How to Design Shoe Outsole Tooling Part 1

Outsole Tooling

shutterstock_264364937 How to make shoe outsoles eva outsoleThe outsole tooling for athletic shoe is the most complicated and most expensive piece of equipment required for production.  The outsole tooling for footwear comes in many different styles and configurations.  Shoe outsoles are made from many different types of rubber, plastic, foam, leather or fabric each requiring it’s own tooling requirements and manufacturing technology.

We are going to talk about the design requirements and tooling for the rubber, plastic and foam outsoles found in the modern athletic sports and casual shoes.   The outsole design you select for your shoe design is critical to it’s comfort, performance and price.   You will need to know about the equipment requirements and unit price for each type of outsole design.

Design shoe mould Mold It’s critical that you understand the Tooling and manufacturing requirements for each outsole type.  If you are designing for Nike go ahead and design a complicated outsole with blow molded air bags, plastic injections etc…. The sky is the limit. $20,000 per size is no problem.  If the production is a million pairs $150,000  for the tooling is no problem.  However if you are start up strapped for cash,  a cup sole unit is $1400 per size is more realistic.

Of course performance matters.  You would never use Rubber cupsole for a running shoe or likewise a combat boot with the huge air bag is also a bad idea.

Basic Outsole Types:   Rubber Cupsole,  Cut and Buff EVA wedge sole, Combination Cut and Buff/Cupsole,  Two piece EVA rubber sole, Vulcanized Rubber sole,  Lightweight EVA Outsole, EVA Sole unit, Injection Molded EVA, Injection Molded plastic Sole unit, Blow Molded Air Bag Sole Unit.

Outsole Types

shutterstock_285892169 Air Bag Midsole The air bag midsole is made by the blow molding process. The midsole starts out as hot semi-liquid plastic extrusion tube (called a parison).

Air Bag Midsole

The air bag midsole is made by the blow molding process.  The midsole starts out as hot semi-liquid plastic extrusion tube (called a parison).  A steel mold clamps around the tube and the air is injected inside to fill the bag and inflates the shape to fill the mold.  The tooling and machines are very expensize. The plastic can be tinted and the bag top and bottom surfaces can be painted.  In this case the air bag is attached to an EVA tray that is then bonded to the shoe outsole by cold cement process.  The type of sole unit is great for running and cross training.  The air bag does look cool but due to the blow molding process the plastic walls of the bag can be a little thick.  This sole unit requires an EVA Compression mold, Rubber compression mold and blow molds.
TOOLING:$$$$    UNITPRICE:$$$$

The standard two part sole is made with light weight CM EVA midsole, bonded to a rubber outsole.shutterstock_279056639

Compression Molded EVA or CMEVA

The standard two part sole is made with light weight  CM EVA midsole, bonded to a rubber outsole.   The EVA foam is expanded into blocks then cut down to fit into a mold.  The mold is heated causing the EVA to re-expand and fill the compression mold.  The density and durometer is set by how much foam is compressed into the mold and the formula of the foam.   More foam is harder and gives the sole design more definition.  Midsole is bonded to the rubber in the stock fitting room before the unit meets the upper in assembly.  This sole unit requires an EVA compression mold and a rubber compression mold.
TOOLING:$$   UNIT PRICE:$$

 

Many firms have been experimenting with foamless injection molded midsoles. The shoe has a stiff moderating plate under the heel to keep the shoe stable shutterstock_220781398
Injected Midsole

Many firms have been experimenting with foamless injection molded midsoles.  The shoe has a stiff moderating plate under the heel to keep the shoe stable. The Midsole structure is likely made of Nylon or TPU plastic.  The rubber tread is attached by stock fitting.  This sole unit requires an EVA Compression mold for the midsole hidden inside, Rubber compression mold for the tread and Injection molds for the midsole component.
TOOLING:$$$$    UNITPRICE:$$$$

 

This running shoe uses an injection molded EVA midsole with rubber inserts. shutterstock_227205646Injection EVA Midsole

