Thermoforming machine is also called thermoplastic molding machine. It heats plasticized PVC, PE, PP, PET, HIPS and other thermoplastic sheet or rolls, and vacuum form them into various shapes. They are used for advanced packaging and decoration boxes, frames and other products.
With vacuum suction generated by vacuum pump, the heated and softened PVC, PET and other thermoplastic sheets are sucked into various shapes, like covers, blister trays and blisters.
General introduction of vacuum forming machine
The main parts of thermoforming machine include: material feeding, material pulling, upper and lower electric heating furnace, lower gate, multi-functional adjustable size, lower die plate, upper die, upper gate, knife gate, slicing, sheet release and with vacuum device, etc.;
Thermoforming machines are divided into thin-gauge and thick-gauge thermoforming machine, according to the thickness of the sheet to be processed.
Main applications of thermoforming machine
Thermoforming machine is usually applied in such industries as:
1. Plastic packaging industry (blister packaging, plastic, batteries, toys, gifts, hardware, home appliances, electronics, stationery, decoration)
2. Food packaging industry (fast food boxes, fruit trays, cookie boxes)
3. Pharmaceutical industry (pill packaging, pill packaging)
4. Industrial cooling tower cooling water deflectors, etc.
5. Decorative three-dimensional relief patterns, plastic ceilings, wall panels, automotive materials, sanitary equipment and other manufacturing industries.
Thermoforming technology
Thermoforming molding technology, or plastic sheet (plate) thermoforming processing technology, is one of the secondary processing of plastics industry technology.
Thermoforming is different from injection molding, extrusion and other primary processing technology. It is not to use plastic resin or particles for heating molding or continuous molding with the same cross-section of the over-mouth mold. It is not to use machine tools, cutter and other mechanical processing means to cut down part of the plastic material to obtain the required shape and size
It use plastic sheet (plate), heating, the use of mold, vacuum or pressure to make sheet (plate) deformation, to achieve the required shape and size, complemented by supporting processes to achieve the application purpose.
To achieve the required shape and size, supplemented by supporting processes to achieve the purpose of application.
Thermoforming molding equipment includes clamping system, heating system, vacuum and compressed air system and molding tool.
Mold types for thermoforming molding equipment
- A single-positive molding
Single-positive molding is also called convex molding or bending molding, vertical molding. It is a molding method in which the heated and softened plastic sheet is formed into a certain shape by machinery.
- Single-negative molding
Single-negative molding is also called concave molding.
- Three-pair molding
The mold for pair molding is composed of a male mold, a female mold, a jig and other accessories.
- Composite molding
It is composed of all above.
Thermoforming molding equipment parts
Clamping equipment
When forming plastic sheets, the sheets are fixed to the clamping device. Most of the thermoforming machines of general-purpose and compound thermoforming machines use clamping devices that facilitate fixing sheets of various sizes. In some cases, the entire molding machine is equipped with a set of clamping frames.
Clamping devices can be divided into two categories: one is the frame type, and the other is the split-flap type. The frame type clamping device consists of two frames, upper and lower. The sheet is clamped between the two frames. When the frame is opened, the lower frame generally remains fixed. The lower part of the upper frame of various types of single-station molding machines is fixed directly to the molding chamber. For manual and semi-automatic molding machines that load and remove the molded parts by hand, a safety operating device within the frame opening range is provided when the frame size is large.
For the molding of large slippage type blanks, the clamping force is required to be adjustable in a relatively wide range, and for this reason, two cover rollers are used, pressed against each other with springs, and equipped with a pressure adjustment device. The clamping of the continuous pulling sheet forming machine is the joint action of the two side zippers and the front and rear gates.
Clamping device is best to use automatic control, in order to move quickly, can help improve the quality and efficiency of the parts.
Heating equipment
One of the main processes in the process of vacuum blister molding of thermoplastic sheets and films is sheet heating. The duration and quality of electrical heating depends on the structure of the heater.
The thermal inertia of the temperature transfer after the radiation surface. The distance between the sheet and the heater, the radiation energy absorption coefficient, the characteristics of the heater surface and the thermophysical properties of the material. Commonly used heaters are electric heaters, crystal emitters and infrared heaters.
