Arthur C. Clarke, one of the highly influential British science fiction writers from the last century, had once said that “any science or technology which is sufficiently advanced is indistinguishable from magic.” It’s quite the same when one talks about sewing a garment without a thread – that’s heat sealing.
Though it’s a technology that has existed since the last 70 years, Thai Son SP Sewing Factory is all set to bring the technology yet again on the centre stage. “It’s an outerwear seam that is so strong that one cannot tear it with bare hands,” averred Chris Walker, Marketing Manager, Thai Son SP Sewing Factory, Vietnam while speaking to Team Apparel Resources. “Heat seal seam is already popular for woven but it is new for knitwear in Vietnam. This year we want to bring heat seal seam to the forefront,” added Phuong Thai, COO, Thai Son SP Sewing Factory, Vietnam.
Having started as a manufacturer of leather jackets and down jackets, the company today sews garments for men, women and children using circular knitted fabrics. Embroidery and screen printing facilities are outsourced, whereas sourcing trims, sewing, quality control, and packaging are all done in-house. Their 15 sewing lines and 2 sample lines produce more than 2,00,000 pieces every month. The company caters to various renowned brands across Russia, UK, Poland and France, and believes in enhancing the relationship with their clients. However, the focus of the management at Thai Son SP, of late, has been on relaunching the heat seal seam technology.
The process of joining fabric pieces by using the correct pressure and heat coupled with adhesive films or reinforcing tapes is what defines heat seal technology. The two main methods of joining the fabrics through heat sealing are dielectric welding and rotary welding – the latter being the process of feeding both pieces of fabric into a continuous roller.
Thai Son SP specializes in using ultrasonic vibration method of heat sealing at an economical cost and has purchased two heat seal seam machines. Corroborating on the way the method works, Chris says, “The power supply converts the electricity from 60 to 20,000 Hz. Once the incoming high frequency electrical signal is converted into mechanical vibration, the booster emits the vibration energy and serves to increase its amplitude. A horn transfers the vibration energy to the fabric to be worked upon. The anvil supports the fabrics as they are exposed to the vibrational energy, which is heat. The ultrasonic vibration is then transmitted from the horn to the material developing frictional heat where they touch. This transient heat fuses the fabric edges to create an inseparable bond.”
Does heat sealing work on any fabric? 100 per cent synthetic materials are the ones on which heat sealing works best. Similarly, blends with 40 per cent natural fibres are also suitable for heat sealing technology. The ultrasonic vibration method that Thai Son SP specializes in works best on materials such as nylon, polyethylene, polypropylene, spandex, acrylics, acetates, polyester and PVC. “We can source these fabrics for you and sell to you on freight on board (FOB) basis or landed duty paid (LDP),” mentioned Chris.
Thai Son SP also offers two seam variations namely butted or overlapped. While the butted seam uses an ultrasonic cutter or laser-welding machine to trim and produce a butt joint between two sections, the overlapped seam is where the two cut sections overlay each other and the bonding agent, if used, bonds the face side of one section to the back of the other. In the case of butted seam, the resulting seam requires a reinforcing tape to ensure joints are strengthened. These tapes are available in several colours.
Heat sealing is unique because it is done without any use of thread or even adhesives and that too at a speed that is twice the speed of the traditional sewing machines. It significantly reduces the labour cost, which is already low in Vietnam – embracing heat seal technology gives Thai Son SP an edge over several of its competitors.
Is there any substitute to comfort especially when it comes to wearing dresses? The answer is ‘No’– and it’s same for tight fitting undergarments as well. That’s why welded heat seal seams are these days used in large numbers for babies’ training pants and women’s bra. The skin gets rubbed much less in finished seams than conventional seams as the former are lighter and flatter. “It is comfortable, beautiful, durable, tensile and easily washable and that’s what we always look for,” remarked Phuong Thai.
There are few factories in Vietnam that can do what Thai Son SP does in low quantities like 1,000 pieces per two colourways – not to mention sourcing trims and accessories. “We source trims and accessories from Korea, China, Taiwan and locally. Working with medium-sized brands that have clear technical specifications and an experience design team is our goal. We can match their professionalism,” explained Chris. With an excellent sourcing team, both locally and globally, the company also sources screen printing, embroidery, sequins and embellishments – adding to the strength of Thai Son SP.
What makes Thai Son SP stand out among several other SME factories in Vietnam is the exuberance and pro-activeness of Thai Van Thanh, Director, Thai Son SP Sewing Factory, Vietnam – exuberance to add value to services. Chris adds, “We offer services ranging from sourcing raw materials, sewing them together, doing quality control, packaging them, putting them into cartons and getting them to the nearest port.” There are still many steps in the supply chain and Phuong Thai is very keen to add lot of value to all those steps. Her keenness to add lot of value to each of the steps in the supply chain is intended to make things easy for every customer thereby enabling to make the final FOB price-competitive.
Thai Son SP, an SA8000 and BSCI-certified firm, has already made a name for itself as a complete Vietnamese family owned business – and with their new endeavour to make garments for brands using expensive technology at an affordable price, there seems to be no stopping for Thai Son SP.