Silicon injection molding and variety of ways

Silicon Injection molding services produce molded parts made from silicon. Silicone rubber is a 2 part, flexible and synthetic rubber-like material from silicone elastomers that can be cured at room temperature into a powerful elastomer used in molding. It is durable, heat resistant and free of allergens or leachable chemicals. Liquid silicone is similar to general silicone but has different processing features. It is purchased as a 2 part raw material with a grease-like viscosity.

Nowadays the silicone molding parts made by liquid silicone injection molding are becoming very vital. One reason is the increased performance needs of the finished articles. Further, more and more producers of rubber parts are viewing advantages in the high level of automation and productivity.

Different ways of silicon molding

Silicone injection molding
Silicone injection molding

Molding processes used by providers of liquid silicone injection molding services contain cast molding, dip molding, compression molding, rotational molding, reaction injection molding, and transfer molding.

While in the cast molding process, liquid stuff is poured into an open mold, in solidity molding a slug of silicone is pressed between two heated mold halves. On the other hand dip molding is a process similar to warm dip coating, in which the finished product is the fused plastisol stripped from the dipped mold.

Anyway in injection molding, liquid silicone is forced into a chilled mold under wonderful force. In the RIM process, 2 or more reactive chemicals are combined at high speed as they are being injected into a mold. In rotational molding hollow molds packed with silicone material are secured to pipe-like spokes that spread from a central hub. In transfer molding, the 2 mold leaves are clamped combine and silicone is forced by pressure into the mold.

Why the favored use of silicon rubber in injection molding

Silastic silicon rubber is shear stuff and so its viscosity depends on shear rate. As the shear rate increases, the product becomes lower in viscosity. It is this effect that is extremely favorable for the injection molding process. At the starting of the injection process speed profile should be programmed in such a way that the volume flow is top sufficient for the liquid silicon rubber-not to start to vulcanize before the cavity is filled, in order to reject scorch of the material. Thus liquid silicon rubber is largely used for the process of injection molding due to its following features:

  • Simple mixing and pigmentation
  • Solventless with low and flexible viscosity.
  • Quick processing matched to solvent dispersion and generally permits a full coating to be applied in one pass.

Do you have any project that needs liquid silicone injection molding service? If so you are welcome to send us the email, We are professional custom mold maker in China that offers plastic mold, injection molding, rubber molding parts, silicone molding parts, liquid silicone injection molding service to the world

Transparent plastic injection molding

Transparent plastic due to higher light transmission rate, which inevitably calls demanding surface quality of plastic products such like PC injection molding, PMMA injection molding, etc, can not have any markings, holes, white, fog halo, black spots, color, luster is not so good a result, the entire injection molding process on raw materials, equipment, molds, and even product design, we must pay great attention to a strict and even special requirements. Second, because of transparent plastic, mostly high melting point, poor mobility, so as to ensure the surface quality of products that often require a higher temperature, injection pressure, injection speed and other process parameters have to make minor adjustments to make when both full of plastic injection mold, Also does not produce the internal stress caused by deformation and cracking products.

PMMA injection molding

Therefore, from raw materials preparation, equipment and tooling requirements, raw material for injection molding processes and products must be strictly deal with several aspects of the operation.

(A) the preparation and drying of raw materials

Since any point in the plastic contains impurities, may affect the product transparency, and storage, transport, feeding the process must pay attention sealed to ensure a clean raw material. In particular, raw materials contain moisture, heat, might cause deterioration of raw materials, they must be dry. In the injection, the feeding must be used a dry hopper. Would also like to note that the drying process, the type of air should preferably be through a filter, dehumidification, in order to ensure no contamination of raw materials. The drying process the following table, transparent plastic drying process: material drying temperature (℃) drying time (h) Material thickness (mm) Remarks PMMA 70 ~ 80 2 ~ 4 30 ~ 40 PC 120 ~ 130> 6 <30 with hot air circulating dry PET 140 ~ 180 3 ~ 4 with continuous drying is better feeder

(B) the barrel, screw and its annexes clean

In order to prevent contamination of raw materials and in the screw and accessories depression there is old stuff, or impurities, in particular, the existence of thermal stability of the resin, so before use, stopping applications after they screw cleaning agent to clean the parts, so that it can not stick with impurities, when there is no screw when the cleaning agent can be used PE, PS and other resins cleaning screw. When the temporary shutdown, in order to prevent the raw materials at high temperatures to stay a long time, causing lower solution should be drying machines and barrel temperature decreases, such as PC injection molding, PMMA injection molding, etc. barrel temperature should be reduced to 160 ℃ below (hopper temperature for the PC should be down to 100 ℃ below).

