Custom ABS Injection Molding Factory / Manufacturer

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Table of content

●Good overall performance

●Low price

●Easy injection molding process

ABS Injection Molding has become a larger plastic variety at present and wide range applications, such as:Electronic appliances, household appliances,home appliances, office equipment,instruments,machinery, automobiles and other industrial equipment accessories.

Our ABS injection molding services cover all of these industries, We have made ABS injection molding products for the following finished products：

●Housing and other parts for TVs
●Recorders
●Washing machines
●Refrigerators
●Telephones
●Computers
●Vacuum cleaners
●Electric fans and
●Air conditioners,
●And many more

ABS injection molding services is used to make instrument panels, instrument cases, cameras, clocks, musical
instruments, bracket,pellet,cabinet etc.

ABS injection molding services is used to make drainage and exhaust ducts, pipe fittings, window and door frames, shutters and safety caps, etc.

ABS injection molding services is used to make interior and exterior assemblies parts, radiator grilles, lamp covers, instrument panels and control panels, etc.

The main reasons for the bad appearance of plastic molded parts are mold, the injection molding process, and raw materials.

As a professional ABS injection molding manufacturer, we make the following details on this topic.
Please correct us if we are wrong; we will learn together!

3.1.1 If the mold cavity manufactuirng is poor, such as scars, microporous, wear, roughness and other deficiencies, will inevitably react to the plastic parts, so that the plastic parts appearance is not good, for this, to carefully build the mold, make sure the surface of the cavity has a small roughness, if necessary, polishing chrome plating for custom ABS plastic injection molding .

3.1.2 If the surface of the cavity has oil and water stains, or the mold release agent makes too much, it will make the surface of the plastic part dark and lusterless. In this regard, we should remove the oil and water stains in time, and use the mold release agent in a limited amount for custom ABS plastic injection molding . .

3.1.3 If the product draft angle is too small, it is difficult to demolded, or the demolded force is too large when eject the parts out, so that the surface of the plastic parts is not shiny, in this regard, we should increase product draft angle during DFM stage.

As a professional Custom ABS plastic injection molding supplier, we will make the details DFM report to Analyze the customer’s design.

3.1.4 If the mold venting system is bad, too much gas stays in the model, which also leads to bad appearance, for this, check and correct the mold venting system system for custom ABS plastic injection molding ..

Our mold reviewing checklist requires every our mold designer to carefully examine the mold venting system.

3.1.5 If the gate or runner cross-sectional area is too small or suddenly changed during melting flow , the melt flowing in which the shear force is too large, is turbulent dynamic flow, resulting in poor luster, in this regard, should be appropriate to increase the gate and runner cross-sectional area for custom ABS plastic injection molding ..

Most injection molding suppliers do not pay attention to this point, we have professional mold flow analysis engineers to analysis the gate and runner dimensional for you plastic injection molding project.

3.2.1 If the injection speed is too small, the surface of the plastic part will not be dense and show poor appearance during custom ABS plastic injection molding .

3.2.2 For thick-walled plastic parts, if the cooling is not sufficient, the surface will be hairy and the luster will be dark, in this regard, the cooling system should be improved during custom ABS plastic injection molding .

3.2.3 If the holding pressure is not enough and the holding time is short, the density of the plastic part is not enough and the luster is not good, for this, the holding pressure and holding time should be increased during custom ABS plastic injection molding .

3.2.4 If the melt temperature is too low, which makes the liquidity poor and leads to bad appearance, the melt temperature should be increased appropriately during custom ABS plastic injection molding .

3.2.5 If the injection speed is too large and the gate cross-sectional area is too small, the vicinity of the pouring product will be dark and bad luster, in this regard, the injection speed can be properly reduced and the gate cross-sectional area increased during custom ABS plastic injection molding .

3.3.1 The plastic granule size of raw materials varies greatly, which makes it difficult to melt evenly and makes the appearance bad; the raw materials should be sieved before starting ABS injection molding.

3.3.2 Too much recycled material or sprue material is added to the raw material, which affects the uniform melting and makes the appearance bad, so the ratio of adding recycled material or sprue material should be reduced before custom ABS injection molding .

The plastic injection molding manufacturer should not add overmuch recycled materials or sprue materials into the raw plastic materials, Remember, the plastic injection molding factory should put quality in the first place.

3.3.3 The content of moisture or volatile matter in raw plastic materials is too high, and evaporates into gas when heated, and condenses in the mold cavity, resulting in poor appearance on plastic parts, so the raw plastic materials should be pre-drying treatment a few hours before ABS injection molding.