Vacuum Equipment
The vacuum system is composed of vacuum pump, gas storage tank, valve, pipeline and vacuum meter, etc. In vacuum forming, a separate type of vacuum pump is often used, and the vacuum degree of such pump should reach 0.07~0.09 Mpa (520mmHg) or more.
The gas storage tank is usually a cylindrical box welded with thin steel plate, and the bottom is oval. The capacity of the gas storage tank should be at least half larger than the capacity of the largest molding chamber. The vacuum pipeline must be equipped with proper valves to control the vacuum narrow capacity.
The rotating power of vacuum pump is decided by the size of molding equipment and molding speed, larger or faster molding speed equipment is commonly used as large as 2-4KW. The size of the vacuum central system depends on the specific production and development requirements of the plant.
Compressed air equipment
The pneumatic system can be composed of the molding machine itself with compressor, storage tank, workshop main road set, valves, etc. Forming machine needs pressure of 0.4-0.5MPa compressed air, a variety of vacuum suction molding machine widely used piston air compressor. Can also be supplied with a large screw-type air compressor whole plant.
Compressed air in addition to a large number of should be used for molding, there is when part of the external cooling for demolding, initial products and manipulation of the mold frame and running sheet and other machine movements of power.
Cooling equipment
In order to improve production efficiency, vacuum blister molding products often need to be cooled before demolding. Ideally, both the inner and outer surfaces of the part in contact with the mold should be cooled, and it is best to use a mold with an internal cooling coil. For non-metal molds, such as wood, gypsum, glass fiber reinforced plastic, epoxy resin, etc., since water cooling is not possible, air cooling can be used instead, and water mist can be added to cool the outer surface of the vacuum blister molded parts.
If natural cooling is used in the production, the annealed parts can be obtained, which is helpful to improve the impact resistance of the parts. Although the production efficiency is high with water cooling, but the internal stress of the parts is larger.
Demolding equipment
The demoulding is to move the products out of the mould, usually both concave and convex moulds, most of the time the products are shrunken and tightened to the mould due to cooling, so they are demoulded by vacuum attraction hole or blowing air in the opposite direction.
Especially for molds with small release slope or with concave molds, the mold is also released by using a release mechanism to jack or shock the mold, and sometimes a release agent is applied to the sheet and the mold or the mold surface is sprayed with Teflon treatment.
Control equipment
The control system generally includes control of instruments, meters, pipes, valves, parameters and actions in the process of vacuum blister molding, finishing, etc. Control methods are manual, electrical-mechanical automatic control, computer control, etc. The specific choice should be based on the initial investment in labor costs, technical requirements, raw material costs, production and maintenance equipment costs and other factors.
High speed vacuum forming molding machine
Features of high speed thermoforming machine
1. Adopt vertical sheet pulling design: pulling sheet quickly and evenly, stable, shorten pulling sheet occupying time, more adaptable to environmental protection materials and reduce power consumption, ensure product forming quality.
2. Independent grouping temperature control: using special dense plane far-infrared ceramic hair piece assembly, uniform temperature: 50% higher than the traditional machine power saving.
3. The electric furnace adopts closed heating to make the heating more uniform and reduce the heat loss, and is equipped with a manual switch to control the vertical lift of the furnace, which is conducive to controlling the product quality during the production process. Thick film or PP sheet can be heated by double electric furnaces (customized) to speed up the heating time and increase the production speed.
4. The machine is equipped with vibration de-filming device, which is not easily deformed for difficult products and easy to de-mold.
5. Double rows of sharp needle chain drive, high-speed operation to ensure accurate and stable, with width adjustable device, so that the machine can maximize the use of film, reduce waste.
6. The whole machine is equipped with water cooling device and high speed cold water spray to speed up the molding speed and ensure the quality of molding, the production speed is twice as fast as traditional.
7. The built-in secondary vacuum makes it easier to form difficult products, improves product quality and reduces scrap rate.
8. The whole machine adopts imported electrical appliances and pneumatic components of international famous manufacturers, the quality is absolutely reliable, safe and durable.