(C) It should be noted on the mold design issues (including product design)

To prevent backflow of poor or uneven cooling caused by plastic molding bad, resulting in surface defects and deterioration in general in the mold design, should pay attention to the following points.

a) wall thickness should be uniform, stripping slope be large enough;

b) the transition part should be a smooth and gradual transition to prevent any sharp corners, sharp edges produce, especially in PC products must not have gaps;

c) gate, flow channel as large, chunky, and the condensation process of contraction set in accordance with gate location, if necessary, add cold material should be well;

d) die surface should be smooth, roughness low (preferably less than 0.8);

e) Vent. Trough must be sufficient, as well as air and melt when the exhaust gas;

f) In addition to PET, the thickness should not too thin, generally not less than 1 mm.

(D) injection molding process should pay attention to the issues (including injection molding machine requirements)

In order to reduce internal stress and surface quality defects in the injection molding process should pay attention to the following aspects.

a) should use special screws, with a separate temperature-controlled radio Tsui injection molding machine;

b) injection of the temperature in the plastic resin is not decomposed under the premise of injecting suitably high humidity;

c) Injection pressure: a general high melt viscosity in order to overcome the shortcomings, but the pressure is too high will produce stripping difficulties caused by internal stress and deformation;

d) Injection speed: In the case of filling to meet in general should low, it is best to adopt a slow-slow a fast multi-level injection;

e) holding pressure time and molding cycle: to meet the product filling and do not produce depression, the case of air bubbles; should as short as possible to minimize the melt residence time in the barrel;

f) screw speed and backpressure: in meeting the quality of plastics under the premise should be as low as possible and prevent the possibility of the lower solution;

g) Mold temperature: cooling products, good or bad, a great impact on quality, so mold temperature must be able to precisely control the process, if possible, die Wenyi higher good.

(V) other aspects of the

In order to prevent the upper surface due to deterioration in the quality, generally when you minimize the use of injection mold release agent; When we go back to the materials used shall not be greater than 20%.

For addition to PET, the product should be carried out post-processing to eliminate stress, PMMA injection moulding should be 70-80t hot air circulation drying 4 hours; PC should be clean air, glycerin, liquid paraffin, and other heating 110-135 ℃, time as a product may be the highest need for more than 10 hours. The PET must be bi-oriented processes in order to get good mechanical properties.

Seamless Injection Technology results

Seamless Injection Technology results – Chinese Konka LCD TV below 8K.

Konka LC42DT68AC LCD TV appearance with a seamless injection molding, high-performance materials to make the fuselage light shine, while the super-slim look and elegant style. Has a resolution of 1920 * 1080 full-HD panel, comes with 120Hz frequency-doubling technology, can effectively enhance the picture smooth and clarity. Currently sells for 7999 yuan (also on behalf website prices prevail). Like the best place to store the user to find out!

Konka LC42DT68AC appearance with popular ultra-thin design, the overall thickness of the fuselage just amazing to 3.5 cm, the aircraft before and after the panels are used once a seamless injection molding, high-gloss surface material to make shiny body, while the bottom border of the Red decorative pieces of transparent acrylic covering the above material gives a strange texture, while a circular base and a straight section of the fuselage is also in stark contrast. It is thin not only the fashion but also quality.

Specifications, Konka LC42DT68AC use of high-quality high-definition LCD TV panel with 1920 × 1080 resolution, this TV also has a 120Hz frequency-doubling technology, easy to get smooth frame display. Chi-controlled energy-saving technology that can automatically detect the various parts of each image brightness level and brightness based on the image itself needs an instant reduction in dark scenes the picture looks the same part of the brightness to ensure screen brightness, but also protect the eye. Sound quality, the support for automatic volume adjustment, supports multiple audio modes.

Interface area is equipped with TV input, AV-Video, component video terminals, D-Sub port, headphone port, and HDMI digital high-definition interface, and so on, to meet the general family of digital entertainment needs.

Acetal Injection Molding

Welcome to our product page of Acetal Injection Molding, in which you can find detailed information of Acetal Injection Molding. Our Acetal Injection Molding is good in quality and competitive in price. 

Acetal Thermoplastic Material for GC Injection molds China Manufacturing 

GC MOLD is injection molding china company can custom mold and manufacture acetal resins for strong and rigid plastic parts and components that are resistant to moisture, heat, and solvents. As a leading plastic injection molding and manufacturing company, GC MOLD invests in homopolymers by Dupont Co. (Delrin®) and copolymers by Celanese Engineering Plastics Div., Hoechst Celanese Corp. (Celcon®) to provide the highest quality thermoplastic materials for international, national, and regional customers in Bucks County and Philadelphia, Pennsylvania, New Jersey, Delaware, and Maryland.

