Offset blankets and printing characteristics of the structure – 940nm diode lase
First, the structure of offset blanket
The structure is based on offset printing blanket cylinder spacing, the thickness of rubber lining roller outsourcing, incorporating the requirements of printing technology (such as inks, solvents and printing pressure and other factors), etc. out of the overall effectiveness of the design. Offset Blanket structure shown in Figure l.
l, total thickness: the thickness of the blanket made with the similar foreign products, the total thickness of l.80 ~ 1.90 Haomi. There is also a small amount of the total thickness of 160 ~ 1.7O mm blanket, which is composed of three layers at the end of cloth.
2, the surface adhesive thickness: the thickness of the surface of rubber should be appropriate, generally in the 0.6 ~ 0.7 mm, if it is too thin flexible low, high hardness, will wear plates, lower plate Indian resistance force, but also make network is not full screen from Mexican bars (that is, since the screen section head), black shades vary; the surface of plastic is too thick will print outlets deformation (such as the network expanded, elongated, etc.) lead to blot move, overprint inaccurate picture blurred.
3, cloth layer of adhesive thickness; cloth layer of adhesive bonding since the end of the main cloth, to increase the role of flexibility. It is the thickness of the plastic due to the thickness and the total thickness of the surface of the restrictions, the general control of 1.2 ~ 1.3 mm (including four at the end of cloth).
Four-layer thickness between the end of cloth are not the same, see Figure 2.1 ~ 2 layers of fabric between the end of the adhesive layer thickness and performance design, mainly taking into account an increase of nearly printing surface layer compressibility and softness sex. 3 ~ 4 layers at the end of the adhesive layer between the fabric thickness and performance, only to play the role of bonding at the end of cloth.
4, bottom fabric layers and thickness: printing blanket of the radial force is a big, nearly 100O kg, therefore, blanket to choose a higher intensity of long-staple cotton cloth as reinforcing materials.
5, air-cushion blanket structure: air-cushion shape with ordinary blanket blanket no significant difference between the thickness of its roughly 1.65 to 1.9 mm is divided into several specifications, air-cushion ordinary blanket blanket The main difference is that not only have different fabric layer and rubber layer, but also between the folder in which there is an inflatable layer, thus constitutes a flexible layer, inflatable floor is divided into micro-bubble-shaped gas tank-like.
Second, the characteristics of offset blanket
Offset Blanket Unlike most rubber products, which will be responsible for the ink on the printed version delivered to the paper’s role. In order to print ink evenly, outlets clear, rich layers, offset blankets must have moderate hardness, compressive deformation is small, Chuan-Mo and elongation of good performance and small features in the chemical properties of ink on it has to have the absorption and adsorption Fount The role also have the non-oil and syrup with the chemical reaction and are oil, syrup erosion performance. Also because it is offset printing, so the blanket of the very high flatness. The technical requirements of the offset blankets are as follows:
l, hardness: is resistance to other substances, rubber pressed into its surface capabilities. From the printing requirements, the hardness is too high too low will not work, we must take into account three aspects: the quality of printed matter, printed version of the life, press and blanket their accuracy.
2, flexible: that blanket in the removal of the external force immediately after its deformation ability of restitution. The printing process, when the rubber drum skin contact with the embossing roller, blanket under a certain pressure on the deformation, when the impression cylinder roller surface, away from the rubber surface, requires prompt restitution Zaiqu blanket acceptance of the Internet printing plate point part of the ink, so blanket must have a very high flexibility.
3, compression deformation: refers to compressed rubber blanket after repeated deformation strength. Blanket in the printing, the thousands of times per hour, subject to compression, numerous compression reply process, blanket will give rise to compression fatigue brought about by permanent deformation, when, blanket thickness will be thinning, flexibility will be reduced, resulting in blanket can not continue to use. Therefore, the blanket of compression deformation as small as possible.
4, tensile strength: that blanket is used when tensile force.
Blanket is subject to the tension in the printing of nearly 1,000 kg, therefore, in considering the skeleton materials, at the end of fabric warp to have very high intensity, because the blanket under tension, the main by the end of cloth to withstand these forces; In addition, the surface of rubber layer must also have a certain intensity, so that there would not be paper, plastic surfaces inside the folded paper, sand or broken by the crowd.
5, the transfer of ink: refers to the ability to blanket the transfer of ink. Blanket should not only possess a strong ability to accept ink (ie, adsorption capacity), but also the transfer of ink with the appropriate capabilities.
