BMC injection molding machine uses BMC (unsaturated polyester bulk molding compound) as molding material for injection molding.
BMC is a thermosetting plastic, which is mixed with various inert fillers, fiber reinforcements, chemical agents, stabilizers and pigments to form an adhesive "putty" composite material for compression molding or injection molding. Bulk molding compound (BMC) is highly filled and reinforced with short fibers, glass fiber reinforcement accounts for 10% to 30%, and length of glass fiber is generally 6~12mm, sometimes 25mm is used to meet high mechanical properties; 3mm is used to meet requirements of molding fluidity.
BMC is added from hopper into barrel. A screw driven to rotate by an external power motor is installed in barrel. Under action of screw, material is transported forward along screw groove and compacted and pushed to screw head. At the same time, screw retreats under reaction of material, so that a storage space is formed at screw head. Then, under action of thrust of injection cylinder piston, screw injects material in storage chamber into mold cavity through nozzle at high speed and high pressure. After molten material in cavity is pressure-maintained, heated, and solidified, mold is opened under action of mold clamping mechanism, and shaped product is ejected from mold through ejection device.
Operation cycle of injection molding machine is as follows:
1) Locking mold: Upper mold plate quickly approaches the lower mold plate (including fast-slow-slow high pressure), and after confirming that there is no foreign matter, system switches to high pressure to lock mold plate (maintain pressure in cylinder)
2) Shooting platform moves forward to specified position (nozzle is close to mold)
3) Injection molding: Screw can be set to inject molten material at the front end of barrel into mold cavity at multiple speeds, pressures and strokes.
4) Heating and holding pressure: According to setting of multiple pressures and time periods, pressure of barrel is maintained, cavity is cooled and formed at the same time.
5) Heating and melting glue: Product in mold cavity continues to be heated, and at the same time, hydraulic motor drives screw to rotate to push BMC material forward. Screw retreats under control of set back pressure. When screw retreats to predetermined position, screw stops rotating, injection cylinder is loosened as set, and melting glue ends.
6) Shooting platform retreats: After melting glue ends, shooting platform retreats to specified position.
7) Mold opening: mold plate retreats to original position (including slow-fast-slow speed)
8) Ejection: ejector ejects product

Thermosetting injection molding machines are very similar to thermoplastic injection molding machines as a whole, as shown in figure below. However, there are still significant differences in details.
1: Mold clamping system
2: Injection molding system
3: Hydraulic transmission system
4: Electrical control system
5: Lubrication system
6: Heating and cooling system hydraulic

 

Injection molding machine operation screen

 

Function of mold clamping system:
Function of mold clamping system is to ensure closing, opening and ejection of mold. At the same time, after mold is closed, mold is supplied with sufficient clamping force to resist mold cavity pressure generated by molten plastic entering mold cavity, prevent mold from opening, and cause product to be in a bad state.
Composition of mold clamping system:
Mold clamping system is mainly composed of a mold clamping device, an ejection mechanism, upper and lower fixed mold plates, a movable mold plate, a mold clamping cylinder and a safety protection mechanism.
Mold clamping system of thermosetting plastic injection molding machines has two types: hydraulic and hydraulic-mechanical.

 

Open and lock mold settings
Press "page selection key" lock mold key to enter "open and lock mold settings" page

 

Open and lock mold position setting
Manually open mold to the highest point, install mold in the center between upper and lower molds, and adjust "lock mold stop" proximity switch stroke block to the lowest point. Press "mold adjustment" button on operation panel, then press "lock mold" key. At this time, upper mold plate starts to close mold at low pressure and slow speed. When mold is locked to mold, adjust "lock mold stop" proximity switch stroke block to position where proximity switch light can be turned on.

