Common sewing equipment and maintenance

First, the basics of industrial sewing machines

 

(A) classification of sewing machine

Sewing is a major step garment processing, in this process, to complete the seam allowance, put together, pack seam, sew borrowing, Shang sleeves, keyhole, clinch, Shang zipper variety of jobs.

Industrial sewing machines crude into the kind of general, special, decorative and special sewing machines.

1, General Sewing

① industrial sewing machine is used in a wide range of apparel production amount of equipment, mainly for flat seams. In recent years, industrial sewing machine is the high-speed, computerized direction, speed from 3000r / min up to 5000 ~ 6000r / min; sewing functions except for general purposes, but also has an automatic reverse sewing, auto trimming, auto dial line, automatic presser foot pine needle position and automatic control up and down needle stop and protection features.

② overedger points 3 and 4-wire and 5-wire package sewing machine, in which a wide range of 3 packets of sewing machine (sewing machine, code-machine) and a 5 pack sewing machine applications.

③ stretch sewing machine is mainly used for knitted underwear cotton cloth, jersey stitching, rolled collar, trim, fold, stretch joints and so on.

2, special sewing machine sewing machine is used to accomplish a special sewing process of sewing machines, such as keyhole machine, button sewing machine, hub machines.

3, decorative sewing Decorative sewing machine for sewing a variety of beautiful decorative stitches and seam sewing machine, such as embroidery machine, zigzag sewing machine, crescent machines.

4, special sewing machine special sewing machines are able to process according to the set procedures, automate strict operating cycle of sewing machinery, such as automatic bag machine, automatic Shang sleeve machine, automatic sewing machines and other small pieces.

 

Second, the type of sewing machine

Industrial sewing machine is used in the production of clothing the largest number of aircraft. Bear in garment processing in the fight, together, Shang, sodium and other processes, installing different sewing accessories that you can complete crimping, cigarette, complex jobs fillets and other industrial sewing machine is therefore the most important garment sewing equipment.

1, according to the appropriate sewing material thicknesses have thin, medium thick and heavy types.

2. The number of the needle can be divided into single-needle machine, double needle machine and multi-needle machine, double needle machine according to two needle motion profile is divided and double needle sewing machine needle bar linkage can be sewn from flat machine.

3. The feed material dispensing mode can be divided into single-tooth under way to feed formula, front and rear differential, needle tooth synchronous, differential up and down and so on.

4. The operation speed industrial sewing machine can be divided into sub-low sewing machine, sewing machine speed and high-speed sewing machine.

5, according to the operation mode can be divided into ordinary sewing machine and computer-controlled sewing machine.

Third, the sewing machine configuration and usage

The use of industrial sewing machine

1, the needle selection and installation in general, sewing thin, crisp, dense sewing materials should be used in small (fine) needle, and sew thick, soft, sparse sewing material is suitably large (coarse ) pin. Sewing thin material with a thick needle, needle due to friction with the sewing material is large, random needle sewing materials needle rise rises presser foot tank, delaying the formation of loops, causing jumper; sewing thick When material such as the use of needle, it will cause the needle to bend or break.

In the high-speed sewing needle and intense friction timing sewing materials will lead to machine needle temperature is too high, a serious form Rongdong in synthetic fabrics or cause molten synthetic sutures, increased resistance to pinholes over the line, so that the upper thread forming condition deteriorates The cause skipped stitches or broken, and hence, special needle selection and cool.

When the high-speed low-melting synthetic fabric sewn, the needle may be double or high-speed machine needle, the needle section thick double needle increase rigidity, fine under section reduces friction needle and sewing materials, so that the needle temperature lower; tip portion and a pinhole size on both sides of the high-speed needle than the needle bar with diameters of 5% to 7%, can reduce the friction and heat of the needle bar and sewing materials.

Plus silicone oil and cooled by way of the suture needle can effectively reduce operating temperature, silicone oil colorless, transparent, easy volatile, can take away some of the heat when the needle high-speed sewing.

When you install the needle off the motor power, turn the last round, the needle bar to its highest position, loosen the screw mounted needle, the needle length tolerance toward the operator trough the left, then insert the needle handle lower portion of the needle bar needle hole, it hit the top of the needle bar hole, then tighten the screws mounted needle. Figure 3-9.

 

2, sewing thread and threading the choice in the selection of sewing thread should first consider their sewing ability, strength and uniformity, so as to ensure seams fastness. High-speed sewing needle thread should be selected using L line, and moderate twist, bottom left, D lines can be used. The manner shown in 3-10 suture rotation plans may identify, hands grasping the suture, turn right in the direction of the arrow fell sutures, if the twist strands more tightly, is left-handed lines.

