Plastic Injection Molding Services Molded Plastic Manufacturer

According to your design, we have the ability to complete different kinds of Plastic injection Molding Services for you！

Insert molding is the process of injecting plastic with an inserted component.

See Our Insert Molding Services

Gas assisted is an molding tech that uses compressed gas assisted plastic to fill into the mold cavity.

See Our Gas Assist Molding

2K & 3K injection molding involve two & three materials or colors in one process.

See 2K & 3k Molding Services

Customize(OEM) to meet all injection molding requirements of your products

Custom Injection Molding Services

Test part geometry, validate design, flexibility to economically iterate prior to manufacturing.

Low Volume Injection Molding

Polypropylene (PP) Injection Molding

ABS Injection Molding

Injection Mold Making

Strictly follow international quality standards, through multiple quality inspection links to ensure that each product meets your requirements.

Molds quality determines the molded plastic parts quality, Click the link to See our plastic injection molds factory.

We provide expert engineering support, helping guide customers through the process from design to production.

Whether it’s a small prototype batch or large-scale production, PTS can handle various production quantities.

1 = Not recommended

2 = Average

3 = Good

4 = Highly recommended

Table of content

Injection molding is an important method in the molding process of high-polymer materials.

It is characterized by short molding cycle time, high production efficiency, complex shape and precision size products, used in a wide range of products, and it is easy to achieve fully automated production.

It is widely used in almost all thermoplastics, and a variety of thermosetting plastics can be injection molded, and Of course, rubber products can also be injected.

Except for a few thermoplastics, almost all thermoplastics can be molded by OEM plastic injection molding services.

As an molded plastic manufacturer with rich experience in injection molding industry, we have used hundreds of plastic injection materials.

With the development of the petroleum industry, plastic injection molding technology has developed greatly, especially with the emergence of plastics as structural engineering materials.

The application of injection molding products has been expanded to various fields of the national economy, injection molding products account for about 30% of the total number of plastic products.

Plastics Injection molding is injecting the granular or powdered plastics from the hopper into the barrel of the injection machine after heating and melting plasticized, under the rapid and continuous pressure of the plunger or moving screw of the injection machine is compressed and moved forward through the nozzle at the front of the barrel, with high pressure and very fast speed into the closed mold, after cooling (thermoplastic) or heating (thermosetting) curing, open the mold to get the product.

Injection molding is an intermittent production process that can produce plastic products of various shapes and sizes, except for very large profiles such as tubes, rods, and plates, which this method cannot produce.

It is commonly used not only for the direct resin injection but also for molding composite materials, reinforced plastics, and foam injection molding. It can be combined with other processes, such as injection-blow molding in conjunction with blowing.
The bottles are made through the blow molding process.

We are an molded plastic manufacturer located in the south of China, our customers are all over the world, we export to more than 40 countries, Including but not limited to USA, India, Germany, New Zealand, Australian, South Africa etc.

The plastic injection molding process is usually divided into three stages at most of plastic injection molding company:

The first stage is the preparation work before the injection molding production.

The work in this stage includes the inspection of raw materials, color matching, granulation of powdered raw materials, drying of raw materials, selection of suitable injection screws, barrel cleaning of the injection molding machine, heat treatment of insert, selection of mold release agent, installation and commissioning of injection molds etc.

The second stage is the selection of optimal injection process parameters and the process parameter control, adjustment and operation.

The third stage is processing injection molded products after demolding, including cleaning, dimensional measurement, appearance inspection, functional testing, assembly, packaging, etc.

If you want to know more about injection molding, don’t hesitate to contact us, professional molded plastic manufacturer, we will be very happy to share the knowledge of injection molding with you.

This stage starts when the machine screw moves forward until the mold cavity is filled with plastic melt.

The holding pressure is a period of time “from the melt fills the mold cavity until the screw returns”. During this time, the plastic melt will shrink in the mold cavity due to cooling, and the screw needs to hold the pressure on the plastic to further compact the plastic in the mold cavity.

At the same time, the plastic melt in the barrel continues to flow into the mold cavity to fill the void left by the shrinking.

This stage is from when the plastic melt at the gate is completely frozen until the mold is ready to open.
While cooling, the screw starts to return at the same time.

This stage starts from the end of cooling time until the mold is opened and the product is ejected from the mold cavity.