 

Adjustment of mold opening and locking
Clamping process is divided into three stages, generally fast-----slow-----high pressure, and mold opening is divided into three stages, generally slow--.-fast-----slow.
Clamping force, generally 2ton/in2, 1in2=6.45cm2, or F=(nA+B)*Pc/(0.6-0.8)
n: number of cavities
F: clamping force (kg)
B: projection area of runner and gate on parting surface (cm2)
A: projection area of product on parting surface (cm2)
Pc: pressure of plastic melt in cavity (BMC used by our factory is generally 10-20MPa)
It is not good to have too much or too little clamping force. Too little will cause flashing, too much will damage mold and equipment, and exhaust of parting surface will be affected.
Mold opening force is generally 10-20% of clamping force.
1bar=1.02kg/cm2=0.1MPa

 

Schematic diagram of injection device of Tianbo injection molding machine
1-Hydraulic motor; 2-Thrust seat; 3-Injection cylinder; 4-Injection seat; 5-Feeding hopper; 6-Seat shift cylinder; 7-Plasticizing part; 8-Clamping part
Function of injection system: injection system is one of the most important components of injection molding machine, generally there are three main forms: plunger type, screw type, screw pre-plastic plunger injection type. The most widely used one is screw type. Its function is that in one cycle of injection molding machine, a certain amount of plastic can be heated and plasticized within a specified time, then molten plastic can be injected into mold cavity through screw at a certain pressure and speed. After injection is completed, molten material injected into mold cavity is kept in shape.
Composition of injection system: injection system consists of plasticizing device and power transmission device.
Plasticizing device of screw injection molding machine is mainly composed of feeding device, barrel, screw and nozzle. Power transmission device includes injection cylinder, injection seat moving cylinder and screw drive device (hydraulic motor).
1. Plasticizing device
Plasticizing device is mainly composed of a screw, a barrel, etc., as shown in figure below
(1) Screw. Screw of a thermosetting injection molding machine is mainly used to plasticize, mix and inject material into mold cavity.
(2) BMC material is a thermosetting plastic, which is generally required to be used at a temperature above 15℃. Otherwise, its viscosity is high and pressure required for molding is high. However, a cross-linking and curing reaction occurs above 60℃, so temperature of barrel must be strictly controlled. Temperature control of barrel generally adopts a constant temperature controlled water heating system, and structure is shown in figure on the right below. When temperature is controlled, temperature of BMC material is controlled in barrel jacket.

 

Screw structure
Screw is divided into three sections, namely feeding section, compression section, and melting (metering) section:

 

Three sections of screw: feeding section; melting section (compression section); homogenization section (metering section)
Feeding section is long, feeding is sufficient, preheating is good, and it is conducive to plasticization;
Compression section is long, compression transition is slow, melt plasticization is sufficient, and it is not easy to decompose:
Homogenization section is long, melt mixing uniformity is good, plasticization quality is good, and it is conducive to color mixing; it may degrade

 

Screw parameters and indicators
Screw compression ratio refers to ratio of volume of one groove in feeding section of screw (h1) to volume of last groove in homogenizing section (metering section) (h3). Relatively speaking, the larger compression ratio, the more uniform plasticization of plastic.
Ratio of effective working length (L) of screw to outer diameter (Ds) of metering section is called aspect ratio of screw.
Aspect ratio and compression ratio of BMC injection screw are relatively small: aspect ratio = 14-16,
compression ratio = 0.8-1.2.
Injection setting
Press "page selection key" injection key to enter "injection setting" page

 

Overview of multi-stage injection molding
Multi-stage injection molding means that in an injection molding process, when screw pushes melt into mold, different injection speeds and pressures are controlled by feedback from position sensing element at different positions. For this reason, speed/pressure switching distance should be set according to size and structure of part.
Talking about position setting
First-stage injection position: It should be between 20%-30% of the total injection volume. For example, if the total injection position is 100mm, then you should set it at about 80mm. It is mainly to fill flow channel part and also to exhaust mold.
Second-stage injection position: It depends on specific situation. For example, size and thickness of product are different, and set position is also different. Premise is to fill mold cavity (70-95% of space of the entire cavity)
Third-stage injection position: Injection volume of last segment just fills remaining cavity space. In order to know injection distance, we can only set pressure and speed of the first segment, and set all others to 0; based on this, we can preliminarily judge how to set distance reasonably. The latter segment is similar.

