How to Calculate Plastic Molding Price and How to Save Injection Molding Cost?

The plastic molding price has subjective factors in it, but the cost is relatively objective and can be assessed. Estimating the price of plastic injection molding is a complex task. Reasonable and intelligent design and processing flow will provide higher quality and lower cost for new plastic product development and mass production.

Six Core Contents of Plastic Molding Price

There are many factors that influence the price of injection molded products. In general, plastic molding costs contain: product design cost, rapid prototyping cost, steel mold manufacturing cost, injection molding cost, assembly cost, and transportation cost. This article mainly analyses the principles of evaluation of prototype production cost, mold tooling cost and plastic injection molding cost.

Rapid Prototyping Cost in Plastic Molding Price

A prototype is a product sample or model made from the appearance or structure drawing of a product design. Besides being used to test and evaluate the appearance and reasonableness of the mechanism, it is also used to provide samples to customers, who are satisfied or after modifications to make them satisfied, then open the mold for mass production.

Uses for Prototyping Plastic Parts

• Verify the aesthetics of the appearance.
  The appearance prototype is a visible and tactile entity, which can reflect the designer’s creativity intuitively in the form of real objects. The appearance prototype can intuitively evaluate the human-machine rationality of the modelling design scheme, give color, material expression, and the overall shape of the product, which plays a pivotal role in inspecting and optimizing the appearance design of the product.
• Verify the rationality of the structure.
  A structural prototype is a product model that can be assembled according to the structural design drawings of the product and can realize real functions. Structural prototype plays a very intuitive role in the rationality of product assembly process, the difficulty of assembly, the analysis and review of mold manufacturing process and production process, and it is convenient for designers to find problems early, optimize the design plan, and reduce the risk of direct mold opening.
• Test the market in advance.
  A model prototype is a product model produced at a certain (enlarged/reduced) scale according to the product or product drawings. Model prototypes are generally used to participate in market promotion and business negotiation activities such as exhibitions, so as to win market opportunities for enterprises.

Prototype Processing Methods for Plastic Parts

With the advancement of science and technology, the rapid development of CAD and CAM technology has provided better technical support for prototype manufacturing, CNC machining centres (CNC), engraving machines, CNC gongs, laser forming machines, and a large number of post-process production The popularization of supporting equipment has made prototype production “accurate”, “fast” and “brilliant” in the true sense; on the other hand, with the increasingly fierce market competition, the speed of product development has become the central contradiction of Prototype production of craftsmanship can effectively improve the efficiency of product development. There are two main methods of fast prototyping:

• One is 3D printing (laser forming) (additive production mode).
  The advantages of the 3D printing prototype are mainly reflected in its rapidity, but it is mainly formed by photosensitive resin accumulation technology, so the RP prototype is relatively rough and the material is single, which cannot reflect reality. The material characteristics of the product, and there are certain requirements for the wall thickness of the product, for example, if the wall thickness is too thin, it cannot be produced. It can be solved by the vacuum complex molding process, and the finished product is very beautiful, but the cost will increase slightly.

• One is CNC machining (computer-controlled machining center) (subtractive production mode).
  The advantage of CNC machining is that it can very accurately reflect the information and material properties expressed in the drawing, with a beautiful surface and reasonable cost. Therefore, CNC prototyping has become more and more mainstream in the prototyping industry.

Before developing molds and mass injection molding for customers, Sungplastic will cooperate with customers to make prototypes to verify the product design, so as to obtain the best processing and manufacturing process.

Injection Mold Cost in Plastic Molding Price

The injection mold cost for product development is a major part of the plastic molding price. The cost of mold manufacturing mainly includes: mold design cost, raw material cost, mold processing cost, surface treatment cost of mold core and insert, and mold trial cost.

Mold Design Cost

The cost of mold design has a great relationship with the difficulty of design. Products with a simple structure will of course be cheaper. If the structure is complex and the mold has higher requirements, the mold design cost will be higher. Similarly, the design price of the original mold and the copy mold is also different. Existing molds or customers have given mold drawings, which will save part of the design process.