 

 

Relationship Table 3-1 needle, thread, sewing materials

 

No sewing machine needle stitch material

9 # 80-100 thin public support material, crepe, georgette, organza yarn

11 # 80 - 100 public support of thin, silk, cloth, poplin

14 # 50 to 60 public support ordinary materials, cotton, wool fabric

16 # 30 to 50 public support in the thick material, wool fabric, waterproof cloth, thin leather, etc.

 

 

 

(1) threading: upper threading rod should be at the highest position of the hour, and then the lead wire frame head, threading sequence shown in Figure 3-11.

 

The bottom line when cited, the first upper thread pinch, turn the wheel, the outer rod downward, and then picked up on behalf of the highest position, and then pull the pinch of the upper thread, namely pulling up the bottom line. Finally, the bottom surface of the thread together the two placed in front of the presser foot.

(2) the bottom line around the law: ① into the winding bobbin rotating shaft, suture the bobbin around a few times; ② Press the full line springboard to make contact with the belt reel; ③ adjust the winding amount adjustment screw, the winding is about 80%, turn the adjustment screw to the right, winding amount is increased, and vice versa to reduce the amount of winding; ④ bias winding should be moved around the winding bobbins to correct state; ⑤ around At the end of the line full line springboard disengaged, the reel automatically stops, remove the bobbin. (Figure 3-12)

 

(3) bobbin loading of law: ① Hold the bobbin, the wire to turn right around and put it into the bobbin case; ② the thread through the bobbin sleeve trunking pulled through cramping By spring the line drawn from the thread hole; ③ pull when the bottom line should be the direction of the arrow to rotate the bobbin (Figure 3-13)

 

  Detachable bobbin case: ① Unlock the door cover that is capable of taking the shuttle bobbin case, if you open the door the shuttle bobbin cover should be prevented from falling out; when the bobbin case ② installed, it is fully plugged into the axis of the bobbin and closing the shuttle door. (Figure 3-14)

 

3, the stitch regulator down (cis) feed stitch length, stitch length dial can be rotated to adjust the A, digital dial gauge plate indicates the length of the dimensions (in mm). (Figure 3-15)

 

4, presser foot pressure should be adjusted according to the thickness of the fabric, first loosen the nut, as shown in Figure 3-16, load the thick material, should increase the presser foot pressure, presser foot that is forward rotation of the adjustment screw, so pressure. When sewing thin material, the opposite.

 

5, the bottom line of suture stitch adjustment tension adjustment, as long as the shuttle approved small screwdriver to turn the screw on the bobbin case A. shown in Figure 3-17.

 

In general, the bottom line such as the use of cotton thread 60, after the bobbin into the bobbin case and pull the thread through the bobbin case thread hole, pinch head straight lift bobbin case, bobbin case if they can slowly fall, can be used.

The upper thread tension lower thread tension as a benchmark. Adjust the upper thread tension mainly by adjusting the tension nut to achieve, after a trial sewing, stitch formation was observed, as shown in Figure 3-18.

 

① indicates a normal line of sewing thread stitch.

② represents the upper thread tight, upper thread tension is too large, should rotate counterclockwise clamp nut, loosen the upper thread pressure, shown in Figure 3-19. Random surface, the bottom line should mutually cooperate, shown in Figure 3-20.

 

③ indicates tight bottom line, indicating lower thread tension is too large, it should loosen the screw spindle skin.

④ represents surface, the bottom line is loose, should also adjust the surface, the bottom line of tension, so it fit.

⑤ represents surface, the bottom line is tight, should be on the hook clamp wire nut and screw simultaneously loosen skin.

6, the thread spring adjustment to change the thread tension spring ① swing amount, can loosen the thread tension spring seat adjustment screws ②, and turn the clamp screw ③; when you want to change the thread tension spring, loosen Location screw ②, and remove the clamp screw. Then loosen the clamp screw screws ④, and make adjustments.

7, feed dog working height adjustment Working height feed dog means exposing the needle plate surface feed rose to its highest position height. Sewing thick or stiff fabrics, feed dog working height is higher, and vice versa lower.

Tighten the screws to release the lift when the teeth when adjusting pendulum fastening screws, lift the teeth in the regulation of the pendulum reaches the appropriate height (Figure 3-22)

 

8, the needle and bobbin regulate the relationship between the needle and the hook should meet the following.

9, the thread take-up lever to adjust the amount of sewing different fabrics line should adjust the position of the hook, which relates to the merits of sewing stitch. When sewing thick material, move the line should be left hook to increase the amount of the thread. When making thin, hook line should move right to reduce the amount of the thread.

   10, sewing machine lubrication due to the rapid industrial sewing machine speed up to 5500r / min, and the requirements of the various sports bodies cooperate with each other exactly, as the machine can be maintained for a long time due to work precision and performance, can have a longer life, There are good sports stability and low noise, lubrication important link in use.

