The reasons for yellowing, blackening

    MOBEST  has the MTO nozzle for  the professional shaping transparent /color changing product. The MTO type nozzle has no dead corner, quick color change, less pressure loss.

        The plug of  runner joint place use rounded transaction, particular location adopts the mosaic structure to guarantee the joint rounded.

        Plastic material injection molding amount and dwell time detail calculation :

 Product info.

 Hot Runner Info.

 Product Name

 rear shell

 Nozzle type


 Product color


 Nozzle runner Diameter


 Product material


 The total weight of runner material


 Every single product &gate total weight


 The dwell time of runner material

 about 3 molds

 The circle time of every mold


The total weight of product& gate is 42 grams, within 3 molds can be finished , no longer dwell time problem.

     All of MOBEST manifold runner inner wall adopts runner polishing machine to polish,

which is to guarantee the inner wall smooth without dead corner, not the finishes to cause yellowing.


  1.In the process of shutdown, more than 15 minutes need turn off power of  the temperature control box or to set the temperature to  reduce 50 degrees to guarantee the material not dwell too long to degrade.

  2.Shutdown while not in the production, turn off the hot runner power, continue to shaping products until no more product can produce.

  3.For the fireproof material or Strong corrosive material, can use the PP material to test the hot runner to reduce the steel  corrosive of  long term placement.

   The reasons for the gate wire drawing

  • 1. The nozzle tip has no reasonable cooling.

  • 2.Unreasonable nozzle type choose. Around nozzle gate should choose reasonable cooling water line, adding the cooling water line can avoid gate heat depositing, which resulting wire drawing drooling etc.MOBEST nozzle is the one with spreader nozzle tip of anti-wire drawing structure, which will not wire drawing. The extreme injection condition resulting wire drawing , we suggest adopt valve gate nozzle.

  • 3. Nozzle unstable temperature , Long term production stability poor.
  • MOBEST heating accessories adopts import accessories and also the Copper sleeve type heating to make sure the stable quality ,reliable qualityand long term good stable production .


 Import elements

    Thermocouple import from Germany HOTSET, temperature sensitive point close to nozzle tip, precise temperature, gate stable temperature ,reliable quality.

    Quality Guarantee

    Heating coils import from America, the nozzle adopts copper sleeve heating circle, uniform heating, stable temperature, reliable quality.

    Spare parts

    Heating coils with sensor for the spare parts, another group thermocouple with independent sensor.

   The reasons for system leakage:

1.Manifold plug leakage

MOBEST manifold adopts inserts plus runner polishing , along with heat distribution (Interference fits),without leakage.

2.Nozzle sealing leakage.

MOBEST has strict testing training and requirements for all installation person, all measure and size according to the draft precise process then install, make sure no leakage existing.

3.Nozzle and manifold fitting surface leakage.

MOBEST design has already avoided all possibility for the process error.

Nozzle temperature difference  accuracy.

Product standard

1.90% standard product,90% abundant stock, standardized production can guarantee the quality consistency.

Imported material

2.The nozzle part material are the imported ASSAB steel , strictly control the process technical, effectively guarantee the interconvertibility of nozzles.

Technical standard

3.Strictly testing for heating coils winding,  Winding process standardization, high quality requirements to ensure quality and stability.

   The reasons for pin seal stuck

1. If the valve pin and guide sleeve is of poor quality, the valve pin is easy to wear out.
MOBEST adopt valve pin and guide sleeve from Punch Japan, valve pin is HRC60, coated with special material. The lifetime is 3 times than common brand.

2.The unreasonable of pin seal and bushing match tolerance .

MOBEST guide bushing and pin seal match tolerance according to the fiber material customized and repeated testing and verification to guarantee no leakage glue and no stuck.

3.Process tolerance results unqualified quality or unstable quality.

MOBEST ways to guarantee the elements quality & process precision:

Raw material purchasing:

valve guide bushing and pin all customized from Punch to guarantee the precise tolerance.

Technical control:

Manifold adopts big shuimo to wear down, and computer gongs to process valve pin bushing hole to effective guarantee valve pin bushing hole verticality and accurate location tolerance .

Testing confirmation:

3D to test verticality and concentricity of manifold and guide bushing match.

Ex-work testing:

Preheating to test valve pin before the products leave factory ,which to guarantee the smooth operation.

All of MOBEST valve pin and guide bushing are customized from PUHCH to guarantee stable quality .