High speed vacuum forming machine functions
All kinds of film such as (PVC, PET, PP, PS, etc.) can be blistered into different shapes of plastic cover. Such as toys, hardware, food, electronics, pharmaceuticals, etc. with transparent film overlay sealed on the cardboard to form a dense packaging. This machine can also produce three-dimensional embossed patterns of plastic ceiling, wall panels, pie boxes, automotive materials and sanitary materials, etc.
High speed vacuum forming machine equipment structure
The main structure is composed of feeding, pulling, upper and lower electric heating furnace, lower gate, multi-functional adjustable size, lower die plate, upper die, upper gate, knife gate, slicing, releasing and vacuum device, etc.
The pneumatic device is the main power source, and the electric, reducer, time relay, intermediate relay, travel switch and other electrical appliances are used for pulling and feeding the film to form a fully automatic control system.
The requirements of the control system for the blister machine are to ensure easy operation, high precision of mechanical action and temperature control, short production time, and to save the power consumption of the machine as much as possible under the same production conditions.
High speed vacuum forming machine Operating Instructions
1. First turn on the total power system
2. start the air supply, air pressure requirements 5-6 kg
3 start the chiller, chiller temperature system to about ten degrees
4. Press the blister power switch ON, so that the power indicator three light up at the same time
5. then press the main light of the electric furnace heating torque on, meaning that the electric furnace will be turned on, and each heat control is adjusted.
6. line up the mold and use the adhesive paper to occupy the mold.
7. Press the middle gate to the last side of the mold.
8. Need to be on the mold immediately mold frame well adjusted
9. Adjust the heat shield to the same length as the total length of the mold.
10. Put the adhesive material into the front material frame and adjust the inlet.
11. Adjust the length of the pulling piece count to the length of the mold put into the machine (the counter length is adjusted according to MODE, such as SET2 for the pulling piece length (such as 1000MM). Press MODE to show SET1 for pulling piece buffer should be less than SET2.(if 850MM).RST is reset. Press RST to reset when the puller reaches the counted number in manual. (Before opening the automatic must also check whether RST reset).
12. hit to manual start each switch is normal.
13. adjust all the time system.
Note: The electric furnace time is the total time
Will vacuum + spray water + demoulding blowing + delayed vacuum + 1-2 seconds not more than the electric furnace time # film thickness and time ratio to 0.5 glue = 20 to 0.5 glue = 20 # 1 # film for 1 second.
14. degree forming height adjustment in the gate, slitting, close to the switch position and line degree nut.
15. start the heating furnace, according to the molding area of the mold, adjust the heating furnace heating area, adjust the temperature regulating device, observe the corresponding current and heating brick reddening phenomenon, the general current is high around, low in the middle.
16. Load the film on the feeding shaft, adjust the straddle according to the width of the film and the position of the feeding port, and fix the feeding rotor at the corresponding position of the film feeding positioning wheel.
17. Preheat the furnace for 10-15 minutes, after the temperature is adapted to the production requirements, adjust the digital display time corresponding to each program on the control panel, generally set to the number of heating time is greater than the number of vacuum, on the cold air, demoulding the sum of time and turn on the vacuum pump.
18. Raise the furnace, dial the cell phone for manual and automatic switch, select the feeding switch in the corresponding gear to put the sheet in parallel between the pressing wheel and the chain tip teeth, tap the pulling button to feed the material into the heating area, at this time the sheet should stick out about 20mm at the lower gate outlet.
19. Put down the heating furnace, set the manual and automatic switch to automatic, the heating time will start, when producing the first product, the heating time should be set at more than 1.5 times of the time required by the process, start the lower gate, observe the heating of the sheet, when the heating area of the sheet reaches the temperature in line with the forming, tap the advance pulling button to make the sheet come out of the heating area under the drive of the chain and enter the forming action, and modify the heating time setting number.
20. After the sheet is formed and cooled, it will be brought out of the forming area by the chain and enter the cutting area. At this time, the knife gate should be closed, the receiving box should be moved, the cutting position should be adjusted, the receiving box should be positioned, and the knife gate should be opened.
21. When the blister machine automatically carries out production, the operator should check the product quality to see whether the temperature is adapted to the product quality requirements and carry out temperature adjustment, and then carry out details to check whether the uniformity of the film forming of the production varieties is consistent and carry out local temperature adjustment to maintain the good product quality requirements.