 

    Fourth, analysis and maintenance of industrial sewing machine with a common mechanical failure

 

1. Jumper

(1) contingency jumper.

One reason: the machine tip hairy, bending the needle, and the needle slot is not smooth or inappropriate choice.

Remedy: Replace the appropriate new needle.

Two reasons: the installation skew needle, and the needle and bobbin distance properly.

Remedy: Adjust the needle and hook point distance, so that within the standard range.

Three reasons: the suture uneven thickness, twist uneven influence lines ring.

Remedy: Press the criteria for selecting good quality sewing thread.

Four reasons; the needle bar height is wrong.

Remedy: Adjust the height of needle dry.

Five reasons: bobbin mouth wear.

Remedy: grinding and polishing.

Six reasons: presser foot pressure is too small, the suture jitter, hid the line, the impact into the ring.

Remedy: increase the presser foot pressure.

Seven reasons: presser groove is too wide, the time machine needle cloth exit, the impact of rising fabric line ring. This affects the maximum sewing thin material,

Remedy: According to the fabric of the presser foot move left, right, can be wide slot solder filled.

Cause eight: thread tension spring too, fabric, needle, thread mismatch.

Remedy: appropriate adjustment tall wire spring.

Nine reasons: needle plate hole is too large, when sewing thin fabrics fabrics random drop, form a delay line ring.

Remedy; replace the needle plate.

Cause ten: bobbin positioning is not standard, hook tip and the needle is too far away or so.

Remedy: standard appropriate adjustments.

(2) Continuity jumper.

One reason: high-speed sewing machine needle and thread heat, soften the suture line is difficult to form the desired ring.

Remedy: When using fiber line speed sewing, can be used in surface line over the line at the plus silicone oil cooled, or the use of compressed air to blow needle cooling.

Two reasons: the line quality is too large, the suture subject to greater stretching action, not easy to form loops.

Remedy: transfer of small on-line tension, sewing thread sewing materials when subjected to stretching below as small as possible.

Three reasons: the transition parts of different thickness of sewing, or sewing different hard and soft, elastic fabric caused by the jumper.

Remedy: Depending on the nature of the fabric Bohou and timely adjustment of the machine with the size of the various components.

2, section (a) line

   Lock stitch made on-line, off the assembly line interwoven, it can be divided into two types of cross-hatching and breaking the bottom line. Surface (top) line through which large parts, the reason is more complex.

(1) sewing machine a start on the line that is broken.

One reason: anti-loaded needle or needle handle is not the top place.

Remedy: Check the needle and the needle handle.

Two reasons: the last round reversed.

Remedy; check last round rotation.

Reason Three: The needle thread tension is too much pressure.

Remedy: Check whether the tension is normal.

Four reasons: on-line threading sequence undesirable.

Remedy: Required to wear lead on the line.

Five reasons: less than assembly requirements.

Remedy: Check the registration gap hook and bobbin, needle and shuttle between the mouth.

(2) during normal sewing section line

One reason: the sewing machine needle or mismatch.

Remedy: use the fabric to adapt to the needle and thread.

Two reasons: poor quality sewing thread.

Remedy; selection of high strength sewing thread.

Three reasons: the pinhole edge is not smooth or has a burr on the needle groove.

Remedy: polishing.

Four reasons: bobbin mouth or hook tip burr, flaws or finish is not enough.

Remedy: triangular Whetstone, polishing paste, grinding gap and so on.

Five reasons: thread tension spring too tight, too inflexible or gripper uneven pressure.

Remedy: Adjust the thread tension spring height, properly adjusting the clamping pressure.

Six reasons: thread tension spring too tight, loss of elasticity, when the bobbin door shuttle tilt operation, the suture blocked.

Remedy: The shuttle door bottom springs stretched or replaced.

Seven reasons: Needle overheating, suture is blown.

Remedy: a "needle heat measures."

Eight reasons: plane thread guide hole portion nap, when sewing movement blocked.

Remedy: polished with emery cloth strip, and then wire coated with polishing paste pull ground smooth or polished.

(3) reverse stitching break

One reason: feed dog and needle mismatch.

Remedy: adjust according to the standard feed dog and needle fit.

Two reasons: the on-line through the site smooth cloth.

Remedy: sew the side lines when the site after polishing.

3, breaking the bottom line (offline)

One reason: the feed dogs edge acute angle.

Remedy: polish or polish with gauze.

Two reasons: the location of the feed dog too low, offline and bottom feed dogs occurs outlet access to the suture wear off.

Remedy: Adjust the feed dog height position.

Reason Three: The shuttle leather pressure line port threading gap due to wear.