 

Pressure and speed setting: Generally, injection pressure of BMC molding materials is within range of 20-90MPa (mostly in order to prevent damage to package (such as very small enamel packages between 20-70MPa), during plastic molding, wires and inserts, etc.), and injection pressure at this time is 10MPa.
First-level injection pressure: medium pressure, medium speed or medium pressure and low speed;
Second-level injection pressure: high pressure, high speed, high pressure, medium speed or medium pressure, medium speed.
Third-level injection pressure: medium pressure, medium speed or medium pressure and low speed.
Injection time:
Time required for BMC materials to fill mold cavity from barrel through nozzle and runner system is called injection time. Since BMC for injection has good fluidity, its injection speed is very fast, sometimes even less than 1S. Such a fast injection speed can obtain products with bright surface and fast curing. Injection filling time is very short, which is also beneficial for maintaining physical properties of product. However, from perspective of exhaust, demoulding and preventing breakage of glass fibers in material, injection speed should not be too fast, because too fast injection speed will not only increase breakage rate of glass fibers, but also may bring air into mold cavity. Injection time generally used is 3s-15s.
Holding pressure and time
When injection molding process is about to end, screw continues to move forward, and injection molding enters holding stage. During holding process, nozzle of injection molding machine continuously adds material to cavity to fill volume vacated by shrinkage of part. If cavity is filled without holding pressure, part will shrink by about 25%, especially ribs will shrink too much and form shrinkage marks; rubber in cavity will flow back due to reduction of external pressure. Holding pressure and speed are generally about 65-85% of maximum filling pressure/speed, of course, it should be determined according to actual situation.
The best time setting for holding pressure is based on principle of gate condensation without backflow.
Melt glue setting
Press "page selection key" melt glue key to enter "melt glue setting" page

 

Melt glue is storage material, which means adding material to screw in layman's terms.
Melt glue pressure: commonly known as back pressure, refers to pressure that screw bears when it retreats. During melting and plasticizing process of plastic, molten material continuously moves to the front end of barrel, more and more, gradually forming a pressure that pushes screw backward. In order to prevent screw from retreating too quickly and ensure that molten material is evenly compacted, it is necessary to provide screw with a reverse pressure. This reverse pressure that prevents screw from retreating is called back pressure. Back pressure is also called plasticizing pressure. For BMC injection materials containing a large amount of glass fiber, back pressure and screw speed cannot be too high, which can prevent material from solidifying prematurely in barrel, reduce breakage rate of glass fiber, and obtain a higher screw conveying capacity. Generally, screw speed can be selected between 30-50r/min, and back pressure can be selected at about 50bar.
Melting glue speed: When injection molding machine pushes injection screw, moving speed of screw is speed at which plastic enters the screw. Screw time should be as slow as possible. Too fast will easily cause excessive shearing of melt and a. rupture and degradation b. uneven plasticization c. gas inclusion.
We should follow laws of mechanics in sol process, that is, we need to go through three processes of acceleration--constant speed--deceleration, which can also be regarded as a reference for your sol. Front melt position is greater than injection position by 10MM, because after injection, theoretically, 10MM of glue should be reserved and not injected.
Key point: cooling time; cooling time refers to period from product solidifying in heated cavity after pressure holding until mold is opened and ejected.
BMC material undergoes cross-linking reaction (solidification) above 60 degrees, and solidification accelerates between 135-185 degrees, with a solidification speed of about 10 20s/mm.
Glue extraction is an action that refers to screw moving backward without rotating, also called ejection. Generally, ejection is used to exhaust or discharge when there is air or a small amount of paste in barrel.
Action of glue extraction is selected according to whether injection seat retreats before and after pre-plastic feeding, that is, whether nozzle leaves mold. Injection molding machine has two options.
(1) Front glue extraction: Nozzle presses against mold to feed and extract molten glue. After glue extraction is completed, ejection seat retreats and nozzle leaves the mold. Purpose of choosing this method is to use injection hole to press against nozzle during glue extraction to prevent molten material from flowing out of nozzle when back pressure is high. After glue extraction, nozzle and mold can be prevented from contacting for a long time to generate heat transfer, affecting relative stability of their respective temperatures.
(3) Back glue extraction: After injection is completed, injection seat retreats, nozzle leaves mold and then molten glue is extracted. After molten glue is extracted, injection seat moves forward. This action is suitable for processing plastics with a particularly narrow molding temperature. Since contact time between nozzle and mold is short, heat loss is avoided and solidification of molten material in nozzle hole is also avoided.
Glue extraction is to prevent glue from spreading, that is, to prevent glue from overflowing at nozzle.
Then press "Page Selection Key" and "Melting Key" to enter "Automatic Clearing Setting" page.

