The thick-gauge thermoforming machine is a key process equipment for producing thermoformed plastic parts from plastic sheets. It uses thermoplastic plastic sheets as raw materials. The sheets are heated to the softening temperature in an oven, and then, through the vacuum negative pressure between the plastic sheet and the thermoforming mold, the thermoplastic plastic sheet is drawn onto the working surface of the mold and cooled to form the desired shape.
Organization and Function
編輯A thick-gauge thermoforming machine generally consists of a sheet positioning system,a mold positioning system,a frame system,a heating system,a cooling system,and an electrical control system.
(1)The sheet positioning system typically comprises a crisscross material clamping frame,power cylinders(pneumatic or hydraulic),and a balancing and synchronizing mechanism.Its function is to clamp and position the plastic sheet.For the rack-type heating method,the clamping frame has an upper and lower structure and is equipped with a lateral locking mechanism to ensure a tight seal between the clamping frame and the sheet support plate.The frame can be adjusted according to the size of the mold,either manually or automatically.
(2)The mold positioning system generally consists of upper and lower mold platforms,upper and lower mold cylinders(pneumatic or hydraulic),and a synchronizing mechanism.Its function is to clamp and position the thermoforming mold and to connect the mold to the vacuum piping.The positioning methods include manual screw tightening or pneumatic automatic locking.The synchronizing mechanism ensures synchronous lifting and lowering of the upper and lower molds,guaranteeing the precision of the thermoforming process.
(3)The frame system usually includes a profile frame,a sealing chamber,and a protective door,which can be either automatic or manual.
(4)The heating system generally comprises heating bricks or heating tubes,an oven frame,and power cylinders or motors.
(5)The cooling system typically consists of air and water pipes,as well as spray nozzles.
(6)Electrical control system:The electrical control system,in conjunction with the pneumatic or hydraulic system,can meet the process requirements of the thermoforming machine(temperature,speed,time)and various procedural actions.It mainly consists of a PLC and touch screen,contactors,electronic components,temperature controllers,solenoid valves,sensors,etc.There are generally three control modes:manual,automatic,and adjustment.
(1)The sheet positioning system typically comprises a crisscross material clamping frame,power cylinders(pneumatic or hydraulic),and a balancing and synchronizing mechanism.Its function is to clamp and position the plastic sheet.For the rack-type heating method,the clamping frame has an upper and lower structure and is equipped with a lateral locking mechanism to ensure a tight seal between the clamping frame and the sheet support plate.The frame can be adjusted according to the size of the mold,either manually or automatically.
(2)The mold positioning system generally consists of upper and lower mold platforms,upper and lower mold cylinders(pneumatic or hydraulic),and a synchronizing mechanism.Its function is to clamp and position the thermoforming mold and to connect the mold to the vacuum piping.The positioning methods include manual screw tightening or pneumatic automatic locking.The synchronizing mechanism ensures synchronous lifting and lowering of the upper and lower molds,guaranteeing the precision of the thermoforming process.
(3)The frame system usually includes a profile frame,a sealing chamber,and a protective door,which can be either automatic or manual.
(4)The heating system generally comprises heating bricks or heating tubes,an oven frame,and power cylinders or motors.
(5)The cooling system typically consists of air and water pipes,as well as spray nozzles.
(6)Electrical control system:The electrical control system,in conjunction with the pneumatic or hydraulic system,can meet the process requirements of the thermoforming machine(temperature,speed,time)and various procedural actions.It mainly consists of a PLC and touch screen,contactors,electronic components,temperature controllers,solenoid valves,sensors,etc.There are generally three control modes:manual,automatic,and adjustment.
Principle of Thick-gauge Thermoforming
編輯The principle of thick-gauge thermoforming is similar to that of thin-gauge thermoforming.It involves heating a positioned plastic sheet in an oven until it reaches a softened state.The thermoforming mold then forms a sealed space around the sheet and instantly evacuates the air from the mold cavity.This action draws the sheet tightly onto the mold surface,where it is cooled and set into shape.
Thermoforming is a cyclical process,with each cycle mainly consisting of the following steps:loading the material—softening through heating—pre-stretching with reverse blowing—forming—cooling and setting—demolding and removing the part.After the part is removed,a new sheet is placed(either manually or automatically)to begin the next cycle.
Thermoforming is a cyclical process,with each cycle mainly consisting of the following steps:loading the material—softening through heating—pre-stretching with reverse blowing—forming—cooling and setting—demolding and removing the part.After the part is removed,a new sheet is placed(either manually or automatically)to begin the next cycle.
Applications and Development Prospects
編輯Thick-gauge thermoforming machines are capable of producing large-sized,complex-shaped plastic products with less stringent dimensional requirements in a single molding process.In some aspects,they can replace injection molding,fiberglass,and metal enclosures,among others.Thermoforming molds offer the advantages of low manufacturing costs and short development cycles,with costs ranging from 1/10 to 1/20 of those of injection molds.They are increasingly widely used in various fields of daily life,including automotive interiors and exteriors,transportation,construction materials,packaging,medical devices,home appliances,educational and sanitary ware,and sports equipment.With the rapid development of the plastic industry,the application areas of thick-gauge thermoforming are continuously expanding,and the importance of thermoforming machinery is also increasing.However,the current supply of such machines is struggling to meet user demands.At present,most users of thick-gauge thermoforming machines rely on imported machinery from Taiwan and other regions.Energy efficiency,production efficiency,and the ability to handle high-difficulty thick-gauge thermoforming are the main development bottlenecks for these machines.There are very few domestic manufacturers of thick-gauge thermoforming machines that can replace those from Taiwan.For example,in terms of energy saving,the thick-gauge thermoforming machines produced by Dongguan Pudi Machinery Equipment Co.,Ltd.use a new type of energy-saving radiator that can save more than 30%of electricity.The company's positive pressure thick-gauge thermoforming machine is particularly suitable for the thermoforming of difficult-to-mold materials such as PC and foamed plastic sheets.Another example is the heating and forming synchronous thick-gauge thermoforming machine produced by Jiangxi Wanzai Pioneer Machinery,which is recommended on the website of the Science and Technology Innovation Fund.This machine solves the problem of continuous production processes for heating and forming of thick sheets and has a production efficiency about twice that of ordinary thick-gauge thermoforming machines.
