The Pros and Cons of the 3 Primary Rubber Molding Production Methods

Custom rubber molding products have many usesOnce complete, the rubber remains in the mold until it is
across a wide range of applications. In fact, it is difficultfully cured.
to imagine an industrial or manufacturing setting thatTransfer molding offers faster curing times than the
doesn't employ these items in some capacity. Forcompression method because of the heat produced
example, the automobile industry utilizes manyduring the transfer process. Also, because the mold
customized rubber components in the production ofremains closed throughout the process, less excess
new vehicles. How each of those components ismaterial is able to seep out, which results in less waste
produced depends largely on a number of factors,material. In terms of consistency, this process offers
including how it will be used and the costs associatedbetter results than compression molding. On the other
with its production.hand, these molds have a more complex design and
There are 3 Primary Methods of Producing Rubbercarry a correspondingly higher price tag to produce.
Molding Products:3. Injection molding is the most sophisticated method of
1. Compression molding is the oldest and most simpleproducing rubber molding products and produces the
rubber molding process available. With this process, anmost consistent results. With this method, the uncured
uncured "slug" of rubber is placed in a cavity betweenrubber is softened prior to being injected into the mold
two plates that are then pressed together. (The cavitythrough a series of small openings. This method is
between the two plates is in the desired shape of theentirely automated and uses a precise amount of raw
final product). Pressure is applied to both plates whichmaterials. With injection molding, the cavity plates
forces the uncured rubber to conform to the shape ofremain closed throughout the process, thereby limiting
cavity. The mold remains closed until the rubber isthe amount of excess rubber that can escape the
cured and the process is complete.cavity. This, in turn, limits the amount of excess flash
Compression molds are the most simple to create andthat is produced. However, injection molds are the
are therefore the most economical to use. However,most complicated to create and represents the most
producing rubber molding products in this manner is aexpensive option.
manual process which requires more time and effortEach rubber molding production method is better suited
to perform. Of the 3 production methods, compressionfor some applications than others. This is due to the
molding also yields the most inconsistent results andinherent advantages and disadvantages associated
takes the longest time for the rubber to cure.with each process. As with most things, there is a
2. With transfer molding, an uncured slug of rubber isclear relationship between cost and quality, with the
placed in a chamber above the mold's customizedhighest-priced alternative (injection molding) yielding the
cavity. Pressure is then applied directly to this chambermost consistent and uniform results. However, not all
in an effort to force the rubber through small openingsjobs require this level of sophistication and precision. In
called "sprues." The rubber then passes throughthose cases, less precise but more cost-effective
("transfers") those openings to fill the mold's cavity.options are worth exploring.