Shrinkage should be distinguished according to the size of the product and the thickness of the glue. Our general design will have a range. For large molds, it is generally necessary to test a set of molds of basically the same size with materials first, and then open the mold after determining the actual shrinkage rate. The shrinkage of small molds is not much different. There are also different types of materials, and the shrinkage will be different, so it must be considered before opening the mold.
In my opinion, ABS, PC, ABS+PC, and AS have a small shrinkage rate, but it is quite different for new or recycled materials with a large shrinkage rate such as PP, PA, and PVC.
PMMA (acrylic): 5/1000
POM (race steel): 20/1000
PS (hard glue): 5/1000
PP (100% glue): 16/1000
PC (bulletproof rubber): 5/1000
ABS (super non-breakable glue): 5/1000
HIPS (not broken glue): 5/1000
AS (transparent super glue): 5/1000
GPPS: 5/1000
PBT: 15/1000
PA66 (nylon): 16/1000
PA6 (nylon): 9/1000
TPR (soft rubber): 18/1000
TPU (soft rubber) 18/1000
PE: (soft rubber) 20/1000
KVA (rubber rubber): 20/1000
GP (hard glue): 5/1000
CA (acid glue): 5/1000
K Tang (KRATON): 20/1000
ACETAL (AC): 20/1000
PU: 20/1000
PVC (soft): 20/1000
PC+ABS:5/1000
BDS(K-RESIN0)/K material: 7/1000
PA66+50%GPT: 2/1000
PA66+30%GPT: 3/1000
PA66+15%GPT: 8/1000
PBT+30%GPT: 3/1000
PP+20%GPT: 5/1000
PP+30%GPT: 3/1000
The above shrinkage rate has been obtained after several years of practice, and it is absolutely reliable when the average glue thickness of the product does not exceed 300mm and does not exceed 3MM. If the size of the product exceeds 300mm, the subtotal is 0.0005. If the size of the product is too different, the X-axis, Y-axis, and Z-axis should be calculated separately. When the average glue position of the product is too thick, too thin (below 0.5) and the product Pay special attention to size.
In addition, the actual mold shrinkage rate is very different for different products of the same plastic! The following is a summary of the shrinkage rate summarized by a senior engineer based on years of practical experience. Let's take a closer look~