Thick-gauge thermoforming machines represent a branch of China's plastic machinery industry,and there is still a significant gap compared to industrially developed countries.In terms of the variety of large-scale,special-purpose,and dedicated thick-gauge thermoforming machines,some products are still non-existent,which is the main difference from industrially developed countries.Against the backdrop of economic globalization and the diversification of product applications,domestic thick-gauge thermoforming machinery is expected to develop rapidly and will be continuously improved with the help of imported foreign technologies.Especially with the rapid development of electric vehicles today,which require energy-efficient,lightweight,and diverse designs,the development and application of thick-gauge thermoformed parts are gradually increasing,and the potential market for thermoformed parts is continuously expanding.It is estimated that in three years,the annual output value will exceed ten billion yuan.However,the requirements for thick-gauge thermoforming processes and subsequent processing are becoming more systematic and standardized.This presents both opportunities and challenges.There will come a time when we can ride the wind and break the waves,and with determination,we can navigate through the vast ocean.
Thick-gauge thermoforming machines represent a branch of China's plastic machinery industry,and there is still a significant gap compared to industrially developed countries.In terms of the variety of large-scale,special-purpose,and dedicated thick-gauge thermoforming machines,some products are still non-existent,which is the main difference from industrially developed countries.Against the backdrop of economic globalization and the diversification of product applications,domestic thick-gauge thermoforming machinery is expected to develop rapidly and will be continuously improved with the help of imported foreign technologies.Especially with the rapid development of electric vehicles today,which require energy-efficient,lightweight,and diverse designs,the development and application of thick-gauge thermoformed parts are gradually increasing,and the potential market for thermoformed parts is continuously expanding.It is estimated that in three years,the annual output value will exceed ten billion yuan.However,the requirements for thick-gauge thermoforming processes and subsequent processing are becoming more systematic and standardized.This presents both opportunities and challenges.There will come a time when we can ride the wind and break the waves,and with determination,we can navigate through the vast ocean.
Selection of Machine Model and Mold
編輯Generally speaking,customers who have been in the thermoforming industry for many years usually have the capability to judge and select the appropriate thermoforming machine for production on their own.However,for the majority of customers,they may need the assistance of the manufacturer to decide which specification of thick-gauge thermoforming machine to use.In some cases,customers may only have a product sample or an idea,and then inquire whether the manufacturer's machine can produce it,or which model would be more suitable.
The important factors that usually determine the selection include the mold,product,type of plastic,and production volume requirements,etc.Therefore,before making a selection,it is necessary to collect or have the following information:
• The external dimensions of the product(length,width,height);
• The wall thickness of the product;
• The type and quantity of the product to be used.
After obtaining the above information,the appropriate thick-gauge thermoforming machine can be selected according to the following steps:
• The maximum external dimensions of the product determine the size of the machine's opening.For a forming area of less than 1.5 square meters,a small thick-gauge machine should be selected;for an area between 1.5 and 3.7 square meters,a medium-sized thick-gauge machine is appropriate;and for an area above 3.7 square meters,a large thick-gauge machine is required,as described in the aforementioned machine classification.
• If the product's wall thickness is between 1.5 and 2MM,and the product's stretch ratio(the ratio of height to the average dimension of length plus width)is greater than 1,it is advisable to select a machine with double-layer heating.If the stretch ratio is less than 1,a single-layer heating machine should be chosen.
• If the product's wall thickness is below 1.5MM,regardless of the stretch ratio(although products with a stretch ratio exceeding 1.5 are generally not suitable for thermoforming),a single-layer heating machine can be selected.
• If the product's wall thickness is above 2MM and the stretch ratio is below 0.5,a single-layer heating machine is recommended;if the stretch ratio exceeds 0.5,a double-layer heating machine is more appropriate.
The important factors that usually determine the selection include the mold,product,type of plastic,and production volume requirements,etc.Therefore,before making a selection,it is necessary to collect or have the following information:
• The external dimensions of the product(length,width,height);
• The wall thickness of the product;
• The type and quantity of the product to be used.
After obtaining the above information,the appropriate thick-gauge thermoforming machine can be selected according to the following steps:
• The maximum external dimensions of the product determine the size of the machine's opening.For a forming area of less than 1.5 square meters,a small thick-gauge machine should be selected;for an area between 1.5 and 3.7 square meters,a medium-sized thick-gauge machine is appropriate;and for an area above 3.7 square meters,a large thick-gauge machine is required,as described in the aforementioned machine classification.
• If the product's wall thickness is between 1.5 and 2MM,and the product's stretch ratio(the ratio of height to the average dimension of length plus width)is greater than 1,it is advisable to select a machine with double-layer heating.If the stretch ratio is less than 1,a single-layer heating machine should be chosen.
• If the product's wall thickness is below 1.5MM,regardless of the stretch ratio(although products with a stretch ratio exceeding 1.5 are generally not suitable for thermoforming),a single-layer heating machine can be selected.
• If the product's wall thickness is above 2MM and the stretch ratio is below 0.5,a single-layer heating machine is recommended;if the stretch ratio exceeds 0.5,a double-layer heating machine is more appropriate.
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