Printing equipment refers to the production of printed matter and complete the printing process using the machinery, equipment and instrument.

The classification of the printing press

Printing machine is divided into the form of the plate letterpress, offset, gravure and printing; Install version and pressure seal structure can be divided into flat flat, circular pressure flat and round circle printer

reliefprintingpress

Use letterpress complete machine of printing process. Such as business card machine (resin), type printing, zinc letterpress, set of number words, etc.

planographicpress

Use machine lithographic finish printing process. Such as multi-color machine, four-color machine, two-color machine, monochrome machine, fast printing machine, etc.

intaglioprintingpress

Use gravure complete machine of printing process. Such as glass printing bag of instant noodles, biscuits aluminum foil bag packing, etc.

screen - processprintingpress

Using silk screen version of the complete machine in the process of printing. Hole printing, such as screen printing, circuit board printing, fabric printing, canned engaged in printing, printing, local glazing, etc.

According to the form of the paper classification

sheet - fedprintingpress use sheet-fed printer.

This web press: roll - fedprintingpress; Using web printing press.

Pressure seal structure classification

platenpress; Plate supporting body and embossing body is flat printing machine `

This round flatten the printer (platform printing machine) : flat - bedcylinderpress; Plate bearing body is flat, and embossing is cylinder printing machine.

3. Stop rotary printing press: stop - cylinderpress

Plate reciprocating motion of cooperation, advance, embossing roller rotates, returns, stop rotating impression cylinder, complete a printing process of printing machine.

4. A rotary printing machine, single - revolutionprintingpress; Plate every reciprocating motion, the embossing roller turn a week and complete a printing process of printing machine.

â’?two rotary printing machine: two - revolutionprintingpress; Plate every reciprocating motion, complete a printing process of printing machine

6 to to transfer to other tasks the printer: reversibleprintingpress; Impression cylinder every reciprocating rotation, complete a printing process of printing machine.

But circle pressure circle press: rotaryprintingpress

Plate bearing, transfer printing cylinder, all finished printing process for the rotary motion of the printer.

Maintenance of common sense

Equipment maintenance and equipment maintenance, the content is different, the effect is different also, repair mainly malfunction, troubleshooting, repair and replacement of damaged parts or wear, corrosion, the device can run properly. Equipment repair is divided into electrical parts and mechanical parts.

(1) the electrical part of the maintenance of common sense

In daily printing equipment repair work, proportion of electrical parts is bigger, with the continuous development of printing technology and equipment, automation degree is more and more high, control system is also more complex. Therefore, electrical maintenance personnel requirements have a higher level of technical skills and quality, and will know computer principle, operation. For printing electrical maintenance personnel, in the daily maintenance work should pay attention to the following:

A) read the equipment of the electrical schematic diagram and related documents, master the equipment from the principle of the electric principle, principle of control system. Find out where electrical components, wiring, pipe and code, to.

B) for the machinery and equipment in fault, careful analysis may appear the fault part, according to the principle of electrical diagram, wiring diagram, etc to find could lead to failure of components and circuit, diagnosis, ruled out one by one.

C) in the electrical repair, should first check the power supply voltage? Current is normal, the pump pressure is up to standard, whether the lubrication oil pressure up to standard, etc., will load off when necessary, to determine whether the mechanical overload

Load caused by electrical failure or protection.

D) for web offset printing machine used the PC for automatic control, which brought many convenient to the electrical breakdown? General in the control cabinet has a light-emitting diode troubleshooting tips, parts can be produced according to the prompt to find fault? In more advanced equipment, can find the prompt on the console screen, first using a laptop or in the control cabinet "dialogue" with industrial computer, find the malfunction of the system? Place, then go out?

E) often encountered electrical fault can be summarized as: fuse damaged, contactor, relay contact damage, loose connection, poor contact, buttons, limit switch failure, safety protection system in a certain position control switch is not reset, tension control system, the photoelectric detection part of the paper system failure, the electromagnetic valve leakage, damage, etc.

F) motor is the source of power in the printing equipment, the following are a brief introduction to dc motor and ac motor common faults.

Dc electric runtime common faults are two aspects of mechanical and electrical. Mechanical failure mainly for bearing and fever, vibration motor, the armature and stator core touching and abnormal noise. Is generally caused by the armature rotation, when check with manual rotational armature, observe whether the armature and stator collision of vibration is caused by the motor itself or caused by bad gearing. Motor vibration caused by its own dynamic balance is not good is less likely, often is the concentricity is not good and cause vibration of gearing, after the occurrence of this phenomenon easy to cause the motor bearing damage, and even lead to the armature output shaft deformation.

Dc motor electrical fault is the most common is the spark between brush and commutator, normal operation, the spark between brush and commutator with pale blue, faint, fine, smooth light brush contact surface, the commutator surface oxidation film can form a layer of reddish-brown. Spark machine when not in normal operation, size and color are change, minor fault, sparks appear red, yellow is bright, the commutator surface black, burn mark. If the spark is serious, would be a large number of jet red green, Mars, and mixed with flash fire, will be accompanied by sound gaga, if not timely stop check, will soon commutator and brush, brush burn out. When the brush position deviation from geometric center line, armature winding internal short circuit fault, open circuit fault can be severe. In addition, brush type, performance, brush pressure is too big, too small, brush grinding is bad, the contact area is too little, can cause failure.

Ac three-phase asynchronous motor mechanical failure of basically the same as the dc motor. Here in view of the common electrical failure are introduced briefly, one is single-phase fault operation, the motor in the three-phase winding one phase winding disconnect, then greatly reduce the motor torque, speed slow, abnormal sound, time is a bit long telegram opportunity due to fever severe burn out; Second, motor severe fever, and even smell the paste, this failure may be due to the load is too heavy, can also be caused by power supply voltage is too low, too high.

