BAS Bridge Sewing Series – A Mighty Sewing Innovation
Updated: Jul 21, 2021
One of the advanced sewing technologies of Japanese technology giant Brother is ‘Bridge’ type sewing technology that is applied to electronic programmable machines such as 360 and 365 series machines on NEXIO platform. The biggest plus of these machines is a combination of ‘fast sewing, accuracy and compactness’.
There are a number of sewing technologies that are marketed today by individual companies for component assembly in garment products and for streamlining the production in different ways. Though the developments keep happening in the industrial sewing sector, the apparel or textile manufacturing industry many times misses on the opportunities to understand the technicality of a new sewing innovation. Added to this is the fact that no sewing technology exhibitions are happening in COVID-19 era, so there are high chances that the end-consumers of industrial sewing machines are unaware of the latest developments in the sewing arena.
Therefore, to spread awareness about new sewing innovations, Messe Frankfurt conducted a webinar some time ago which saw experts from Brother International Corp., JUKI and Mitsubishi Electric Industrial Sewing Machines share the latest available technology to sew and seal materials and led discussion that dived deeper into efficiency improvements, production improvements and maintenance impacts in the sewing and sealing marketplace.
This feature talks about the new BAS Bridge technology launched by Brother and the information is shared by Rick Frye, Director of Engineering & Sales, Brother.
Bridge Type Sewing Machine Technology by Brother
One of the advanced sewing technologies of Japanese technology giant Brother is ‘Bridge’ type sewing technology that is applied to electronic programmable machines such as 360 and 365 series machines on NEXIO platform. The biggest plus of these machines is a combination of ‘fast sewing, accuracy and compactness’. It’s worth mentioning here that programmable machines have been there for years and Brother was one of the first companies to introduce these, probably in late ’70s, at a time when other sewing companies started to get some recognition in the market for their innovations. A number of products can be made using BAS Bridge type machines including outerwear, apparels, shoes, hand bags, airbags and can be of both types – small area and large area.
Technology of BAS Bridge model machines aims at addressing current issues in sewing…
Brother’s unique control technology prevents pattern shape loss when sewing at high speed which is a key addition in BAS Bridge machine, leading to higher sewing quality and productivity even at high sewing speeds. The highly rigid ‘feed mechanism’ suppresses deflection while providing precise movement; hence it keeps accuracy of stitch point.
Movement of needle and feed plate – The working principle of BAS Bridge machines is completely advanced and differs from stitching process with large sewing area in conventional arm bed type models. When arm bed type models’ sewing area gets expanded, it needs to lengthen the arm and the feed of Y-direction that increases the incidence of slacks and deflection when sewing happens at high speed. Therefore it needs to decrease the sewing speed and this reduces not only sewing quality but also productivity.
Whereas BAS Bridge type machine technology allows the needle (sewing head) to move in X-direction and the sewing fixtures move in the Y-direction. As the feed mechanism of X and Y are separated, the load to each feed point is reduced – realising the ideal spec, ‘Large and Fast’. This is where BAS Bridge type machine stands out!
In Image 1, the needle can be seen moving in X-direction (red coloured arrows) in the top view of bridge type machine, while the feed plate (clamp fixture) moves in Y-direction (blue coloured arrows). On the other hand, in the conventional arm bed type model, needle point remains fixed. This allows the higher speed in bridge type machine without the concerns or issues of inertia or having to use extremely high-weight material. This is where new models of BAS Bridge machines hold an edge over conventional arm bed type models in terms of accurate stitch point and stitch placement. Major difference is the fixture movement.
Footprints – Further, the bridge type models provide small footprint. As mentioned above, the needle (machine head) also moves in these machines which decreases the driving area of X and the same thing goes for feed plate’s movement in Y-direction so the table for setting the bed isn’t needed and it provides smaller footprint. (See Image 2)
Sewing accuracy – Another shortcoming in conventional arm bed type model is that it gets sometimes difficult to keep it on high-rigid mode if some parts rise in the size with the upsizing sewing area even if it has been highly evaluated for its accuracy of pattern sewing. Thus it needs to sew parts at low speed to maintain sewing quality with large sewing area in such models. On the other hand, the movements of needle and hook in such machines never shift in BAS Bridge models as they are placed separately and each feed belt is connected by one drive shaft. This is another reason the sewing quality is never compromised in such bridge machines.
Closed loop servo control – Since inception, there has been a rigorous use of open loop control in majority of sewing machines…But, the new-age BAS Bridge type machines are equipped with closed loop servo controller. According to Brother, feed drifting doesn’t occur in these machines even at high speed because the user has an option to send signals to motor and at the same time the feedback is sent back to control box with proper suggestions, eliminating any sort of drifting error chance. (See Image 3)
Key Product Features of BAS Bridge Type Machines
Intermittent Sewing – The sewing is called ‘intermittent’ when the movement is stopped each time the needle enters and exits the workpiece during stitching process. In BAS Bridge type machine, the data is resolved at 0.05 mm per pulse – making slanted stitch lines and curves more accurately sewn that provides excellent ‘Intermittent’ sewing movement! (See Image 4)
Digital Tension – Bridge technology also provides powerful digital tension. Various sizes of sewing threads can be used by the new digital tension which increases the setting range of the upper thread tensions and that helps in sewing of extra heavy materials like airbags, leather, etc. (See Image 5)
Pulse motor advantage – In new BAS models, the thread trimming mechanism is driven by the pulse motor. The upper thread cutting amount can be kept constant because the thread can be cut after the needle or thread take-up lever stops by a single drive. The use of pulse motor has improved the cutting force.
In conventional machine, the presser foot stroke is controlled mechanically so that stroke remains the same always, no matters what. While with the pulse motor, stroke of presser foot can be changed any time. So, if an operator is joining 2 layers, 4 layers or more, the stroke can be increased accordingly and pressure can be increased. Stroke adjustments have been brought down to 30 seconds in new BAS Bridge models from 300 seconds in BAS-H models.
Reduction in thread breakage – In BAS Bridge type machines, defects that occur due to needle breakage have been reduced down to negligible by bringing the sensor closer to the needle. This improvement reduces time loss in sewing. The conventional models have the sensor in the centre of the arm but this new machine series has it closer to thread take-up lever (faceplate) where thread breakage is more likely to occur.