UPVC Pipe Fitting Manufacturing

PVC Injection Molding Machine

For the PVC molding machine, normally we are talking about UPVC pipe fitting injection molding machine.

There are 2 kinds of PVC: soft-PVC and hard-PVC. The hard PVC is for the pipe. While the UPVC Pipe is made by the extruding process and its fitting is through injection molding process.

UPVC Pipe Fitting
UPVC Pipe Fitting

Raw Material: UPVC

The melted UPVC has high viscosity and poor fluidity. And the state of raw material will be resin granule or powder.

Injection Molding Success Request:

The injection molding for the pipe fitting, it requests core pullers, 1-3 sets even more.

UPVC mold with core puller
UPVC mold with core puller
UPVC pipe fitting mold with core puller
UPVC pipe fitting mold with core puller

Measuring the melting temperature accurately.

Viscosity melted plastic requests more power for the screw shear.  

Customized machine will be applied normally:

– Extend the housing to cover the mold core puller, so that the maximum platen may be used fully.

The molds with core pullers are in different directions. For installation of these molds, some factories keep the machine saft door open. But this has seriously violated the basic safety operating principles of the machine. On the other hand, using the machine without  extending  the housing,  one  or  two  grade  upper is needed  just  for  the  safe  door  close  well,  like  the  following  one:

UPVC mold with normal machine

– Install the fan to measure temperature accurately

– Increase the screw motor capacity to drive the viscosity melted plastic.

The screw motor may be upgraded one level or even two levels to increase the output.

The hydraulic motor which is applied as the screw motor normally. The bigger hydraulic motor with higher cost. Nowadays, more and more servo motor is applied as the screw motor.

For more information, please check the section in the following page:

-Other machine features

Some molds have the unscrew function, so the hydraulic motor to drive is needed. The point is this device is installed per mold or instaledl on the top of the machine platen.

These two options are as followings:

UPVC pipe fitting mold with unscrew device
UPVC pipe fitting mold with unscrew device
UPVC pipe fitting mold with unscrew device 2
UPVC pipe fitting mold with unscrew device 2

As for the question that how the motor is connected to the machine hydraulic system, you should consult with the machine manufacturer.

Injection Molding Machine

Let’s take a look at our PVC Injection Molding Machine. 
Including the PVC Pipe Fitting Production Line.

PVC Machine

Pipe Fitting Injection Molding Machines

PVC injection molding machine

The melted PVC with high viscosity and is easy to decompose. And the decomposition has a corrosive effect on iron. Tekwell’s Pipe fitting injection molding machines with special plasticizing parts and temperature control systems, includes

  • Screw& barrel set special for UPVC
  • Screw with chrome-plating, high corrosion resistance
  • Barrel with cooling fans to adjust the temperature of melting UPVC material
  • Special design for screw structure(UVPV powder)
  • Optimized design for machine safety door – Upgraded hydraulic motor with high torque
  • Upgraded motor and pump
  • Multi core pullers

Tips For Production Parameters Setting


Melting temperature: ranging from 185-205℃

The exact melting temperature of UPVC can be known from the smoothness of the injected material. If the material is rough and uneven after injection, it proves that the material is not uniform (insufficient plasticization), indicating that the set temperature is too low; if there is foam and a lot of smoke after injection, it indicates that the temperature is too high.


Injection speed

It must be slow, otherwise excessive shearing will degrade the material.


Back pressure

It is determined according to the molding cycle time. The screw surface speed should not exceed 0.15-0.2m/s.


Injection speed

It is up to 150bar, the lower the better, usually 5bar.

Retention time

At a temperature of 200 °C, the retention time of the barrel should not exceed 5 minutes at most. When the temperature is 210 ℃, the barrel retention time cannot exceed 3 minutes.

Brief Introduction


The melted PVC with high viscosity and poor fluidity. Even if the injection pressure and melt temperature are increased, the fluidity does not change much. In addition, the molding temperature of the resin is very close to the thermal decomposition temperature, making it difficult to mold.

1. Treatment of plastic: with water absorption less than 0.02%, no need to dry it. If dry, put them into a dryer at 80°C for 1-1.5 hours.

2. Percentage of recycled material is no more than 20%.

Dryer Hopper - Tekwell Machinery
PVC raw material
PVC raw material-1

PVC Pipe Fitting Moulds

UPVC Pipe Fitting Moulds-1
UPVC Pipe Fitting Moulds-2
UPVC Pipe Fitting Moulds-3

PVC Pipe Fittings

UPVC Pipe Fitting
PVC Pipe Fittings - Couplings
PVC Pipe fittings - adapters
PVC Pipe Fittings - Vent ells

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