Topworks PET  preform mould features:

• The cavity number of PET molds ranges between 1 and 96;
• Developed on the premise of the latest technological developments, state-of-the-art preform mould construction has been designed in consultation with European mould style.
• Over 2.5 million injections of the same quality preforms held over the course of his lifetime.
• Moldflow analysis diminishes the amount of NG you can see.
• The global criterion screw neck was developed with premium nitride steel to increase its durability and hardness at the same time.
• ASSAB s136 or DIN 1.2316 steel is used for mould impression and insert and for the slide insert because the steel is the best available quality and precision. Its excellent hardness, superior polish, anti-rust and accuracy make it an excellent choice for PET preform moulds making.
• Patented correcting technique allows for better control of thickness and reduces possible the preform thickness disorder that might occur during preform injection molding.
• Innovative water hoses have been developed to reduce the leaking and reduce water spots on the preforms.
• The nozzle pin is connected to the hydraulic cylinder (Japanese or European Origin) and designed to be synchronized with the PET preform mould plates movement.
• 26MM,PCO28MM,25/30MM,32MM,38MM,48MM,52MM,62MM, Standard PCO neck finish

PET Mould Price Classifications:

• High price: Pneumatically-driven valve, shut off nozzle.
• Low price: Long relics
• Medium price: Short relics

PET preform Mould design:

Typically, to fulfill the requirements for designing a PET preform Mould for production, a preform mold must have functional strength, possess sales appeal, be competitively priced, and fulfill practical characteristics.

It is important to design a preform mould so that the most appropriate steel and processes will be utilized to make it economically feasible for the manufacturer to manufacture the PET preforms.

Our Preform mould features as follows:

• Cooling Channel set-up

An especially designed set-up of water cooling channels combined with special finishing reduced the overall cycle time. Each particular water channel was specially processed to minimize the chance of jamming.

• Correction Technique for Core Off-Centered

It is possible to make a difference in preform’s wall thickness of less than 0.006 mm by utilizing the Off-Center Correction Technique. The application of this system does not affect the longevity of the PET mould throughout its useful life;

• Pin-valve System

Using a Pin-valve type of Hot Runner System for the PET preform mold, this type of Hot Runner System is effective in reducing processing times, reducing part wear & tear and lowering gate trim costs, and at the same time cutting electricity consumption.

• Coil Heating

The Dual Heating and Cooling system can ensure that the result of heating and cooling is excellent and quality control is reliable. Heat coils keep the nozzles at a constant temperature through the full cycle time. Moreover, the Heater System is utilized to increase the hot-runner plate’s heating capacity with long life and effectiveness. We imported the heating band for the preform mould from Germany.

• Technique of self-locking

Our PET preform mould incorporates world state-of-the-art bi-axis insert alignment and self-lock system in line with global best practices.

Preform mold spare parts and after-sale services:

we are a devoted PET mould, preform mould, PET bottle mould manufacturer in Huangyan, China.

Each set of PET preform mould undergoes strict mould trials, and preform mould trial video will be sent to the customer for confirmation before shipping from the factory and attaches a full set of the recorded parameter depending on their own and sole serial number.

Together with the PET preform mould, a full set of spare parts will be supplied for free to keep mold normal operation.

In the use of the PET preform mold, Topworks provides adequate spare parts to any request.

Topworks service department is very willing to provide technical support immediately for any possible request at any time. Also, we could send our engineers overseas for mold installing and adjusting.

