The suction molding machine, also known as the thermoplastic forming machine, is a machine that blister-forms heated and plasticized thermoplastic plastic coils such as PVC, PE, PP, PET, HIPS, etc. into various shapes of advanced packaging boxes, frames, and other products. Using the vacuum suction force generated by the vacuum pump, the heated and softened thermoplastic plastic sheets such as PVC and PET are blister -formed into various shapes of vacuum covers, blister trays, blister shells, etc. through molds.

Machine Introduction

Principle of blister forming machine: blister forming is also called thermoplastic forming. This forming process mainly uses the vacuum suction force generated by a vacuum pump thermoplastic plastic sheets through a mold to form vacuum covers of various shapes, or attach them to the surface of products of various shapes. Blister forming is divided into thin sheet blister forming and thick sheet blister forming according to the thickness of the sheet.

The main structure of the machine is composed of feeding, pulling, upper and lower electric heating furnaces, lower gate, multi-function adjustable size, lower die plate, upper die, upper gate, knife gate, slice, put and vacuum device.

Common products of thick-film blister packaging include: household appliance liner shells, luggage, display rack accessories, decoration, automobile interiors, bumpers, fenders, beauty equipment, light box shells, toy car shells, industrial panels, advertising light boxes, blister logos, bathroom products, refrigerator liners, etc..

Main Applications

1. Plastic packaging industry (blister packaging, plastics, batteries, toys, gifts, hardware, home appliances, electronics, stationery, decoration)

2. Food packaging industry (fast food boxes, fruit trays, biscuit boxes)

3. Pharmaceutical industry (pill packaging, tablet packaging)

4. Industrial cooling tower cooling water guide plate, etc.

5. Manufacturing industries such as decorative three-dimensional relief patterns, plastic ceilings, wall panels, automotive materials, and sanitary equipment.

6. Suitable for producing various color sheets: polyethylene PS, polyvinyl chloride PVC, plexiglass, ABS, polymethyl methacrylate ; flocking sheets; environmentally friendly sheets APET, PET, PP, etc.; photodegradable materials; biodegradable materials and other plastic products.

Molding Technology

Vacuum forming technology is a plastic sheet (plate) thermoforming technology, which is one of the secondary processing technologies of plastics. It is different from injection molding, extrusion and other primary processing technologies. It is not to heat and mold plastic resin or particles or continuously mold them with the same die and cross section; nor is it to use machine tools, cutters and other mechanical processing methods to cut off part of the plastic material to obtain the required shape and size. Instead, it heats the plastic sheet (plate) material, uses molds, vacuum or pressure to deform the sheet (plate) material to achieve the required shape and size, and is supplemented by supporting processes to achieve the application purpose.

The blister forming equipment includes a clamping system, a heating system, a vacuum and compressed air system, and a forming mold.

Suction Molding

Main Features

⑴ Strong adaptability of product specifications. Vacuum forming can be used to manufacture various products of extra large, extra small, extra thick and extra thin. The sheet can be as thin as 1~2MM, or even thinner. The product area can be as large as 10㎡ or as small as a few square millimeters. The wall thickness can be as large as 20mm or as small as 0.1mm.

⑵ The products have a wide range of applications, including daily necessities blister packaging, small hardware blister packaging, automotive products blister packaging, electronic products blister packaging, food blister packaging, cosmetics blister packaging, computer peripheral equipment blister packaging, toy blister packaging, sports goods blister packaging, stationery blister packaging, etc.

⑶ Less equipment investment

⑷ Easy to make molds (plaster molds, copper molds, aluminum molds~~~~)

⑸ Higher production efficiency.

(6) It saves raw and auxiliary materials, is light in weight, convenient to transport, has good sealing performance, and meets the requirements of environmentally friendly green packaging; it can package any special-shaped products, and no additional cushioning materials are required for packing; the packaged products are transparent and visible, with beautiful appearance, easy to sell, and suitable for mechanized and automated packaging, which is convenient for modern management, saving manpower and improving efficiency

Commonly used plastics and properties for thermoforming

Plastics can be divided into two categories according to their thermal behavior: thermoplastics and thermosetting plastics. Most materials used for thermoforming are thermoplastics.

