How to Make a Two Part Mold

There are several different ways to make molds. The most common mold types are one-part and two-part molds, with the complex three-part molds used a little less often. One part molds are best suited to flat-backed designs, as they typically require one side of the mold to be completely open at all times. Two part molds are used for most other projects, as they can be taken apart to retrieve a cast object. Three part molds are like two part molds, but have an added inner piece that makes the casting hollow.

Instructions

1

Coat your model with mold release, so that the mold material does not stick to the model.

2

Create an open-top box that will hold your liquid mold material. You can make the box out of pieces of thick cardboard or even wood, although cardboard will be easier to take apart later. Make sure that the box is at least 1/4 inch bigger than the model in all dimensions.

3

Seal the corners, edges and bottom of the box with modeling clay, so that none of the mold material leaks out of the box.

4

Mix together a batch of your mold-making material. Typically, two-part molds are made from either plaster or rubber. Make sure to take the appropriate safety precautions for the material you have chosen.

5

Pour the mold material into the box. Stop pouring once the box is half-filled. Discard the rest of the mixture.

6

Let the mold material sit for several minutes to firm up slightly. When the material is ready, press the model into it so that half of the model has sunken into the material. Let the other half of the model sit above the surface.

7

Let the mold material harden completely. If you have used plaster or rubber, this will set in 12 hours.

8

Coat the top of the mold, which has the model sticking out of it, with mold release. This will make the mold easier to separate later.

9

Make another batch of your mold material. Pour the material into the box, covering the model completely. Fill the box.

10

Let the mold material harden completely. When the material has hardened, take the box apart.

11

Pull each side of the mold apart and remove the model from the inside. Fit the mold back together.

12

Tie the mold together with rubber bands or cording. Carve a hole in the mold, at the seam, that reaches the inside cavity. Use this hole to pour your casting material.

Research and Forecast of Injection Molding Machine Industry in China, 2014-2018

The injection molding machine belongs to the plastic machinery type that has the largest output and application volume in China, as well as being the main force of China's plastic machinery export. In 2013, the export volume of injection molding machines was 22,946 sets with the export amount of USD 932 million; in 2012, the export volume was 24,830 sets, so the export volume in 2013 declined, but the export value in 2013 increased 3.78%, which fully shows that the average price of export products of China's injection molding machines is gradually growing. With the increasing demand for plastics, plastic machinery industry has huge market potential. From the global perspective, the top three plastic machinery types are injection molding machine, extruder/extruder production line and blowing molding machine, which account for more than 80% in the plastic machinery total output value. Among them, injection molding machine accounts more than 50% of the total output value of these three main types of plastic machines. 

In 2013, the output of China's injection molding machines was about 82,000 sets, rising by 4.21% compared with 2012. On the whole, the growth of China's injection molding machine industry gradually slowed during the year of 2007 to 2013, but the output was still rising. During 2007 to 2013, the average growth rate of output of China's injection molding machines was 4.77%. 

As this report estimates, the market supply volume of China's injection molding machines will reach 86,175 sets by 2014, 89,612 sets by 2015 and about 101,095 sets by 2018

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How to Texture Injection Molds

Injection molds receive a finish to eliminate the machining marks from the mold. High-speed machines typically do this polishing. In some cases, a textured finish is desired. A chemical etch procedure creates the texture based on a pattern. This process usually is manual.

Mold Texturing

1

Create a design of the desired texture as a photocopy or digital file.

2

Transfer the design to a negative. This can be easily done with a scanner. Most scanners have the capability to scan to a negative output file. Or, if the file is already digital, many photo editing software packages have the option to convert a file to a negative.

3

Transfer the negative to a flexible elastomeric material with the desired texture. This is not a do-it-yourself activity for the average person. In general, commercial equipment, often a laser engraver, is required to complete this step. A commercial provider of this type of service should be considered.

4

Placing the textured elastomeric material on the mold surface and add the chemicals to etch the mold. The exact chemical used depends on the specific metal of the mold. It is generally one of the stronger acids.

5

Completely wash the mold of all chemical residues.

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what's color mold? double shot molding two shot mold double injection

Color mold : two on the same plastic injection molding machine , a two- molding, but the product just only in one mold die . In general, this is also called double injection molding process. it is usually done by a mold , and need specialized color injection molding machine . Color mold growing popularity on the market today , it can make the appearance of the product is more beautiful from the process, easy to change colors and no no painting, also expensive and high technically demanding .

1 two female molds are different , each forming one kind of products, and the two male molds are the same.

2 before the mold, the mold in the center of the rotation after 180o, must match. This inspection must be done during mold design , this points have high demand for the mold base positioning  process.

3 The total thickness of the front plate plus A plate must be not less than 170mm. Please carefully review the reference data of the injection molding machines. for example, the maximum and minimum thickness of the mold, KO -hole distance etc.

4 the gate of three plates mold preferably designed to automatically release action. Particularly pay attention to the gate release of soft part..

5 when design the second injection of the female die , in order to avoid secondary mold insert ( or rub ) the first part with good product molding, can make some clearance . However, the intensity must be carefully considered . During injection ,if there will be a big injection pressure , it will cause deformation , resulting in flash problem in the second injection ?

6 during the injection , the first injection molded product may be slightly larger size , so that it can be formed in the second well tightly, in order to achieve the effect of sealing compound .

7 pls note that in the second injection , the plastic flow will impulse the first product and cause part deformation ? If there is the possibility, must find ways to improve .

8 Before A, B plate clamping , pay attention to the mold slider or lifter ,if they will be reset and the crushed product ? So , we must find ways to make the A, B plates first clamping , then make the slide or lifters reset second.

9 the water of two female molds and the male mold transport as fully and balance as possible

10 99% of the injection molded hard plastic case is the first part of the product , and then injection molded soft part . Because soft part have deformation problem .