Random access plays a critical role in mMTC networks that consist of a myriad number of heterogeneous IoT devices to meet the demand of applications in a large geographical area. In this paper, we propose using packet alignment for framed slotted Aloha, where packets are aligned to the chunks of time slots according to the lengths of the packets generated by the devices. The packet length dependent alignment ensures that the collision windows are relatively small, where the devices with varying packet lengths view the frame partitioned into chunks of time slots differently. In this paper, packet alignment is used in combination with the packet squeezing to enhance the throughput in framed slotted Aloha. Furthermore, the age of information can be easily included in the proposed approach to emphasize the importance of data freshness. In the performance evaluation, analytical model of the proposed packet alignment alongside with packet squeezing demonstrates that the throughput of framed slotted Aloha in the context of massive machine type communications in 5G can reach 0.9.