Whether single-layer or multi-layer composite plastic sheets (plates) used for thermoforming processing must have the following process properties

1. Plastic Memory

2. Heat stretching

3. Thermal strength

4. Molding temperature

Commonly used plastics for thermoforming

PVC (characteristics are low impurity content, good transparency, low price, good dielectric properties, flame retardancy and self-extinguishing properties)

PP (abundant sources, cheap price, excellent performance and wide range of uses.

1. Low density (PP is colorless, odorless, tasteless, non-toxic, flammable, white in appearance and has a density of 0.90~0.91g/cm3.)

2. Good mechanical properties PP has excellent rigidity, ductility and resistance to stress cracking

3. Good heat resistance

4. Good chemical stability

5. Transparency, good water resistance and waterproofness

6. Strong processing and usability

PE (one of the largest and most widely used plastics, odorless, tasteless, non-toxic and flammable)

PS (Plastic is hard, brittle, transparent, odorless, emits black smoke when burned, is easy to dye and process, has low hygroscopicity, dimensional stability, and good electrical and thermal insulation.)

1. High transparency and glossiness

2. Excellent colorability and hygienic performance

3. Excellent dielectric properties

4. Excellent molding performance

Disadvantages:

1. Fragile

2. Poor heat resistance

3. Moisture-proof and oxygen-resistant

ABS (opaque, non-toxic, odorless)

PET (colorless, odorless, tasteless, non-toxic, excellent transparency, excellent mechanical strength, wear resistance and electrical insulation properties, good creep resistance, rigidity and strength. Excellent hygiene allows it to directly contact food)

Basic methods of thermoforming

There are many methods for plastic thermoforming, which can be divided into two categories according to the molding power: compression molding and differential pressure molding. According to the molding mold, it can be divided into several methods such as single positive mold, single negative mold, double mold, and moldless mold.

Compression molding, also known as mechanical stretch molding, is a molding method that uses a single mold or a pair of molds to mold plastic sheets into various parts with the help of external mechanical pressure or deadweight. The positive mold refers to the shape of the mold is convex, and the negative mold refers to the shape of the mold is concave. The mold only molds one side of the product, and the other side is exposed to the air. It is different from the compression molding of the one-time molding process. This method is basically applicable to all thermoplastics.

Molding Types

One-piece male mold forming

Single male mold forming is also called convex mold forming or bending mold forming, vertical mold forming. It is a molding method that uses a machine to mold the heated and softened plastic sheet into a certain shape.

Single female mold forming

Single female mold forming is also called concave mold forming.

Three-pair mold forming

The mold for double-mold forming is composed of a male mold, a female mold, a clamp and other accessories.

Composite mold forming

Function composition.

Clamping equipment

When the plastic sheet is formed, the sheet is fixed on the clamping device. The universal and composite thermoforming machines for thermoforming mostly use clamping devices that are convenient for fixing sheets of various sizes. Sometimes the entire forming machine is equipped with a set of clamping frames.

Clamping devices can be divided into two categories: one is frame type and the other is split 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 forming machines is directly fixed to the forming chamber. On manual and semi-automatic forming machines that manually load the preforms and remove the finished products, when the frame size is large, a safety operating device within the frame opening range is installed. For preforms with large molding slippage, the clamping force is required to be adjustable within a relatively wide range. For this purpose, two rubber-coated rollers are used, which are pressed against each other by springs and equipped with a pressure regulating device. The clamping of the continuous pull-tab forming machine is the combined effect of the zippers on both sides and the front and rear gates.

It is best to use automatic control for the clamping device so that it can act quickly, which can help improve the quality and efficiency of the product.

Heating equipment

One of the main processes in the vacuum forming process of thermoplastic sheets and films is sheet heating. The duration and quality of electric heating depends on the structure of the heater, the thermal inertia of the temperature transfer after the radiant 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 include electric heaters, crystal radiators and infrared heaters.