Since the melt plasticization and flow molding are carried out in the barrel and the mold cavity respectively, the mold can always be in a condensing state which makes the melt condense quickly, thus helping to shorten the molding cycle.

Our plastic injection molding service has done the fastest molding cycle time of 6 seconds with high speed injection molding machine, Most conventional injection molding cycles time are in the range of 30-60 seconds.

The melted plastic is injected only after the mold is locked during molding, and the melted plastic with good flowability has little wear on the mold cavity, so a set of molds can produce large quantities of injection molded products.

Our molds last 50% longer than other molds, They can run up To 15-20 years in most cases with our plastic injection molding services.

One operator can often manage two or more injection molding machines, especially when the injection molding process can be automated, so the labor cost is relatively low, Of course, there are slight differences in labor costs for different locations of molded plastic manufacturer.

For high volume injection molding, our plastic injection molding service will implement fully automatic injection molding production for our customers, to get lower cost and more stable quality molded products.

All the molding processes, such as mold closing, material feeding, plastic melting, injection, mold opening and demolding, are completed by the injection molding machine, which makes the injection process easy to be fully automated and programmed.

Due to the high pressure during molding, complex shapes, clear surface patterns and markings, and high dimensional accuracy parts / components can be done together with injection molding.

Our plastic injection molding service accuracy can reach 0.01mm with no geometry limited.

By co-injection, more than one material can be molded, and materials with hard skins and soft interiors can be molded effectively, two or three colors can be molded by strong molded plastic manufacturer.

we are able to provide 2k / 3k plastic injection molding services.

Since the molding can be done with precision molds and precision electrical control systems, and with microcomputer control, it is possible to obtain products with high precision and volume tolerances of up to 1µm. Ultimately, it depends on your molded plastic manufacturer’s ability, we are able to acheive tolerance +/-5µm.

A single mold can contain dozens or even hundreds of cavities, so dozens or even hundreds of parts /components can be molded in a single run.

We have a maximum of 128 cavities, but we also offer small run plastic injection molding services.

The key point of injection molding process is the injection mold, the mold is the whole core of injection molding, the mold quality determines everything, if the mold quality is not excellent, your injection molding is a nightmare every day.

Most of the injection molding factories do not have mold making workshop, their molds are outsourced and they are not professional in designing and making molds, which makes it very difficult to control the molds quality.

PTS Industrial Limited, a molded plastic manufacturer / provider,has been known for its high quality molds for over 20 years and we have our own mold making shop, we are able to make molds fast and high quality. This is the basis for providing high quality and stable plastic injection molding services.

Due to the limited of cooling conditions, it is difficult to mold thick-walled parts with large variations, usually with a wall thickness not exceeding 5 mm.

For thick-walled parts, foaming agent should be added to the material to assist in molding.

Since almost all injection molded products are not universal parts, there is no standard price, All molded plastic manufacturer estimate the price according to the customer’s drawings and requirements, Usually our plastic injection molding service can provide you sense quotation within 1 hours.

The cost is evaluated according to:
●Product size
●Product structure
●Plastic material
●Plastic part surfaces finish
●Dimensional accuracy
●Injection molding quantities
●And special requirements etc.

Not only we can evaluate the cost of your product design, we can also We Help You to Develop and Evaluate New Products Quickly, Economically and With Less Risk.

There are many kinds of plastic, about 300 kinds, and commonly used plastic about dozens of them for plastic injection molding services, also many classification methods and two commonly used ones.

One is according to the change of performance after heating, divided into thermoplastic and thermosetting plastic two categories.

The other is according to different uses, divided into general plastics, engineering plastics and special plastics.

Today We will introduce to you in detail the classification of these 5 types of injection molding materials based on our decades of rich plastic injection molding services experience .

Thermoplastics are molded under heating, softening, melting, and cooling conditions, This thermoplastic injection molding process can be repeated many times, and the material is always malleable.

●Good physical and mechanical properties

●Simple thermoplastic injection molding process

●Varieties and production developed rapidly.

●Heat resistance and rigidity are generally poor except for a few varieties.

●Polyethylene(PE)
●Polypropylene(PP)
●Polyvinyl chloride(PVC)
●Polystyrene(PS)
●Polycarbonate(PC)
●Polyamide(PA/ Nylon)
●Acrylonitrile Butadiene Styrene(ABS)
●Acrylic (PMMA)
●Polyoxymethylene (POM)
●Thermoplastic elastomer (TPE)—Soft material
●Thermoplastic polyurethane (TPU)—Soft material

Thermosetting plastics are soluble and fusible before molding and soften first under the heat condition; then the internal chemical changes, It will no longer melt when it is heated again After molding and curing, and not soluble in organic solvents, it can only be charred at high temperatures.

