Protomold: Rapid Injection Moulding
March Design Tip

 Protomold: It Isn't Just for Prototypes Anymore

Protomold has long been the place to go for fast, affordable, injection moulded prototypes. But for an increasing number of customers, Protomold is also a source of production parts in quantities of up to 25,000. Depending on the number of parts you need, Protomold can be significantly less expensive than a traditional moulder using steel tooling. And regardless of quantity, you still get Protomold's speedy turnaround for unmatched speed to market.

There are several ways that Protomold can help control cost and slash production time on large orders. Multi-cavity moulds, which produce up to eight copies of a part in each press cycle, increase tooling cost somewhat, but can more than offset that increase by reducing press cycle time and cost. The ideal number of parts per mould depends on various factors.

Obviously, part size can be a limiting factor, but even for small parts the ideal number of cavities per mould can vary. For example, a customer needing 24,000 identical small parts might maximize savings by using an 8-cavity mould. For a customer needing fewer parts, say 2,000, the lower tooling cost of a 4-cavity mould might be the better choice. "What-if" scenarios using the "cavities" option of the ProtoQuote® (see fig. 1) or Protomold's sales or customer representatives can help you choose the most cost-effective solution.

Fig. 1

Fig. 1: ProtoQuote® Cavity Specification

There are a couple of limitations to keep in mind as you consider the use of multi-cavity moulds:

  1. Side actions: Because they tend to use so much of the mould's maximum "footprint", multi-cavity moulds don't leave room for side-action cams and must be simple straight-pull moulds.
  2. Hot tips: Due to mould complexity issues, multi-cavity moulds cannot use hot-tip gates.

In addition, until the part has been thoroughly prototyped and tested, you should probably stick to single cavity moulds. Once your design has been proven, you may elect to convert to a multi-cavity mould for production.

Fig. 2

Fig. 2: Multi-Cavity Mould

If you have questions regarding the use of multi-cavity moulds for production parts, check with your Protomold sales representative, who will be happy to help you find the best and most cost effective solution.

 

ProtoQuote®
Interactive Quotes

ProtoQuote

ProtoQuote is new and improved! Try it out today:

Upload your 3D CAD model and we will e-mail you an informative quote.

ProtoFlow Analysis

ProtoFlow® Analysis
Select ProtoQuotes include a ProtoFlow analysis to predict potential mould fill issues.
Watch a video demo.

Design Guidelines

As always, you can visit the Protomold Design Guide for helpful Rapid Injection Moulding design information.

Design Tips Volumes

Design Tips Compilation Volumes

Download Design Tips compilation volumes and catch up on what you've missed.

Plastics Trivia Question

So-called "plastic blood":

 A. was first developed at Israel's Ma'ariv University.

 B. is made up of plastic molecules with an iron atom that bonds to oxygen.

 C. has been described as being "the colour and consistency of honey."

 D. is twice as effective as natural blood at conveying oxygen to tissues.

 E. has not yet been made stable at room temperature.

(Honour System: No Googling, Yahooing, or Dogpiling until after you've submitted your guess.)

Last month's question/results:
Which of the following is true of Neoprene?:

A. Its chemical name is polyfluoroprene.

B. It's original brand name was Polyprene.

C. It was introduced in 1938 when natural rubber became scarce.

D. It was developed by the Goodyear Rubber Company.

E. Its air spaces can be filled with nitrogen for increased insulation.

The correct answer is
E. Its air spaces can be filled with nitrogen for increased insulation.

The responses are represented in the following chart:

Last Month's Results

Upcoming Tradeshows

Want to talk in person? Stop by to discuss your design.

 Eurostampi
3 - 5 April, 2008
Exhibition Centre Parma
Italy

 PDM
15 - 17 April, 2008
International Centre Telford
UK

For more information, visit our web site at Protomold.co.uk.

Get a ProtoQuote

Suggestions

Please e-mail suggested topics for future Design Tips, questions for future Designer Surveys, and obscure bits of Plastics Trivia to news@protomold.co.uk.