Vacuum equipment

The vacuum system consists of a vacuum pump, a gas storage tank, valves, pipelines, and a vacuum gauge. A separate vacuum pump is often used in vacuum forming. The vacuum degree of this pump should reach 0.07~0.09 Mpa (520mmHg) or above. The gas storage tank is generally a cylindrical box welded with thin steel plates, and the bottom is elliptical. The capacity of the gas storage tank should be at least half the capacity of the largest molding chamber. Appropriate valves must be installed on the vacuum pipeline to control the vacuum capacity.

The rotational power of the vacuum pump is determined by the size of the molding equipment and the molding speed. Larger or faster molding equipment often uses 2-4KW. The size of the vacuum central system depends on the specific production and development requirements of the factory.

Compressed air equipment

The pneumatic system can be composed of the molding machine itself with a compressor, air storage tank, workshop main pipeline, valves, etc. The molding machine requires compressed air with a pressure of 0.4-0.5MPa. Various vacuum forming machines widely use piston air compressors. Large screw air compressors can also be used for the whole factory supply.

In addition to being used in large quantities for molding, compressed air is also used in part for demoulding, external cooling of primary products, and for operating the mold frame and running sheets and other mechanical parts.

Cooling equipment

In order to improve production efficiency, vacuum blister formed 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 a built-in cooling coil. For non-metallic molds, such as wood, gypsum, glass fiber reinforced plastic, epoxy resin, etc., since they cannot be cooled with water, air cooling can be used instead, and water mist can be added to cool the outer surface of the vacuum blister formed part.

If natural cooling is used in production, annealed parts can be obtained, which is beneficial to improve the impact resistance of the parts. Although water cooling has high production efficiency, the internal stress of the parts is relatively large.

Demolding equipment

Demoulding is the process of removing the product from the mould. Usually, whether it is a concave mould or a convex mould, in most cases, the product shrinks due to cooling and sticks to the mould, so it is demolded through the vacuum suction hole or by blowing in the opposite direction.

Especially for molds with small demoulding angles or with concave molds, demoulding is performed by knocking or vibrating the demoulding mechanism at the same time. Sometimes, a release agent is applied to the sheet and the mold, or the mold surface is sprayed with Teflon.

Control Equipment

The control system generally includes the control of various parameters and actions of instruments, meters, pipelines, valves in the process of vacuum forming and finishing. The control methods include manual, electrical-mechanical automatic control, computer control, etc. The specific selection should be based on the initial investment labor cost, technical requirements, raw material costs, production and maintenance equipment costs and other factors.

High-speed vacuum

Features of high speed vacuum forming machine

1. Adopt vertical pull-tab design: the pull-tab is fast, uniform and stable, shortens the pull-tab occupancy time, is more adaptable to environmentally friendly materials and reduces power consumption, ensuring product molding quality.

2. Independent group temperature control: using special dense flat far-infrared ceramic hair assembly, uniform temperature: saving 50% more power than traditional machines.

3. The electric heating furnace adopts closed heating to make the heating more uniform and reduce heat loss. It is also equipped with a manual switch to control the vertical lifting of the electric furnace, which is beneficial to control product quality during the production process. Thick film or PP sheet can be heated by upper and lower double electric furnaces (customized by customers) to speed up the heating time and increase production speed.

4. This machine is equipped with a vibration demoulding device, which prevents high-difficulty products from being deformed and makes demoulding easy.

5. Double-row needle chain drive, high-speed operation ensures accuracy and stability, and is equipped with a width adjustment device to maximize the use of film and 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 molding quality. The production speed is twice as fast as the traditional one.

7. Built-in secondary vacuum makes it easier to form difficult products, improve product quality and reduce scrap rate.

8. The whole machine adopts imported electrical appliances and pneumatic components from international famous manufacturers, with absolutely reliable quality, safety and durability.