●High heat resistance

●Good dimensional stability

●Low price.

●Mechanical properties are poor

●Thermosetting plastics are not recyclable

●Phenolic Formaldehyde resin (PF)
●Urea Formaldehyde resin (UF)
●Melamine Formaldehyde resin (MF)
●Aniline Formaldehyde resin (AF)
●Epoxy resin (EP)
●Polyurethane resin (PU)

General plastics are very versatile plastics, they have wide values, Its production is very large, accounting for about 3/4 of the total production of plastics, low price, used in large quantities to make daily necessities, such as:
●TV housings
●Telephone housings
●Plastic tubs
●Plastic buckets
●Plastic bins
●Plastic containers

●Polyethylene(PE)
●Polypropylene(PP)
●Polyvinyl chloride(PVC)
●Polystyrene(PS)
●Acrylonitrile Butadiene Styrene(ABS)
●Phenolic Formaldehyde resin (PF)
●Urea Formaldehyde resin (UF)
●Melamine Formaldehyde resin (MF)

Engineering plastics can be used as engineering materials and replace metal for machine parts.

It can be used for a long time in harsher chemical and physical environments, and it can be used as an engineering structural material instead of metal, but it is more expensive and the production volume is smaller.

●Excellent heat and cold resistance properties

●Excellent mechanical properties over a wide temperature range, suitable for structural material

●Good corrosion resistance, less affected by the environment, good durability

●Light weight, high specific strength, and outstanding friction reduction and wear resistance

●Good dimensional stability and electrical insulation

●Compared with metal materials, easy to process, high production efficiency, and can simplify the manufacturing process and save money

●Polycarbonate(PC)
●Polyoxymethylene(POM)
●Poly(Butylene Terephthalare)(PBT)
●Poly（Ethylene Terephthalare)(PET)
●Polyamide—6(PA6)
●Polyamide—66 (PA66)
●Polyamide—9 (PA9)
●Polyamide—10 (PA10)

There is no uniform understanding on the definition of special plastics at domestic and overseas, In terms of material name, there are special engineering plastics (SEP ), super engineering plastics, high performance thermoplastics and high performance polymers, etc. It is called differently by molded plastic manufacturer.

The definition of specialty plastics will change with the development of science and technology

●Has a rigid skeleton

●Good regularity of molecules

●High strength, high buffering properties

●Outstanding high temperature resistance and self-lubrication

●High rigidity and high melting point (or high viscous flow temperature)

●Relatively fixed arrangement of the molecular chains even at high temperatures

●Polyarylate(PAR)
●Polyphenyl ester(POB)
●Polysulfone(PSF & PSU)
●Poly(ether-ether-ketone)(PEEK)
●Polyethersulfone(PES)
●Polyimide (PI)
●Liquid Crystal Polymer
●Fluoroplastic

When designing injection molded products, plastic material selection is the main point.

The product performance is determined by the raw plastic material, it should meet the requirements of the use of plastic parts, even the injection mold design is also governed by the properties of raw plastic materials, such as the injection mold design must take into account the plastic fluidity, Molding shrinkage, use temperature, etc.

●The maximum and minimum working temperature.

●Indoor or outdoor working.

●What forces are applied on the plastic parts.

●What kind of medium is affected during working.

●The voltage, frequency and temperature in the electrical environment, etc.

●Then according to the plastic parts may encounter environmental conditions to determine the appropriate material.

●Contact our plastic injection molding services, We will recommend the most economical materials for your design.

There is a big difference in the injection processability of different raw materials, such as engineering plastics PA and PSF, in terms of processability, PA is much better than PSF.

In the case of meeting the use of the requirements should be selected for the economic one.

If the working environment is 150’C, the PSF can be selected to meet the requirements, and do not need to choose a better performance, higher price of PPSU.

We have more than 20 years of experience in the plastic injection molding services, and we are very familiar with the properties, costs and processing technology of various plastic raw materials.

We believe our rich plastic injection molding services experience will be useful to you on selecting plastic materials.

