7: Injection Mold Making

Titoma > How We Work > 7: Injection Mold Making
Titoma HWW Molds

Plastic Injection Mold making in China

Once the shape of the plastic and metal parts is frozen we make the steel molds used to mass produce the housing and other parts. Our local engineers discuss the mold drawings with the Chinese mold makers to assure the robustness and the aesthetic quality of the parts. Mold making in China tends to be a lot more affordable than in the West, and a lot faster as well, with first shots often ready in 5 weeks. It’s hard for one mold maker to be good at everything, so over the years we have built up a roster of specialised shops for precision molds like cosmetic parts, optical lenses, gears, metal brackets anddie-cast parts.. When all these custom parts come together in an complex electro-mechanical assembly a lot of tiny adjustments are needed and every iteration comes with a negotiation.To make sure the project does not lose momentum our engineers stay at the mold shops until the job is done properly. (Extra tekst; brontekst https://titoma.com/molds-parts.php)

 

What is an injection mold?

A mold is a hollowed-out block of steel that is injected with molten material such as plastic, which then hardens to take on the counterpart shape of the mold. An injection mold is necessary when an electronic project requires a custom plastic or metal housing.

 

What are injection molds made of?

Molds are made from a variety of steels. Examples of some common steels used in plastic injection include P20, NAK80, H13, and S7. Each vary in terms of hardness, wear resistance, compression strength, corrosion resistance, machining ease, polishability, weldability

 

What are the cost considerations of injection molds?

China is well known for its unprecedented value for money with regards to mold making, yet some businesses choose Western- over Chinese moldmakers, assuming the quality of the steel improves the endurance of the mold result, resulting in a lower percentage of the costs. Choosing for a higher quality steel might constitute to a lower percentage of the costs when made by western mold makers, yet this is only due to the high labor costs. In fact, plastic enclosure is the cost component on which you can realize the largest cost difference between Asia and the West. From our experience it makes financial sense to invest in a mold at quantities of 250 pieces and up. And once you have invested in molds, the more you produce the more you save.

 

What are the challenges of plastic injection mold?

Injection molding is an art in itself. A good mold design will increase the chance of getting well-molded enclosures and parts, yet it is also essential to use the correct plastic injection parameters appropriate to the parts being produced and material used; otherwise the parts may come out defective. Common Molded Part Defects:

  • Burn Marks: Burnt areas at furthest points from injection gate caused by an injection speed that is too high so the mold lacks venting
  • Flash: Excess material caused by a too high injection speed/material injected, a damaged parting line or a too low clamping force.
  • Flow marks: Wavy lines or patterns caused by an injection speed that is too slow
  • Knit lines: Small lines on parts caused by the plastic flowing around an object; can be minimized or eliminated with a mold-flow analysis.
  • Sink marks: Depressions caused by either a pressure that is too low; cooling time too short; or enclosure walls mthat are too thick
  • Short shot: Incomplete parts caused by an injection speed or pressure that is too low
  • Splay marks: Lines/Marks caused by gas or moisture flowing along the part during injection process
  • Warping: Warped part caused by a cooling time that is too short or material that is too hot

 

What types of plastic injected enclosures (housing) can you choose from and why?

 

Plastic enclosures

Custom plastic enclosures give your electronic products the greatest freedom in shape and the lowest cost per unit.

 

PC(Polycarbonate)

has excellent impact strength, clarity, and optical properties and can be molded to tight tolerances. Its disadvantages are its subjection to stress cracking and/or yellowing after long time.

 

ABS(Acrylonitrile Butadiene Styrene)

ABS plastic has good mechanical toughness, dimensional stability, chemical resistance, and ease of fabrication. Its disadvantages are its poor solvent resistance and it melts easily.

 

PP(Polypropylene)

Polypropylene is widely used and inexpensive but is difficult to mold to precision. Its disadvantage is its degradation caused by UV

 

Metal Enclosures

Plastic is often the most cost effective option for production in large quantities, but a metal enclosure will give your device a high-end quality look and feel. A custom metal enclosure made in China or Taiwan can become cost effective at quantities as low as 200 pieces. Our partners can develop fast turn-around milled (CNC) metal enclosures at reasonable prices. Once you get to quantities of 500 units, you can significantly lower the unit cost by going for a stamped metal housing produced using a progressive die. Alternatively, to get more freedom of form you could go for die-cast housings in zinc or magnesium.

WHAT’S YOUR TIME TO MARKET?

FIND OUT

Design to China Manufacturing in 10-Steps

  • Product Architecture

    Titoma HWW Architecture

    We work closely with your team to define the user and functional requirements of the new product, and we determine the key technological challenges. Next our China sourcing team evaluates the full spectrum of costs effective components available, in China and elsewhere, so we can..Read More

  • Industrial Product Design

    Titoma HWW Industrial Design

    Industrial design, the look and feel, is a key factor in the commercial success of your product and every design starts with end-user research; who are your users, how will they use your product, what are the key benefits they are looking for, and what..Read More

  • Mechanical Engineering

    Titoma HWW – Mechanicall engineering

    The job of our mechanical engineers is to realize the original ID design intent as faithfully as possible, while meeting a host of other requirements as well. Our mechanical engineering team not only optimizes the design of every plastic and metal part for robustness and..Read More

  • Electronic Engineering

    Titoma HWW Electronic Design

    Titoma’s electronic engineers have been designing and manufacturing electronic products in Asia since 2003. We have the in-house skills and experience to develop embedded solutions, IoT Devices and Industrial Equipment and we are a Preferred Microchip Design Partner:…  

  • Embedded System Firmware Design

    Titoma HWW Firmware Design

    Unlike with a PC or Android device the programming language for every microcontroller is different. At Titoma we design firmware mostly for embedded processors from STM32 and PIC32, and we take care to properly structure and annotate our code so that it can be easily..Read More

  • Electronic Prototyping

    Titoma HWW Prototyping

    During the development we produce several prototypes, often first a partial electronic prototype to compare key components. Then a few iterations of complete working prototypes. For reasons of IP protection and speed we do our prototyping in-house, the housings 3D printed and the electronic circuits often hand-soldered...Read More

  • Injection Mold Making

    Titoma HWW Molds

    Once the shape of the plastic and metal parts is frozen we make the steel molds used to mass produce the housing and other parts. Our Taiwanese mechanical engineers discuss the mold drawings with the Chinese mold makers to assure both the robustness and the..Read More

  • Pilot Production Run

    Totoma HWW Pilot Run

    While earlier prototypes have been carefully assembled by our engineers, the test is now if we can replicate the same quality in mass production, and so for a pilot to be valid it needs to be done on the same assembly line by the same..Read More

  • Testing & Certifications

    Titoma HWW

    The pilot run product are subjected to a battery of test, such as accelerated aging, temperature shocks in our heat chamber, drop tests with and without packaging, water & dust ingression tests to meet for example the IP67 standard. But with all the testing we..Read More

  • Mass Manufacturing in China

    Titoma HWW Mass Manufacturing

    Design For Manufacturing (DFM) it is not something that can be done as an afterthought when a design is 95% ready, for us Design For China Manufacturing drives our design process right from the start, beginning with the electronic product architecture.  

CONTACT