Function

It can blister various types of films such as (PVC, PET, PP, PS, etc.) into plastic covers of different shapes. For example, toys, hardware, food, electronics, medicines, etc. are covered and sealed on cardboard with transparent films to form a close-fitting package. This machine can also produce plastic ceilings, wall panels, cake boxes, automotive materials and sanitary materials with three-dimensional relief patterns.

Equipment structure

Its main structure is composed of feeding, pulling, upper and lower electric heating furnaces, lower gate, multi-functional adjustable size, lower mold plate, upper mold, upper gate, knife gate, slicing, unloading and equipped with vacuum device; the pneumatic device is the main power source, and its pulling and feeding are electric, reducer, time relay, intermediate relay, travel switch and other electrical appliances 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 movement and temperature control, short production time, and save as much power consumption as possible under the same production conditions.

Instructions

1. Turn on the power supply first.

2. Turn on the air source, the air pressure is required to be 5-6 kg

3. Start the chiller and adjust the temperature to about 10 degrees

4. Press the blister power switch button to turn on, so that the three power indicator lights will light up at the same time

5. Press the heating button of the electric stove again and the main light will come on. Turn on the electric stove and adjust the heating control.

6. Arrange the molds and cover them with tape.

7. Place the middle gate pressure regulator at the back of the mold.

8. If molds need to be placed, the mold frame should be prepared and adjusted immediately.

9. Adjust the heat shield to the same length as the total length of the mold.

10. Put the rubber material into the front material rack and fix it, and adjust the feed port

11. Adjust the counting length of the pull tab to the length of the machine mold (press MODE to adjust the counter length. If SET2 is displayed, it is the pull tab length (such as 1000MM). Press MODE to display SET1, the pull tab buffer must be less than SET2. (If it is 850MM). RST is reset. In manual mode, press RST to reset when the pull tab reaches the counted number. Before turning on the automatic mode, you must also check whether RST is reset).

12. Check whether each switch is normally turned on manually.

13. Adjust all time systems.

Note: Electric furnace time is the total time

Combine vacuum + water spray + demoulding air blowing + delayed vacuum + 1-2 seconds, not more than the electric furnace time. The ratio of film thickness to time is 0.5 glue = 20, 0.5 glue = 20, and 1# film is 1 second.

14. Adjust the center gate, slitting, proximity switch position and horizontal nut for forming height adjustment.

15. Start the heating furnace, adjust the heating area of ​​the heating furnace according to the molding area of ​​the mold, adjust the temperature control device, and observe the corresponding current and the reddening phenomenon of the heating bricks. Generally, the current is high around and low in the middle.

16. Install the film on the feed shaft, adjust the film according to the film width and the feed port position, and fix the feed rotor at the corresponding position of the sheet feed positioning wheel.

17. Preheat the heating furnace for 10 to 15 minutes. After the temperature meets the production requirements, adjust the digital display time corresponding to each program on the control panel. Generally, it is set so that the heating time is greater than the sum of the vacuum, cold air and demoulding time, and turn on the vacuum pump.

18. Raise the furnace, turn the manual and automatic switches on the phone, select the feeding switch to the corresponding gear, put the sheet in parallel between the pressing wheel and the chain teeth, press the pull-tab button to feed the material into the heating area. At this time, the sheet should extend about 20mm at the lower gate outlet.

19. Put down the heating furnace, turn the manual and automatic switches to automatic, and start the heating timing. When producing the first product, the heating time should be set to more than 1.5 times the time required by the process, start the gate, observe the heating of the sheet, and when the sheet heating zone reaches the temperature that meets the molding requirements, jog the advance pull of the sheet so that the sheet moves out of the heating area driven by the chain and enters the molding action, and modify the set number of the heating time.

20. After the sheet is formed and cooled, it is taken out of the forming area by the chain and enters the cutting area. At this time, the knife gate should be closed, the receiving box should be moved, and after adjusting the cutting position, the receiving box should be positioned and the knife gate should be opened.

21. When the blister machine is automatically producing, the operator should check the product quality to see if the temperature meets the product quality requirements, adjust the temperature, and then conduct a detailed inspection to see if the uniformity of the film forming of the product varieties is consistent, perform local temperature adjustment, and maintain the product quality requirements.