 

Machine needs to be stopped for a period of time due to some reasons (such as long holidays), so it is necessary to clean residual material in barrel. In this cycle, machine will perform following steps
(1) Start injection until screw stops
(2) Start extraction
(3) After extraction is completed, start metering
(4) Number of times of material cleaning: repeat above steps according to set number of times.
(5) Automatic material cleaning: Function selection switch of automatic material cleaning is turned on. When this function is not used, material cleaning key on operation panel will not work
If shift change exceeds 4 hours, residual material in barrel must be cleaned
Ejector mechanism

 

Press "Page Selection Key" or other keys to enter "Shooting Table/Ejector Setting" page.
Refer to setting of mold opening and locking mechanism.

 

Core entry and exit settings

 

Press "page selection key" or other keys to enter "core pulling settings" page

 

Sliding mode/positioning setting

 

Press "page selection key" or other keys to enter "sliding mode/positioning setting" page

 

Action selection
Press "Page Selection Key" function key to enter "Action Selection 1" page

 

Press "Page selection key" function key again to enter "Action selection 2" page

 

Temperature setting
Thermocouple must be closely connected to temperature measuring hole of mold, otherwise it will affect accurate reading of actual heating temperature. Mold cavity temperature must be checked regularly with a digital thermocouple.

 

Press "Page Selection Key" temperature key to enter "Temperature Setting" page
For BMC materials based on unsaturated polyester resin, mold temperature is between 140-160℃. Generally speaking, upper and lower molds usually use same temperature, but sometimes in order to facilitate removal of product, or to selectively make it stick to mold for purpose of demolding, temperature of two half molds should be different. Generally speaking, temperature of half mold on which product is expected to remain should be about 5℃ lower.

 

Then press "Page Selection Key" temperature key to enter "Temperature Preheating Setting" page
When preheating switch is on, on a certain day of set schedule, preheating time will be reached and automatic heating will be turned off when preheating off time is reached. When preheating switch is off, no automatic heating will be performed.

 

Time setting
Press "page selection key" time key to enter "time setting" page
Focus is on lubrication timing and lubrication cycle. In principle, guide rails and coring columns need to be lubricated once every 4-5 hours.

 

Model setting
Press "Page selection key" model key to enter "Model setting" page

 

Press "Page Selection Key" and model number key to enter "Mold Management" page

 

Status monitoring

 

Press "Monitor" key next to number keys to enter "Machine Monitoring" page

 

When machine is in motion, action bar will display corresponding action to indicate machine's operating status. When action is wrong, problem point of machine action will be displayed next to alarm.