Remedy: Replace.

Four reasons: winding the bobbin too full, not readily qualify.

Remedy: about the bottom line can not be higher than the bobbin.

Five reasons: bobbin leather feathering, wipe off the bottom line.

Remedy: grinding only at the bobbin edge skin.

Six reasons: the bobbin and bobbin with accuracy, periodic re-rolling phenomenon occurs.

Remedy: Check the bobbin and bobbin thread tension is uniform when viewed.

Seven reasons: the quality of the bobbin.

Remedy: Check the outlet is located in the upper left side of the groove of the bobbin holder.

4, bottom or floating noodles

One reason: the bottom line, the upper thread tension is too large or too small.

Remedy: Adjust the clamping nut and the adjusting screw shed skin.

Two reasons: the feed dog and needle and thread take sports mismatch.

Remedy: Adjust the position of the needle mechanism and the feed teeth mechanism.

5, towels, floating,

One reason: the rotary hook beak and plane rough, scratched, causing the line when tightening blocked.

Remedy: grinding bobbin over the line each site.

Two reasons: sewing thread around the hook on the positioning flange, the upper line outlet poor.

Remedy: Clear the wound on the positioning hook of the suture.

6, when not floating float float

One reason: the bobbin and bobbin case with inaccurate.

Remedy: Optional for the bobbin and bobbin case.

Two reasons: the toe plate under the pressure of the shallow groove is too short, hid wire.

Remedy: drawing with a fine gauze, elongated toe plate under the knife out of the pressure trough.

7, needle

(1) of the needle occasionally

One reason: the needle becomes bent, hairy or fixed needle tip is not tightened screws.

Remedy: replace or tighten.

Two reasons: seam thickness uneven films garment sewing speed is too fast, the needle shifted, causing the needle to break.

Remedy: should be appropriate to slow down.

Reason Three: The operator incoordination, sliding sewing sewing material is too complicated to make the shifting of the needle, and the needle plate collision.

Remedy: correct use, action should be coordinated.

(2) Continuity needle

One reason: the clamp fixing screws are not tightened.

Remedy: Check the presser foot screw and the presser foot position and tighten the screws.

Two reasons: the narrow needle plate, pinhole and needle concentricity error is too large.

Remedy: re-matching needle plate or needle plate adjusting screw until the needle and the needle plate hole concentricity error of less than 0.2mm.

Three reasons: the needle and feed dog with the bad, are not synchronized.

Remedy: Adjust the needle and feed dog sports complexes.

Four reasons: the needle stroke is not correct, and other kinematic mismatch.

Remedy: Check machine needle stroke crank screws are tightened at recess.

8, bad cloth, fabric stagnation not before.

One reason: the presser foot pressure.

Remedy: transfer of small presser foot pressure.

Two reasons: the feed dog tilt.

Remedy: The feed dog position adjustment accurate alignment.

Three reasons: the feed dog position too low.

Remedy: Adjust the feed dog is exposed from the needle plate to the correct position.

Four reasons: the presser foot pressure is too small or the pressure section is not smooth.

Remedy: appropriate to increase the presser foot pressure or light pressure repair department.

Five reasons: the knife mounted too high, or too blunt knife trimming.

Remedy: After grinding in place.

Six reasons: Feeder pieces badly worn, with too loose.

Remedy: repair and adjustment.

9, fabrics wrinkle

One reason: the feed dogs velocity greater than the speed of the needle bar movement.

Remedy: The speed to standard or slightly slower than the speed of movement of the needle bar.

Two reasons: the feed dog position is incorrect.

Remedy: The feed dog position adjustment, or adjusted from high to low state, the pressing surface reduce foot and feed dog contact surfaces to prevent fabric wrinkling.

Reason Three: The feed dog needle plate up too much.

Remedy: Adjust the feed dog is exposed from the position of the needle plate, feed dog above the needle plate when sewing thin fabrics to 0.6mm.

Four reasons: use of needle too thick.

Remedy: needle exchange,

10 stitches bad.

(1) stitch length uneven

One reason: the high speed sewing machine.

Remedy: reduce speed within the permitted range.

Two reasons: The presser foot pressure is weak.

Remedy: increase the pressure appropriately.

Reason Three: The tension on the line, or small thread tension.

Remedy: down or increase tension.

(2) trace skew

One reason: the feed dogs and presser plane is not parallel.

Remedy: grinding or replacement.

Two reasons: the needle bar thread hook and needle bar thread sets malposition.

Remedy: install positive wire hooks and wire sets.

11, poor lubrication

One reason: the oil sump oil level is too low

Remedy: to add oil as required between the two lines.

Two reasons: the oil plug, oil network congestion, the suction line is short.

  Remedy: clear, inspection and replacement.