How do you calculate the weight of mold?
To figure the weight, the next step is to divide the volume of the rubber needed to make the mold by the specific volume yield of the mold rubber: 37 in³ ÷ 27.7 in³/lb = 1.34 lbs. (606.31 cm³ ÷ 0.962 cm³/g = 630 g). 1.34 lbs. (630 g) is the total weight of rubber that you will need to make the mold (Part A + Part B).
What is shot size in injection Moulding?
The shot size is the maximum amount of plastic injection mold that can be injected in one molding cycle. Pellets are fed through the hopper into the barrel and screw assembly.
What is injection weight?
The injection weight is the weight of the polymer melt from the nozzle of injection molding machine. The conventional injection weight based on the injection volume control method is related to the diameter of the injection screw and the injection stroke.
How do you measure injection molds?
Calculating Tonnage for Injection Molding This is done by measuring the length and width of the mold’s cavity, and multiplying the two together. If there are multiple cavities of the same size in the mold, multiply the number of cavities by the number of cavities.
How do you calculate weight tolerance for molded parts?
The most common method is: Shot to shot weight variation calculated as (three standard deviations) divided by (average weight) must be less than 1\% and should be less than 0,5\%. In general it is possible to achieve 0,1-0,4\% weight variation using scientific molding.
How do you reduce part weight in injection molding?
the lT method, part weight control is achieved by controlling the temperature and pressure of the melt in the cavity at gate freeze time. This time is considered to occur when the cavity melt pressure starts to decrease from its peak value.
How do you calculate barrel capacity?
How to Find the Volume of a Barrel
- volume = h × π × ((2 × r22) + r12)3.
- To get the total volume in cubic feet, convert from cubic inches using the formula ft3 = in3 × 0.000578704.
- Gallons can be found using the cubic feet to gallons formula:
- gallons = h × π × ((2 × r22) + r12)3 × 7.480507.
What is injection rate in injection molding?
Injection rate refers to the volume flow rate that can be achieved per unit time at the time of injection, such as the ratio of injection capacity and injection time.
How do you calculate shot capacity?
To calculate the injection stroke or shot size, we can put all values in the formula of shot volume, i.e., Shot Volume = π x r2 x Shot Size. Here, r=1.4 and shot volume is 26.71 cm^3.
How do you calculate injection mold tonnage?
Now you can calculate necessary tonnage based on the projected area times the clamp factor for the material used. T = A x cf. For example, the projected area of the molded part is 150 sq/in times a clamp factor of 3 (tonnage needed/square inch from material data sheet). 150 x 3 = 450 tons needed.
How do you calculate the weight of plastic parts?
The mass of the piece of plastic = density × volume = 1.18 g/cm3 × 50.0 cm3 = 59 g = 0.059 kg. Step 4: Calculate weight with the acceleration due to gravity. The weight (N) = mass (kg) × acceleration due to gravity (m/s2). On Earth the weight would be 0.059 kg × 9.81 m/s2 = 0.58 N.