaminating the glass laminating oven.

A range of widths are available. We can provide this open mesh in rolls or sheets.

2370mm * 4570mm

1870mm * 3370mm

1950mm * 3500mm

2200mm * 100M

2570mm * 200M

Never Forget the Package and Shipment.

The packaging of the vacuum bags should be sturdy and protective to ensure that the bags arrive in good condition. Look for vacuum bags that are individually packaged in airtight bags or sealed in a carton box to prevent damage during transportation. The packaging should also include clear labeling of the bag size, material, and seal type.

The shipment method you choose will depend on your location and how quickly you need the bags. Most suppliers offer various shipping options, such as standard, expedited, or overnight shipping. Consider the cost of each option and choose the one that best fits your needs and budget.

Affordable Prices

Finally, price is an important consideration when choosing a silicone vacuum bag. While it is important to stay within your budget, you should also consider the quality of the bag and its suitability for your specific application. Choosing a cheaper bag that is not suitable for your needs may result in poor lamination results and wasted time and money.

Which is Better for Glass Lamination, U seal or E seals?

Well, that’s really a tricky question.

Glass lamination is a process of bonding two or more layers of glass together with an interlayer material, such as polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA). This process is used to create safety glass, which is designed to hold together when shattered, reducing the risk of injury from broken glass.

Laminated glass is commonly used in car windshields, skylights, and architectural glass applications. The use of silicone vacuum bags in the glass lamination process helps to ensure a strong bond between the layers and a high-quality finished product.

If you’re looking for a more convenient way to seal your thinner laminated glass, you might want to consider U-seal bags. These bags have modified edges and corners that make opening and closing them much smoother than regular E-seal bags.

If you’re searching for a vacuum bag that can handle thicker or curved laminated glass, consider using an E-seal vacuum bag. These bags are designed with superior air tightness, making them a great choice for a variety of glass applications.

Of course, whether you prefer U-seal or regular E seal bags ultimately depends on your personal preference.

Tips for Maintaining and Prolonging the Life of Your Bags

To get the most out of your silicone vacuum bags for glass lamination, it’s important to take proper care of them. Here are some tips for maintaining and prolonging the life of your bags:

(1) Clean them regularly with soap and water to remove any debris or residue.

(2) Store them in a cool, dry place away from direct sunlight.

(3) Avoid exposing them to sharp objects or rough surfaces that could damage the silicone material.

(4) Use a vacuum pump with a filter to prevent any debris from entering the bag and potentially damaging it.

(5) Replace any damaged or worn out bags immediately to ensure a strong and effective vacuum seal.


U seals and E seals are two types of silicone vacuum bag seals used in glass lamination. U seals have a U-shaped cross-section and are typically used for flat or slightly curved laminates. E seals have an E-shaped cross-section and are used for more complex shapes, such as curved or irregular laminates.

Both types of seals are made from high-quality silicone rubber and are designed to withstand high temperatures and pressures. However, the choice between U seals and E seals depends on the specific requirements of your glass lamination application.

Now I’d like to hear your take:

What are you doing to get, U seals silicone vacuum bags or E seals?

Or maybe you have a question about something from today’s guide.

Either way, let me know by leaving a quick comment from the right table sheet.

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