This running shoe uses an injection molded EVA midsole with rubber inserts.  The Injected midsole has a thicker, smoother skin than compression molded EVA midsole.  The Injected EVA midsole has a more uniform density and better detail definition than the compression molded EVA.  This unit is very light, very flexible but will wear quickly.  The Injection molded tooling has a high production rate but the molds are over $3,000 per sizes and requires an expensive machine.  The compression EVA tooling is half the price and can be made in the most basic pressing room. This sole unit requires an EVA injection mold and rubber compression mold.
TOOLING:$$$   UNIT PRICE:$$

This classic Die Cut EVA wedge midsole is bonded to a compression molded rubber bottom. shutterstock_289873175

The EVA Wedge

This classic Die Cut EVA  wedge midsole is bonded to a compression molded rubber bottom.  The top wedge shape of the EVA is cut by pressing the EVA with a profile roller while a blade splits off the bottom layers.  The white layer is buffed and bonded to the rubber bottom.  All three parts are them buffed to create the angled side wall.  Labor intensive but required very little tooling.  In fact one bottom tool can be trimmed to make 4 to 6  sizes. This New Balance shoe requires a rubber compression tool.
TOOLING:$   UNIT PRICE:$

The shoe is made by PU foam direct attach.shutterstock_86681128

Poured PU Midsole

The shoe is made by PU foam direct attach.  In this process the Upper is clamped into the top of a mold.   The mold is filled in two shots, first the sole is molded, once the bottom cools in a few minutes a second shot of light weight PU will fill the space between the Upper and bottom. The PU fuses directly to the upper.  This sole requires a 2 part PU rubber injection mold AND a million dollar machine.
TOOLING:$$$   UNIT PRICE:$

 

This classic cup shoe with a one piece rubber cupsole. shutterstock_219385027Classic Rubber Cupsole

This classic cup shoe with a one piece rubber cupsole.  The white side wall and black rubber are molded together in one operation.  The mold has a middle plate allowing the to parts to be formed separately, before the rubber is fully cured the middle plate is removed the rubber colors can fuse together without a messy seam.  The side logo is painted after molding.  Inside you will find a die-cut piece of EVA foam.  The stitch groove is an under cut in the mold but the stretchable rubber is easily removed after molding.  The channel stitching is done after assembly. This requires only a rubber compression mold.

This is a rubber cuo sole with eggcrate inside
TOOLING:$   UNIT PRICE:$
The cup sole mold can be made with no foam filler inside.  The cheapest shoes may have rubber egg crate filler.

This classic air bag shoe midsole is made by over molding PU but in this case the air bag is clipped in heel and exposed. shutterstock_312082184PU poured Air

This classic air bag  shoe midsole is made by over molding PU but in this case the air bag is clipped in heel and exposed.  The window is where the clamps hold the bag in place and they stop the PU from covering the bag.  The rubber sole is made by compression,  the top of the black part is molds parting line.   The Yellow part with specs is the same PU part holding the air bag but this area is masked off and painted.   After the PU parts are cleaned and painted , they are bonded to the rubber parts by the stock fitting line.  The toe channel stitching is done after assembly. This outsole requires a rubber compression tool, Air bag mold and PU midsole mold.
TOOLING:$$   UNIT PRICE:$$

This indoor soccer shoe is a combination cupsole and cut and buff. shutterstock_317387078

Cup & Cut and buff sole

This indoor soccer shoe is a combination cupsole and cut and buff.  The rubber is pressed then the EVA wedge is cement in place.  The EVA is then buffed down to match the rubber side wall.  This construction is more flexible and lighter than a standard rubber cupsole.  This outsole requires a rubber compression mold.

