Warm Global Customers
With China Plastic Machinery
With China Plastic Machinery
Plastic welding refers to a method of connecting two plastic parts by heating them to melt the contact surfaces at the same time, so that they are combined into a whole. It is only applicable to thermoplastic plastic connection. Welding can be done with or without welding rods. When using welding rods, the end faces to be welded need to be made into a certain shape (such as U-shaped, X-shaped, etc.) of the joint, and the molten body of the welding rod drips into the joint, and the two welded parts are connected into one; when not using welding rods, the welding surface is heated and melted, and then vertical pressure is applied to the welded surface until it is tightly fused into one.
For round or tubular workpieces such as PE, PP, nylon, PET, etc. that are not easy to be melted or ultrasonically welded, high-speed rotation and pressurization movement are performed to make the upper and lower workpieces melt and combine in a very short time. This principle makes the bonding force after processing have extremely high watertight and airtight effects. Features of this machine:
1. Provide high-torque motion device, which can be customized from 1 horsepower to 50 horsepower.
2. Stable mechanism to prevent the reaction force when starting and stopping.
3. More than 500 sets of technology and market experience.
Electricity: 1.4KW. 220/380V б╙ 3/50бл60HZ
Air pressure: 5KG/cm2
Productivity: 10бл15 pcs./1 Min.
Applicable: PE, PP, nylon, PET, PTR and other round tubular objects such as: filter element, plastic double-layer cup, cartoon cup, thermos liner, etc.
Electric body lifting, convenient and fast machine adjustment, saving time and effort
Electric precision limit fine adjustment, high precision
The welding head center position limit structure is adopted to ensure that the welding does not deviate
Linear ball slide rails ensure long-term high-precision welding movement of the welding head
Adjustable bottom plate structure, convenient and fast mold adjustment
High-precision power trigger function, high welding stability
Digital welding parameter setting, intuitive and accurate
Imported original piezoelectric ceramic transducer, strong and stable output
Titanium alloy horn, durable
A full set of high-quality imported components assembled, reliable performance
Famous brand pneumatic components, high-quality electrical components
High-quality piezoelectric ceramic transducer, strong and stable output
Titanium alloy horn, durable
Adjustable bottom plate structure, convenient and fast mold debugging
Integral structure, easy to operate; split structure, avoid interference
Toy industry: plastic toys, toy guns, plastic phones, play instruments, airplanes, cartoon plastic toys, etc.
Stationery industry: staplers, PP file folders, plastic pen barrels, etc.
Electronics industry: computers, mobile phone batteries, chargers, SD cards, electronic watches, musical instruments, video cassettes, CD shells, mobile phone shells, etc.
Automotive industry: rear lights, rearview mirrors, front corner lights, indicator light sockets, instrument panels, speakers, stopwatches, etc.
Food industry : Thermos cup, inner loose box, sealed container, etc.
Electrical industry: power switch box, relay, setter, battery shell, rectifier, antenna junction box, etc.
Accessories industry: punching, key chain, photo frame, acrylic drill, etc.
Daily necessities: lighter, glasses case, portable flashlight, clock, etc.
Others: PP box, kitchen supplies, communication equipment, etc.
I. Before work
1. Workers must wear work clothes when entering the workplace, and those with long hair must wear work hats.
2. Check whether the nozzle and gun body screws of the welding gun are loose or falling off, and whether the power cord is intact.
II. During work
1. When using the welding gun, it must be handled with care to avoid damaging the heat-resistant ceramic strips in the welding gun.
2. During welding, be careful not to let the nozzle and the head of the welding gun get too close to the human body, clothing and the welding gun power cord to avoid burns and melting the power cord.
3. It is strictly forbidden to use the welding gun as a hair dryer or other purposes.
4. During welding, if the welding gun makes abnormal noises, the gun should be turned off or the power supply should be cut off immediately.
5. When welding is completed, the gun must be turned off in the correct operating sequence. Keep enough cooling time to avoid damaging the welding gun.
3. After work
1. Place the welding gun gently on the workbench to avoid contact between the gun head and the plastic plate and power cord.
2. Cut off the power supply, clean the work area, and put away all tools and materials.
4. Pay attention to safety
1. If a personal or equipment accident occurs, the scene should be kept and reported to the relevant departments.
Plastic welding, hot plate machine, spin melting machine According to the different heating and softening methods used, plastic welding methods can be divided into softening by external heat source, softening by mechanical movement, and softening by electromagnetic action.
Welding technology using external heat source to soften: hot plate welding, hot air welding, hot rod and pulse welding;
1. Hot plate welding may be the simplest plastic welding technology, but this method is particularly suitable for welding large plastic parts that require a large area of welding surface. Generally, the flat electric heating plate melts and softens the two planes to be welded, then quickly removes the electric heating plate to merge the two planes and applies force to cool. This method has a simple welding device, high welding strength, and the shape design of the product and the welding part is relatively easy. However, the heat generated by the hot plate softens the product, and the cycle is long; the molten resin will adhere to the electric heating plate and is not easy to clean (the surface of the electric heating plate can reduce this phenomenon by coating F4), and impurities will form over time, affecting the bonding strength; the pressure and time must be strictly controlled to ensure the appropriate amount of melting; when different types of resins or metals are combined with resins, insufficient strength will occur.
2. Hot air welding When the hot air flow blows directly to the joint area, the filler wire of the same material as the parent material in the joint area melts. The weld is formed by melting the filler material and the plastic to be welded together. This welding method has light and easy-to-carry welding equipment, but it requires relatively high welding skills from the operator.
