Molding process (below)
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
Three common molding failures and troubleshooting methods
Die-cut indentation to produce qualified products, the cutting position should be accurate, the cutting is clean, no burrs, flower knives, indentation clear, moderate depth.
Common faults and solutions in die cutting and indentation operations:
1 Indentation is not clear, there are dark lines, and the line is fried. (Dark line refers to the indentation that should not be present; the line of weakness refers to the breakage of the cardboard due to the pressure of the indentation)
Cause: The paper quality is poor, the water content of the paper is too low, which makes the brittleness increase, the toughness is reduced; the steel wire is not selected correctly; the steel wire mat is too low or too high; the pressure of the molding machine is improperly adjusted.
Solution: Re-adjust the steel wire height; check whether the steel wire selection is appropriate; adjust the pressure of the die-cutting machine appropriately; adjust the process conditions of the die-cutting indentation according to the condition of the molded cardboard, so that the two can adapt as much as possible.
2 The incision is not smooth.
Cause: The steel knife has poor material, the cutting edge is not sharp, and the die-cutting property is poor; when it is not timely, the cutting edge is seriously worn; the pressure of the die-cutting machine is small or the pressure adjustment is not coordinated with the height adjustment of the steel knife, and the die-cutting operation is not compact. .
Solution: Always check the edge of the steel knife to replace the steel knife; to select the steel knife with different quality characteristics according to the cutting performance of the paper used for the printed matter; increase the pressure appropriately; re-adjust or replace the steel knife or paper, so that A more realistic pressure effect is obtained in die cutting.
3 The position of the die-cutting indentation is not accurate.
Cause: The position of the cutter is not in conformity with the printed matter; the position of the paper feed in the die-cutting operation is inconsistent; the rule of the cardboard jaw is not accurate; the deformation and overprinting of the cardboard during operation are not allowed.
Solution: According to the sample requirements, re-correct the position of the plate; adjust the die-cutting paper positioning rules to keep the position consistent with the paper feeding; reduce the influence of the print defects on the die-cut quality for the cause of the position.
4 The indentation line is out of order.
Cause: The knives and the fixed degree of the knife are not suitable. The bottom can not achieve the ideal contact effect with the plane of the iron table. The indentation is prone to twisting (the steel wire is too tight); the indentation is easy to move around (the steel wire is too loose) ); the thickness of the steel wire mat is insufficient; the groove angle is not standardized, and extra round corners appear; the indentation groove on the steel wire pad is too wide, and the position at the time of the indentation is not fixed.
Solution: Replace the steel wire pad paper to keep the groove tight; increase the thickness of the steel wire pad; correct the groove angle;
5 The cardboard has a continuous knife after die cutting.
Cause: The pressure on the stencil is not uniform, and the pressure is small. The knives are not sharp, causing the knife to be connected. The thickness of the paper is too large to completely cut through the paper.
Solution: Replace the die cutter according to the actual situation; increase the partial pressure.
6 After the die-cutting, the cardboard sticks to the knife.
Cause: The rubber around the knife line is too sparse and the resilience is insufficient; it is not suitable according to the performance of the rubber; the steel knife is not sharp, the paper is too thick, causing the knife or pressure to be too large.
Solution: According to the condition of the plate steel knife, the rubber of different hardness is used reasonably, and when it is blocked, pay attention to the mastery of the density distribution, and the main knife edge should not be missed; adjust the pressure appropriately to make up for the lack of the blade edge, if it still cannot be solved The problem is to replace the steel knife in time.
7 Fold the cardboard crease at the fold.
Cause: If the outer side of the cardboard indentation is cracked, the indentation is too deep or the width of the indentation is insufficient; the inside of the cardboard is cracked; the molding pressure is too large or the crease is too deep.
Solution: Appropriately reduce the height of the steel wire, and appropriately widen the indentation line according to the thickness of the cardboard; reduce the die cutting pressure or change the steel wire which is slightly lower.
8 Paper deformation die cutting solution:
Due to the influence of objective factors, the printed paper has different degrees of deformation, which brings about the problem that the die-cutting position is not correct and the die-cutting plate is re-made, which brings great difficulty to the post-forming die-cutting. , greatly reducing the pass rate of finished products.