TOOLING:$$   UNIT PRICE:$$

Classic Vulcanized Outsole

shutterstock_324031223 This outsole is standard vulcanized shoe constructionThis outsole is standard vulcanized shoe construction.  This is how Vans makes it’s shoes, and how the Converse All Star is made.   The sole bottom is bonded to the upper, then striped rubber  foxing tape wraps them both.  After this assembly operation is done the entire shoe is cooked to cure the rubber making the bonds permanent. See Vulcanized VS Cold Cement  This outsole requires a rubber compression mold for the bottom and a specialized vulcanize production factory.
TOOLING:$   UNIT PRICE:$

Injection Molded Outsole

Soccer Cleat Injection Molded Outsole
This soccer cleat outsole is made by injection molding process.  Cleated shoes for soccer, football and baseball require stiff supportive bottoms with heavy cleats.   Cleated shoes are made by the cold cement process.  The Sole unit may be sewn to the upper after the cementing operation.   This outsole requires a plastic injection mold.    Complicated designs with several colors require an expensive mold, Simple designs require a less expensive tooling.  Cleats with metal spikes or inserts require over molding processes.  This type injection tooling requires a specialized injection molding factory.
TOOLING:$$-$$$$   UNIT PRICE:$ to $$$$

Learn more about shoe outsole mold design and manufacturing of shoe soles check out chapter 5 Outsole Tooling & Chapter 10 Rubber pressing in the new book  How Shoes Are Made 

Shoe sole molding How to make a shoe bottom Shoe_sole_rubber_pressing

Learn more about making shoes:

Footwear design book Free PFD Shoe Design Book DownloadDo you want to learn how big brands make shoes?  Now you can!  How Shoes are Made will show you how modern shoes come to life! More than just a tour through a sneaker factory and more than your average shoe making book!  From drawing shoe designs to sample development and footwear manufacturing, you will learn how it is all done. Written by veteran shoemaking pros, How Shoes are Made will give you a look inside the REAL world of shoe design, development, and mass production. 220 pages with over 400 color photos and drawings. 26 chapters explaining shoe design, footwear pattern making, sample development, footwear materials selection, upper stitching, outsole and tooling design, shoe lasts, shoe costing, quality inspections, starting you own shoe brand, and much more!  A must read for young shoe designers, sneaker heads, or any footwear fanatic! Over 2500 copies sold! Read in 60 Countries! See Preview Video On YouTube

Download Now! 

Print Edition Now Available!  

Table of Contents:

The Design Process, Shoe Development, Shoe Patterns, Shoe Specifications, Outsole Tooling, Development Process, Pre-Production, Material Preparation, Stitching Operations, Rubber Pressing, EVA Forming, The Assembly Line, The Shoe Last, Footwear Costing, Importing Shoes, Shoe Logo Design, Leather for Shoes, Textiles for Shoes ,Synthetics for Shoes,  Foam for Shoes, Know Your Footbeds, Material Suppliers, Shoe Designers Tools, Jobs in the Shoe Trade ,Quality Control, Starting a Shoe Company, Life at a Shoe Factory, Shoe Making Dictionary

If you want to learn more, check out our new books.

Print Editions and Instant Downloads Available Now!

E-Book edition 170 pages. PC and Mac compatible PDF file. Download Now!

E-Book edition 220 pages. PC and Mac compatible PDF file. Download Now!

Now enjoy the double download of two Sneaker Factory books.

Print Edition, 220 pages with over 400 color photos and drawings.

Print Edition, 250 Pages with over 400 color photos and drawings.

A must have for anyone serious about launching a new footwear company!

E-Book edition 170 pages. Profit margin and Size run calculators. Download Now!

Download Edition + Paper Pattern + Blue Prints and Spec sheets

Start-up Pack is all you need to get your own shoe business started.

Print Edition + Paper Pattern + Blue Prints and Spec sheets

A complete technical specification, drawings, blueprint, pattern and spec.

Computer cut shoe pattern for a classic jogger.  Factory Blue Print included.

Entire pattern size run for the Arris classic trainer, Men’s US 7-13 (Euro 39-47)

Shoe last measuring step. Measures last heel lift from 1cm to 11.5 cm.

24 inch tape specifically designed for measuring shoe lasts.

Ready to Print! Men's size 9 last. The .STL file can be scaled in X, Y and Z.

Great for checking leathers and synthetic materials. Features adjustable dial.

Beaked pincers with built in hammer face. For shoe lasting and sole nailing.

Try the first 3 chapters for Just $3 bucks! With discount code good of $5.00 off!

Great for DIY Shoemaking. This casual rubber outsole is durable, comfortable, and easy to work with.

Purchase