What is Bemis Sewfree®?
Bemis has developed a series of adhesive films specifically for adhesion to the textiles most commonly used in the apparel market. “Sewfree” is the registered trademark for this series of adhesive films. These adhesives bond a variety of fabrics together to form a soft, durable and elastic bond.
Why should I use Bemis Sewfree®?
Sewfree® adhesive films allow you to replace sewing. Sewfree® makes garments lighter and more comfortable, and with a lower profile. They also enhance the water-resistant properties of your garments and gear. It allows designers unprecedented flexibility to design unique features into the garment that are not possible with stitching. Since it is film adhesive, it offers a continuous bond. When the correct adhesive and proper sealing conditions are used, delamination during wash cycles is eliminated.
How does Bemis Sewfree® work?
Bemis Sewfree® adhesive is a thermoplastic film. It requires heat to activate it, pressure to make it penetrate the fabric, and time under heat and pressure to make sure the adhesive reaches the proper temperature and melt flow. A combination of chemical and mechanical bonding will result in a strong, durable and elastic bonded garment.
Are there different Sewfree® adhesives?
Yes, Bemis offers a variety of adhesives under the Sewfree® trademark. Each has its own unique properties. We can offer adhesives with low activation temperatures, highly elastic adhesives and high-temperature adhesives for molding applications. Our Selector Guide shows you different adhesives that are offered for Sewfree® application.
Are Sewfree® adhesives durable?
Bemis adhesive films have been used in the apparel market for 25 years. They have been used to adhere a variety of fabrics in many different applications. When the adhesive is properly selected and bonded, the bonded parts are extremely durable. Bonded garments withstand many wash and dry cycles without delamination.
I want to use Sewfree®. Can you help me evaluate my fabric and concept?
Absolutely. Our technical centers in both the US and Hong Kong can work closely with you to test your selected fabric and help evaluate which Sewfree® adhesive should be used in your design. Our dedicated technical staff will work closely with you to select the correct adhesive and establish the proper sealing conditions.
What type of testing should I do to make sure I am using the correct Sewfree® adhesive and proper sealing conditions?
When you have selected your fabric and have a design concept, a series of tests can be run on the fabric to select the correct adhesive and establish the proper sealing conditions. In the prototype phase, garments should be run under control conditions and tested for bond strength, elasticity and moldability (where needed). The bonded garments are washed to test durability. In this evaluation, minimum bond-strength and elasticity requirements are established.
How do I test my garments during production?
Based on initial testing of fabric and evaluation of the prototype garments, minimum bond-strength requirements and elasticity numbers will be generated for the garment. Simple bond testing and elasticity testing can be done during production to ensure durability and consistent fit of the garments.
I already use Sewfree®. Can I apply heat to the adhesive more than once?
Sewfree® adhesive films are thermoplastic and they melt and flow into the fabrics to form a bond. The final bond is the result of both chemical bonding (adhesive adheres to fibers of the fabric) and mechanical bonding (adhesive penetrates the fabric and anchors itself). In many applications, the adhesive must be transferred to a fabric first, and then bonded to a secondary fabric. In this type of process the adhesive is exposed to two, sometime three, heat cycles. The adhesive can give very good bond strength depending on sealing conditions in each cycle. However, if the adhesive is exposed to repeat heating, it is possible to push the adhesive completely into one fabric and not leave anything on the glue line. This will result in poor bond strength. We highly recommend you do the testing on the part of the garment where the adhesive is exposed to the same sealing conditions more than once to make sure it has not been completely driven into the fabric.
What are the recommended storage conditions for Sewfree® adhesives? Do they have a shelf life?
Bemis adhesive films are composed of thermoplastic polymers and can be stored in a wide range of temperature and humidity conditions without adverse effects. Our records and tests on retained materials allow us to conclude that the useful life of Bemis Adhesives is greater than two years [from the date of manufacture].
The quality of Bemis adhesive products may be extended by storing in the range of 20-35°C and relative humidity between 45-75%.
As Bemis products are thermoplastic, excessive temperature and humidity can alter performance. If material is older than two years or suspected to have been exposed to excessive temperature and/or humidity, a test application is recommended. We also recommend that our customers use a FIFO (first in/first out) system.
Does Sewfree® adhesive yellow?
Sewfree® adhesives have been used in the sportswear and intimate apparel market for over ten years. The adhesive does not yellow under normal conditions.
When using white fabrics, it is advisable to make sure the pH of the fabric is below seven to eliminate any reaction with the adhesive, which could cause discoloration. We also recommend the bonded garments be stored in such way as to minimize high exposure to nitrous oxide.
I have an ultrasonic machine. Does Bemis Sewfree® work using ultrasonic?
Bemis Sewfree® adhesive can be activated using an ultrasonic sealing machine. In many instances, dwell time can be reduced using this method.
What about Radio Frequency (RF) or High Frequency (HF)?
Yes, the chemistry and flow properties of Bemis Sewfree® adhesives make them suitable to be used with RF or HF machines.
Where are Bemis’ technical centers?
We have two complete and well-equipped technical centers. Our USA technical center is located in Shirley, Massachusetts (40 miles west of Boston) and our Hong Kong technical center is located in Quarry Bay, Hong Kong Island. Both technical centers are open to our customers for demonstration and testing of their fabrics and concepts.
What about factory support?
Bemis has technical resources positioned globally to provide factories prompt support on issues related to seam tape or Sewfree® processing, training needs, establishing QC protocols to ensure consistent bonded and/or taped garment quality, etc.