Mould Raw Material Steel Cost

Different steels are selected according to different injection material properties and mold life. Commonly used plastic mold steels are: 718, 718H, S136, 8407, NAK80, P20, 2083, etc.

For example, some transparent products with very high requirements, such as optical lenses, need steel with good polishing performance, such as S136. If the wrong steel is selected, the polishing effect of the mold will be poor, and the product requirements will not be met.

The price of raw materials in each country and region varies according to the origin and demand. For example, the price of stainless steel in China.

Mold Processing Cost

The cost of mold processing is mainly affected by the type of processing technology. The main processes of processing moulds are lathe processing, milling, grinding, CNC machining, EDM (electrical discharge machining), wire cutting, and mold adaptation.

Surface Treatment Costs for Mold Cores/Inserts

For the surface requirements of different plastic products, some require surface treatment after injection moulding of plastic parts, and some plastic surface textures need to be styled in advance on the mold. Such as polishing, wire drawing, drying pattern, etc. In order to improve the service life of the mold, the surface strengthening treatment methods of the mould parts include: carburizing, nitriding, cyanidation, chromizing, aluminizing, boronizing, and vandalizing, surface quenching, etc.

Mold Trial Cost

The number of mold trials, whether to idle or not, and whether the mould trial is taken manually or by a robot will affect the trial cost.

Injection Molding Cost in Plastic Molding Price

The cost of injection molding mainly includes material cost, processing cost, pass rate, assembly cost, etc.

Plastic Material Cost

Multiply the unit price of the corresponding plastic raw material by the weight and loss of the injection moulded part. The price of raw materials in each country and region varies according to the origin and demand. For example, the price of plastic PP in China.

Injection Processing Cost

The processing cost is related to the tonnage size of the injection molding machine, the number of mold holes, the molding cycle and the product weight.
According to the tonnage of the machine, it can be calculated how much money per second. Assuming that the number of mold cavities is large and the molding cycle is short, the processing cost is low and the unit price is low.

Quality Pass Rate of Injection Molded Parts

The price of injection molded products is also greatly affected by the yield rate. Such as white or transparent products, their appearance requirements are very high and will affect the qualification rate of injection moulding. If a black plastic product needs a glossy finish, this will reduce the product pass rate due to obvious surface imperfections.

Assembly Cost

Labour cost, packaging cost, assembly machinery cost. According to needs, some products need to develop fixtures.

How to Reduce Plastic Molding Cost?

Reduce Mold Costs

According to the actual mass production demand, on the premise of ensuring the mass production demand, the service life of the mold is reduced, thereby reducing the material selection standard and material cost.

Reduce Mold Tooling Accuracy

According to product requirements and usage scenarios, the mold machining accuracy can be adjusted. For example, the appearance surface requires high precision. The internal surface of the product is hidden, which can reduce surface requirements and surface accuracy.

Reduce The Cost of Plastic Raw Materials

If the product requirements are very low, the nozzle material can be added appropriately. Injection molding using recycled materials.

Improve The Quality Pass Rate

Strengthen training for processing personnel and quality inspection personnel, minimize defects in the processing process, find and solve problems early, and reduce losses.

Automotive Injection Molding Production

It can realize 24-hour automatic production and save labour costs in the injection molding process.

China Low Cost Plastic Molding Manufacturer

In conclusion, evaluating the plastic molding price is a systematic work. Sungplastic is an experienced injection molding manufacturer. For more than 18 years, we have served more than 1000 international customers with customized plastic products. From product design, prototype manufacturing, mould production, injection molding processing, assembly and transportation, our company provides a one-stop service to provide customers with comprehensive project evaluation. With timely and smooth communication, accurate and efficient production, and a rich manufacturing experience, we are committed to providing customers with efficient and high-quality services.