Button holing and button sewing together is a fastening mechanism that is a must operation in most of the garments. The operation is so stereotyped that small developments over the years have gone unnoticed although performance of button holing and button sewing has improved substantially. In this article, Team StitchWorld takes a look at the button sewing and button holing machines, their evolution of technology, common features offered by different brands and their individual USP.
Button Sewing
In earlier button sewing machines, the x-y direction movement of fabric clamp was controlled by cam-follower driven mechanism, resulting in long machine setup time during changing from parallel-stitch to cross-stitch. Nowadays, the x-y direction movement of fabric clamp is controlled by microprocessor based drives, which require no physical change of cam but only change of programme by a mere press of a button, thus offering unprecedented flexibility of sewing various patterns.
Another important changeover from past was moving forward from chainstitch to lockstitch button sewing. Nowadays, most of the button sewing machines are lockstitch due to retailers’ preferences as lockstitch button sewing is more secure than chainstitch button sewing. Button sewn by chainstitch is prone to falling off due to unravelling characteristics of any chainstitch. The security aspect was started with children’s garment where if any button falls off during use and is swallowed accidentally by a child, may lead to paying millions of dollars of compensation if sued. Now retailers prefer or demand lockstitch button sewing for all garments, and due to its popularity it is rather difficult to find suppliers offering chainstitch button sewing machines today. Whereas a few brands still offer chainstitch button sewing with knotting mechanism, the newly developed needle thread grasping mechanism helps produce consistent knot tying at the beginning of sewing. To prevent the buttons from falling off, the chainstitch button sewing models are equipped with secure stitch device which provides double end stitch knotting.
Flexibility with speed being the motto nowadays, button sewing machines can sew not only 2- or 4-hole buttons but also 3-hole and 6-hole buttons with finger touch setting change at the speed between 2,500 ~ 3,200 RPM.
The machines are generally provided as standard between 30 ~ 99 different sewing patterns for easy changeover of sewing patterns with the memory capacity of storing 2,00,000 stitches.
Auto-lifter is present in many models that use a new stepping-motor system reducing operator fatigue. It is also possible to changeover the stroke of the auto-lifter from a one-step stroke to a double-step stroke, which offers easier positioning of a material on the machine. The work clamp foot lift is maximum 13 mm to accommodate the thick working material, also to have better clamp grip on differential thickness area, nowadays split clamps are used, which is becoming common among brands.
[bleft] Another important changeover from the past was moving forward from chainstitch to lockstitch button sewing. Nowadays most of the button sewing machines are lockstitch due to retailers’ preferences as lockstitch button sewing is more secure than chainstitch button sewing. [/bleft]
To prevent material from being stained, almost all brands have adopted dry head technology; hence no need of lubrication, here the needle bar is oil free type, preventing any oil or grease dirt on the product.
Many brands offer active tension mechanisms standard feature which enables setting of needle thread tension that matches various sewing conditions such as thread, material and sewing speed. All the models can be used to sew buttons with the diameter ranging between 8 mm – 32 mm capable of sewing varying stitch length between 0.1 mm – 12.7 mm with intermittent or continuous feed system. Even the button sewer patterns can be reduced or enlarged (10% to 200%) to suit different buttons, by using the simplified push button given on operator control panel.
[bleft] Auto-lifter is present in many models that use a new stepping-motor system reducing operator fatigue. It is also possible to changeover the stroke of the auto-lifter from a one-step stroke to a double-step stroke, which offers easier positioning of a material on the machine. [/bleft]
Some of the models are equipped with auto thread trimmer and automatic button feeder. Nowadays, most of the models use direct drive technology instead of belt driven motor. Some models are equipped with skip stitch detection device which controls the formation of a secure seam and gives a signal for missed stitches or sewing errors and shows functional deficits of the machine, such as an incorrect setting of the sewing parts.
Button Holing
Button holing machines are primarily variation of zigzag lockstitch machines or zigzag chainstitch machines with clampfeed system for feeding material. Similar to button sewing in earlier generation of button holing machines, the x-y direction movement of fabric clamp was controlled by cam-follower driven mechanism, resulting in long machine setup time during changing of shape of button holes. Nowadays, the x-y direction movement of fabric clamp is controlled by microprocessor based drives, which require no physical change of cam. By press of a button, different shapes of button hole can be made in same machine.
One very important change from the past is that no change of blade is required for different length of button. Earlier, with change of length of button hole cutting blade size was also required to be changed; this resulted in machine downtime. Now one small size blade does the cutting by multiple cutting strokes along the length of button.
In the past there was clear difference between straight button holing and eyelet button holing machines, while the straight button hole machines are lockstitch type with cutting happening after sewing of button hole, eyelet button hole machines were chainstitch machines with cut-before or cut-after mechanism. However, with electronic shape control mechanism and having multiple blade options in one cutting block, straight button hole machines are offering unlimited choices.
Other important features that improved the quality and performance of button hole are separate upper and lower thread tension control mechanisms, tacking or stabilising stitch around the cut, etc. and ergonomic and user-friendly features like integrated LED-sewing light, semi submerged sewing head, etc. The “active tension” (electronic thread tension mechanism), enables not only duplicating the same sewing conditions with ease but also of ensuring upgraded seam quality with consistency.
Select the machine carefully based on the product one is doing presently and also keeping the future expansion plans in mind since the machines come with variety of specifications to handle varied designs and usability. The speed of the sewing button hole can vary between 3600 – 4200 SPM with the maximum width of 2.4 mm – 5 mm. The length of the button hole may vary from 6 mm – 70 mm in various models available in the market, while 30 – 51 patterns are provided in the system of the operation panel as standard for easy changeover of pattern.
Some button holing machines are equipped with basting stitch mechanism, which is effective for button holing on elastic materials such as knits. Due to the free programming possibility and a sewing field of 6 mm x 70 mm, the fields of application are unlimited. The fine adaptation of the button hole to various materials is done at the touch of a button.
The optimized sewing kinematics guarantees an excellent stitch pattern, even with difficult materials. Some brands not only allow a longitudinal, but also a transversal installation so that an easy change of a long and crosswise button holes can be made. Generally, the upper and lower thread trimmers were driven by one motor. However, in some brands and models, the upper and lower thread trimmers operate independently. Almost every brand offers an alternate cutting device for a clean cut without pulling (chopping cut mechanism) the thread.
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