3.3.4 The dispersion of additives is too slow to lead to poor appearance on plastic parts, in this regard, should be replaced the additives with better flowability before custom ABS injection molding.

3.3.5 There are foreign materials, miscellaneous materials or insoluble materials mixed in the raw material, they can’t be mixed with the raw material evenly and lead to bad appearance, in this regard, these miscellaneous materials should be strictly excluded beforehand.

3.3.6 If the amount of lubricant is too little, the fluidity of the melt is poor, and the surface of the plastic part is not dense, which makes the luster bad, for this, the amount of lubricant should be increased appropriately before custom ABS injection molding .

4.1.1 The moisture absorption of ABS is relatively strong, and the high moisture content of the raw material will lead to the poor gloss of the plastic parts and the poor quality of the internal molecular structure, so the ABS injection molding factory should dry the raw material to make sure the moisture content is not more than 0.3% before custom ABS plastic injection molding .

4.1.2 ABS melt has obvious non-Newtonian, increasing the injection pressure can make the melting viscosity decrease significantly

4.1.3 ABS has a small molding shrinkage, with a range of 0.3% to 0.8%, so it can be designed for high accuracy of the injection molded part.

4.1.4 ABS has good molding performance, and there is no special requirement for injection molding machine, and general screw type and plunger type injection molding machine can be used.

But The product quality will be better with screw type injection molding machine, our injection molding factory 100% use screw type injection molding machine for ABS injection molding.

Our mold reviewing checklist requires every our mold designer to carefully examine the mold venting system.

4.1.5 When using screw type injection molding machine, in order to improve the quality, dimensional stability, surface gloss and eliminate residual internal stress, The injection volume should be limited to 50% of the maximum volume of injection molding machine, all injection molders needs to confirm the density of the raw material and the weight of sprue & product when calculating the volume.

4.1.6 The viscosity of ABS material is medium, better than PC, PVC, but worse than PS, it is better to use straight-through nozzle for mass production.

4.1.7 The main runner of ABS molds should be as short as possible, usually around 50 mm, and not longer than 100 mm.

4.1.8 The sub-runner must be large enough to allow the melting to fill the mold cavity before the sub-runner solidified and is compacted in the mold cavity. The sub-runner diameter should generally be larger than 5mm, but not more than 10mm.

4.1.9 The ejecting force of custom ABS injection molding ejector mechanism should not be too large, otherwise the surface of the plastic part will easily have whitening.

4.1.10 Although the molding shrinkage of ABS is small, but it is easy to have internal stress after injection molding, so the plastic parts generally need to be heat treatment, Usually we put the products in a 70 degree room for 2-4 hours.

4.2.1 Barrel temperature for custom ABS injection molding.

ABS is an amorphous plastic with no clear melting point, and the melt flow temperature is not too high, above 160°C, which is sufficient fluidity, but the high temperature does not increase the fluidity.

There are many varieties of ABS resins, and the barrel temperature varies from one variety to another,
180-230°C for general ABS,
190-240°C for heat resistant ABS,
170-220°C for flame retardant ABS.

The nozzle temperature is 20-30°C lower than the front of the barrel.

4.2.2 Injection mold temperature for custom ABS injection molding.

The injection mold temperature should be controlled within the allowable range during the molding process, generally at 50-70°C, The injection mold temperature has a great impact on the quality of the parts.

4.2.3 Injection pressure for custom ABS injection molding.

The injection pressure depends on the product structure and wall thickness. Generally, the injection pressure is
50-70MPa for general ABS,
60-85MPa for heat resistant ABS,
60-100MPa for flame retardant ABS.

If the flow resistance is high when filling the mold,a higher injection pressure shoule be used; conversely,a lower injection pressure should be used,Usually wholesale doesn’t know it, Our company is very familiar with ABS plastic injection molding.

Table of content

● Product Name: Printer Enclosure
● Product Color: White
● Product Size: 520mm*200mm*10mm
● Wall Thickness: 1.5-2.0mm
● Product Material: Polylac PA-757 Grade ABS
● Product appearance Requirements: No welding line, No any appearance defects

At the early stage of product development, MoldFlow can be applied to analyze the manufacturing feasibility of the product. Through MoldFlow, the filling pressure, the location of the welding line and air trapping, short shot defects, the deformation, and many more points can be predicted before plastic injection molding.

We are able to make detailed DFM and mold flow analysis reports for our injection molding customers

●Import the product to mold flow software
●Divide the grids
●Set up the runner and gate size
●Set up the cooling system

▲ Gate position and cooling system

Set the analysis sequence as “Cooling+Filling+Pressure+Warpage”, select the analysis material as “Polylac PA-757 ABS”, the cooling inlet temperature as 25˚C.