●Coefficient of linear expansion, water absorption, product clearance and assembly tolerance.

●Use strength ranges and permissible contact medium.

●Some materials has big stress that causes the product to crack, need to strictly evaluate product design.

●The low thermal conductivity of plastics must be fully taken into account when designing cooling systems.

●The creep,shrinkage and deformation.

At the end, more communications with the molded plastic manufacturer, listen to their advice, you will get unexpected surprises from your molded plastic manufacturer.

There are 3 ways to get a wide variety of colors for injection molded products at our injecton molding factory:

Floating dye coloring method is used for screw injection molding products, The color matching is relatively simple, mixing resin, pigment and dispersant together in a certain ratio.

Mix the resin and dispersant first, then add the pigment and resin into the mixer, stir and mix well, then put it into the injection molding machine for production.

Add pigment, about 2%-3% of the resin weight, and dispersant (white oil, turpentine) about 1% of the resin weight.
injection molding manufacturer or molded plastic manufacturer should noted:

If the raw material is powder, the mixture must be mixed well and then extruded to granules before it can be added to the injection machine for production.

Usually these can be done by the molded plastic manufacturer itself.

Color masterbatch is a pigment of color concentrates for plastics,The color masterbatch method is to mix raw materials and color masterbatch in a certain ratio, and then put it into injection molding production after mixing well.

This color matching method is easy to clean the barrel of the injection molding machine and economical, Now it has been widely used. This is also the most common method used in our injection molding factory.

In order to ensure the quality of injection molded products and to obtain better dyeing effect(to get better color), injection molders should pay attention to the following matters when using this way at your injection molding factory.

A: In order to make the pigment melt and spread as soon as possible, and mix with raw plastic material well when the pigment goes into the barrel, the injection manufacturer needs to be noted that the temperature of the barrel feeding section is slightly higher.

B: In order to improve the plasticizing and mixing quality of raw materials,The molding manufacturer should increase the back pressure of the screw appropriately.

C:The injection molder must carefully audit the mixing, proportioning and measuring of several color masterbatches.

D:The injection molding facoty should pays attention to improving and maintaining the brightness of the inner surface of the injection mold to achieve the best color effect on products.

The operation sequence of liquid color coloring method is as follows:

Step1:Mix the pigment and dispersant (PE wax) according to the experienced ratio;

Step2:heat—stir;

Step3:Three rollers grinder to grind the color paste mixed well particles fine;

Step4:Add the resin and color paste into the mixer according to experienced the ratio, Mix and stir well;

Step5:Put it into injection machine production.

Comparison of liquid coloring method and floating dye coloring method, Its raw material and pigment ratio is the same, but its operating environment can be better improved, There is no pigment flying and environmental pollution is reduced, and the produtc quality is better guaranteed.

Clean environment in injection molding factory is very important for high quality injection molding, Especially for medical injection molding, or for some clean room injection molding(Dust-free injection molding workshop),All injection molding suppliers should be aware that the environment directly affects the quality of the injection molded parts.

Above are the three common color matching methods used in our injection molding factory, if you have products that need injection molding process, welcome to contact us!

Some raw materials are different due to their molecular structure and element composition, It is very easy to absorb moisture in the air during storage, which Makes the moisture content of raw materials larger, so all molded plastic manufacturer will dry the raw materials before injection moulding.

The production of this raw material will make the injection molding products appear bubbles or markings and other apparent quality problems, more serious will also make the raw material degraded in the injection process, reducing the performance of the product indicators.

Therefore, ABS, polycarbonate, polyamide, Polymethyl methacrylate, PA, PC and cellulose acetate etc used for injection molding products must be dehumidified and dried before production by your injection molding supplier or molded plastic manufacturer. For polythene,polypropylene and polyformic acid etc, If the packaging is not broken, generally can be used without drying treatment.

For materials easily oxidized and discolored by drying under high-temperature conditions (such as the drying of polyamide), the vacuum drying method should be used to remove moisture from raw materials. molded plastic manufacturer need to pay special attention to this.

The raw material after drying treatment should not be stored for a long time at injection molding shop. An ideal injection molding production method is continuous production, The dried raw material is directly fed into the hopper of the injection molding machine by the conveyor belt and put into injection molding production. This can also greatly save the operating costs for the molded plastic manufacturer, So usually molded plastic manufacturer or wholesale prefer to produce more quantity in one batch to save the injection mouling cost.