22. Secondary mold: used to protect the product from deformation, cracks, fragility, and difficulty in demolding when demolding. Function setting: select the mold function in the secondary mold. When the upper mold is lowered to the surface of the product, the cold air stops and the bottom air starts. Adjust the time for the secondary mold to come down: the water spray time counts to the time value less than the cold air counts to the time value by about 2 seconds. If the upper mold comes down too early, increase the water spray, otherwise, reduce the water spray time.

23. Vibration demoulding: usually used in products with high or deep molding and difficult demoulding. The vibration demoulding button is turned on, and the bottom blowing time is set to more than 2 seconds. It is set according to the number of vibrations during product demoulding. The more vibrations, the longer the bottom blowing time is set. Open the control box on the lower right, which contains two 10-second timers. The left timer controls the time for the lower mold, and the right timer controls the total time of the next cycle of the mold plate. The current limiting valve is adjusted according to the upper and lower reactions of the mold plate, and the purpose of vibration is achieved through electrical combination.

24. Electric synchronous mold adjustment: According to the degree of combination of the upper and lower molds, when the function button is selected to rise, the mold adjustment is super-moved, and the upper mold rises, otherwise it falls.

25. Pull the sheet in advance: During the heating time, start the gate and observe the heating of the sheet. When it meets the product forming requirements, press this button to make the sheet move out of the heating zone under the drive of the chain and enter the forming action.

26. Lower gate: This function can be operated in manual and automatic mode. In manual mode, local adjustment can be performed. In automatic mode, it is used to observe the heating status of the sheet.

27. Stop gate: In the automatic state, according to the needs of product molding, the upper gate will be closed when it is not needed.

Stop switch: In the automatic state, after the product is formed and cooled, when it enters the cutting area, for safety reasons, the knife switch is closed, and the cutting position is adjusted and the material receiving box is fixed before it is opened again.

28. How to set the electronic counter:

1) In the setting state: When the required mode is displayed, press the MODE button to select and enter the next step. Press DISPLAY at any step to end the setting.

2) Press the MODE key to check the settings.

3) The value of SET2 of the 2-group setting product must be greater than the value of SET1. If it is less than or equal to the value of SET1, FFFFFF will be displayed to remind the user to make changes. After the change, please press the panel reset key RESET and FFFFFF will disappear (if FFFFFF appears, the key protection will be invalid for the panel RESET lock until FFFFFF disappears)

4) After the setting is completed, please use the key protection function to protect the data you set from being changed by others (the key protection will only work when the KP of the first terminal is connected to the common terminal. At this time, the display K/P indicates that the key protection function has worked).

Precautions

1. When you reach under the rail to operate, the power supply must be cut off. No accidental power supply should occur.

2. When the machine is using the secondary mold function, do not put your hands into the molding area to touch the cooling product to prevent your hands from being crushed when the second mold is lowered.

3. In the heating area, do not touch the heating device or the baked items with your hands. When stopping the machine, the heating furnace should be raised.

4. When the product length is less than 800mm, the gate and the upper mold must be opened synchronously. When adjusting the machine locally, the gate should be opened first and then the upper mold.

5. When adjusting the machine locally, such as using a solenoid valve to energize for debugging, you should pay attention to whether power outages may cause damage

6. When manually receiving the material and feeding it into the knife gate and adjusting the slicing position, the knife gate should be closed. Do not put your hands into the knife gate cabinet in the automatic state.

Maintenance

1. Keep clean and hygienic. After stopping the machine, remove the surrounding debris and dirt inside the machine.

2. Each sliding guide column, bearing and sprocket must be kept in good lubrication condition and lubricated frequently.

3. The water filter in the gas circuit should be drained once every work shift, and the oil mist collector should be refueled frequently to ensure the normal use of the solenoid valve and cylinder.