▲Injection parameter setting

1. Filling Time:

Checking the filling time results, in the area where the product is labeled with the nameplate, the air trapping is generated because the wall thickness is thinner than the surrounding thickness.

View the core side through isoline, a ribs area where stagnation occurs.

2. Welding line, below picture showed the welding line, The welding line usually occurs at the filling end.

3. Deformation status
Since the main concern of the product is the overall flatness, we mainly look at the deformation in the Z-direction. below picture shows the overall deformation in Z-direction, and the overall deformation value is about 3.8mm, which is larger.

Problem points such as the above were identified through Moldflow software prediction, and the problems could be eliminated by modifying the product design before actual production, thus ensuring the quality of the design.

That’s why it is so important to work with a professional injection molding factory, which can help you to develop and evaluate new products quickly, economically and with less risk.

PTS is custom injection molding company On-demand from prototype to production, leader in injection molding, rapid prototyping,helping you bring your concepts to market faster, Our company export injection molding parts to more than 60 countries, including but not limited to The United States, Australian and Canada and so on.

For the problem points identified in the preliminary analysis, there are different improvement countermeasures for different problem points.

As shown below, the maximum wall thick of the product is 2.5mm(fair wall thick), the rib thickness is jsut 1.0mm, and the rib height reaches 40mm.

After thickness analysis, the air trapping of the ribs is mainly due to the hysteresis of the front melting.
The melting will preferentially flow towards the place with less filling resistance during the filling process. And the melting with stagnant flow is rapidly cooled by the mold, thus risking to cause a short shot.

Since the cause of the short shot has been identified, increasing the thickness of the product rib can reduce the flow resistance and thus eliminate the stagnation problem. The thickness of the product rib is thickened from 1.0 mm to 1.5 mm (as shown below).

While increasing the rib thickness, it is important to note that too much flesh thickness can cause shrinkage, and usually 0.6 times the thickness of the base surface at the root of the rib will not cause shrinkage.

There are two similar ribs at the core side of the mold. Although the other one is at the end of the flow and does not show stagnation in the analysis, the flesh thickness is also changed to 1.5 mm to avoid the risk in actual production.

Due to the difference in thickness, welding lines and air trapping are created together.

In the picture below, the area of 1.5mm is the area where the nameplate is placed. Increase the wall thickness here by 0.3mm to improve the stagnation in this area, thus eliminating the welding line and the air trapping here.

To improve the deformation, it is necessary to know what causes the deformation of the injection molded product. For injection molded products, there are several main reasons of deformation as follows:

●Volume shrinkage is nto uniform

●Cooling is not uniform

●Molecular orientation

In Moldflow software, when analyzing warpage, the deformation results caused by different reasons can be analyzed separately, so that the main cause of deformation can be easily judged.

The following picture shows the deformation caused by different reasons, and the deformation trend shows that the uneven shrinkage is the main cause of product deformation.

By looking at the “volume shrinkage at ejection” graph below, we can see that the uneven shrinkage is mainly caused by the shrinkage of the main product and the shrinkage of the ribs on the core side of the mold.

The shrinkage of the base surface was about 2%, while the shrinkage of the rib was about 0.5%, so the difference between the shrinkage of the top and bottom was too large. Since the shrinkage of the base surface was large, so the product warped upward.

Removing the ribs to eliminates the difference in volume shrinkage, but the strength of the product also decreases, so the method of reducing the height of the ribs (as shown below) is used to reduce the unbalance of shrinkage to improve warpage.

The changed design is analyzed to verify that the above design changes are effective in improving the problem.

After the design change, the difference of wall thickness between the nameplate area and the surrounding area became smaller, and the problem of trapped air was improved.

After the design change, the welding line was also improved, and although there are still two short welding lines, they are within the acceptable range for the customer.

In the original design, the deformation is 3.8mm, and after optimization, the deformation is 1.8mm, and the improvement of deformation is about 55%.

From the above, it can be found that at the early stage of product design, it is difficult to predict the possible problems in product production through experience. With the assistance of Moldflow software, it can help designers to predict risks and find problems in a timely manner, so that problems can be avoided in advance by optimizing the product in order to prevent problems from appearing in the production stage and then come back to solve them. The resulting development cycle is shortened and efficiency is improved.

PTS Manufactures And Supplies OEM ODM Plastic Injection Molding From An Industry Leader With The Expertise Experience And Resources To Handle Large-Scale,Complex Projects From Concept Through Manufacturing Via Our Digital Injection Molding.