Role of hydraulic transmission system
It provides power for various actions required by process of injection molding machine and meets pressure, speed, temperature and other requirements of various parts of injection molding machine. It is mainly composed of various hydraulic components and hydraulic auxiliary components, among which oil pump and motor are the power sources of injection molding machine. Various valves control oil pressure and flow to meet various requirements of injection molding process.
Regularly check hydraulic transmission system to see if oil level is within specified index, whether oil has deteriorated, whether oil temperature is too high, whether display and setting of the oil pressure are consistent. Whether oil pipe is aging, whether joints and hydraulic valves are leaking, if there is any abnormality, report to superior for processing.

 

 

Electrical control system and hydraulic system cooperate reasonably to realize process requirements (pressure, temperature, speed, time) and various program actions of injection molding machine. It is mainly composed of electrical appliances, electronic components, instruments, heaters, sensors, etc. There are generally four control modes: manual, semi-automatic, fully automatic, and adjustment.
Regularly check whether temperature of electrical box and control cabinet is too high, whether wires are aging, and whether fastening screws are loose. If there is any abnormality, report it to superior, and non-professionals are not allowed to handle it by themselves.

 

Heating system is used to heat mold and is detected in sections with thermocouples. Cooling system is mainly used to cool oil temperature. Too high oil temperature will cause various faults, so oil temperature must be controlled.
Regularly check whether there is water leakage at inlet and outlet, and whether cooling effect is within required range. (Oil temperature must be lower than 60 degrees, otherwise oil life will be halved for every 8 degrees increase)

 

Regularly check whether circuit is aging, whether thermocouple is in good contact, whether rubber-coated part is loose, and whether fastening screws are loose. If there is any abnormality, report it to the superior, and non-professionals are not allowed to handle it by themselves.

 

Lubrication system is a circuit that provides lubrication conditions for parts with relative motion such as injection molding machine's shooting platform, mold adjustment device, connecting rod hinge, etc., in order to reduce energy consumption and increase life of parts;
Regularly check lubrication system to see if oil level is within specified index, whether oil has deteriorated, whether oil temperature is too high, whether oil pipe is aging, and whether there is oil leakage at each joint. If there is any abnormality, report it to superior for processing.

 

① Mold loading

 

② Adding materials:
After taking out refrigerated BMC material, it can be added after heating at room temperature for more than 3 hours, otherwise fluidity will be affected.Outer packaging must not be damaged. For BMC molding materials that have been unpacked but not used up, they must be re-sealed and packaged for next pressing.

 

③ Preheating of mold
BMC molding compound is a kind of thermosetting reinforced plastic. For thermosetting plastic, mold should be preheated to required temperature before molding. Actual temperature is related to type, formula, shape and wall thickness of BMC molding compound, molding equipment used and operating environment. It should be noted that injection molding cannot be performed when mold temperature does not reach set value and is uniform.
④ Placement of inserts
When inserts need to be set, inserts used should be placed in mold cavity before loading and pressing. Inserts should meet design requirements. If they are metal inserts, they need to be cleaned before use. For larger metal inserts, they need to be preheated before placement to prevent defects such as cracks due to large shrinkage difference between material and metal.
In same mold cavity, if inserts of different types and specifications are placed, placement of inserts should be carefully checked. Misalignment of inserts will not only produce waste, but more seriously, it may damage cavity. In short, inserts should be placed in place, accurately and securely.
⑤ Injection molding
a. Mold closing, pressurized heating and curing
After injection of glue into mold cavity is completed, pressure is maintained and heated for curing.
b. Mold opening and demolding (ejection of products)
When product is completely cured, in order to reduce molding cycle, mold should be opened and product should be ejected immediately. If shape of product is relatively simple, mold demolding slope, surface brightness of mold cavity, etc. are relatively suitable, then demolding of product will not be difficult. For products with more complex shapes, difficulty of demolding may increase.
⑥ Post-processing of products and cleaning of molds
a. Post-processing of products
Molding shrinkage of BMC molding materials is very small, and warping of products due to shrinkage is not serious. For some products that have above phenomenon, they can be placed in an oven for slow cooling to eliminate it.
b. Finishing of products
Since BMC injection molding often produces some flash connected to it, it needs to be removed. Maximum thickness of flash should be limited to 0.1mm. If thickness of flash is too large, it will not only be difficult to remove, but also material waste will be too large, and cost will be greatly increased. If time permits, operator can use tools such as file blades, modified sanding belts, press rods to clean flash and holes on product during interval of closed curing.
c. Cleaning of molds
After product is ejected, mold should be carefully cleaned. First, all BMC debris, flash and other debris remaining in mold should be cleaned up, especially materials that have penetrated into gaps at various places on joint surface of mold cavity should be completely removed, otherwise it will not only affect surface quality of product, but also may affect opening, closing and exhaust of mold. To clean mold, compressed air, brushes and copper non-iron tools are generally used to avoid damaging surface of mold cavity during cleaning. After cleaning mold, a certain amount of release agent can be applied to the places where mold is prone to sticking, then carefully check whether there are other foreign objects in mold cavity. After completing above work, you can proceed to next process.