3. Hot rod and pulse welding are two technologies mainly used for welding plastic films with smaller thicknesses. And these two methods are similar, both of which press two films together and use the instantaneous heat generated by the hot rod or nickel-chromium wire to complete the welding.
Welding technology that uses mechanical movement to soften: friction welding, ultrasonic welding;
1. Friction welding: It can be divided into linear and rotary types according to the movement track; the linear type can be used for the welding of linear welds and plane welds, and the rotary type can be used for the welding of circular welds. The friction heat generated by the two parts under pressure during the friction process melts and softens the plastic in the contact part, and is aligned and fixed until it solidifies firmly.
2. Ultrasonic welding: Use high-frequency mechanical energy to soften or melt the thermoplastic plastic at the joint. The connected parts are fixed together under pressure, and then subjected to ultrasonic vibrations with a frequency of usually 20 or 40 kHz. The transducer converts the high-power vibration signal into corresponding mechanical energy and applies it to the contact interface of the plastic parts to be welded. The weld joint is violently rubbed and instantly generates high heat, so that the molecules alternately fuse, thereby achieving the welding effect. The ultrasonic welding process is very fast, the welding time is less than one second, and it is easy to automate. It is widely used in various industries such as electronics, electrical appliances, auto parts, plastic toys, stationery, daily necessities, handicrafts, cosmetics, etc. Motion welding is an automatic welding process, which requires special welding equipment. Once the correct welding parameters are determined, the operator can produce stably. Its advantages are: fast, flexible, short and stable welding, no flux or protective gas is required, no harmful gas or slag is generated, and the product welding quality is guaranteed.
Welding technology using electromagnetic softening: high-frequency welding, infrared welding, laser welding;
1. High-frequency welding: Using the principle of electromagnetic induction and high-frequency induction heating technology, penetrate plastic products to generate induction heating for the induction body or magnetic plastic buried inside the plastic parts. The welded plastic can generate heat in the fast alternating electric field to quickly soften and melt the welded parts, and then fill the interface gap, and use a perfect mechanical device to assist in achieving perfect welding. The most common method of generating high-frequency induction is to use a high-frequency current to pass through a coil to obtain a strong high-frequency magnetic field. The induction body (i.e. the heating body) is generally made of iron, aluminum, stainless steel and other materials, but magnetic composite plastic processed by adding magnetic substances are also used. Products welded in this way include stationery clips, inflatable items, waterproof clothing and blood bags.
2. Infrared welding: This technology is similar to hot plate welding. The two parts to be welded are fixed close to the hot plate but not in contact with the hot plate. Under the action of thermal radiation, the connecting part is melted, and then the heat source is removed, the two parts are butt-jointed, and pressed together to complete the welding. This method does not produce welding slag, is pollution-free, and has high welding strength. It is mainly used for the connection of pipeline systems with high precision requirements such as PVDF and PP.
3. Laser welding: In the 1970s, lasers began to be applied to plastic welding. Its principle is to focus the beam generated by the laser (usually a concentrated strong radiation wave in the infrared region of the electromagnetic spectrum) on the area to be welded through an optical path system composed of reflectors, lenses or optical fibers to form a heat action zone. The plastic in the heat action zone is softened and melted. In the subsequent solidification process, the melted material forms a joint, and the parts to be welded are connected. It is usually used for PMMA, PC, ABS, LDPE, HDPE, PVC, PA6, PA66, PS and other materials with good light transmittance. Absorbents such as carbon black are added to the heat action zone to enhance the heat absorption effect. Plastic laser welding has many advantages: fast welding speed and high precision; automation and precision CNC are easy to achieve; and the cost is relatively low. Therefore, plastic laser welding technology has been widely used in the fields of automobiles, medical devices, packaging, etc.
When welding, pressure, time, and heat absorption (melting amount) are the three elements to ensure welding quality.
Applying appropriate pressure to the welding surface will cause the welding material to transition from elasticity to plasticity. It can also promote the mutual diffusion of molecules and squeeze out the residual air in the weld, thereby increasing the sealing performance of the welding surface.
There must be appropriate hot melt time and sufficient cooling time. When the heat power is constant, insufficient time will result in a cold weld, and too long time will cause the weld to deform, slag to overflow, and sometimes hot spots (discoloration) will appear in non-welding parts. It is necessary to ensure that the welding surface absorbs enough heat to reach a fully molten state to ensure sufficient diffusion and fusion between molecules, and sufficient cooling time must be ensured to ensure that the weld reaches sufficient strength.
The most appropriate melting volume can be obtained by coordinating the hot melt time and the heat power to ensure sufficient fusion between molecules and eliminate the phenomenon of cold welds. In addition to the welding equipment and the skill level of the operator, various factors from inside or outside the plastic have a certain impact on the welding quality and should be taken seriously.
Hygroscopicity of plastic
If wet plastic products are welded, the water contained in them will turn into steam after being heated and escape, and bubbles will appear on the weld surface, which will weaken the sealing performance of the weld surface. Materials with more serious hygroscopicity include PA, ABS, PMMA, etc. Products made of these materials must be dried before welding.
Fillers in plastic
Such as glass fiber, talcum powder, mica, etc., they change the physical properties of the material. The content of fillers in plastic has a great relationship with the weldability and welding quality of plastic. Plastic with a filler content of less than 20% can be welded normally without special treatment. When the filler content exceeds 30%, the sealing will be reduced due to the insufficient proportion of plastic on the surface and insufficient fusion between molecules.
Cleanliness of welding surface
The welding surface must be clean and free of impurities to ensure sufficient welding strength and airtightness.
In addition to selecting the correct welding materials and eliminating the adverse factors that affect the welding effect, it is also necessary to adopt appropriate welding methods according to the type of material, product shape, and cost.
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