Injection molding

[WombSlider]

Anyone know how the process of injection molding of knife handles is accomplished? Also what are your opinions of knives with injection molded handles?

 

[powells85]

I took a class last semester where we actually got to use an injection molder. What you do is take the material to be used, which is in small pieces/pellets, then put it in top into a "pot" that helps to melt it. Then you push it down into a cylinder where a rod comes down to push it out thru a small opening which lines up with the hole in the mold that the hot material spreads out into and then cools and hardens. I'm guessing that this is the same way used for knife handles.

I think the general concenus is that they are cheap or just called "plastic" handles, but for a beater knife or a real user, it is perfectly fine.

 

[TLM]

The process can produce anything from scrap to technically high class products, no ivory though. It all depends on the designer and producer how good materials they want to use, also on the design of the tang.

It is a fairly straightforward process but somewhat timely to explain all the details.

TLM

 

[STR]

I have one knife made by Mike England that is his own mixture of steel with all the qualities he wanted in it. He melted it to liquid and injection molded the whole knife into a ceramic mold. When it cooled it became solid and he put an edge on it, cleaned it up and sold it. It is a custom made divers knife. Very heavy for its size. I love it. Only problem is that since Mike passed away I've been afraid to use it anymore. I'd love to find out what happened to the mold that was used to create this knife.

 

[Gollnick]

Most of the plastic things in our lives are injection molded. This ranges from the toy in the bottom of a cereal box to parts for jet engines.

Injection molding can produce anything from dime-store trinkets to parts that are literally bullet-proof.

 

[WombSlider]

I guess the better question is how is it done in regards to knife handles. How is it held? Do they use adhesives?

 

[dialex]

Although there are lots of Chinese POS with cheap ordinary plastic handles, a serious brand (like say CS, BM or Spyderco) uses Zytel or derivates (fibre reinforced nylon). This is an excellent material for handles: tough, lightweight, corrosion resistant and gritty (depending on the mould). No adhesive are required, except maybe for inserts.

 

[WombSlider]

Anyone know anything about the material used on the old Timberline Specwar fixed blade? I think it's the same stuff used on the current production Timberline Aviator, and the Emerson police utility fixed blade. It seems much tougher and more durable than most plastics.

 

[Hawaiian]

I know Benchmade uses this process to make the Ti handles on their balisongs. Some owners who have cut the end of the handle off to make the knife latchless have found air pockets in the metal. Not a great thing. I do not know if Benchmade uses this process in making other knives.

 

[powells85]

I know Benchmade uses this process to make the Ti handles on their balisongs. Some owners who have cut the end of the handle off to make the knife latchless have found air pockets in the metal. Not a great thing. I do not know if Benchmade uses this process in making other knives.

You sure that they aren't cast?

 

[Will P.]

Actually, only the BM31 was injection modeled - the process wasn't quite the same as plastic injection molding, but involved sintering Ti powder together. This prcess eliminated the voids found in the cast handles. BM's other Balis have cast handles. You can read about it more detail at Mr. Gollnick's site:

http://www.balisongcollector.com/bm31.html

 

[mete]

Some metals such as aluminum and zinc can be injection molded [die cast]. I have an old Gerber skinning knife that has an aluminum injection molded handle.