22. Secondary on the mold: used to protect the product when the mold is released, the product is not deformed, no cracks, fragile, difficult to release the product used in the mold. Function setting: select the upper mold function in the second upper mold, according to the upper mold down to the surface of the product, the cold wind stops and starts blowing bottom wind. Adjust the time of the second upper mold down to be: about 2 seconds less than the value of the water spraying time count to the value of the cold air count to the time. If the upper mold down too early, increase the use of water spraying, and vice versa, reduce the water spraying time.
23. vibration demoulding: usually used in products with high or deep molding and difficult demoulding. Vibrate the mold release knob to select the open, blowing the bottom air time set at 2 seconds or more, according to the number of vibrations to set the product off the mold, the more vibrations, the longer the setting of the bottom air time. Open the bottom right control box, there are two 10 seconds time system inside. The left side time system controls the time under the mold, the right side controls the total time of the mold plate up and down a cycle, and according to the reaction of the mold plate up and down to adjust the restriction valve, for electrical combination to achieve the purpose of vibration.
24. Electric synchronous mold adjustment: according to the upper and lower mold combination degree needs, the function knob system will select the rising time, tap to adjust the mold super motion, the upper mold will rise, and vice versa will fall.
25. Pull the sheet in advance: within the heating time, start the lower gate, observe the heating of the sheet, when it meets the product forming requirements, tap this button to make the sheet come out of the heating area under the drive of the chain service and enter the forming action.
26. Lower gate: This function can be operated in both manual and automatic state. In manual, it can be adjusted partially, and in automatic, it is used to observe the heating condition of the sheet.
27. Stop gate: In the automatic state, the upper gate is closed when the upper gate is not needed according to the product forming needs.
Stop gate: In the automatic state, after the product is formed and cooled, when it enters the cutting area, for safety reasons, close the gate and adjust the cutting position to fix the receiving box and then open it.
28. Electronic counter setting method:
(1) in the setting state: when the desired mode appears on the display press MODE key, you can select and enter the next step, press DISPLAY in any step to end the setting
2） Press MODE key to check the setting content
(3) 2 groups of set products SET2 value must be greater than SET1 value if less than or equal to SET1 value, that is, FFFFFFF will be displayed to remind users to modify, please press the panel reset key RESET after modification, FFFFFFF that disappears (if FFFFFFF appears, key protection to the panel RESET lock is invalid until FFFFFFF disappears)
(4) After the setting is completed, please use the key protection function to protect your set data from being changed by others (key protection only works when the KP of the apex is connected to the common terminal, at this time, the display of K/P indicates that the key protection function has worked).
Cautions for using high speed vacuum forming machine
1. The power must be cut off when the hand reaches under the guide rail for operation, and there must not be any accidental connection of power.
2. Do not touch the cooling product in the molding area when the machine is in the second molding function to prevent the hand from being crushed when the second molding is down.
3. In the heating area, please do not touch the heating device and baked goods with your hands, and raise the heating oven when stopping.
4. When the product length is lower than 800mm, the upper gate and the upper mold action must be synchronized. When partial adjustment of the machine, should open the upper gate first, then open the upper mold
5. In the local adjustment machine, such as the use of solenoid valve power for debugging, should pay attention to whether the power failure will cause injury
6. When feeding the material slices into the knife gate and adjusting the slicing position by hand, the knife gate should be closed, and the hand should not be put into the knife gate cabinet in the automatic state.
High speed vacuum forming machine maintenance
1. Maintain cleanliness and hygiene, after shutdown should be cleared around debris and dirt in the machine
2. Each sliding guide column, bearing and sprocket must be kept in good lubrication condition, often oil lubrication
3. The water filter in the air circuit should be drained once per working shift, and the oil mist collector should be refueled frequently to ensure the normal use of the solenoid valve and cylinder.
4. The oil level of the vacuum pump should be inspected in every working shift (the oil should not be lower than the oil level line); the vacuum pump oil should be put and changed once a month.
5. often observe the oil volume of the oil atomizer, adjust the size of the oil volume at the right time, the role of the new machine to adjust the larger (about 3 days 1 bottle of oil) can be reduced after a week of use to ensure that the pneumatic components have sufficient lubrication.