4. Check the oil level of the vacuum pump before each work shift (the oil level must not be lower than the oil level line); replace the vacuum pump oil once a month

5. Always observe the oil level in the oil mist collector and adjust the oil level in time. When a new machine is in use, increase the amount (about 1 bottle of oil every 3 days). After a week of use, you can reduce it to ensure that all pneumatic components have sufficient lubrication.

Features of automatic continuous vacuum forming machine

Features:

1. Control system: Artificial intelligence, the system uses Siemens CPU224 host and Siemens EM222 module, the human-machine interface uses Delta 10.4-inch color touch screen, professional operation screen, corresponding to the ordinary operation method, solves the problem of upgraded control. Powerful memory space, set up interfaces including automatic operation, manual operation, function setting, mechanical animation, fault display, equipment documentation, safety instructions, etc., the whole system is safe and stable.

2. Loading area: The loading area is lifted by a motor, and the supporting weight can reach 200 kg. The sheet feeding is driven by a rubber roller, and two large feed rods are provided for changing sheets.

3. Electric heating area: The electric furnace is made of stainless steel, Taiwan heating tiles, Japanese high-temperature wire, high-frequency porcelain joints, 60 heating tiles for the upper furnace, 42 heating tiles for the lower furnace, maximum power 40.8KW, Korean DPC digital proportional regulator, one control and one temperature adjustment, and a temperature sensor to display the temperature of the electric furnace for convenient data management. The electric furnace is driven by a cylinder, and the electric furnace can be removed from the machine during power outage or maintenance, which is safe and convenient.

4. Forming area: The forming length is unlimited within 1220mm, the forming width is 470~720mm, the mold plate is made of aluminum alloy water-transporting type with a total of 5 pieces, which can be disassembled independently. A quick vacuum tube and water pipe to facilitate the replacement of the mold plate. The mold plate has a specification of 50mm width, the maximum forming height is 200mm, and the sheet width is 510~760mm. The bottom mold cylinder is 150×350 mm, which can be electrically adjusted in height. The maximum mold plate stroke is 320mm, and it is equipped with vibration demoulding, multiple demoulding and blowing, and demoulding and blowing delay functions. The upper mold cylinder is 125×450 mm, the stroke can be electrically adjusted, and it is equipped with secondary upper mold independence and upper pressure demoulding isolation functions. The lower gate and the middle gate are designed with quick push-pull type.

5. Chain rail drive: The chain rail cover is made of imported 718 steel through special precision processing, and the middle plate and lower plate are made of high-quality 45# steel through precision processing, with high docking accuracy, low friction coefficient and long service life. The pull piece adopts frequency conversion control technology and cooperates with the encoder to input the required length, and the pull piece is fast and accurate.

6. Cooling system: equipped with 10 Japanese Meiji A-100 sprinkler heads, 1 Nichirin 3-HP water chiller, water transport by mold tray, equipped with 2 powerful fans, and the air inlet of the fan is designed as an air duct to avoid sucking in circulating hot air.

7. Material collection area: The material collection box is designed to be movable, with hand-cranked gear transmission, pneumatic tableting and tablet release, and precision screw drive for slicing.

8. Vacuum system: German Ritchie or Pusch vacuum pump, power 4kw, vacuum speed 150-160m3 per hour, vacuum cylinder 0.25 m3.

9. All functions: secondary vacuum function, vacuum delay function, upper mold buffer function, upper mold electric adjustment function, lower mold electric adjustment function, multiple back-blowing function, multiple demoulding function, shift production metering function, secondary mold loading function, upper mold isolation function, delayed water spraying function, delayed air blowing function, air blowing isolation function, secondary independent mold loading function, automatic exit function of the hot furnace during power outage, push-pull adjustment function of the middle and lower gates, motor loading setting function, bottom air delay function.

10. Other specifications

Gas consumption: 6.5kg/cm2000-3000l/h

Power supply: 380V50HZ/220V60HZ/3?

Production speed: 100~300 molds/hour

Power consumption of the whole machine: about 25kw/hour

Mechanical dimensions: L7800×W1650×H2560mm

Machine weight: Approximately 4800kg