The double-die die cutting position can be added at an appropriate position in the deformation direction of the printed product to form a front-rear or left-right separation unit, and an adjuster is installed between the double-die die-cutting positions, and the die-cutting is adjusted according to the deformation direction of the printed product. Adjust the adjustment position of the hex screw of the adjuster according to the deformation of the printed paper. The square increases the distance between the two knives, and the reverse direction reduces the distance between the two knives. The maximum adjustable distance is three millimeters.
Four die cutting machine operating procedures
★ Operating procedures before starting
(1) View the handover record to understand the operation of the equipment
(2) Check the quantity of die cutting and product quality according to the production scheduling plan and the requirements of the production construction order.
(3) After checking and confirming that there is no foreign matter on the machine, thoroughly check and adjust the machine.
★ Operating specifications before starting production
1 Check if the die cut is the same size as the box
2 Check if the product has a mouthwash
3 Select the bottom plate material according to the number of products, paper type and carton structure
4 Install the die-cut version and lock the fastening screws to prevent the die-cut version from falling. Make a bottom plate, the thickness of the bottom mold is the thickness of the die-cut product
5 Install the bottom mold to clean the surface debris and lock it
6 According to the thickness of the paper, adjust the die-cutting pressure. When adjusting, the pressure should be gradually increased from light to heavy to 80% penetration, otherwise it will cause equipment damage.
7 Adjust the position of the upper and lower ejector pins of the release unit and lock it
8 After adjusting the parts, the sample is produced in comparison with the box sample, and no quality problems are checked. After the sample is signed by the supervisor, normal production can be performed.
★Operational specifications in production
(1) According to the production requirements and the sampling standards of the construction orders.
(2) During the production process, every 5-10 minutes shall be sampled and inspected, and quality problems shall be reflected in a timely manner. After the solution, production may continue.
(3) After each version of the die-cutting, a comprehensive inspection shall be carried out, and the “die-cutting process order” shall be filled out. In case of quality problems, the products should be placed separately in time and the "abnormal product flow sheet" should be filled out.
(4) When discovering material problems, production should be stopped, and the “Feedback Sheet for Quality of Production Materials” should be filled out so that relevant departments can coordinate and solve them and prepare for subsequent production.
★Operational specifications after production
(1) The captain shall fill out the "Calculation Daily Report", "Process Quality Status Statistics Table" and "Production Equipment Daily Inspection Form" every day.
(2) Separate the die-cut products according to the qualified products and the defective products, and clearly mark them.
(3) At the end of production, the equipment shall be stopped at the mold opening position.
(4) Maintain the equipment according to the daily maintenance content.
(5) Fill in the record of the handover class carefully.
(6) Turn off the power.
Five die cutting and creasing equipment
According to the shape of the main working parts of the die-cutting plate and the press-cutting mechanism, the die-cutting machine can be divided into three types: flat flat, round flat and round pressed; and the flat plate and press plate in the flat-pressing press The direction of the direction is different, and can be divided into vertical and horizontal.
▲ Flat die cutting machine
When working, the platen is fixed, and the pressure plate is pressed against the plate by the transmission to apply pressure to the plate.
The vertical flat pressing and cutting machine has the advantages of simple structure, convenient maintenance, easy operation and replacement of the incision and indentation plate, but the labor intensity is high, the production efficiency is low, and the number of working times per minute is 20-30 times. Produced in small batches.
The platen and the platen working surface of the horizontal flat-pressing press are horizontally positioned, and the lower platen is driven by the mechanism to press upward against the plate to perform the indentation. Since the stroke of the horizontal molding machine is small, it is difficult to manually insert or remove the cardboard, and usually has an automatic paper feeding device.
▲ Round flat die cutting machine
The die-cut version is embedded in the reciprocating platform and is in reciprocal contact with the impression cylinder. Because the circular flat die adopts a cylindrical pressure roller instead of the pressure plate, the die cutting is not a "face contact" but a "line contact", so that the pressure exerted by the machine during molding is small, and It is evenly distributed over a long period of time, so the load of the machine is relatively stable, and the die cutting of a larger format can be performed.
▲ Round die cutting machine
The circular die-cutting machine is a die-cutting indentation and embossing for precise, continuous, high-speed rotation of a web print by using one or more sets of die-cutting rolls. Its characteristics: it can run synchronously with the printing line, become a unit in the line, realize the completion process of the web from printing to die cutting to the waste paper; high-precision registration device and die-cut phase high-speed device can get very High die cutting accuracy; continuous rolling die cutting up to 350m/min.