1. Before operation, confirm whether materials and molds are consistent with production instructions. You must be clear about production requirements and quality of product.
2. Prepare (i) production tools (files, pliers, copper rods), (ii) fixtures (screws, pressure blocks), (iii) operation materials "Injection molding operation instructions", other record forms, (iv) auxiliary materials (turnaround vehicles, etc.).
3. Before starting machine, check and confirm integrity and safety of machine, and operate according to "Equipment Operation Procedures".
4. After injection molding machine is turned on, wait for 1 minute; put it in manual mode, start electric heating switch to heat mold to a constant temperature, then start oil pump motor switch, stay for 1 minute (wait for motor to run stably before moving to next action. If you find any abnormalities in machine, mold, or other conditions, report to team leader immediately and continue after problem is solved.
5. Turn on system cooling water as required and check cooling of machine at any time.
6. After oil pump motor runs normally, debug and test it, then produce it after product is qualified.
7. After product is ejected from mold, self-inspect, pack, label it, and keep a record of self-inspection according to "Operation Instructions".
8. According to the first inspection regulations, products produced after material and mold change shall be mass-produced after quality inspector confirms sealing sample for the first inspection.
9. During semi-automatic production, garbage in mold shall be removed in time; parting surface shall be cleaned at least once every 4 hours.
10. Mold that has been debugged can be produced immediately. Select semi-automatic mode → mold closing, mold locking, injection, pressure holding, heating and curing, mold opening, ejection, and take out product according to regulations. Reinstall insert and enter next cycle.
11. Due to abnormal product quality during production, after process adjustment, self-inspected qualified products are handed over to workshop quality inspector for re-inspection before production.
12. When machine is shut down due to the end of production task or other reasons, close blanking port and finish remaining material in barrel first; machine should be placed in manual mode, injection seat should be withdrawn, motor and cooling water should be turned off.
13. When handing over shift, product quality situation, equipment performance data statistics, and other production-related situations should be handed over clearly.
14. Before leaving get off work, clean equipment site, make production records and other records such as equipment inspection form handover form.

In order to effectively control number of reworks and supervise self-inspection of operators, the first inspection and self-inspection should be carried out as follows:
1. Before continuous production, operators must send the first mold product to quality inspection for first inspection. Production can only be carried out after the first inspection is qualified and sample is sealed. Sealed sample label must have product number, plastic part name, sample sealer, and sample sealing time.
2. The first mold product produced after mold change, material change, mold repair must be sent to quality inspector for first inspection and confirmation of sealed sample after self-inspection before mass production can be carried out.
3. Products produced in each shift are self-inspected against sealed sample and "Injection Molding Operation Instructions", and self-inspection records are filled in truthfully.
4. Before taking over, check whether production instructions, products, materials, and colors after mold change correspond; whether sealed samples and operation instructions are in place.
5. When taking over, product must undergo a self-inspection first inspection, be inspected item by item according to "Injection Molding Operation Instructions" and other quality documents, then production can be carried out after confirmation of qualification.
6. Each shift shall conduct 8 comprehensive self-inspections as required, and keep records of self-inspections. Mark "V" if qualified, and indicate cause of defect if unqualified.
7. Before leaving get off work, conduct a final inspection of product. If final product does not meet the quality requirements, immediately re-inspect products produced by this shift.
8. When product does not meet quality requirements, it is necessary to promptly find a mechanic or team leader to make adjustments. After product quality requirements are met, it is sent to quality inspector for confirmation before production.
9. When you do not understand or know product quality or cannot make an accurate judgment, you should send product to quality inspector for confirmation and make a judgment, understand and know quality situation from quality inspector.
Self-inspection method:

 

Product quality
Factors affecting product quality
Factors affecting product quality are mainly divided into five factors:
1. Mechanical factors of injection molding machine;
2. Mold factors;
3. Raw material factors;
4. Human factors;
5. Environmental factors, etc.

Preparation before mold installation
1. Measure length, width and height of mold, and determine whether mold can be installed on this machine based on measured data.
2. Measure outer diameter of mold's positioning ring to see if it matches mounting hole on fixed mold plate.
3. Measure R position size of mold's gate nozzle to see if it matches injection seat nozzle of this machine
4. Check position, size and number of mold's ejector holes to see if they are suitable for machine.
5. According to actual thickness of mold, use manual mold adjustment to roughly adjust mold thickness, then set mold opening spacing based on space required for product to fall off smoothly after mold is opened.
6. According to design parameters of mold, set ejector stroke. (Ejector stroke is less than ejector stroke of mold top plate) so that mold will not be damaged when mold thickness is adjusted later.
7. Prepare mold pressing plate, pressing plate pad, clamping bolts, nuts, flat washers, spring washers, wrenches, pipe fittings, etc.
Mold loading steps
Attention!
Mold loading needs to be done manually. All mechanical operations below should be done manually or in mold adjustment mode. Oil pump motor should be turned off before manual operation (non-mechanical operation) to ensure safety of operator.
Step 1: Start oil pump motor
Step 2: Open mold and open mold plate
Step 3: Move injection seat backward
Step 4: Turn off oil pump motor
Step 5: Adjust position and number of ejector pins to match mold.
Step 6: First clean mold plate plane, as well as dirt and burrs on mold surface, then lift paired mold flaps and put them into mold plate (be careful not to let mold collide with other machine parts when putting them in), so that mold plane is in contact with installation surface of slide.
Attention!
Before lifting, make sure that front and rear molds will not separate!!
Step 7: Start oil pump motor.
Step 8: Close mold in a jog mode, so that moving mold plate gradually contacts mold until they are close together.
Step 9: After mold is completely closed, align nozzle center with mold gate center and adjust reliable contact to ensure that nozzle center is accurately aligned with mold gate center. Note: Before moving nozzle, first observe nozzle length and depth of mold feed port to see if there is any conflict. This may cause damage to nozzle.
Step 10: Turn off oil pump motor.
Step 11: Tighten mold pressure plate bolts on moving and fixed mold plates to lock molds on moving and fixed mold plates.
Step 12: Use bolts, mold pressure plates, pressure plate pads, flat washers, spring washers, etc. to fix fixed mold plate part of mold on mold plate. At this time, injection molding machine does not need to use a large locking force.
Note: Depth of screw thread into screw hole of machine tool fixed plate should be at least 1.5-2 times diameter of bolt
Note!
Bolts should be tightened firmly to ensure that mold does not fall when mold is opened.
Step 13: Remove belt or steel rope used for lifting.
Step 14: Set pressure and speed of each position of mold opening and closing, especially high-pressure clamping pressure is set to pressure required for molded product.
Step 15: Start oil pump motor.
Step 16: Set parameters of mold opening and closing and mold adjustment.