What is Acetal Thermoplastic Material?

Acetal, also known as polyoxymethylene, is a highly crystalline plastic, which derives from formaldehyde polymerization technology. Homopolymers and copolymers are two derivations of available acetal resins; each exhibit different properties that make them suitable for diverse applications. At GC MOLD Components, we offer customers both homopolymers and copolymers to meet the specific needs of their product or system.

Injection molds China

Acetal Plastic Properties

Delrin®, a homopolymer, has high tensile strength, rigidity, resilience, long service life, and moderate toughness under continuous impact conditions. Delrin® is available in various grades based on viscosity and impact resistance. Lower viscosity grades are best used in GC’s plastic injection molding and manufacturing, while higher viscosity grades are most appropriate for GC’s custom-molded plastic parts or components requiring extreme durability.

Celcon®, a copolymer, has a high tensile and flexural strength, long service life, and excellent hardness. Celcon® maintains its hardness under a broad range of temperature changes and, when compared to other crystalline thermoplastic materials, is most resistant to creep. Celcon® is available in various grades based on UV resistance, glass reinforcement, low wear, and impact resistance. GC MOLD Components features a choice of grades for customers to choose.

Advantages of Acetal Plastic Include:

• Resistance to chemicals

• Very low water absorption

• Resistance to hydrolysis by the base

Delrin® has a high resistance to organic solvents, superior dimensional stability, a low coefficient of friction, and, among thermoplastic materials, has a remarkable resistance to abrasion. For tight tolerance, high-performance custom plastic parts or components, Delrin® is commonly utilized due to its low moisture absorption, excellent creep resistance, and high deflection temperature. GC MOLD does not recommend using Delrin® in applications where prolonged exposures to strong acids and bases extend outside the range of pH 4 to 9, however, Delrin® is recommended in applications where exposure to environmental conditions is long-term.

Celcon® has exceptional resistance to most chemical and solvents as well as good thermal stability and plastic molding and manufacturing characteristics. For electrical applications, Celcon® exhibits good electrical properties with high mechanical strength and a UL electrical rating of 100°C. For environments involving humidity changes, Celcon® is a viable choice due to its low moisture absorption. Although GC injection molding China does not suggest using Celcon® in constant contact with strong oxidizing agents, we do suggest using this thermoplastic material in prolonged exposure to mineral acids such as sulfuric, nitric, and hydrochloric acids in various inorganic solutions kept at room temperature.

A recognized injection molding China manufacturing company, GC MOLD Components can mold several unmodified and glass-reinforced, plastic injection molding grades as well as polytetrafluorethylene (PTFE) or silicone-filled grades of both homopolymers and copolymers. Grades of both types adhere to the regulations established by the Food and Drug Administration for repeated contact with food and the regulations established by The National Sanitation Foundation for use in drinkable water. We manufacture the custom plastic parts or components you need to make your product or system perform to the highest level possible.

Case Study

We have been with ST plastics since Royston and Bob took the reins some 3-4 years ago. ST have designed injection moulding tools to our specifications for over 20 product lines and supply us with a continuous stream of plastics which are used in our product and exported globally. Staying on shore and particularly with ST has proved to be a very smart management and fiscal move. Their co-operation, liaison, reliability, communication and willingness to accommodate change far outweigh any perceived savings one might achieve using resources off shore. Not to say ST are not competitive, they are, but the quality and reliability from the ST team are second to none.

plastic moulding

managing director


I have had dealings with ST for the past 5 or so years, and the service and response to any given problem is truly fabulous. I design machinery for a living, and plastics and associated materials form a very important part of the design process. Most important to the process is, I find, the need to obtain advice and assurances that a certain design is possible, and this is often required very early in the design process. I have found that ST Plastics are very capable of this, and it saves many days , even weeks in design work.

Their early evaluation of the design and how it might be cast in what product has been close to faultless. This is, in my opinion, what sets them apart from the typical toolmaker who often requires detailed drawings before you can get past the front door.

Their tool making expertise has been very good, allowing and preempting the shrinkage rates and distortion that will occur with many moulding procedures.

Very Very impressed with your entire business and service. Regards Paul Willett, Managing Director,

I am writing to endorse and highlight ST plastics .Bob & Royston have provided us with fantastic service right from the first contact , besides being professional and friendly they have made themselves available to us , which can be very reassuring .

