Output end pallet product is shown in Figure 1. Maximum size of product is 142.00 mm * 72.41 mm * 6.90 mm, average thickness of plastic part is 1.60 mm, material of plastic part is ABS+PEBA, shrinkage rate is 1.005, and weight of plastic part is 15.60 Grams. Technical requirements for plastic parts are that there must be no defects such as peaks, underfilling of injection molding, flow lines, pores, warpage deformation, silver streaks, cold materials, jet lines, etc.

 

Figure 1 Product picture of output end pallet
It can be seen from Figure 1 that plastic part structure is a flat tray, plastic part structure and 3D mold design drawing are shown in attached 3D drawing. Plastic material is composed of ABS+PEBA. PEBA material is a block copolymer prepared from polyether and polyamide blocks. Their unique performance is attributed to their unique phase separation structure. There is a hard phase, which mainly includes polyamide blocks, and a soft phase, which mainly includes polyether blocks. Because these two blocks are linked together by esters. It is a material that can withstand more than 150,000 cycles without damage, even if temperature is as low as -40℃, no cracks can be seen. PEBA material has good low-temperature impact resistance; at the same time, it has good elasticity, which leads to its excellent impact performance at extremely low temperatures.
Output pallet is output pallet of a Japanese brand printer, and printed paper is output through top of pallet. Therefore, there are special technical requirements for printer pallet, that is, surface must not have factors that hinder movement of paper, and there must be no deformation, warpage of both ends to top surface cannot exceed 0.3, and ends to bottom surface cannot be warped, see Figure 1. Raised bone position on the top surface is for supporting paper, not for reinforcing ribs. Size must be accurate, and shape must conform to direction of movement of paper flowing out. Level difference between front and rear molds on parting surface is controlled below 0.03. A special fixture is designed for inspection of plastic parts, as shown in Figure 3.
Structure of plastic part is flat, without various core pulling and complicated mold structure. In view of actual situation of plastic parts, mold design cavity rank is 2 cavities. Mold design drawing is shown in Figure 2. Gating system adopts a three-plate mold with fine nozzles and three-point glue feeding.

 

 

 

 

Figure 2 Die diagram of output end pallet

 

Figure 3 Structure diagram of testing fixture
Mold base adopts DCI3335 standard mold base, and panel code mold part is milled to 30mm thin, which is convenient for mold code fixation. Four sides of mold base are designed with a slope positioning block to provide positioning for mold; mold base is designed with positioning pins to increase rigidity of mold base. Mould core steel adopts Japanese mould steel NAK80, and standard mould parts adopt Japanese MISUMI standard. In order to ensure mold life of 500,000 times, a bushing 3 is designed on the outside of sprue bushing 2, which is convenient for replacement and maintenance. Code pattern of mold adopts V-shaped block code pattern. This code pattern method is particularly suitable for code pattern of large and medium-sized molds, which can be quickly coded and has characteristics of high safety. After mold bears weight of V-shaped block (there is no V-shaped groove on rear mold), code mold only needs to be tightened with 8 bolts, which can realize fast code mold.
Both AB board and nozzle board are designed with corresponding cooling water transportation. Front and rear mold cores are fully cooled through multiple direct water cooling circuits. Plastic part is ejected by a thimble, and travel switch 9 detects return of ejection system.