 

PET preform mould with 8 cavities 发布人 stevencheng

PET preform molding troubleshooting

PET preform neck finish categories

PET preform specification
Neck size	Weight (for carbonated soft drink and mineral water)
26mm	13g 16g 18g
PCO28mm	11G 15G 17G 18G 20G 21G 24G 25G 26G 27G 28G 32G 35G 40G 43G 45G 48G 52G 56G
25/30mm	14G 15G 16G 18G 20G 23G 25G 32G 34G 38G 43G
38mm	28G 30G 35G 45G 48G 50G 60G 65G 68G 72G 87G
Neck size	Weight(for cooking oil)
32mm	20G 30G 35G 40G 47G 50G 55G 60G 70G  80G
37mm	48G 60G 65G 70G 73 G 85G
46mm	55G 60G 65G 70G 75G 80G 84G 90G 95G 100G 103G 105G 110G 115G 130G 140G
72mm	175G 140G 238G 255G 290G 300G

PET injection moulding processing introduction

PET, also called polyethylene terephthalate, is also known as polyester. At present, the most used kind is PET-GF; it is mainly for bottle PET preform manufacturing.

The rheological property of PET is better in the molten state, and the pressure effect on the viscosity is greater than that of temperature.

Therefore, it is mainly to change the fluidity of the melt by changing the pressure.

1.  Plastic processing .due to pet macromolecules containing grease, it is hydrophilic. Pellets in high-temperature water are more sensitive. The moisture will decrease the molecular weight of the pet, which would lead to poor color and brittle parts.
2.  Dry; the drying temperature is 150 degrees, time more than 4 hours. And generally, it is 170 degrees, about 3-4 hours. Whether the material is completely dry can be tested by a shot to air. The recycled material ratio is generally not more than 25%, and also the reground material should be completely dry.
3.  Injection moulding machine .due to the shorter stable time after melting and high melting point, it is necessary to use the injection machine with more multi-step temperature control and less plasticizing friction heat system .and all weight(products and runner) is not less than 2 / 3 of machine injection volume.
4.  PET preform mould and its gate design. Generally, PET bottle preform mould is installed with a hot runner system. There should have insulation plates (about 12 mm thickness) between the PET preform mould and injection moulding machine, and the heat insulation plate can withstand high pressure. Air venting must be sufficient to avoid local overheating or fragmentation, but the depth of the slot is generally not more than 0.03 mm. Otherwise, it is easy to invite flash.
5.  Melt temperature .it is 270-295 degrees Celsius by a shot to air, PET-GF can be set to 290-315.
6.  Injection speed. The fast shot can prevent premature injection solidification. But too fast will lead to a high shear rate and brittle products. The shot is usually completed within 4 seconds.
7.  Backpressure. The possible low back pressure is a better way to avoid wear. Generally, the backpressure is not more than 100 bar.
8.  Stay time and temperature. Stay time shouldn’t be long to prevent the decline of molecular weight, and the temperature should possibly avoid more than 300 degrees Celsius.

If the downtime is less than 15 minutes, shot to air is OK; But if it is over 15 minutes, it should use PE to clean the barrel, and the barrel temperature decreases to PE temperature.

Note: recycled materials cannot be added much. Otherwise, it easy to produce poor quality products.

If the mould temperature or material temperature is not proper, it is easy to produce “opaque” pet preform.

The low mould temperature and the fast cooling rate would achieve POOR transparent PET preform.

