What you should know about printing!
Rotary printing with automatic gauge pin
Round objects are usually printed with several inks in silk screen printing processes. However, overlapping inks can only be applied in several printing operations, respectively after drying. With the help of the parts holder shown here, it is possible to apply the ink to the desired location. The items have a groove/fitting on the bottom for this purpose, where a gauge pin automatically engages as the object is transported under the silk screen printing template. Up to 1,500 prints per hour are possible depending on the shape and size of the objects being printed.
Rotary printing with slide-on pin
Sleeves, tubes, cups etc. are usually fitted according to a register mark for printing. For multicolour printing, the items have to have a land on the inside which fits into a recess in the slide-on pin. Systematic fitting of the components makes a high output possible here as well. There is a fixture with an automated collet chuck for printing camera components in combination with a special holder for clamping the templates with metal frames. This holder is of special interest when the requirements for printing precision are very high. Adjustable three-point contact makes it possible to exchange the silk screen printing templates quickly (quick-change fixture).
Conical objects are basically printed the same way as round objects. Depending on the slope of the cone/degrees however, a screen positioner has to be used that transforms the linear motion of the screen carriage into an arc motion. It is possible to print both items with a small bottom and large opening, or a large bottom and small opening. In the latter case, the fixture is turned by 180° so that the pivot point is at the front.
Printing oval objects requires a special tool which turns the objects under the silk screen printing template according to their surface curvature. The insert adapted to the object is attached on the tool. A control shaft moves the corresponding gear wheel, synchronised with the silk screen printing template. Bottles are usually centred at the mouth and inflated with air to stabilise them for printing. The tool is adjustable so that items with different curvatures can be printed.
For printing flat objects, the tool shown here is mounted and the machine is set up so that, in contrast to rotary printing, the silk screen printing template remains motionless while the scraper moves. The flat printing tool is adjustable to all sides and serves to hold the inserts assigned to the objects. Objects with a flexible surface, such as bottles, are centred and inflated with support air. A special fine pressure controller is used to precisely adjust the required support air pressure.
Body and neck pressure
Glass bottles in particular are often printed on the body and neck of the bottle. A special fixture makes it possible to print the body and neck in one operation. The template for cone printing moves synchronously with and in front of the rotary printing template. For multicolour printing, glass bottles usually have a groove along their circumference where the gauge pin can engage automatically. Templates covered in steel mesh can be warmed using a variable heater, so that thermoplastic inks can be used for printing. The ink is dry immediately after printing. UV inks can possibly be used as well.
Printing on glass instruments
Graduated cylinders and pipettes etc. can be printed in precise relation to the calibration mark with the help of a tool. A hand wheel is used to move the support until the pipette with its calibration mark is opposite the measurement indicator. An illuminated magnifier with triple magnification can also be supplied for more precise adjustment. Very long scrapers are often used for printing pipettes. The sturdy and precise scraper head of our silk screen printing machines guarantees that all scale markings are fully printed.
Vacuum printing table
Combined with the flat printing fixture according to Figure 5 or 15, the vacuum printing table can be used for printing foil or paper blanks as well as radio scales, PCBs etc. The perforated base plate features a floating mounting so that it can be adjusted to all sides. The vacuum is activated automatically and turned off again after printing.
Small round parts up to Ø 80 mm can be printed in one colour using the revolver head. Since loading and unloading during the printing process is supported, the machine can achieve a high output. Up to 2,500 prints per hour are possible depending on the item. In the rest position (print position), the revolver head is locked by an index pin that ensures high repeat accuracy.
Rotary table/indexing table
A vertical or horizontal rotary table is used to print flat small parts such as boxes, cans or also cylindrical components in on or more colours with a high output. Depending on the shape of the parts, it is possible to automatically transport them to a dryer via a ramp or conveyor. An operator can achieve up to 2,500 prints per hour. The rotary table has an index pin locking mechanism for high repeat accuracy, so that multicolour printing can be carried out with high precision.
Plates, platters, bowls etc. can be printed in one or more colours, entirely or in part, with the help of the rotary scraper. Printing is possible even if these components have a slightly concave or conical surface. The rotary scraper is inserted in the existing opening on the machine instead of the standard scraper. An intermediate transmission transforms the linear movement of the screen carriage into a rotary movement of the scraper. The adjustable hold-down device presses the mesh of the screen into the recess of the object so the parts can be printed.
Rotary printing on items with a handle
Cups, mugs, jugs etc. have a handle which can be used as a register mark for multicolour printing. The items are clamped between the gauge plate and clamping plate, and then laid against an adjustable stop with the handle. When printing begins, the stop retracts automatically so the item can rotate under the silk screen printing template.
Round pails and similar containers are printed with this special tool. The Rountec RS 8 machine model is preferred for printing pails. A vacuum is used to firmly suction the pail onto the pin. This compensates for small pail size tolerances. Multicolour printing of pails is no longer a problem. The existing handle lug on the pail is used as the register mark. The handle itself is kept away from the silk screen printing template by magnets. This tool can also be supplied with control elements to connect an electronic pre-treatment unit. Then pre-treatment and printing are performed in one operation.
Oval pails are printed with the help of a special tool after installed corresponding integral parts. Since the tool changeover can be performed quickly, efficient printing is possible even when the type of pail keeps changing. Electronic pre-treatment can also be used here so that pre-treatment and printing are performed in one operation.
Universal clamping table with canister
The universal clamping table is preferred for printing flat objects, especially large and unwieldy items such as canisters etc. It swings forward during the downward movement and therefore makes it easy to exchange the items. Since canisters often have a corrugated surface, they have to be inflated with supporting air before printing. Due to the size of the canisters, selecting the quick inflation fixture is recommended in order to achieve rapid printing. Regulated by a time relay, the full pressure of the compressed air network flows for a short time to pre-fill the canister before the supporting air pressure is applied.
Bottle crates/boxes or similar items
Horizontal printing template:
With this fixture, boxes of all sizes (including blown boxes) can be printed in one or more colours on the long and face sides. The box being printed is pushed into the fixture with proper orientation. After tripping a limit switch that serves as the stop, the box is centred and clamped by two pneumatic cylinders. Printing follows automatically. Easy handling with centring and clamping of the boxes makes precise multicolour printing possible with high output.
Hanging printing templates, 2 or 4:
With this solution, mouldings/boxes or similar components/products can be printed in one or more colours on the long and face sides. A conveyor transports the article into the block where it is centred and printed. An important point to note is that this version makes it possible to print various motifs at the same time. UV dryer modules are used for drying (gas flame/corona or also plasma). Pre-treatment where required can be installed upstream by request.
Printing on large containe
Large containers that are blown or rotationally moulded can be printed in one or more colours with the model rs 8 silk screen printing machine. We fabricate the required tools as special designs tailored entirely to the type and shape of the objects.
Rotary printing on bowls
Round objects, e.g. round bowls, can be immaculately printed in several colours with a special tool. The tool is similar to an automatic gauge pin but more sturdy. The item is positively driven by the gear wheel and control shaft which is equipped with a fine adjustment mechanism for the gauge pin.
More about our hot stamping machines >>