Our line of work is in commercial construction, so time lines and installation schedules are tight & limited. Taking this into account Bob &Royston not only took the projects on but created working drawings & helped with design issues together with managing to supply us the finished product before the due date, enabling us latitude to complete our manufacture. In closing I can do nothing but recommend ST plastics to anyone that is in the market for their services. Dealing with them is easy & you can be confident of the service & outcome you require which makes them a perfect choice to help grow & improve product lines & productivity.

Yours thankfully



I have had a long business relationship with ST Plastics and have always been happy with their service and expertise. Since taking over the business a few years ago, Royston and Bob have worked hard to take the company to another level. Their commitment to service, quality and customer satisfaction is honest and real. If you have need of injection mouldings look no further.


Managing Director

As manufacturers of the Odalog Gas Logger and Gas Detector range, Thermofisher Scientific, like our customers, demand only the highest quality and accuracy from our high-end gas instruments. Our instruments meet the needs of their industry, whether in a rugged underground mining environment or in the corrosive wastewater monitoring, so we need to be sure that the plastic parts that house our compact electronics are up to the job. At ST, our extremely high standards are completely understood and catered for with high quality, precision and repeatability of our ‘unconventional’ plastic moulding – even in small batches. With the experience, technical advice and superior customer service ST offer, we wouldn’t consider going anywhere else.

plastic molding

Design Engineer (Mechanical Engineer / Industrial Designer)

I have to compliment you, and all others of your company – and I don’t hand out compliments freely. As you might expect, in looking for a company to do this work for us, I contacted multiple Australian companies who advertise on the net claiming a high tech capability for tooling and production of prototype runs. All other replies I received demonstrated incompetence (at least in communication) or just plain disinterest.

You replied with intelligent communication and followed up with a phone call. Subsequently you have been most courteous in all contacts with me, and have demonstrated a high level of competence in the quality of the samples received today. Thus, in my view, ST sets a benchmark to which others should aspire. May your company enjoy well deserved success.

Geoffrey Wickham A.O.


Plastic Mold Manufactuers

Plastic Mold manufacturers

Plastic Mold manufacturers

As one of Australia’s leading plastic mold manufacturers, we are committed to excellence in injection moulding. Our company specialises in the design and manufacture of plastic moulds and products at any stage of development. With decades of experience as suppliersand manufacturers, we offer a comprehensive range of injection services encompassing concept and component design, 3D models and prototyping, tool design and mould making, through to testing and final production.

We will work with you at any stage of your project. Be it drafting the initial concept or testing and production, we will ensure a satisfying result is achieved at any stage.

Comprehensive Plastic Injection Services

We offer extensive plastic injection moulding services including innovative design and sustainable manufacture. Our company uses the most advanced machines to design and develop plastic moulding of the highest standard. Below is a list of our broad injection plastic moulding capabilities.

  • Product design & development

We understand the creative process starts with a great idea, but ideas sometimes need assistance to turn them into sustainable plastic products. Our designers and manufacturers have decades of experience and can help you to work through your “light bulb moment” to determine the viability of your idea and to create a project plan to take your idea to market. We can help you with product development, brainstorming meetings, project planning and risk analysis.

  • Concept sketches

Before you take your idea and move to formal design from plastic machines, it helps to have concept sketches developed to give structure to your ideas. We have years of experience working with clients to create concept sketches to help identify early problems and build stakeholder buy-in. The concept sketches we create are of sufficient quality to use in market testing, buyer meetings and licensing discussions.

  • Engineering Analysis & Development of Specifications

Converting concepts to cost effective manufactured products requires effective design engineering from qualified manufacturers and designers. We are experienced in ensuring the functional specifications for your product are efficient, effective, and practical. This means you end up with the ideal polymer for the use and environmental conditions, and the product is optimised to reduce unnecessary manufacturing costs.

You are left with details of material needs and target production costs, as well as a clear idea of production feasibility. 3D Solid Modelling software is used through every stage of the process to give you the best possible indicative model.

  • Component design

As one of Australia’s leading plastic mold suppliers, manufacturers and designers, we have extensive experience in component design. We convert concepts into compelling 3D drawings utilise the latest Solid Works 3D software in order to provide meaningful information to your team, so any component design issues are identified and resolved before tooling begins. We have the expertise and experience through our Computer Aided Design (CAD) software to assist you with component design or refinement.

We can also provide design assistance to help you optimise your part design to improve quality and reduce unnecessary manufacturing cost.

  • Polymer & materials analysis

We strive to stay at the forefront of manufacturing and design technology. Our company is innovative in product design and development and attends tradefairs and tradeshows to keep up to date with the latest polymer technologies. There are thousands of polymers to choose from; B&C Plastics offering an extensive range to almost any industry. As trusted suppliers, we use and are fully conversant with an extensive range of polymers, supplying products to the building and mining industry alongside others.

