(1) Component structure of the handle
The structure of the handle consists of three parts, that is to say, the handle consists of three parts, namely, the external part, the middle part and the internal part. The external parts have the face and half circle, the middle parts have the core and pad core, and the internal parts have the base plate.
① surface: surface is the outer surface of the handle, is the most conspicuous part of the handle, the fabric used is generally the same as the main material and need to use the better part of the fabric, it requires a smooth surface, fabric thickness in 0.5 ~ 1.0mm. such as artificial leather for the fabric requirements to take the cross-wire direction. Put the surface of the shape diagram and size.
② core: core is the core part of the handle, it determines the shape and comfort of the handle. The core is shaped like a shuttle, and is made of several layers of yellow cardboard and several layers of leather overlapping and glued together. Cardboard with three to four layers of yellow cardboard, and in the middle of the yellow cardboard sandwich two layers of leather material. The purpose of leather material in the middle of the cardboard is mainly to enhance the strength of the core, to prevent the cardboard core fracture defects when bending molding. The total thickness of the core is generally 12~15mm.
③The base plate: the base plate is the core part of the handle to bear the weight. The handle is connected to the half circle by the bottom plate, and then the half circle is connected to the bracket and become, it bears all the weight of the box when carrying.
The bottom plate is made of 2.5mm or 3.0mm leather, also available in two or three layers of thin leather glued together. If you use a layer of artificial leather, you need to glue with yellow cardboard, and in the middle of the molding needs to be lined with 15mm wide, 0.3~0.5mm thick iron, in order to increase the strength of the bottom plate to bear the weight. Generally speaking, the bottom plate should be able to bear the weight of more than 50kg. The choice of materials for the base plate determines the life of the handle.
④Pad core: pad core is the pad in the bottom of the plate below the parts, handle in the molding it can make the bottom of the plate round and full. Pad core is made of three to four layers of yellow cardboard overlap composite, positioned under the bottom of the board. When the handle is bent and shaped, the two end pieces of the core will be bent diagonally on the base plate, and then fixed with needle stitching.
⑤ semi-circle: semi-circle is the metal circle connected to the handle, it has a semi-circle and rectangular two.
(2)The production process of the handle
The production process of the handle is complex, detailed, and requires a high level of technology. The operation process is as follows:
① gluing core: the yellow cardboard cut into four pieces of 165mm long, 26mm wide material block, and then cut the leather into two pieces of 70 long 165mm, 26mm wide material block. Then use the adhesive to glue the cardboard overlapping together piece by piece, in the first layer of cardboard and the second layer under each sandwich layer of leather blocks, if a layer of thick leather then use the cardboard to sandwich the leather blocks in the middle. After gluing in the press for 10~15min, take out and wait for the adhesive to dry and then use.
② cut the core: the glued core two ends cut flat, length size is 160mm, and then the core sample composite in two fluorine head cut flat on the core, with an awl or paddle cardboard cone along the edge of the core sample to draw lines, the depth of the line for a layer of cardboard thickness of 1/2. with a knife along the painted lines to cut off the excess cardboard edge outside the line. The cut core is spider-shaped, and can be cut and punched on the cutting machine with the knife mold when producing in batches.
③Take the core: Firstly, paste a layer of yellow cardboard of 160mm in length and 38mm in width on one side of the web-like layer of the bottom board blank, and then apply adhesive to the cut core on the front side ( the side of drawing lines ), and take the cardboard on the paste, with both ends at equal distance from the edge.
④ cuttings put the core: put the core of the glue hitch in the bottom of the put the core across the flat pad, on, first in the two ends of the core with a piece of blade slant, the operation from the right piece to the left, the starting knife from the end of the core cuttings core length for the core of about 1/3. Put the core end of the thickness of the retained cuttings round cuttings core for the core thickness of 3/4 or 2/3. put the core at both ends of the piece of slant after the core will be placed vertically on a flat mat, with a scribe will cut the core into a semicircle. Cut the core with the left thumb, index finger surface snap on the end of the bottom plate, the beginning of the knife into the cuttings can be larger, and later, with the gradual formation of the surface round, cuttings into the amount of knife can be gradually reduced, until the surface cut round. Note that the surface should be cut round, no joint knife marks, cuttings and then sandpaper sanding, and then do both ends chamfering. When operating, put the cuttings of the core across the flat pad, use the index finger of the left hand to snap on the 271 head of the base plate, the right hand holds the knife, the knife mouth and the core intersect, the knife surface and the core intersect into 45 ° ~ 55 ° angle. Cut the knife mouth to the core to the bottom plate, but can not cut the surface of the bottom plate, so that the core head becomes 45 ° -55 ° oblique head, pay attention to the size of the two heads to be equal.