(2) mechanical parts maintenance knowledge

Mechanical failure generally can be divided into two categories, accidental failure and natural failure, accident fault for maintenance or improper adjustment, violation of operating procedures, etc., should be avoided. Natural fault is difficult to avoid, but can be improve the level of use and maintenance, extend the effective working hours of machinery.

There are three main failure mode of the mechanical parts: fracture, deformation and failure surface, the following respectively introduce printing machinery parts wear, deformation, the cleaning method and dismantle assembly.

A) wear of printing machinery parts

Machinery in the process of work, if the relative motion of the surface of the parts size happened? Shape and surface quality of change, is called the wear and tear.

Produce parts wear is the main reason of the friction and molecular attraction. Can be divided into the abrasive wear, the wear of mechanical friction and wear and adhesive wear. Impact wear causes of mechanical parts is commonly: speed, pressure, lubrication, temperature, material, processing and coordination, etc.

B) printing deformation of mechanical parts

Printing machinery is used bearing type

In the process of maintenance, the wear is the one of the main factors of mechanical damage, but the micro deformation of parts are easy to be ignored, often in the after the repair of wear parts assembly, machine technical performance can not meet the requirements. This is related to the metal deformation. Based part deformation in actual production, pay special attention, because if the foundation deformation of parts produced, will affect the assembly parts on the basis of the interrelation of all parts and mechanical properties of the organization. So in the process of parts, both must check the abrasion of mating surface, and to check all the parts (especially the base parts) location accuracy? The mechanical deformation situation for first overhaul, must pay attention to it in the role of internal stress, 12 ~ 20 months after deformation. For hot working parts, shall have the corresponding measures to remove internal stress.

(3) printing machinery disassembly and assembly

Mechanical repair personnel to repair of printing machinery, are faced with the problem of disassembly and assembly, assembly, in particular, good or bad will directly affect the mechanical properties, assembly quality is not high, can cause mechanical serious wear and tear.

A) mechanical disassembly

Because the printing machine type is more, a variety of shapes and parts difficult to blieve. Here are the general principle of disassembly.

First, remove the former must understand the structure, function and principle of machinery, first consult relevant technical information and specifications. From set out actually, make sure remove the part, not dismantle the part should try not to hurt, but to not remove the part must pass the overall inspection, to ensure the quality.

Second, should be adopted in the process of disassembly disassembly, situated in order to remove the external accessories, tubing, etc., to remove, in accordance with the order of the first after the assembly parts for more important parts with position, remove the tag comes, list number, avoid by all means is intricately piled up. When remove it's also important to reasonably use tools, tools must be adapted to be disassembled parts. If remove the threaded fittings should choose appropriate wrench, remove the interference fit to use special tools, not indiscriminate hammer, pry, etc.

In addition, disassembled, creates the condition for assembly of interchangeable parts, disassembly should also be well marked or placed in pairs, so that the reset when assembling, doing so can ensure the assembly accuracy and reduce unnecessary wear and tear.

B) mechanical assembly

Assembly time must make the pledge that we shall cooperate with precision and dimensional accuracy, in order to guarantee the matching accuracy, matching method, replacement method can be used in assembly and adjustment method. Dimensional accuracy is mainly refers to assembly parts in the assembly dimension error degree, that is to say, in the assembly, should pay attention to eliminate cumulative error, avoid the cumulative error increase adverse impact on the machine.

Assembly of the seal is also very important, in the printing machine, seal is mainly used for air pump, gear box, in areas such as the seal failure happens when the air leakage, oil leakage. Therefore, the selection of sealing material in repairing to appropriate, to reasonable assembly, choose liquid sealant for static seal storage, according to the different use of nature, respectively adopt dry type, dry can peel, not dry glue and half dry viscoelastic model and other varieties.

The preparing work before assembly must not be ignored, the content including check before assembly, assembly at the time of the cleaning and assembly of components. The final test run after the assembly, its function has two, one is to check the quality of assembly; The second is to adjust machine.

C) cleaning of mechanical parts

Mechanical parts cleaning is not lack of part of the overhaul, clean content mainly oil removal and cleaning.

Degreasing cleaning methods mainly include alkali solution degreasing method, organic solvent degreasing method and metal cleaning oil removal method of three. Here said the alkali solution, mainly joined the emulsifier, alkali solution it for mineral oils have good cleaning effect. Solvent machine generally refers to the gasoline, kerosene, etc., it can dissolve all kinds of oils, and don't damage parts, in addition to gasoline, kerosene, small parts, adhesive parts of high precision, can choose different organic solvent such as alcohol, acetone, ether. Metal cleaning is a new type of synthetic detergent, the result of the base surface active substances to reduce the interfacial tension of moist, osmosis, emulsification, dispersion, etc, has the very strong decontamination ability. Using the cleaning agent non-toxic, non-corrosive, not burning, not the explosion, pollution-free, there are certain rust resistance, and a low cost, has been widely used.

Derusting cleaning methods mainly include mechanical method and chemical method. Mechanical descaling is generally use wire brush, spatula, emery cloth, etc, sometimes also can use electric grinding wheel and the wire wheel. Method of mechanical descaling easily leave scratches in the surface of work, only should be used for surface rust removal is not important parts. Chemical cleaning generally use hydrochloric acid, sulfuric acid and phosphoric acid to alkali metal oxide, method is simple and good cleaning effect. When using this method derusting, to grasp the concentration ratio of good solvent.