6, the surface adhesive oil, solvent resistance: refers to blanket the surface layer plastic to resist infiltration of oil or the ability of certain solvents. If the absence of such resistance to blanket parts of contact with ink and solvent will be inflated, but can affect printing.
7, flatness: processing blanket when the thickness of the various points of its uniformity is required, that is, there must be a certain thickness of processing accuracy. Offset printing blankets for offset printing, in printing rubber roller and the impression cylinder compression is only 0.1 ~ 0.2 mm, therefore, the flatness blanket must be determined properly and flatness error is not more than 0.04 millimeters, If more than 0.04 millimeters, printed in ink will be uneven, dot shape will change and so on. Sometimes have to fill in the blanket on the back of sticky trap can be used after the Ping. Therefore, the smoothness of the offset blankets are particularly important.
8, elongation: refers to blanket under a certain tension beyond the original length of the volume, the size of the blanket elongation elongation for general use, said the smaller the better blanket elongation, elongation big, rubber Yi are stretched, layer will be thinned, flexibility will be reduced. Elongation of the size of the blanket depends largely on the strength of four at the end of cloth.
9, appearance quality: blanket on the surface should be the same as with the plate surface treatment to go through to the surface of numerous small uniform trachoma, and reach the surface of thin-cleaning smooth, non-small impurities, if not by the surface treatment, surface Blanket is too smooth, its backward in ink absorption. On the other hand, experimental proof of smoothness (also known as smoothing degrees) high blanket, adsorption strength of paper when the hair of impurities rough blanket much larger surface area.
-Sided offset paper printed with the poor quality of the field or large-scale graphic product, prone to paste blanket phenomenon, which the operator is pieces of a headache thing. Paste blanket not only affect the production rate, increasing labor intensity, waste of raw materials, a little neglect can also cause the quality of the accident. Here I encountered at work caused by various reasons, the phenomenon of paste blanket for analysis.
1. Printing pressure is too small
Printable version of the ink printing process is selective adsorption, and the ink through the blanket will be transferred to the substrates on the process. However, paper wool, paper and powder to join, hindered the transfer of ink, so that ink can not be smoothly transferred to the substrate, while on the left in the blanket. Through appropriate increase in the pressure between the three rollers, forcing the unconditional transfer of ink to the printing material on the Blanket paste resolve the issue. But while increasing the pressure between rollers at the same time should also be considered anti-Indian force plate. In the printing high-volume products, can be baked version, to enhance printed version of the anti-Indian forces.
2. Blanket formation of local non –
If the use of blanket and cushions for too long, there will be uneven phenomenon. Concave down the local paper is easy to accumulate hair, paper powder, resulting in partial paste blanket. Concave down in place, wipe reducing agent or a layer or two layer of transparent plastic tape stuck in the back of the blanket can be made smooth. If you still can not solve the local paste blanket phenomenon can only replace the blankets and cushions.
3. Poor mobility of ink
If the flow of ink is bad or too sticky on the paper surface of the peel strength will increase, the paper surface, paper wool, paper and powder can easily be stripped down, then transferred to the printed version through the blanket, the ink or ink roller slot, resulting in a vicious cycle.
In the printing high-volume products, should be based on ink roller, ink tank paper the amount of wool and paper powder, timely cleaning and that can ensure the printed version of the anti-Indian forces.
In the ink by adding an appropriate amount of supporting material (No. 6 oil or diluent), can increase the mobility of ink, then add an appropriate amount of withdrawal of light dose, but also increased the live transport of ink so that ink can be properly transferred to the printer material on the Blanket to reduce the phenomenon of paste.
Experience such a situation, some operators may mistakenly believe that adding an appropriate amount of the withdrawal of thickening agent, can increase the flow of ink, but by adding to withdraw sticky agent also reduces the transport of live ink, making the paste in the printing plates and rubber The ink on the cloth hard to clean, paste blanket will not reduce the phenomenon.
4. Printing color sequence of the arrangements are not reasonable
If it is 4-color machine, can be less graphic, with a small amount of ink on the front side to make paper wool, paper, printed on the powder in the former one. Paste blanket for numerous reasons, the above-mentioned points are summed up in practice, the author some experience of peer reference purposes only.
The e-commerce company in China offers quality products such as 940nm diode laser module , blue diode laser K41S14F-0.10W, and more. For more , please visit laser module suppliers today!
Processing your request, Please wait....