plastic preform moulding troubleshooting

faults	causes	solutions
bottom whitening of PET preform	too low temperature of nozzle of hot runner too low temperature of plastic materia	improve the insulation increase the nozzle temperature increase the material temperature increase the injection speed lower the packing pressure lower down the cooling water speed
Opaque pet preform body	poor material drying insufficient material plasticizion too thick wall and poor cooling foreign material mixed too low material temperature	ensure 4+ hrs drying increase material temperature increase the rotation speed of screw verify the drying temperature and shot volume, drying temperature 165 ℃ and moisture<0.02% improve the cooling and make the wall thinner
Pet preform from transparency to Opaque	too high ejection temperature	improve cooling prelong the cooling time change injection time
haze on the one side of the preform	too high hold pressure eccentric gate	lower the hold pressure fix the PET preform mold
sliver streaking or yellowing of PET preform	plastic decomposition	lower drying temperature and prelong drying time change the injection speed lower the material temperature lower nozzle temperature
voids in Pet preform	insufficient drying	improve the drying increase the material temperature lower the rotation speed of the screw
uneven ring groove on the inner wall	vapor condensation in the core and cavity	improve the workshop drying increase the cooling water temperature drain the PET preform mold
breakage on the gate of the PET preform	misalignment of hotrunner nozzle and gate undercut on the gate gate too hot	fix the PET preform mold fix the gate prelong the cooling time increase the injection speed or prelong the injection time improve the insulation of the gate
short fill or welt line on the neck of PET preform	poor venting eccentric gate position	enlarge the venting groove clean the screw neck lower the injection speed fix the gate
uneven wall thickness of PET preform	poor quality of PET preform mold eccentric gate orifice too high injection pressure eccentric core	fix the PET preform mold increase the material temperature lower down the pressure improve the accuracy and use adjustable core and cavity
surface dent of the PET preform	too high material temperature too short injection time too short hold time too quick injection speed insufficient cooling	lower the material temperature prelong the injection time increase the hold pressure lower the injection speed increase the cooling water pressure
nozzle drooling	poor insulation insufficient cooling too much pressure on the melt poor non-return on screw head too low hold pressure	secure the gate insulation improve the cooling clean the screw increase the hold pressure
PET preform bend after ejection	eccentric gate orifice uneven cooling	fix the PET preform mold; lower hold pressure increase the injection speed; prelong the cooling time clean the cooling line; increase the cooling water pressure
PET preform bend after heating	eccentric core eccentric temperature adjust orifice uneven density of PET preform	fix the PET preform mold fix temperature adjust base lower the temperature,especially on the bend section.
PET preform local whitening	insufficient PET preform heating temperature	increase the PET preform heating temperature and even the all body temperature
insufficient expanding of PET preform	insufficient air pressure insufficient heating temperature injection fault of PET preform	increase the air pressure and air increase the temperature of the PET preform verify the PET preform even soften by 100 C water
crack of the preform bottom	too high preform bottom temperature too low preform temperature severe decomposition	adjust the preform temperature check and change the preform and material,improve the drying
PET preform eccentricity	too early blowing too high air pressure misalignment of blow pin the bottle bottom severe eccentricity too low speed of blow pin distance between blow pin and bottle bottom over 1.5 mm too high PET preform bottom temperature	delay the blowing time lower down the air pressure check and fix the installment check the PET preform adjust the air cylinder pressure adjust the distance between blow pin and bottle bottom to be 1.5mm or smaller lower the preform bottom heating temperature
preform body insufficient extending on the vertical direction	too high heating temperature local cold slug insufficient air pressure and air volume poor venting of blow mold too high blow mold temperature; too thin wall bottle insufficient vertical draw ratio	adjust the PET preform temperature increase the air pressure and air improve the blow mold venting; improve the blow mold cooling fix the blow mold increase the vertical draw ratio
bottle circumferential uneven wall thickness	PET preform eccentricity uneven heating temperature poor venting	fix the PET preform mold improve the heating appratus lower the problem section temperature improve the venting
protrusion on the bottom	low temperature of PET preform bottom	blow earlier and adjust the heating temperature
bottle local whitening	local insufficient heating temperature too much local draw ratio	increase the PET preform temperature check the design of PET preform
bottle poor vertical loading	uneven wall thickness too high PET preform heating poor bottle profile	make the wall thickness uniform try low temperature and high pressure molding improve the design of bottle
bottle ease of broken after falling	unsufficient draw of bottom of preform decomposition after over heating	improve the draw raio of preform bottom improve the material drying before pet preform injection molding lower the blowing temperature
Pitting and whitening on the bottle body	unclean air too much moisture	install the air filter dehumidification of compressed air
too soft bottle body	poor design too high blowing temperature	improve the design try low temperature and high pressure blowing
burning and odour smell after blowing	too high blowing temperature poor quality of compressed air poor quality of material	lower the blowing temperature fix the air compressor and filter use the good quality material
The water taste changed after filling	too much aldehyde content bad quality material	low temperature of injection and blowing check the aldehyde content and expel bad material