⑤ trim the edge of the base plate: put the cuttings of the core of the base plate skin vertically on a flat mat, on both sides of the core of the base plate skin drawn - a line, the line from the edge of the core for 6mm.
After the line is drawn, the bottom board skin will be placed on the board, with a knife to cut off the excess edge material outside the line, cut the edge with the left thumb, index finger pinch the end of the bottom board, the right hand to hold the knife, the knife angle from the painted lines into the mouth and lines into 25 ° ~ 30 ° angle. Make the knife mouth along the line to move, the two ends of the base plate skin slightly relaxed, the line outside the excess edge material cut off, a good side cut with the same method to cut the other side.
⑥Gluing the face skin: before gluing the face skin, first wipe the water on the face skin to make the skin become soft, such as hard leather can be used by hand to rub the skin soft. Put the core of the cut bottom board skin flat on a flat mat, and apply the adhesive on the core and the core outside the bottom board skin, and the adhesive should be evenly coated. Then the middle part of the skin will be pulled on the table corner a few times so that the middle of the skin is curved, and then the skin composite to the core coated with adhesive, with the hands of the skin surface snap firmly so that the skin tightly on the core, and then the skin surface and both sides scraping flat service, so that the core surface is round and smooth without wrinkles. After gluing the leather, put it aside to dry.
⑦nail semi-circle: in the glued leather handle of the two ends from the core 8mm, 2 ~ 3mm from the edge of the base plate, with a knife will be cut vertically, pay attention to both sides of the knife seam must be straight. After the cut is open, wipe the water at both ends of the skin to make the skin soft. Will put the edge of the two ends of the bottom plate on the edge of the skin overlap wrapped in the bottom plate skin head, and then the half circle round head set on, such as overlap of the skin is larger than the edge of the bottom plate skin, the excess skin can be cut off. Half circle set on the head of the base plate will be bent inward and the base plate overlap, so that it wrapped around the half circle. Put the surface of the pad on the smooth pad, with the left thumb finger surface snap the head skin, and then use two 5 points nail to fix the half circle, the first nail from the half circle 5mm, the second nail from the half circle 10mm. two head half circle nailed, with a knife to nail the excess of the head skin piece off, the operation from the right piece to the left, the slope of 10 ° ~ 15 °.
⑧Sewing the surface: After the two semi-circles are nailed, sewing is done on both sides of the core, so that the surface is fixed on the bottom of the skin. The first needle starts at 10~14mm from the handle, the first needle is sealed with a double loop needle, then the needle is dropped along the edge of the core from the front to the back until 10~14mm from the handle, and the last needle is still stopped with a double loop needle. Needle spacing should be consistent, the needle code should be neatly arranged. The two sides of the starting and ending needle position should be aligned.
⑨ pad the bottom board: after sewing on the surface of the handle wipe water can prevent the handle in bending when the leather surface breaks, so that the handle slightly curved like a banana shape, and then on the bottom board pad cardboard core. First cut the cardboard into the same width as the bottom plate skin shape, with 3 to 4 layers, the length depends on the distance between the two halves of the circle, and then cut the cardboard strip to a good length, the same side of the cardboard slant at both ends, the piece of cardboard from the left piece to the right, the slope and the slope of the bottom plate piece compound set. Four layers of cardboard overlap together with 6-point nails will be fixed in the bottom of the board, nails in order to maintain a certain curvature of the handle should be nailed from the middle to both ends. After the cardboard is fixed, cut off the excess core cardboard according to the size of the base plate.
In order to make the bottom surface round and smooth, you need to cut the two sides of the core cardboard pad round. When cutting the core cardboard, fold the top skin to the surface, so that the edge of the core cardboard is fully exposed, the left hand will hold the edge of the cuttings to be exposed, and the right hand will hold the knife to cut the edge of the cardboard round. The thickness of the core cardboard should be uniform in the middle of the two ends of the pad, and the arc on both sides should be even and smooth.
⑩Glued seam: will be wrapped in the pad core cardboard, so that the edge of the glued seam skin in the middle of the pad core meet. When the edge of the skin is larger than the center of the core, cut off the excess, and use a needle to twist the two edges of the skin together, hold the handle in the left hand, and make the core of the pad exposed in the direction of the center of the hand, and take a needle in the right hand to poke through the skin with the tip and tie the knot on the thread. The first needle is poked from the mesh layer of the skin to the grain layer so that the thread is knotted inside, making a double loop needle, and then crossed for sewing (similar to the method of wearing shoelaces) with the stitches 2~3mm from the edge, each needle is 5mm apart.
Note that the core cardboard should not be exposed at both ends of the pad, and the leather surface should be flat and not wrinkled. The thickness of both edges should be even after the hand grip is sewn, the edge of the pad should be rounded, the width of both sides should be equal, and the stitch code should be neat.