  • Toolmaking & Mould Making

ST Plastics have been the leading tool makers in Australia since 1987. Our toolmakingdepartment utilises CNC plastic machines , EDM and a range of manual machines to produce High Quality Injection Moulding Tools, Jigs, Fixtures and General Engineering projects using the latest 3D cadcam technology.

  • Plastic Injection Moulding (Machines 25 – 370 Tonne)

Our injection-moulding department has an advanced knowledge of injection moulding, process control, trouble-shooting and polymer selection. We have a range of modern injection moulding machines with clamp force tonnage ranging from 25 to 370 tonnes, which means we can handle components from 1 gram up to 2kg in weight.

Our highly experienced and fully qualified team has the ability and the resources to deliver a high specification product maintaining critical tolerances.

  • Ultrasonic Welding

Ultrasonic welding is a method of joining two parts by converting electrical energy into heat energy by high frequency mechanical vibration and is suitable for plastics and metals. Ultrasonic plastics welding has advantages over joining methods using solvents or adhesives including production cycle times are usually improved with speeds up to 2000 parts an hour.

  • Prototyping & Prototype testing

We provide high quality functional and non-functional plastic moulding prototypes either from our own information or your CAD data. Our capabilities include:

  • Stereo lithography
  • Selective laser sintering
  • CNC machining
  • RTV machining
  • Tooling
  • Rapid prototyping

We trial plastic injection mould tools to provide you with off-tool samples of your product for design compliance testing and final approval. We also provide prototype-testing services to ensure the design compliance and quality of your products.

  • Trouble Shooting – Tooling & Moulding Faults

Sometimes tools or moulds don’t perform as expected. Our experienced plastic manufacturers, technicians and engineers can trouble shoot tooling or moulding faults, and provide recommended solutions to get you quickly manufacturing again.

  • Tool Repairs & Maintenance

Well-maintained tools and moulds mean longer trouble free service. Our inbuilt maintenance program means at the end of each run we strip back the mould, clean it and prep it for the next run, before safely storing it. If problems are identified, we schedule appropriate repairs, which means your tools and moulds are always in tip-top condition.

  • Assembly, Labelling and Packaging

We offer component assembly, labelling, and packaging for all size businesses. We can handle everything from small niche product low volume runs, right the way through to high volume, commodity-style products. We can even handle bar-coding of items or packaging, which means we can provide you a one-stop shop from concept to manufacture.

For more information on our thorough injection plastic moulding process , specialised machines or to see if ST Plastics can cater to your business requirements call us or submit an enquiry form today

Injection Molding Process

Our emphasis on process control is multifaceted. However, the focus of our efforts can be summarized. The injection molding process has been broken down by RJG associates (an internationally recognized consulting and training firm dealing specifically with plastic processing) into 4 key variables that must be consistently controlled in order to produce parts with the greatest degree of repeatability. They are plastics flow rate, plastic melt temperature, plastic pressure, and cooling imparted to the plastic. Our process control program is designed specifically to control these upstream parameters so that our downstream parts will be as consistent as possible. Documented procedures specifying how we monitor these parameters are in place and records are kept on all of them to ensure that our process control procedures are always carried out. Some of the controlled areas include machine parameters, cooling systems, setup procedures, preventive maintenance, work instructions for machine set ups, in process testing, and process changes.

In 1997 we moved into a new facility offering the infrastructure that has made our growth possible. We currently have 14 injection molding presses ranging from 1.4 oz to 60 oz and 38 tons to 500 tons. We utilize state of the art equipment such as digitally controlled presses, automatic weigh scale blending, and 3 bed desiccant dryers with insulated hoppers to assure only the best product quality and consistency.

We do assembly and sub operations on a regular basis as well as special packaging. Please call us to discuss any special needs you may have.

Part of our commitment to quality is demonstrated by our training programs for our associates. We have documented house training programs both in the form one to one associate training and interactive computer based software covering entire programs in injection molding, safety, and quality control and statistical tools. We have several job classifications which signify the knowledge and proficiency level of a given associate from the most basic press operator right up through manufacturing manager. All levels are specified in training requirements and testing is scheduled and documented to certify advancement.

Safety is a big part of our training programs. We have regularly scheduled safety meetings. We have a documented training program to certify fork-lift operators. We have annually scheduled meetings concerning Chemical Control (MSDS), Personal Protective Equipment, Fire extinguisher, Emergency Action plans, and Energy Control (lock out tag out). In addition, we have been proactive with respect to OSHA regulations and participate annually in a voluntary compliance and inspection program offered by New York State.

If you want to know more about injection molding process, please go to